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Léon, Karelle. "L'hypothermie modérée induite chez un modèle murin : une solution thérapeutique au sepsis ?" Thesis, Brest, 2012. http://www.theses.fr/2012BRES0030.
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Le sepsis, état pathologique lié à une réaction inflammatoire systémique suite à une infection, est lapremière cause de mortalité dans les unités de réanimation médicale et de soins intensifs hospitaliers.Parmi les pistes thérapeutiques envisagées, l’hypothermie est un bon candidat. En effet, l’hypothermiemodérée induite augmente la durée de survie de rats septiques. Ce travail avait pour objectifd’apporter des éléments permettant de comprendre et d’identifier les mécanismes responsables decet effet bénéfique. Pour cela, différentes fonctions couramment affectées lors du sepsis(inflammation, stress oxydant, défaillance rénale, capacités de transport de l’oxygène par le sang etéquilibre acide-base) ont été étudiées sur des rats septiques en hypothermie modérée (34°C). Lesrésultats obtenus révèlent que l’hypothermie modérée ralentit de manière significative la production decytokines pro-inflammatoires et tend à exercer une diminution de la production radicalaire systémiquechez les rats septiques. L’apparition de l’acidose métabolique et la défaillance rénale sont égalementretardées. Enfin, alors que le sepsis en normothermie conduit à une diminution de la coopérativité etde l’affinité de l’hémoglobine pour l’oxygène, synonymes d’une adaptation face à des modificationspotentiellement délétères, en hypothermie modérée, ces paramètres ne sont pas modifiés. Cesrésultats concourent à penser que l’hypothermie modérée en ralentissant l’évolution du sepsis permetd’augmenter la durée de survie des rats septiques. Ainsi, l’hypothermie pourrait constituer une pistepour traiter les patients atteints de sepsis sévère dans le but de temporiser l’inflammation et decontrôler l’agression retardant ainsi les défaillances d’organesDespite numerous studies over the past twenty years, sepsis, a pathologic state related to a systemicinflammatory response following infection, remains the main cause of death in intensive care units.Among the therapeutic approaches proposed, hypothermia is a good candidate. Indeed, mild inducedhypothermia increased the survival duration of septic rats. This work aimed to provide elements tounderstand and identify the mechanisms responsible for this beneficial effect. Consequently, variousfunctions commonly affected during sepsis (inflammation, oxidative stress, renal failure, oxygen bloodcapacity and acid-base balance) were studied on septic rats maintained in mild induced hypothermia(34°C). The results showed that mild hypothermia significantly slows the cytokine proinflammatoryproduction and tends to exert a decrease in the radical systemic production of septic rats. Theappearance of metabolic acidosis and renal failure are also delayed. Finally, while in normothermiasepsis led to a decrease in the cooperativity and oxygen haemoglobin affinity, synonymous of anadaptation when faced with potential deleterious changes, in mild hypothermia, these parameters arenot modified. These results suggest that by reducing the development of sepsis, mild inducedhypothermia increases the survival duration of septic rats. Thus, hypothermia may be an option fortreating patients with severe sepsis by stalling inflammation and controlling aggression, therebydelaying organ failure
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Wladis, Andreas. "Hypothermia and trauma /." Stockholm, 2001. http://diss.kib.ki.se/2001/91-628-4574-8/.
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Islam, Shahed. "Therapeutic hypothermia in cardiovascular disease." Thesis, Anglia Ruskin University, 2017. http://arro.anglia.ac.uk/704083/.
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Introduction: Historical trials demonstrated clinical benefit of therapeutic hypothermia (TH) in unconscious cardiac arrest survivors. However, recent research raised important unanswered questions about this concept. Cardiac arrest associated mortality and morbidity including psychological trauma for survivors and caregivers remain alarmingly high, warranting further research in this field. TH has also been shown to offer additional protection against reperfusion injury in experimental models of myocardial ischaemia. However, co-administration of TH in conscious patients undergoing treatment for acute myocardial infarction (AMI) is potentially challenging. Methodology: (i) Rhinochill®, a novel intranasal cooling device is compared to Blanketrol for TH induction in unconscious cardiac arrest survivors, investigating efficacy and clinical outcome at hospital discharge. (ii) The emotional burden of cardiac arrest in patients and their caregivers is documented and the impact of simple interventions on quality of life is assessed. (iii) The feasibility of co-administration of TH in conscious patients undergoing emergency treatment of AMI is investigated. Results: (i) Rhinochill® is found to be more efficient in TH induction when measured from the tympanic membrane. However, Rhinochill® did not offer any superior clinical benefit. (ii) Simple psychological interventions are shown to improve quality of life in cardiac arrest survivors. (iii) Co-administration of endovascular cooling is shown to be feasible in conscious patients undergoing AMI treatment with minimum disruption to patient care. Discussion: Delays in TH administration may offset any potential benefit that it can offer in neuroprotection and therefore, earlier targeted brain cooling with more efficient portable devices is worth investigating. Improving quality of life of cardiac arrest survivors has been shown to be cost effective and therefore, investing in resources to better identify and help those at risk is justified. Delivery of TH in conscious heart attack patients is feasible and safe but more efficient endovascular cooling devices are required and these will need to be assessed in larger trials to assess the effect on clinical outcomes.
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Islam, Shahed. "Therapeutic hypothermia in cardiovascular disease." Thesis, Anglia Ruskin University, 2017. https://arro.anglia.ac.uk/id/eprint/704083/1/Islam_2017.pdf.
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Introduction: Historical trials demonstrated clinical benefit of therapeutic hypothermia (TH) in unconscious cardiac arrest survivors. However, recent research raised important unanswered questions about this concept. Cardiac arrest associated mortality and morbidity including psychological trauma for survivors and caregivers remain alarmingly high, warranting further research in this field. TH has also been shown to offer additional protection against reperfusion injury in experimental models of myocardial ischaemia. However, co-administration of TH in conscious patients undergoing treatment for acute myocardial infarction (AMI) is potentially challenging.
Methodology: (i) Rhinochill®, a novel intranasal cooling device is compared to Blanketrol for TH induction in unconscious cardiac arrest survivors, investigating efficacy and clinical outcome at hospital discharge. (ii) The emotional burden of cardiac arrest in patients and their caregivers is documented and the impact of simple interventions on quality of life is assessed. (iii) The feasibility of co-administration of TH in conscious patients undergoing emergency treatment of AMI is investigated.
Results: (i) Rhinochill® is found to be more efficient in TH induction when measured from the tympanic membrane. However, Rhinochill® did not offer any superior clinical benefit. (ii) Simple psychological interventions are shown to improve quality of life in cardiac arrest survivors. (iii) Co-administration of endovascular cooling is shown to be feasible in conscious patients undergoing AMI treatment with minimum disruption to patient care.
Discussion: Delays in TH administration may offset any potential benefit that it can offer in neuroprotection and therefore, earlier targeted brain cooling with more efficient portable devices is worth investigating. Improving quality of life of cardiac arrest survivors has been shown to be cost effective and therefore, investing in resources to better identify and help those at risk is justified. Delivery of TH in conscious heart attack patients is feasible and safe but more efficient endovascular cooling devices are required and these will need to be assessed in larger trials to assess the effect on clinical outcomes.
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Covaciu, Lucian. "Intranasal Cooling for Cerebral Hypothermia Treatment." Doctoral thesis, Uppsala universitet, Anestesiologi och intensivvård, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-134278.
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The controlled lowering of core body temperature to 32°C to 34°C is defined as therapeutic hypothermia (TH). Therapeutic hypothermia has been shown to improve neurological outcome and survival in unconscious patients successfully resuscitated after cardiac arrest. Brain temperature is important for cerebral protection therefore methods for primarily cooling the brain have also been explored. This thesis focuses on the likelihood that intranasal cooling can induce, maintain and control cerebral hypothermia. The method uses bilaterally introduced intranasal balloons circulated with cold saline. Selective brain cooling induced with this method was effectively accomplished in pigs with normal circulation while no major disturbances in systemic circulation or physiological variables were recorded. The temperature gradients between brain and body could be maintained for at least six hours. Intranasal balloon catheters were used for therapeutic hypothermia initiation and maintenance during and after successful resuscitation in pigs. Temperature reduction was also obtained by combined intranasal cooling and intravenous ice-cold fluids with possible additional benefits in terms of physiologic stability after cardiac arrest. Rewarming was possible via the intranasal balloons. In these studies brain temperature was recorded invasively by temperature probes inserted in the brain. The fast changes in pig’s brain temperature could also be tracked by a non-invasive method. High-spatial resolution magnetic resonance spectroscopic imaging (MRSI) without internal reference showed a good association with direct invasive temperature monitoring. In addition the mapping of temperature changes during brain cooling was also possible. In awake and unsedated volunteers subjected to intranasal cooling brain temperature changes were followed by two MR techniques. Brain cooling was shown by the previously calibrated high-spatial resolution MRSI and by the phase-mapping method. Intranasal cooling reduced body temperature slightly. The volunteers remained alert during cooling, the physiological parameters stable, and no shivering was reported.
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Finiels, Amber. "Therapeutic hypothermia to prevent neurological deficits." Honors in the Major Thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1404.
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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.Bachelors
Nursing
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Bashir, Shazma. "Mechanism of Paracetamol (acetaminophen) induced hypothermia." Thesis, University of East London, 2018. http://roar.uel.ac.uk/7308/.
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Paracetamol is a potent analgesic and antipyretic with limited side effects compared to the nonsteroidal anti-inflammatory drugs (NSAIDs) and opiates. Worldwide paracetamol is commonly used to treat pain and fever in both children and adults. Although, this drug has been in clinical use for more than a century, the mechanisms of action are not fully understood. Historically some of the actions of paracetamol were attributed to the inhibition of central cyclooxygenase (COX-1 and COX-2) enzymes however given the weak inhibitory effects on COX-1 and COX-2 enzymes, alternative targets have been suggested including a possible novel COX-3. The inhibition of COX-2 is accepted as the mechanism by which paracetamol reduces core temperature (Tc) in febrile animals. However, in non-febrile animals where COX-2 is not induced, paracetamol has also been shown to cause hypothermia by a mechanism that is not fully understood. Both the reduction of pyresis and induction of hypothermia can only occur when peripheral metabolic rate decreases and/or heat loss increases. In terms of antipyresis and hypothermia, the inhibition of lipolysis, fatty acid oxidation and mitochondria function are obvious alternative targets. Studies were undertaken to identify and characterise the putative COX-3 at protein and mRNA level using western blot analysis and reverse transcription polymerase chain reaction (RT-PCR) in mouse brain endothelial cells (b.End3) and whole brain tissues isolated from male C57BL/6 mice. Additional studies were also undertaken to assess if the hypothermic properties of paracetamol could be attributed to direct inhibition of thermogenic pathways in both 3T3-L1 adipocytes and primary brown adipocytes isolated from male Wistar rats. Adipocytes and isolated mitochondria were exposed to paracetamol and lipolysis, fatty acid oxidation (FAO), mitochondrial electron transport chain (ETC), assessed by measuring oxygen consumption rate (OCR). In these studies no expression of the COX-3 protein could be detected in brain endothelial cells and homogenates and no evidence of a COX-3 was detected at mRNA level. However, paracetamol caused a significant decrease (upto 70%; P < 0.01, from control) in both basal and stimulated lipolysis at 1, 3 and 24 hours without affecting cell viability. Paracetamol (10 mM) and its metabolite N-acetyl-p-benzoquinone imine (NAPQI) at 50 μM also significantly (P < 0.01, from control), reduced endogenous and exogenous FAO by 50% and 70% respectively. NAPQI (50 μM) had limited effect on mitochondrial uncoupling. Finally, paracetamol and other antipyretic compounds also significantly reduced ETC activity (upto 90%; P < 0.01, from control). Both the maintenance of normal body temperature (Tb) and the induction of pyresis require increased mitochondrial ETC activity normally initiated centrally and driven peripherally by reduction of substrates such as fatty acids and glucose. The failure to identify the COX-3 protein and the direct inhibition of lipolysis, FAO and ETC activity indicate that antipyretic actions of paracetamol could partly be attributed to it actions on peripheral energy generation systems and provide new drug targets for reducing fever and chemically inducing hypothermia.
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Hutin, Alice. "Etude expérimentale de l’arrêt cardiaque réfractaire chez le porc : nouvelles approches thérapeutiques." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC0030/document.
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L’arrêt cardiaque (AC) extrahospitalier est un problème majeur de santé publique, malgré la mise en place d’une véritable « chaine de survie ». Les durées de réanimation sont souvent prolongées et aboutissent à des séquelles irréversibles avec un assombrissement dramatique du pronostic. Dans de nombreuses situations, l’AC ne parvient pas à être réanimé avec les soins courants, laissant apparaître un AC « réfractaire » qui nécessite une prise en charge thérapeutique avancée. L’objectif général de ce travail de thèse était d’évaluer de nouvelles approches expérimentales pour la prise en charge de l’AC réfractaire. Nous avons étudié deux stratégies expérimentales chez le porc, consistant à induire une hypothermie ultra-rapide par ventilation liquide ou à mettre en place une assistance circulatoire au cours d’un AC d’origine ischémique.Dans un premier travail, nous avons ainsi évalué la faisabilité d’une hypothermie thérapeutique ultra-rapide par ventilation liquidienne totale (VLT) chez le porc. Cette approche consiste à instiller des perfluorocarbones dans le poumon de façon à induire un refroidissement ultra-rapide. Le poumon est ainsi utilisé comme bio-échangeur thermique, tout en maintenant des échanges gazeux normaux. Dans des travaux préliminaires, le laboratoire a montré que la VLT permettait de réduire la température sanguine jusqu’à 32°C en moins de 10 minutes chez le lapin. Le but de notre étude était de déterminer si la VLT pouvait aussi permettre un refroidissement ultra-rapide chez le porc. L'effet de la VLT a ainsi été évalué dans un premier temps à cœur battant, puis à cœur arrêté sur un modèle d’arrêt cardiaque réfractaire bénéficiant d’une réanimation cardio-pulmonaire prolongée. Dans les conditions physiologiques « à cœur battant », la température de 34°C était atteinte en moins de 10 minutes dans tout l'organisme. Lors de la réanimation prolongée d’un AC réfractaire, le refroidissement corporel était également obtenu rapidement, en moins de 25 minutes, quel que soit le site de mesure de la température. La VLT n’altérait aucunement la qualité du massage cardiaque externe, suggérant un intérêt pour cette approche dans l’induction d‘une hypothermie intra-AC, dans une perspective d’augmentation de l’efficacité des défibrillations ou de préservation d’organe.Dans un deuxième travail, nous nous sommes intéressés à l’AC réfractaire compliquant un syndrome coronaire aigu, traité par assistance circulatoire extracorporelle. Notre but était d’évaluer l'importance de la revascularisation coronaire précoce dans cette situation chez le porc, c’est-à-dire son impact sur le statut hémodynamique et les chances de réanimation. Après anesthésie et instrumentation, les animaux ont ainsi été soumis à une occlusion coronaire, suivie d’un AC par fibrillation ventriculaire non traitée pendant 5 minutes. Ils ont ensuite bénéficié d’une réanimation cardio-pulmonaire de base puis d’une assistance circulatoire extracorporelle. Nous avons comparé les effets d’une revascularisation précoce à ceux d’une revascularisation tardive, c’est-à-dire d’une reperfusion 20 ou 120 min après le début de l'assistance circulatoire. La revascularisation coronaire précoce augmentait significativement les chances de reprise d’activité cardiaque spontanée, limitait l’état de choc, améliorait la perfusion cérébrale et limitait la taille d’infarctus. Cela montre bien l’importance d’une prise en charge rapide du syndrome coronarien en cas d’AC de cause cardiaque présumée, y compris dans une situation d’assistance circulatoire extracorporelle.En conclusion, nous avons montré que la VLT permettait d’induire un refroidissement ultra-rapide dans l’ensemble de l’organisme, tant à cœur battant que pendant une réanimation prolongée. Par ailleurs, la revascularisation précoce d’un AC réfractaire ischémique traité par assistance circulatoire extracorporelle permettait d’améliorer globalement les chances de réanimation et le statut hémodynamiqueOut of hospital cardiac arrest (CA) is a major public health issue, despite the implementation of a “chain of survival”. Resuscitation durations are often extended with irreversible organ damage and poor outcome. Frequently, conventional care does not allow the return of spontaneous circulation, leading to a refractory CA, with the need for advanced therapeutic care. The general objective of this work was to evaluate new therapeutic strategies in the management of refractory cardiac arrest. We studied two experimental strategies in swine, involving ultrafast cooling with total liquid ventilation or extracorporeal cardiopulmonary resuscitation in a CA of ischemic origin.As a first step, we evaluated the feasibility of ultra-fast therapeutic hypothermia using total liquid ventilation (TLV) in swine. This approach involves perfluorocarbon instillation in the lungs to induce ultra-fast cooling. The lungs are thus used as a heat exchanger, while maintaining normal gas exchanges. In previous studies, the laboratory has shown that TLV could reduce blood temperature to 32°C in less than 10 minutes in rabbits. The objective of this study was to determine if TLV could lead to ultra-fast cooling in swine. We first studied the cooling capacity of hypothermic TLV in beating heart pigs, and then during ventricular fibrillation with prolonged chest compressions. In physiological conditions, in “beating heart” animals, the target temperature of 34°C was obtained in less than 10 min in the whole body. In prolonged resuscitation of refractory CA, whole body cooling was also rapidly obtained, within less than 25 min. TLV did not alter the hemodynamic effect of cardiac compressions, suggesting further use of this “intra-resuscitation” cooling in order to increase chances of defibrillation or for organ preservation for the purpose of organ donation.As a second step, we addressed the subject of ischemic refractory CA treated by extracorporeal cardiopulmonary resuscitation (ECPR). Our objective was to evaluate the importance of early coronary reperfusion in this situation, i.e., it’s impact on hemodynamic status and chances of defibrillation. After anesthesia and surgical preparation, animals were submitted to a coronaryocclusion followed by 5 min of CA by ventricular fibrillation. Conventional cardiopulmonary resuscitation was then initiated and followed by extracorporeal cardiopulmonary resuscitation.We compared the effect of early versus late reperfusion, i.e., reperfusion after 20 or 120 min of ECPR. Early reperfusion significantly increased chances of return to spontaneous circulation with limited shock status, increased cerebral perfusion and decreased infarct size. This confirms the need for early treatment of acute coronary syndrome if cardiac cause of CA is suspected, even in the situation of ECPR.In conclusion, we have shown that TLV could provide ultra-fast whole body cooling, both in beating heart swine and during prolonged resuscitation. Secondly, early reperfusion in refractory ischemic CA treated by ECPR globally increases chances of return to spontaneous circulation and improves hemodynamic status
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Klock, Julia Cathy. "Rapid whole-body hypothermia : analysis and modeling /." View online ; access limited to URI, 2007. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3276989.
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Collins, Michael. "Dysphagia in Encephalopathic Neonates Treated with Hypothermia." Thesis, The University of Arizona, 2013. http://hdl.handle.net/10150/281173.
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A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine.Objective: The purpose of this study is to determine the rate of dysphagia in neonates treated with targeted body temperature reduction as compared to neonates who have not been exposed to hypothermia. Methods: We performed a retrospective study of encephalopathic neonates who were treated with hypothermia and who underwent a modified barium swallow (MBS). For comparison, a group of neonates who had been evaluated with MBS but did not receive hypothermic therapy was identified. This group consisted of non-encephalopathic patients. MBS results were qualified as either normal or abnormal. Results: There was no statistically significant difference in the percentage of abnormal MBS results between the hypothermic and control groups (Fisher’s exact; P = 0.78). The odds ratio for abnormal MBS results in the hypothermia group relative to the control group was 1.2, with 95% confidence interval of 0.42 to 3.8. Significance: These data indicate that hypothermia does not seem to increase short term risk of dysphagia compared to the control group. There is no apparent association between hypothermia and dysphagia. This supports previous findings that hypothermia is a safe treatment for neural injuries in NICU patients.
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Lundgren, Peter. "Protection and treatment of hypothermia in prehospital trauma care : with emphasis on active warming." Doctoral thesis, Umeå universitet, Kirurgi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-54304.
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Background: In prehospital trauma care active warming is recommended to aid in protection from further cooling. However, scientific evidence of the effectiveness of active warming in a clinical setting is scarce. Also, evaluating the effectiveness of active warming, especially in harsh ambient conditions, by objective measures, is difficult. Objective: To evaluate the effectiveness of field applicabe heat sources (I) and to evaluate active warming intervention in a prehospital clinical setting (II and III). To evaluate reliability and validity of the Cold Discomfort Scale (CDS), a subjective judgement scale for assessment of the thermal state of patients in a cold environment (IV). Methods: In a laboratory trial, non-shivering hypothermic subjects (n=5), were cooled in 8 ºC water followed by spontaneous warming, a charcoal heater, two flexible hot-water bags or two chemical heat pads, all applied to the chest and upper back (I). Oesophageal temperature, skin temperature, heat flux, oxygen consumption, respiratory rate and, heart rate were measured. In two clinical randomized trials, shivering patients during road and air ambulance transport (II) and during field treatment (III) were randomized to either passive warming alone (n=22 and n=9) or to passive warming with the addition of a chemical heat pad (n=26 and n=11). Body core temperature, respiratory rate, heart rate, blood pressure (II) and the patients’ subjective sensation of thermal comfort (II and III) were measured. In a laboratory trial, shivering subjects were exposed to – 20 ºC (n=22). The CDS was evaluated regarding reliability, defined as test-retest stability, and criterion validity, defined as the ability to detect changes in cold discomfort due to changes in cumulative cold stress (IV). Results: In non-shivering hypothermic subjects postcooling afterdrop was significantly less for the chemical heat pads, but not for the hot water bags and the charcoal heater, compared to spontaneous warming (I). Temperature drop during the entire warming phase was significantly less for all the heat sources respectively, compared to spontaneous warming (I). During road and air ambulance transport, ear canal temperature was significantly increased and cold discomfort significantly decreased, both in patients assigned to passive warming only, and in patients assigned to additional active warming (II). During field treatment, cold discomfort was significantly reduced in patients assigned to additional active warming, but remained the same in patients assigned to passive warming only (III). Weighted kappa coefficient, describing test-retest stability, was 0.84 (IV). CDS ratings were significantly increased during each 30 minutes interval (IV). Conclusion: In non-shivering hypothermic subjects, heat sources were effective to attenuate afterdrop, when providing high heat content over a large surface area and effective to continue to increase body core temperature when providing sustained high heat content. In shivering trauma patients, adequate passive warming were sufficient treatment to prevent afterdrop, to slowly increase body core temperature, and to reduce cold discomfort. If inadequate passive warming, additional active warming was required to reduce cold discomfort. The CDS, a subjective judgement scale for assessment of the thermal state of patients in a cold environment seemed to be reliable regarding test-retest stability and valid regarding ability to detect change in cumulative cold stress.
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Belke, Darrell David. "Hypothermia and energy substrate metabolism in the heart." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq21548.pdf.
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Rabinowitz, Patricia. "Malignant Hypothermia Preparedness for Labor and Delivery Nurses." Otterbein University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=otbn1596205650329567.
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Van, Someren Robert Niall Melville. "An investigation into the cause of insidious hypothermia occurring during immersion in lukewarm water, and of the mental consequences of hypothermia." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/27018.
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During the late 1970s, when oil exploration and extraction from the North Sea were at a peak, there was increasing concern about the number of episodes of unexplained confusion, loss of consciousness and deaths during dives. Previous field measurements on divers had demonstrated that divers became hypothermic with little or no sensation of cold, despite suit heating using tepid water pumped from the surface. This thesis describes laboratory experiments designed to document and to determine the cause of 'insidious' hypothermia. Initially, it was shown that uniform skin cooling in tepid water could produce subnormal body temperatures in all subjects tested, whether or not they had been acclimatised to cold. This symptomless fall in deep body temperature could be reversed by further chilling the hands and feet using a separate water circulation system, while the rest of the body remained in tepid water. The rise in deep body temperature was shown to be due to an increase in metabolic rate caused by shivering, with cold-acclimatised subjects shivering less. The main cause of 'insidious' hypothermia is therefore inadequate skin stimulation of thermoregulatory reflexes by lukewarm water, with previous cold water exposure further reducing responses. The next series of experiments was designed, to assess the impairment of memory and reasoning processes by oold, since most previous evidence find been inadequate or anecdotal. Psychological tests were administered during the unusual physiological circumstances on rewarming after oold immersion, where subjects felt warm and comfortable, but had a low or falling deep body temperature. The results clearly showed that the ability to form new memories was seriously impaired, even by mild falls in temperature, and that reasoning processes were greatly prolonged, although remaining accurate. The current work has therefore successfully determined the cause of the hypothermia which occurs in lukewarm water, and has shown that mental abilities are seriously affected early in the development of hypothermia.
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Horwitz, Elizabeth Rachel. "The role of calcium in temperature resistance of hibernator cells." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334127.
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Zheng, Fashan. "Baroreceptors and cardiopulmonary reflexes : afferent pathways and the influence of cold." Thesis, University of Aberdeen, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262348.
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A study was performed on decerebrate ferrets to define the contribution of vagal afferent non-myelinated fibres to the baroreceptor heart rate reflex produced by bolus i.v. injection of phenylephrine, using capsaicin as a selective C fibre blocker. Capsaicin blocked pulmonary chemoreflex substantially without any effects on bradycardia evoked by electrical stimulation of vagal efferent fibres to the heart. The significance of the contribution to bradycardia in response to marked increases in blood pressure by vagal C fibres are discussed in relation to findings in electrophysiological studies. A further study was performed on decerebrate ferrets and chloralose anaesthetised lambs. Baroreflex sensitivity was assessed by the relationship between cardiac interval changes and a rise in systolic blood pressure produced by bolus injection of phenylephrine and descending aorta occlusion. Moderate hypothermia (30-34oC) enhanced the baroreflex heart rate reflex substantially and was without effect on the sensitivity of pulmonary J receptor reflex pathways involved in the heart rate control. Action of vagal efferent fibres in altering heart rate was increased by moderate cooling. Such an effect may be partially responsible for the enhanced heart rate component of baroreflex response. Other possible mechanisms of enhanced baroreflex sensitivity are discussed. The consequence of enhanced vagal efferent fibre on heart was studied by electrical stimulation of the peripheral end of cervical vagus nerves in decerebrate ferrets and anaesthetised lambs. Moderate cooling substantially increases cardiac arrhythmias, such as sinus bradycardia, sinoatrial block, sinus arrest and A-V block. In addition vagal stimulation resulted in lethal ventricular arrythmia during infusion of noradrenaline. The possible mechanisms underlying the collapse and sudden death following rescue are discussed.
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Pakanen, L. (Lasse). "Thrombomodulin and catecholamines as post-mortem indicators of hypothermia." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526208251.
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Abstract Hypothermia deaths pose a difficult challenge from the medico-legal point of view because no specific traces are left on the cadaver to be examined post-mortem. The concentrations of urinary catecholamines, adrenaline and noradrenaline increase in various stressful situations including cold stress, and high levels have been considered to be suggestive of lethal hypothermia. There is, however, a need for a better hypothermia indicator. A potential candidate could be thrombomodulin (TM), an endothelially expressed protein whose plasma concentration has been shown to elevate in response to hypothermia. TM and catecholamine levels were studied in short-term cold exposure (human subjects, n = 7), in mild and severe hypothermia with or without rewarming (rats, n = 96) and in hypothermia deaths compared with deaths from cardiovascular diseases, traumas and other causes (autopsy cases, total n = 552). Myocardial thrombomodulin transcript expression was increased in severely hypothermic rats, but was lower in hypothermia deaths than in other causes. The circulating TM level was transiently reduced in severe hypothermia. The myocardial and urinary TM protein levels were reduced in lethal hypothermia compared with other causes of death. TM and catecholamine levels correlated significantly in blood and urine both in living subjects and post-mortem examination. In severely hypothermic rats, there was an inverse relationship between plasma adrenaline concentration and myocardial thrombomodulin transcript level. The results suggest that TM expression and secretion are altered by hypothermia, possibly linked to the actions of catecholamines. Analysing the post-mortem catecholamine and TM levels provides evidence of ante-mortem cold stress in suspected hypothermia deaths. Further studies should be conducted in order to reveal the exact mechanisms behind the regulation of TM on cell levelTiivistelmä Paleltumiskuolemat ovat oikeuslääketieteellisesti haastavia, koska vainajaan ei jää paleltumiseen viittaavia yksiselitteisiä löydöksiä. Virtsan katekoliamiinien, adrenaliinin ja noradrenaliinin, pitoisuudet kasvavat stressitilanteissa kuten kylmäaltistuksessa. Korkeita pitoisuuksia on pidetty paleltumiseen viittaavana tekijänä. Paremmalle paleltumista osoittavalle merkkiaineelle on kuitenkin selkeä tarve. Eräs mahdollinen merkkiaine voisi olla trombomoduliini (TM), joka on endoteelisolujen tuottama proteiini. Sen plasmapitoisuuden on aiemmin osoitettu nousevan alilämpöisyystilassa. TM- ja katekoliamiinitasoja tutkittiin lyhyessä kylmäaltistuksessa (koehenkilöt, n = 7) sekä lievässä ja vaikeassa alilämpöisyystilassa joko lämmityksen jälkeen tai ilman lämmitystä (rotat, n = 96). Lisäksi verrattiin paleltumisen, sydän- ja verisuonitautien, vammojen sekä muiden syiden aiheuttamia kuolemia (ruumiinavausaineisto, n = 552). Sydänlihaksen trombomoduliini-transkriptin taso oli kohonnut vaikeasti alilämpöisillä rotilla, mutta se oli matalampi paleltumiskuolemissa kuin muissa kuolemissa. Veren TM-taso oli hetkellisesti alentunut vaikeassa alilämpöisyystilassa. Sydänlihaksen ja virtsan TM-proteiinipitoisuudet olivat matalampia paleltumiskuolemissa kuin muissa kuolemansyissä. TM- ja katekoliamiinitasot korreloivat merkittävästi veressä ja virtsassa sekä koehenkilöillä ja -eläimillä että vainaja-aineistossa. Vaikeasti alilämpöisillä rotilla todettiin käänteinen suhde plasman adrenaliinipitoisuuden ja sydänlihaksen trombomoduliini-transkriptitason välillä. Tulosten perusteella alilämpöisyystila muuttaa TM:n ekspressiota ja erittymistä, mikä voi liittyä katekoliamiinien vaikutuksiin. Kuolemanjälkeisten TM- ja katekoliamiinitasojen määritys tuo lisänäyttöä kuolemaa edeltäneestä kylmävaikutuksesta epäiltäessä paleltumiskuolemaa. Lisätutkimuksia tarvitaan TM:n solutason säätelymekanismien selvittämiseksi
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英志麟 and Chee-lun Aaron Ying. "Hypothermia and platelet dysfunction: monitoring and effects of desmopressin." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40722168.
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Harper, Christopher Mark. "Clinical approaches to the prevention of inadvertent perioperative hypothermia." Thesis, University of Portsmouth, 2016. https://researchportal.port.ac.uk/portal/en/theses/clinical-approaches-to-the-prevention-of-inadvertent-perioperative-hypothermia(9b5a8d95-f7d3-4271-8444-acd0b7845fa0).html.
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The contribution of this programme of research has been to improve perioperative temperature management in daily clinical practice. The papers presented in this thesis represent a logical and coordinated programme designed to provide theatre teams with information that will allow them to make clinically, environmentally and financially informed decisions about the most effective means of preventing inadvertent perioperative hypothermia. The areas in which this research has contributed include: • determining the accuracy of new and minimally invasive temperature measurement devices • determining the relative effectiveness of warming devices • the safety of warming devices • increasing the number of patients who benefit from perioperative warming • the adoption of best perioperative warming practice.
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Ying, Chee-lun Aaron. "Hypothermia and platelet dysfunction monitoring and effects of desmopressin /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40722168.
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Kohlhauer, Matthias Quentin. "Étude expérimentale de l'hypothermie induite par ventilation liquide totale au décours d'un arrêt cardiaque choquable et non choquable." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC0081.
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Chaque année, environ 40000 patients subissent un arrêt cardiaque extra-hospitalier en France. Malgré l’amélioration de la prise en charge initiale, ces patients développent fréquemment une dysfonction neurologique, cardiaque et multi-viscérale, à l’origine d’une survie extrêmement faible. L’une des stratégies susceptible d’améliorer la survie chez les patients est l’induction d’une hypothermie thérapeutique modérée à 32-34°C. Cela présente néanmoins un bénéfice très limité chez l’Homme par rapport à celui décrit dans les études expérimentales. L’une des explications pourrait être la vitesse d’induction de l’hypothermie chez l’Homme par rapport à celle réalisée chez l’animal de laboratoire. Dans ce contexte, le laboratoire d’accueil étudie une approche capable de maximiser la vitesse de refroidissement par ventilation liquide totale (VLT). Cette stratégie consiste à ventiler les poumons avec des perfluorocarbones liquides et à utiliser cet organe comme bio-échangeur thermique, tout en assurant des échanges gazeux normaux.L’objectif de mon travail a été de d’étudier expérimentalement les conséquences de l’induction d’une hypothermie ultra-rapide dans différentes situation d’arrêt cardiaque chez le lapin. Cela permettrait à terme de déterminer la situation la plus pertinente pour le transfert clinique de la VLT.Nous avons tout d’abord étudié l’effet d’une hypothermie induite par de grande quantités de fluides froids pendant la réanimation cardio-pulmonaire après un arrêt cardiaque choquable. Cela n’a pas permis d’induire de bénéfice sur les chances de réanimation en l’absence d’administration d’adrénaline. Dans un second temps, nous avons démontré que la VLT était associée à une puissante neuroprotection et cardioprotection à la fois après un arrêt cardiaque choquable avec infarctus du myocarde sous-jacent, ou après un d’arrêt cardiaque non choquable d’origine respiratoire. Ce bénéfice s’exerçait très précocement au décours de l’arrêt cardiaque, par une inhibition de la perméabilité de la barrière hémato-encéphalique, de la production d’espèces réactives de l’oxygène, de l’hyperhémie cérébrale et de la réponse inflammatoire.Ces résultats démontrent l’existence d’une fenêtre thérapeutique très précoce, au cours de laquelle la VLT hypothermisante peut procurer une puissante protection neurologique et cardiaque à la suite d’un arrêt cardiaque. Dans la perspective d’un transfert clinique de la VLT, la situation de l’arrêt cardiaque non choquable serait particulièrement pertinente, en raison du pronostic très sombre qui lui est associéCardiac arrest is a major public health issue, concerning 40000 patients every year in France. Among the successfully resuscitated patients, most of them develop severe neurological, cardiac and multivisceral dysfunctions, leading to an aggravation of the prognosis. One of the strategies that could improve this prognosis is mild therapeutic hypothermia at 32-34 degres°C during 24 hours. However, recent clinical studies demonstrated limited benefits in patients, as compared to experimental studies. One of the explanations could be the relatively prolonged delay for hypothermia achievement in humans as compared to laboratory animals. In order to induce similar cooling rate in humans than animals, the laboratory is investigating a strategy for ultra-fast cooling through total liquid ventilation (TLV). This strategy consists in lungs ventilation with cold perfluorocarbons, which could use the lungs as a heat-exchanger while maintaining normal gas exchanges.The general goal of the present study was to experimentally investigate the consequences of ultra-fast cooling in different situations of cardiac arrest in rabbits. This could lead to determine the most relevant clinical setting for a further clinical translation of TLV in patients.Accordingly, we initially studied the effect of conventional hypothermia through fluid administration during cardiac massage in a rabbit model of shockable cardiac arrest. Such conventional hypothermia did not provide any benefit. Then, we investigated the effect of cooling induced by TLV in rabbits submitted to cardiac arrest from different causes. After ischemic cardiac arrest from shockable rhythm, TLV was associated with potent neuro- and cardioprotective effects, along with strong survival improvement and multivisceral dysfunction limitations. After cardiac arrest from respiratory and non-shockable cause, TLV provided potent neurological benefit. This was exerted very early after resuscitation through the reduction of the blood-brain barrier permeability, reactive oxygen species production, acute cerebral hyperhaemia or inflammatory response.In conclusion, TLV-induced cooling provides potent neurological and systemic benefits after experimental cardiac arrest from different causes in rabbits. These works describe the existence of a therapeutic window for hypothermia, very early after cardiac arrest. This strengthens the relevance of TLV for cooling induction. For a further clinical translation, non-shockable cardiac arrest could be a relevant clinical situation, considering the very poor prognosis
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Silva, Aline Batista da. "Hipotermia inadvertida perioperatória em pacientes cirúrgicos no Brasil: como estamos prevenindo?" Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/7/7139/tde-27042018-145724/.
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Introdução: A hipotermia inadvertida perioperatória é um evento frequente e atinge cerca de 70% dos pacientes cirúrgicos, levando a complicações importantes, como alterações cardiovasculares, infecção do sitio cirúrgico, desconforto ao paciente, aumento do tempo de hospitalização, entre outros. Por oferecer inúmeros riscos ao paciente cirúrgico, a ocorrência da hipotermia não intencional perioperatória tem ganhado espaço na literatura atual. A manutenção da temperatura perioperatória vem sendo sugerida pela literatura com a implementação de métodos passivos e ativos de aquecimento como o aumento da temperatura da sala cirúrgica, uso de cobertor de algodão, uso de cobertor térmico, uso de dispositivos de ar forçado, infusão de fluidos aquecidos, entre outros. No entanto, não há no Brasil nenhum estudo publicado onde se investigue a atuação das equipes que atuam no bloco cirúrgico realizam a prevenção da hipotermia perioperatória nos hospitais. Objetivos: Verificar como se dá o monitoramento da temperatura e a prevenção de hipotermia inadvertida perioperatória em pacientes cirúrgicos internados em hospitais brasileiros. Material e método: Estudo transversal, realizado na cidade de São Paulo através de questionário preenchido pelos enfermeiros participantes do 12° Congresso Brasileiro de Enfermagem em Centro Cirúrgico, Recuperação Anestésica e Centro de Material e Esterilização. Os dados foram analisados descritivamente e demonstrados em foram de tabelas. Resultados: O monitoramento da temperatura no período perioperatório ainda não é realizado sistematicamente por todos os profissionais de centro cirúrgico, porem a realização dessa pratica foi relatada por 92,4% no período pré-operatório, 83,8% no período intraoperatório e 94,9% no período pós-operatório. A prevenção da hipotermia inadvertida no perioperatório é uma pratica exercida pela grande maioria dos participantes (96%), com predomínio nos métodos passivos de manutenção da normotermia nos períodos pré-operatório (51%) e associação de métodos passivos e ativos nos períodos pós (64,6%) e intraoperatório (45,5%) de manutenção da normotermia ao paciente cirúrgico. Os principais profissionais envolvidos para a monitorização da temperatura e a prevenção da hipotermia perioperatória inadvertida são a equipe de enfermagem e os anestesiologistas. Apesar de um número grande de profissionais não informarem a taxa de ocorrência de hipotermia inadvertida perioperatória, nota-se que para a maioria dos respondentes a ocorrência desse evento é baixa. Conclusão: a realização de praticas para a manutenção da normotermia operatória é realidade para a equipe de enfermagem. A monitorização da temperatura ainda não é realizada de maneira constante em todo período perioperatório. A prevenção da hipotermia inadvertida no período perioperatório é pratica bastante frequente entre os procedimentos cirúrgicos.Introduction: Perioperative inadvertent hypothermia is a frequent event and affects about 70% of surgical patients, leading to important complications, such as cardiovascular alterations, surgical site infection, patient discomfort, hospitalization time, and others. Because it offers innumerable risks to the surgical patient, the occurrence of perioperative unintentional hypothermia has gained space in the current literature. Perioperative temperature maintenance has been suggested in the literature with the implementation of passive and active heating methods such as increased operating room temperature, use of cotton blanket, use of thermal blanket, use of forced air devices, infusion of fluids heated, among others. However, there is no published study in Brazil to investigate the performance of the teams that work in the surgical block, and to prevent perioperative hypothermia in hospitals. Objectives: To verify how temperature monitoring and the prevention of perioperative inadvertent hypothermia occur in surgical patients hospitalized in Brazilian hospitals. Material and method: A cross-sectional study was carried out in the city of São Paulo through a questionnaire filled out by nurses participating in the 12th Brazilian Congress of Nursing in Surgical Center, Anesthetic Recovery and Material and Sterilization Center. The data were analyzed descriptively and demonstrated in the tables. Results: Temperature monitoring in the perioperative period has not been systematically performed by all surgical center professionals, but the practice of this practice was reported by 92.4% in the preoperative period, 83.8% in the intraoperative period and 94, 9% in the postoperative period. The prevention of inadvertent perioperative hypothermia is a practice practiced by the vast majority of participants (96%), with predominance in passive methods of maintaining normothermia in the preoperative periods (51%) and association of passive and active methods in the post- 64.6%) and intraoperative (45.5%) maintenance of normothermia in the surgical patient. The main professionals involved in temperature monitoring and the prevention of inadvertent perioperative hypothermia are the nursing team and anesthesiologists. Although a large number of professionals do not report the occurrence rate of inadvertent perioperative hypothermia, it is noted that for most of the respondents the occurrence of this event is low. Conclusion: the practice of practices for the maintenance of operative normothermia is reality for the nursing team. Temperature monitoring is not yet performed consistently throughout the perioperative period. The prevention of inadvertent hypothermia in the perioperative period is a very frequent practice among surgical procedures.
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Barrett, Robert Daniel. "Therapeutic hypothermia and its effects on the preterm fetal sheep." Thesis, University of Auckland, 2011. http://hdl.handle.net/2292/7200.
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There is compelling evidence that 72 h of moderate hypothermia initiated within 2 to 6 h after hypoxia-ischemia can protect against brain injury, disability and death in term newborn infants. Currently, there is no clinical treatment for hypoxic-ischemic encephalopathy for preterm infants. With the worldwide rates of preterm birth steadily increasing, there is much interest in using therapeutic hypothermia to treat preterm hypoxic-ischemic encephalopathy. The goal of this thesis was to investigate the effects and window of opportunity of therapeutic hypothermia on the brain and physiology after asphyxia in preterm fetal sheep. My first study showed that 68.5 h of selective head cooling, initiated 90 min after asphyxia, protected oligodendrocytes in the white matter (WM) and subventricular zone (SVZ) of the preterm fetal sheep brain at 3 days recovery from 25 min of umbilical cord occlusion. Overall proliferation of cells was not reduced by hypothermia in the WM or SVZ. The remainder of the studies focused on the use of 72 h of whole body hypothermia, and assessed effects at 7 days recovery from asphyxia. Two hypothermia protocols were examined, a 30 min onset after asphyxia protocol, and a clinically relevant, 5 h after asphyxia protocol. Whole body hypothermia was associated with mild bradycardia, mild changes in blood pressure and carotid blood flow and transitory suppression of EEG power. All physiological variables resolved to sham values by 96 h after asphyxia. Delayed hypothermia was associated with slower improvement of spectral edge frequency and EEG power than early onset hypothermia. The window of opportunity for SVZ protection was less than 5 h, with significant improvement in numbers of oligodendrocytes after only early onset but not delayed hypothermia. In contrast, there was no significant improvement in number of oligodendrocytes in the white matter tracts, with either early or late cooling. This was associated with reduced proliferation in the white matter, and no induction of microglia and caspase 3, which suggests that lack of replenishment of oligodendrocytes may have contributed to persistent reduction in numbers of oligodendrocytes after therapeutic hypothermia. Overall the studies in this thesis suggest that the window of opportunity for brain protection in the preterm infant is less than 5 hours and that synergistic treatment may be required to protect the WM after hypoxic-ischemic insults.
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Zimmerman, Angela D. "Nursing interventions in the care of patients undergoing induced hypothermia." Honors in the Major Thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/531.
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Use of induced hypothermia for the purpose of lowering intracranial pressure and preserving neuronal function has increased as research data reveals a trend of positive outcomes in patients treated with this therapy. Recently induced hypothermia following cardiac arrest due to ventricular fibrillation has been deemed successful. Current research has expanded to evaluate the effectiveness of induced hypothermia as a treatment modality for severe stroke and head trauma. In spite of its efficacy, complications exist with this treatment modality. The purpose of this literature review is to examine potential complications secondary to induced hypothermia and highlight the nurse's role in managing patient care. At the present, patient protocols for induced hypothermia are lacking. The success of treatment is largely dependent on the skill of the healthcare team to prevent further harm and enhance therapeutic outcomes by providing astute assessment and management of complications in patients undergoing induced hypothermia. The desired outcome of this review is to promote integration of research in the development of evidence-based protocols for induced hypothermia.B.S.N.
Bachelors
Nursing
Nursing
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Phillips, Kristin. "The effects of hypothermia on status epilepticus-induced acquired epilepsy." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/2544.
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Status epilepticus (SE) is a type of neurological injury characterized by continuous seizure activity and can lead to molecular and pathophysiological alterations leading to plasticity changes. SE can lead to the development of AE by the process of epileptogenesis, which is a phenomenon that describes the transformation of normal brain tissue into a hyperexcitable neuronal population. It has been demonstrated both in vivo and in vitro that calcium (Ca2+) dynamics are severely altered during and after SE, and these changes play a major role in the progression of epileptogenesis. It has also been reported that preventing the rise in intracellular Ca2+ ([Ca2+]i) immediately following injury (the Ca2+ plateau) prevents the plasticity changes and ultimate development of epilepsy. Currently, there are no treatments available that can be administered following an injury to prevent the development of AE. Therefore it is clinically important to develop a therapy that can be administered after an injury to block epileptogenesis. Hypothermia is a potential therapeutic intervention. Hypothermia is used clinically to provide neuroprotection following various neurological insults such as stroke and traumatic brain injury (TBI). However, no studies have been performed to evaluate the therapeutic potential of hypothermia following SE. Hypothermia provides protection via multiple mechanisms, one of which includes modulating excitotoxic neurotransmission. It is believed to reduce Ca2+ influx by reducing NMDA receptor activation. It is unclear how hypothermia affects Ca2+ through other modes of entry. This dissertation evaluates the effects of hypothermia on the Ca2+ plateau and demonstrates the novel finding that hypothermia induced post-SE blocks the development of the Ca2+ plateau and reduces the development of AE.
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Johann, Kornelia [Verfasser]. "Mechanisms of thyroid hormone induced hypothermia in mice / Kornelia Johann." Lübeck : Zentrale Hochschulbibliothek Lübeck, 2020. http://d-nb.info/1206388323/34.
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Darbera, Lys. "Etude de la ventilation liquide totale hypothermisante sur le syndrome post-arrêt cardiaque chez le lapin." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST0105/document.
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Chaque année, l’arrêt cardiaque extra-hospitalier, plus communément appelé mort subite, est responsable de plus de 40 000 décès en France. Le plus souvent, cela constitue l’ultime complication d’un infarctus du myocarde ou d’autres maladies cardiovasculaires. Le développement des méthodes de réanimation cardio-pulmonaire (RCP), leur diffusion publique et l’amélioration de la prise en charge pré-hospitalière (« chaîne de survie ») ontpermis une forte augmentation du pourcentage de patients réanimés après un arrêt cardiaque depuis une trentaine d’années. Malheureusement, la reprise d’une activité circulatoire spontanée ne constitue que la première étape de cette prise en charge et la majorité des patients décèdent dans les jours suivants de défaillances multiviscérales regroupées sous le nom de « syndrome post-arrêt cardiaque » 2. Seule une minorité de patients peut i fine survivire et sortirt de l’hôpital après une bonne récupération neurologique. Depuis de nombreuses années, les chercheurs tentent donc de découvrir des stratégies cardioprotectrices et neuroprotectrices dont l’application permettrait d’améliorer le pronostic de ces patientsSummary not transmitted
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Vanhuyse, Fabrice. "Évaluation des bénéfices thérapeutiques apportés par l’hypothermie dans le traitement du choc cardiogénique sous ECMO chez l’animal." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0320/document.
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Le choc cardiogénique est une pathologie grave pouvant mettre rapidement le pronostic vital du patient en jeu. Malgré de nombreux progrès réalisés dans sa prise en charge, la mortalité liée à cette affection reste très élevée. Une des avancées importantes dans le traitement du choc cardiogénique développée ces dernières années est l’ECMO. Mais force est de constater, que malgré la restauration d’un flux circulatoire adéquat, nous restons confrontés à une mortalité élevée chez ces malades. La première partie de cette thèse est un rappel des principaux concepts du choc cardiogénique de l’ECMO ainsi qu’un rappel des effets de l’hypothermie. Nous rapportons dans la deuxième partie notre recherche expérimentale chez le cochon qui a permis de mettre en évidence un effet bénéfique de l’hypothermie sur la fonction cardiaque et sur la réactivité vasculaire chez les animaux en choc cardiogénique traités par une ECMO. Dans la troisième partie, nous discutons et analysons nos résultats en essayant d’apporter des explications physiologiquesCardiogenic shock is still considered as a severe medical condition. Despite much progress in the treatment of the cardiogenic shock, this disease is still associated with a high mortality. An important advance in the treatment of the cardiogenic shock is the use of ECMO. However, despite the restoration of a proper circulatory flow, we are still facing significant mortality in these patients. The first part of this manuscript is a reminder of the main concepts of the cardiogenic shock and ECMO and the concept of hypothermia. In the second part, we report the results of our experimental research who highlighted a beneficial effect of hypothermia in cardiac function and vascular reactivity in animals in cardiogenic shock treated by ECMO. In the third part we discuss our results and we try to rapport physiological explications of our results
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England, Adrian James. "The effect of moderate hypothermia on neuromuscular transmission and neuromuscular blockade." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338687.
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Larsson, Ing-Marie. "Post-Cardiac Arrest Care : Therapeutic Hypothermia, Patient Outcomes and Relatives’ Experiences." Doctoral thesis, Uppsala universitet, Institutionen för kirurgiska vetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-229758.
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The overall aim of the thesis was to study post-resuscitation care of cardiac arrest (CA) patients with a focus on therapeutic hypothermia treatment, outcomes up to six months post-CA and relatives’ experiences during the hospital stay. In Paper I, the aim was to asses effectiveness of hypothermia treatment with cold, 4°C, intravenous crystalloid infusion combined with ice packs. In conclusion, the described cooling method was found to be useful for inducing and maintaining hypothermia, allowed good temperature control during rewarming and to be feasible in clinical practice. The aim in Paper II was to investigate biomarkers and the association of serum glial fibrillary acidic protein (GFAP) levels with outcome, and to compare GFAP with neuron-specific enolas (NSE) and S100B. The result showed increased GFAP levels in the poor outcome group, but did not show sufficient sensitivity to predict neurological outcome. Both NSE and S100B were shown to be better predictors. A combination of the investigated biomarkers did not increase the ability to predict neurological outcome. In Paper III, the aim was to investigate whether there were any changes in and correlations between anxiety, depression and health-related quality of life (HRQoL) over time, between hospital discharge and one and six months post-CA. There was improvement over time in HRQoL, but changes over time in anxiety and depression were not found. Physical problems seemed to affect HRQoL more than psychological problems. The results also indicate that the less anxiety and depression patients perceive, the better their HRQoL. In the fourth paper, the aim was to describe relatives’ experiences during the next of kin’s hospital stay after surviving a CA. The analysis resulted in three themes: The first period of chaos, Feeling secure in a difficult situation, and Living in a changed existence. In conclusion, the results of the thesis have helped to improve knowledge within the areas studied and reveal aspects that should be taken into account in the overall treatment of this group of patients. The thesis have also shown the importance of developing an overall view and establishing a chain of care from an individual’s CA until follow-up for both the patient and his/her relatives.
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Sabharwal, Rasnapreet. "The integrative physiological responses to acute and chronic hypothermia in rats." Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411870.
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Blowers, Stephen John. "Modelling brain temperatures in healthy patients and those with induced hypothermia." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31248.
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Hypothermia has been shown to provide protective benefits to the brain after head trauma. Current treatment methods employ full body hypothermia which can lead to further associated complications, such as a compromised immune system. Alternatively, cooling the brain individually can provide the same benefits whilst minimising the risks associated. Unfortunately, the feasibility of this is still uncertain due to the invasiveness of measuring cerebral temperatures directly and the unavailability of brain temperature maps. Mathematical modelling provides an important alternative avenue for predicting the outcome of hypothermic procedures, such as scalp cooling. However, these tend to rely on Pennes Bioheat Equation which simplifies the blood flow within the system as a single perfusion term. This removes any directional thermal advection which could play an important part in biological heat transfer. In this thesis, an alternative method is developed, tested, and proposed where the full cerebral circulatory system is modelled using vascular channels embedded in a porous tissue simulating the blood vessels and capillaries, respectively. This is dubbed the vascular porous (VaPor) method. This dissertation tests and discusses the feasibility of inducing hypothermia by cooling the scalp using the VaPor model. Initially, the blood vessels were modelled in 3D to fully capture the effects of flow, however, this was deemed computationally inefficient and difficult to manipulate so was subsequently replaced with a system of 1-Dimensional line segments. Temperatures produced from this method conform to expected ranges of values and agree with available data from studies in rat brains. It was observed that core brain temperatures can be impacted by scalp cooling but only with a large number of generated vessels. This is due to the tortuous nature of the vasculature which is not captured by the porous media alone. Various input parameters are also tested to ensure the validity of results from this model. One tested parameter that did not agree with in-vivo results was the measurement of tissue perfusion which appeared to be grossly exaggerated by the VaPor model, although conservation of mass was conserved at each stage. This was investigated further by simulating tracer transport in the cerebral domain in the same manner that in-vivo measurements use. While in-vivo measurements and the predictions by tracer transport produce perfusion values of the same order of magnitude, a full quantitative match cannot be expected because of the differences in the measurement techniques used. Various approximations that can be imposed to resolve this are discussed. The versatility of the VaPor model was explored by simulating a variety of applications relevant to cerebral cooling. The inclusion of counter-current flow within the porous domain showed similar results to trials performed with dense vascular trees. Trials on the scale of a neonatal brain showed that hypothermia could be achieved from scalp cooling alone contrary to previous models. The transient response of scalp cooling was explored as well as the thermal response after simulating an ischemic stroke. All results demonstrated that, due to the inclusion of directional flow, scalp cooling has a larger impact on cerebral temperatures than seen with previous bioheat models.
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Osama, Mohammad. "Function of Vascular Endothelial Cells in Aging and Hypothermia: Clinical Implications." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1534939514503588.
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Nordmark, Johanna. "Aspects of induced hypothermia following cardiopulmonary resuscitation cerebral and cardiovascular effects /." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9562.
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Romsi, P. (Pekka). "Adjuncts to improve neurological outcome following hypothermic circulatory arrest:an experimental study using a chronic porcine model." Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514269217.
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Abstract
Interruption of cerebral blood flow during hypothermic circulatory arrest (HCA) predisposes neurons to glutamate excitotoxicity. Reperfusion is followed by leukocyte infiltration, which results in an inflammatory reaction in the brain tissue. In the first study, the presynaptic glutamate release inhibitor lamotrigine (L) and the leukocyte-depleting filter (LF) were studied to determine if their combination could mitigate brain injury after HCA (I). The aim of the second study was to evaluate the possible neuroprotective effect of a 14-hour period of mild (32°C) hypothermia after HCA (II). Recent experimental research has demonstrated the neuroprotective properties of erythropoietin (EPO) and fructose-1,6-bisphosphate (FDP), whose effects during and after HCA were evaluated in the third and the fourth studies (III, IV).
A chronic porcine model was used. The animals were randomly assigned to the study groups as follows: 8 animals in the L+LF group, 8 in the L group, and 8 in the control group (I); 10 animals in the hypothermia group and 10 in the normothermia group (II); 10 animals in the EPO group and 10 in the control group (III), and 12 animals in the FDP group and 12 in the control group (IV). Monitoring of hemodynamics, metabolism, temperature, electroencephalogram (EEG), brain microdialysis, intracranial pressure (II-IV), and brain tissue oxygen (II-IV) was carried out. A daily behavioral assessment was performed until death or until elective sacrifice on the seventh postoperative day, after which the brain was prepared for a histopathologic examination.
The results of these studies indicate that lamotrigine has a neuroprotective effect during HCA. This is observed in terms of EEG burst recovery, behavioral and histopathologic outcome, and brain microdialytic findings. The combined use of lamotrigine and leukocyte filtration may further improve survival. A 14-hour period of mild hypothermia after HCA is associated with a poor outcome. However, it may preserve its efficacy when used for no longer than 4 hours. Administration of EPO before HCA proved ineffective in reducing mortality or brain histopathologic injury. Findings from brain microdialysis, brain tissue oxygen tension, and neuronal apoptosis, however, suggest that the drug has neuroprotective properties. Administration of FDP before and after HCA is associated with better survival, behavioral outcome, and brain histopathologic scores. The metabolic and brain microdialytic findings also suggest that this drug has supportive effects on myocardial and brain metabolism.
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Roy, Matthew S. "Acute effects of facial cooling on arterial stiffness and wave reflection." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 56 p, 2007. http://proquest.umi.com/pqdweb?did=1397914231&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Bäck, Andreas, and Robin Augustsson. "Oönskad perioperativ hypotermi : En kvalitativ studie om anestesisjuksköterskans upplevelse." Thesis, Högskolan i Borås, Akademin för vård, arbetsliv och välfärd, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-309.
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Många patienter blir hypoterma under den perioperativa vården. Det finns en mängd åtgärder som kan vidtas för att minska oönskad hypotermi. Pre- och intraoperativ uppvärmning med värmetäcke, varmt på operationssalen, cirkelsystem och användning av varma infusioner kan vara en bra kombination. Oavsett vilken terapi som används är normotermi alltid högt prioriterat. Det handlar om patientsäkerhet. Genom att effektivt motverka hypotermi skulle möjligheten öka till snabbare återhämtning, färre postoperativa infektioner, mindre kostnader för sjukhuset och minskat lidande för patienter. Syftet med studien var att undersöka anestesisjuksköterskans upplevelser av att förebygga perioperativ hypotermi hos vuxna elektiva patienter. En kvalitativ intervjustudie med induktiv ansats gjordes inom problemområdet. Insamlingen av data gjordes genom intervjuer som spelades in. Intervjuerna transkriberades och analyserades med kvalitativ innehållsanalys. I resultatet framkommer att, även om normotermi är målet och ambitionen finns, är det många faktorer som spelar in hur vida de hypotermiförebyggande åtgärderna når framgång. Det krävs en god planering samt erfarenhet av förebyggande arbete. Att mätmetoderna är ifrågasatta kan bidra till att mätning inte alltid utförs. Avsaknad av riktlinjer kring hypotermiförebyggande åtgärder bidrar till oklarheter för vårdpersonalen. Alla de olika personalkategorierna kring en operation tenderar att fokusera på sina egna uppgifter. En stor ansvarskänsla samt till viss del ensamhetskänsla i besluten, om vilka åtgärder som skall vidtas samt när finns hos anestesisjuksköterskan. När patienten blir kall trots att anestesisjuksköterskan har gjort allt kan det upplevas som ett misslyckande att inte räcka till. När patienten anländer kall till uppvaket kan anestesisjuksköterskan känna skuld till patientens tillstånd samt lidandet det medför. Strävan är att patienten ska må bra även postoperativt. Genom att informera patienten om varför det är nödvändigt att det tillförs extra värme gör att patienten blir delaktig i omvårdnaden. Anestesisjuksköterskan upplever att värmda täcken, strumpor samt mössa gör patienten mindre spänd samt stressad. På så vis ökar man patientens upplevs av välbefinnandet.
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Cheng, Tan-ning, and 鄭丹寧. "An evidence-based guideline on preoperative warming of patients undergo general anesthesia to reduce postoperative hypothermia." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/193046.
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Operating theatre is a cold environment and hypothermia (core body temperature lower than 36C) is prevalent among patients undergoing operations. Possible causes of this adverse condition include anesthetic effect, body part exposure, blood loss, and the low room temperature in the theatre. Hypothermia can impair wound healing, decrease drug metabolism, increase oxygen consumption, which in turn causing respiratory distress, bradycardia as well as atrial fibrillation. In extreme cases, it can be lethal.
Numerous research studies have explored ways of interventions and new technologies to maintain normal body temperature of patients during operations. However, perhaps without proper translation to clinical practice, the rate of postoperative hypothermia still remains high in many hospital setting.
The objectives of this thesis are to systematically review the current literature on the effectiveness of preoperative warming on reducing postoperative hypothermia of patients undergoing general anesthesia. Data from the relevant literature is extracted for setting up a table of evidence. Also, quality assessment is performed. An evidence-based practice guideline for preoperative warming is developed and its feasibility and transferability to the target patients is examined. The purpose of the guideline is to provide better care for patients undergoing general anesthesia.
In this thesis, preoperative forced air warming is proposed. The target setting is the operating theatre department and day surgery centre in a local public acute hospital. The target population is patients who undergo general anesthesia. Data is extracted from six articles. The implementation potential of the proposed guideline is high, because of the high transferability, feasibility and cost-effective ratio. An evidence-based practice guideline is developed based on the evidence. Well-designed implementation and evaluation plan are developed for the implementation of the proposed guideline.published_or_final_version
Nursing Studies
Master
Master of Nursing
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Winterås, Elisabeth, and Rosth Kerstin Lindberg. "Ofrivillig hypotermi under den perioperativa vården : Inadvertent hypothermia in the perioperativ care." Thesis, Högskolan Dalarna, Omvårdnad, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:du-5554.
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Abstract Syftet med denna studie var att påvisa effekter av ofrivillig hypotermi samt beskriva anestesisjuksköterskans omvårdnadsåtgärder för att belysa vilka förebyggande faktorer som bibehåller normotermi i den perioperativa vården. Metod: Studien genomfördes som en litteraturöversikt. Artiklarna har sökts via Cinahl och Medline. Studiens resultat baserades på sjutton vetenskapliga artiklar med kvantitativ ansats, dessa grupperades under olika teman. Resultatet redovisas i följande huvudteman fysiologiska effekter, komplikationer, perioperativa teamet, aktiv uppvärmning, administrering av intravenösa vätskor, miljön i operationssalen samt riktlinjer för bibehållande av normotermi. Ofrivillig hypotermi i samband med ett kirurgiskt ingrepp ökade risken för komplikationer i form av ökad infektionsbenägenhet, påverkan på koagulationen med ökad blödningsrisk och hjärtpåverkan med risk för myocardischemi. Hypotermi påverkade också läkemedelsmetabolismen. Dessa effekter av ofrivillig hypotermi under den perioperativa vården orsakade patienten onödigt lidande, förlängd sjukhus vistelse och ökade kostnader för samhället.Slutsats: Anestesisjuksköterskans mest framgångsrika omvårdnadsåtgärder i den perioperativa fasen för att bibehålla normotermi var att använda aktiv uppvärmning, (värmetäcke) vätskevärmare och förhöjd rumstemperatur i operationssalen. Därigenom minskade värmeförlusten via strålning från patientens hud till omgivande miljö. Dessa omvårdnadsåtgärder förutsätter gott samarbete och ska vara självklara i det perioperativa teamet.
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Brändström, Helge. "Accidental hypothermia and local cold injury : physiological and epidemiological studies on risk." Doctoral thesis, Umeå universitet, Anestesiologi och intensivvård, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-55602.
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Background: (Papers I and II) The objectives were to first determine incidence and contributing factors to cold-related injuries in northern Sweden, both those that led to hospitalization and those that led to fatality. (Papers III and IV) A further aim was to assess post-cooling hand-rewarming responses and effects of training in a cold environment, both on fingertip rewarming and on function of the autonomic nervous system, to evaluate if there was adaptation related to prolonged occupational cold exposure. Methods: In a retrospective analysis, cases of accidental cold-related injury with hospital admission in northern Sweden during 2000-2007 were analyzed (Paper I). Cases of fatal hypothermia in the same region during 1992-2008 were analyzed (Paper II). A cohort of volunteers was studied before and after many months of occupational cold exposure. Subject hand rewarming response was measured after a cold hand immersion provocation and categorized as slow, moderate or normal in rewarming speed. This cold provocation and rewarming assessment was performed before and after their winter training. (Paper III). Heart rate variability (HRV) was analyzed from the same cold provocation/recovery sequences (Paper IV). Results: (Paper I) For the 379 cases of hospitalization for cold-related injury, annual incidences for hypothermia, frostbite, and drowning were 3.4/100,000, 1.5/100,000, and 1.0/100,000 inhabitants, respectively. Male gender was more frequent for all categories. Annual frequencies for hypothermia hospitalizations increased during the study period. Hypothermia degree and distribution of cases were 20 % mild (between 32 and 35ºC), 40% moderate (31.9 to 28ºC), and 24% severe (< 28ºC), while 12% had temperatures over 35.0ºC. (Paper II) The 207 cases of fatal hypothermia showed an annual incidence of 1.35 per 100,000 inhabitants, 72% in rural areas, 93% outdoors, 40% found within 100 meters of a building. Paradoxical undressing was documented in 30%. Ethanol was detected in femoral vein blood in 43%. Contributing co-morbidity was common including heart disease, previous stroke, dementia, psychiatric disease, alcoholism, and recent trauma. (Paper III) Post-training, baseline fingertip temperatures and cold recovery variables in terms of final rewarming fingertip temperature and vasodilation time increased significantly in moderate and slow rewarmers. Cold-related injury (frostbite) during winter training occured disproportionately more often in slow rewarmers (4 of the 5 injuries). (Paper IV) At ‘pre- winter-training’, normal rewarmers had higher power for low frequency and high frequency heart rate variability. After cold acclimatization (post-training), normal rewarmers showed lower resting power values for the low frequency and high frequency heart rate variability components. Conclusions: Hypothermia and cold injury continues to cause injury and hospitalization in the northern region of Sweden. Assessment and management is not standardized across hospitals. With the identification of groups at high risk for fatal hypothermia, it should be possible to reduce the incidence, particularly for highest risk subjects; rural, living alone, alcohol-imbibing, and psychiatric diagnosis-carrying citizens. Long-term cold-weather training may affect hand rewarming patters after a cold provocation, and a warmer baseline hand temperature with faster rewarming after a cold provocation may be associated with less general risk for frostbite. Heart rate variability results support the conclusion that cold adaptation in the autonomic nervous system occurred in both groups, though the biological significance of this is not yet clear.
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Al-Shargabi, Tareq. "Spectral Analysis of Nonstationary Heart Rate of Neonates Receiving Therapeutic Hypothermia Treatment." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/3273.
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We studied Heart Rate Variability (HRV) evolution during therapeutic hypothermia in newborns with hypoxic ischemic encephalopathy (HIE) using spectral analysis. We hypothesized that HRV measures are predictive of neurological outcome in babies with HIE. Non-stationarity in the data causes inaccurate quantification of the spectral power. A modification was proposed to power spectral analysis approach to mitigate the effect of non-stationarity. The modified and the standard approaches were applied to cardiac beat-to-beat intervals of newborns receiving hypothermia treatment. The performance of the approaches in distinguishing the RRi dynamics of two groups of newborns was assessed using area under the receiver operating characteristic (ROC) curve. Our results showed that the modified spectral analysis distinguished the two groups of neonates better than the standard approach. These results may be useful in identifying the deteriorating physiology of the infants receiving hypothermia treatment early in time and strategize alternate interventions for them.
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McGlynn, Karen Patricia. "The effect of hypothermia and rewarming on cardiac electrophysiology and mechanical function." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/8169/.
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Hypothermia is defined as a core body temperature of 35°C or less and can be induced (i.e. therapeutic) or accidental. It is well established that hypothermia leads to a positive inotropic response which causes an increase in the magnitude of cardiac contraction, however rewarming from hypothermia is associated with a negative inotropic response, and the underlying mechanisms of this remain unclear. Accidental hypothermia is further complicated by risk of ventricular arrhythmias and cardiac arrest. This contributes to high mortality rates among these patients. Although hypothermia is used extensively as a therapeutic intervention and survival is possible after extreme exposure, treatment of arrhythmias during rewarming is still challenging. In order to develop targeted anti-arrhythmic strategies in this very specific situation, we first need to understand the basis for pro-arrhythmia during cooling and rewarming. This study aimed to examine the effect of hypothermia and rewarming on aspects of cardiac inotropy and excitability. An in vitro model of hypothermia and rewarming using isolated rat ventricular cardiomyocytes showed that following 3 hours of hypothermia there was a significant reduction in shortening upon rewarming. This was not accompanied by a change in intracellular Ca2+, suggesting a rewarming induced decrease in myofilament sensitivity to Ca2+. In separate experiments, animals underwent an in vivo hypothermia/rewarming procedure and displayed evidence of rewarming induced contractile dysfunction. Epicardial action potential (AP) measurements on these hearts showed a shortened AP duration (APD) when compared to normothermic control animals, which suggests that a sustained electrophysiological effect that could manifest as a shortened QT interval. In contrast to this, a period of transient hypothermia had alternative detrimental effects on the cardiac APD when compared to prolonged hypothermia, an effect that could predispose to the induction of long QT related arrhythmias and ventricular tachycardia. Separate experiments assessed the effect of moderate (31˚C) and severe (17˚C) hypothermia on cardiac excitability in Langendorff perfused rabbit hearts. Moderate hypothermia prolonged PR and QT intervals whilst in severe hypothermia all ECG parameters were prolonged. Ventricular activation times were unaffected at 31°C whilst action potential duration (APD90) was significantly prolonged. At 17°C there were significant and proportionally similar delays in both activation and repolarisation. Ventricular fibrillation (VF) threshold was significantly reduced at 31°C (pro-arrhythmic), but at 17°C VF threshold was >2x baseline (37°C) (anti-arrhythmic). At 31°C, transverse conduction (CVt) was relatively insensitive to cooling versus longitudinal conduction (CVl) but at 17°C both CVt and CVl were proportionately reduced to a similar extent. The gap junction uncoupler heptanol had a larger relative effect on CVt than CVl, and at 31°C was able to restore the CVt/CVl ratio, returning VF threshold to baseline values. This suggests that moderate hypothermia creates repolarisation abnormalities and is pro-arrhythmic. These divergent effects appear to be linked to a lower temperature sensitivity of gap junctions, a conclusion supported by the anti-arrhythmic effect of heptanol at 31°C.
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Holmberg, Petra, and Carolina Söderback. "Oavsiktlig hypotermi : Operationssjuksköterskans preventiva interventioner." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-34505.
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Kwok, Ka-wai, and 郭嘉慧. "The use of warmed intravenous fluid in reducing hypothermia in patients after major surgery." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44623616.
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邱靜雯 and Ching-man Yau. "Use of occlusive wrap to prevent hypothermia in premature infants immediately after birth." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/193042.
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Hypothermia at birth is strongly associated with mortality and morbidity in preterm infants. Unfortunately, infants are prone to hypothermia immediately after birth. A large proportion of preterm infants, especially those of gestational age at less than 30 weeks, experience different levels of hypothermia. A frequently used possible preventive measure is the application of an occlusive wrap immediately after birth. However, no systematic review on this preventive measure supports its translation into practice. This dissertation aimed to evaluate the current evidence on the application of occlusive warp for preterm infants.
Four electronic databases, Cochrane Library, PubMed, CINAHL, and Medline, were searched. Eight studies met the inclusion criteria of this dissertation. Data were extracted and the quality of the included studies was evaluated by the Scottish Intercollegiate Guidelines Network (SIGN). Six studies were graded as high quality studies and showed that occlusive wrapping significantly prevented the incidence of hypothermia among the preterm infants smaller than 30 weeks.
An evidence-based Superwarm guideline was developed, which was deemed to be transferable to the local setting of neonatal intensive care unit with similar target clients and philosophy of care as with those in the identified studies. Also, the proposed innovation was considered to be feasible after examination of staff competency, resources, and approval methods. The potential benefits to preterm infants, nurses, and also the hospital were high, and risks to the patient were minimal. The estimated set-up cost including manpower and consumable cost was $1,720, and the running cost was also $1,720 per year.
A 12 -month implementation program scheduled including communication with stakeholders, training to the frontline nurses, and a pilot of the guideline. Patient outcomes will be measured by admission temperature, temperature one hour after admission, and mortality rate. Healthcare provider outcomes include compliance rate, workload, acceptance of the proposed guideline, job satisfaction, knowledge, and skill enhancement in thermoregulation of the preterm infants. The quality of patient care was also considered in the system outcomes. Guideline effectiveness will be evaluated by the increase in admission temperature, nurse and physician satisfaction, and controlled program expenditure.published_or_final_version
Nursing Studies
Master
Master of Nursing
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Scott, Chris G. "A comparison of endogenous versus exogenous heating on the subsequent development of hypothermia." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58502.pdf.
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Loidl, César Fabián. "Asphyxia during birth biochemical and morphological study in basal ganglia : implication of hypothermia /." Maastricht : Maastricht : Universiteit Maastricht ; University Library, Maastricht University [Host], 1997. http://arno.unimaas.nl/show.cgi?fid=6771.
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Kerr, Chadwick G. "Hypothermia during Olympic triathlon : influence of body heat storage during the swimming stage." Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1014852.
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The purpose of this study was to determine if mild heat stress induced by wearing a wet suit while swimming in relatively warm water (25.4 ± 0.1°C) increases the risk of heat injury during the subsequent cycling and running stages. Specificlly, during an Olympic distance triathlon in a hot and humid environment (32°C & 65% RH). Five male triathletes randomly completed two simulated triathlons (Swim=30 min; Bike=40 km; Run=10 km) in the laboratory using a swimming flume, cycle ergometer, and running treadmill. In both trials, all conditions were identical, except for the swimming portion in which a full length, sleeveless neoprene wet suit was worn during one trial (WS) and a competitive brief swimming suit during the other (SS). The swim portion consisted of a 30 min standardized swim in which oxygen consumption (V02) was replicated, regardless of WS or SS. During the cycling and running stages, however, the subjects were asked to complete the distances as fast as possible. Core Temperature (T) was not significantly different between the SS and WS trials at any time point during the triathlon. However, mean skin temperature (TSk) and mean body temperature (Tb) were higher (p<0.05) in the WS at 15 (TSk=+4.1°C, Tb=+1.5°C) and 30 min (TSk=+4°C, Tb=+1.6°C) of the swim. These TSk and Tb differences were eliminated by 15 min of the cycling stage and remained similar (p>0.05) through the end of the triathlon. Moreover, there were no differences (p>0.05) in V02, heart rate (HR), rating of perceived exertion (RPE), or thermal sensation (TS) between the WS and SS. Additionally, no significant differences were found in cycling (SS=1:14:46 ± 2:48 vs. WS=1:14:37 ± 2:54 min), running (SS=55:40 ± 1:49 vs. WS=57:20 ± 4:00 min) or total triathlon times (SS=2:40:26 ± 1:58 vs. WS=2:41:57 ± 1:37 min). Therefore, the primary finding was that wearing a wet suit during the swimming stage of an Olympic distance triathlon in 25.4°C water does not adversely affect the thermal responses or the triathlete's ability to perform on the subsequent cycling and running stages.School of Physical Education
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Iwata, S. "Brain temperature, perfusion and metabolism under thermo-neutral condition and with induced hypothermia." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1432502/.
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Background: Therapeutic hypothermia following perinatal hypoxia-ischaemia improves survival and neurological functioning at 18 months of age. Precise brain temperature control commenced shortly after birth may improve the benefit. Aims: The aim of this thesis was (i) to clarify associations between regional brain temperatures, body weight, ambient temperature, cerebral perfusion and oxygen metabolism under normothermia/hypothermia; and (ii) to develop safe/reliable cooling device for pre-hospital cooling. Methods: 1. Brain temperatures were monitored in 14 anaesthetised newborn piglets with normothermia, whole-body cooling and selective-head cooling. 2. The rectal temperature (Trectal), non-invasive (zero-heat-flux) brain temperatures, relative superior vena-cava (rSVC) flow (echocardiography) to the brain weight, and the cerebral metabolic rate of oxygen (near-infrared spectroscopy) relative to rSVC flow (CMRO2 index), were obtained in 32 newborn infants. 3. Eleven anaesthetised newborn piglets were cooled to 33-34ºC 2-26h after hypoxia-ischaemia using either water bottles or phase-changing material (PCM; a heat buffer at 32ºC). Results: 1. In piglet models, brain temperatures were positively correlated with the body weight under normothermia, whole-body cooling and selective-head cooling, the influence of which was prominent under selective-head cooling. 2. In normothermic infants, rSVC flow was positively correlated with CMRO2 index. The rSVC flow, but not CMRO2 index, was positively associated with superficial brain temperatures. Ambient temperatures were negatively associated with temperature gradients between the scalp surface and body core. 3. In piglet models, therapeutic hypothermia was induced and maintained with both water bottles and PCM; the latter provided more stable cooling within the target range. Conclusions: Brain cooling was more efficient with lower body weight due to greater surface-to-volume ratios; body-size adjustment may be required to accomplish consistent regional temperatures. In healthy newborn infants, cerebral perfusion and ambient temperature, but not cerebral metabolism, were associated with brain temperatures. PCM provided stable hypothermia, which may substitute for electronic cooling devices during transportation.
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Horan, Marie. "A pilot investigation of mild hypothermia in neonates receiving extracorporeal membrane oxygenation (ECMO)." Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/29533.
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Objective: To investigate the feasibility of applying mild hypothermia in neonates receiving extracorporeal membrane oxygenation (ECMO).;Design: A prospective, non-randomised pilot study of twenty five neonates referred for ECMO. Whole body cooling was achieved by adjustment of the extracorporeal circuit water bath temperature. Five groups (N=5 per group) were each studied for the first five days of ECMO. The first group was maintained at 37°C throughout the study period. Subsequent groups were cooled to 36°C, 35°C and finally 34°C respectively for twenty four hours and the final group to 34°C for forty eight hours before being rewarmed to 37°C. Patients were carefully assessed clinically and biologically. In addition to routine laboratory tests, cytokines (IL-6 and IL-8) complement (C3a) and molecular markers of coagulation (thrombin-antithrombin III, antithrombin III and plasmin alpha 2 plasminogen) were measured.;Results: No major clinical or circuit problems were noted during cooling or rewarming. In particular there were no problems of bleeding or cardiac arrhythmias. No systematic difference was found between groups in terms of molecular markers of coagulation complement, cytokines and platelet transfusions. This could however not be tested statistically due to small group sizes.;Conclusions: This pilot study has demonstrated that the use of mild hypothermia in patients receiving ECMO is feasible and in the number of patients studied did not produce adverse effects, as indicated by the measurements undertaken.