Letteratura scientifica selezionata sul tema "Periodic breathing"
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Articoli di riviste sul tema "Periodic breathing"
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KELLY, DOROTHY H., DAVID W. CARLEY e DANIEL C. SHANNON. "Periodic Breathing". Annals of the New York Academy of Sciences 533, n. 1 The Sudden In (agosto 1988): 301–4. http://dx.doi.org/10.1111/j.1749-6632.1988.tb37259.x.
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Strohl, Kingman P. "Periodic breathing and genetics". Respiratory Physiology & Neurobiology 135, n. 2-3 (maggio 2003): 179–85. http://dx.doi.org/10.1016/s1569-9048(03)00036-3.
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Burleson, Mark L. "Periodic breathing in fishes". Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 126 (luglio 2000): S20. http://dx.doi.org/10.1016/s0305-0491(00)80039-5.
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Fowler, A. C. "Periodic breathing at high altitude". Mathematical Medicine and Biology 19, n. 4 (1 dicembre 2002): 293–313. http://dx.doi.org/10.1093/imammb/19.4.293.
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Han, Fang, Shyam Subramanian, Edwin R. Price, Joseph Nadeau e Kingman P. Strohl. "Periodic breathing in the mouse". Journal of Applied Physiology 92, n. 3 (1 marzo 2002): 1133–40. http://dx.doi.org/10.1152/japplphysiol.00785.2001.
Testo completoAbstract (sommario):
The hypothesis was that unstable breathing might be triggered by a brief hypoxia challenge in C57BL/6J (B6) mice, which in contrast to A/J mice are known not to exhibit short-term potentiation; as a consequence, instability of ventilatory behavior could be inherited through genetic mechanisms. Recordings of ventilatory behavior by the plethsmography method were made when unanesthetized B6 or A/J animals were reoxygenated with 100% O2 or air after exposure to 8% O2 or 3% CO2-10% O2 gas mixtures. Second, we examined the ventilatory behavior after termination of poikilocapnic hypoxia stimuli in recombinant inbred strains derived from B6 and A/J animals. Periodic breathing (PB) was defined as clustered breathing with either waxing and waning of ventilation or recurrent end-expiratory pauses (apnea) of ≥2 average breath durations, each pattern being repeated with a cycle number ≥3. With the abrupt return to room air from 8% O2, 100% of the 10 B6 mice exhibited PB. Among them, five showed breathing oscillations with apnea, but none of the 10 A/J mice exhibited cyclic oscillations of breathing. When the animals were reoxygenated after 3% CO2-10% O2 challenge, no PB was observed in A/J mice, whereas conditions still induced PB in B6 mice. (During 100% O2 reoxygenation, all 10 B6 mice had PB with apnea.) Expression of PB occurred in some but not all recombinant mice and was not associated with the pattern of breathing at rest. We conclude that differences in expression of PB between these strains indicate that genetic influences strongly affect the stability of ventilation in the mouse.
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Ribeiro, Jorge P. "Periodic Breathing in Heart Failure". Circulation 113, n. 1 (3 gennaio 2006): 9–10. http://dx.doi.org/10.1161/circulationaha.105.590265.
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Agostoni, Piergiuseppe, Ugo Corrà e Michele Emdin. "Periodic Breathing during Incremental Exercise". Annals of the American Thoracic Society 14, Supplement_1 (luglio 2017): S116—S122. http://dx.doi.org/10.1513/annalsats.201701-003fr.
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Liippo, K., H. Puolijoki e E. Tala. "Periodic Breathing Imitating Hyperventilation Syndrome". Chest 102, n. 2 (agosto 1992): 638–39. http://dx.doi.org/10.1378/chest.102.2.638.
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Nugent, S. T., e J. P. Finley. "Spectral analysis of the EMG and diaphragmatic muscle fatigue during periodic breathing in infants". Journal of Applied Physiology 58, n. 3 (1 marzo 1985): 830–33. http://dx.doi.org/10.1152/jappl.1985.58.3.830.
Testo completoAbstract (sommario):
Periodic breathing occurs commonly in full-term and preterm infants. The mechanisms which switch breathing on and off within a cycle of periodic breathing are not certain. Since immature infants may experience diaphragmatic muscle fatigue, one potential switching mechanism is fatigue. Power spectra of the electromyogram, uncontaminated by the electrocardiograph artifact, were studied for evidence of diaphragmatic muscle fatigue during spontaneous periodic breathing in infants. A fall in the high-frequency (103–600 Hz) power and an increase in the low-frequency (23–47 Hz) power during periodic as compared with normal breathing would indicate fatigue. This effect was not observed in any of the infants studied. Hence, there is no evidence that periodic breathing is the result of diaphragmatic muscle fatigue. This finding suggests that the effect of drugs such as theophylline in eliminating periodic breathing may be unrelated to the fact that they also reduce fatigue.
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Keyl, Cornelius, Peter Lemberger, Michael Pfeifer, Karin Hochmuth e Peter Geisler. "Heart Rate Variability in Patients with Daytime Sleepiness Suspected of Having Sleep Apnoea Syndrome: A Receiver-Operating Characteristic Analysis". Clinical Science 92, n. 4 (1 aprile 1997): 335–43. http://dx.doi.org/10.1042/cs0920335.
Testo completoAbstract (sommario):
1. Periodic breathing is known to be associated with cyclic fluctuations in heart rate. The purpose of this study was to evaluate the capability of spectral analysis of heart rate variability to identify episodes with periodic breathing in patients suspected of having sleep apnoea syndrome. 2. Forty-eight subjects complaining of chronic daytime sleepiness were studied using polysomnography and additional monitoring of Holter-ECG and synchronized pulse oximetry. The recordings were divided into 20 min episodes which were identified as recordings registered during normal breathing, periodic breathing, and periods of both normal and abnormal breathing. Power spectral analysis was performed on episodes which met the criteria of stationarity of data (313 episodes with normal breathing, 264 episodes with continuous periodic breathing, 80 episodes with both normal and periodic breathing pattens). 3. The ability of parameters, derived from analysis of heart rate variability, to discriminate between episodes with normal and periodic breathing was assessed by receiver-operating characteristic analysis. 4. The spectral power component in the frequency range 0.01–0.07 Hz revealed the greatest accuracy for discriminating between normal and periodic breathing (area under the receiver-operating characteristic curve = 0.929; standard error = 0.009). The analysis of the episodes classified as false-positive at a given test sensitivity of 90% and a corresponding specificity of 77% revealed that half of these episodes had been recorded during transient central nervous arousal reactions related to periodic leg movements or heavy snoring. 5. We concluded that power spectral analysis of heart rate variability offers a possible means of identifying episodes of sleep-related breathing disorders or periodic leg movements. Therefore, analysis of heart rate variability may be a valuable additional diagnostic tool in patients undergoing Holter-ECG recording.
Tesi sul tema "Periodic breathing"
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Mohr, Mary A. "Quantitative Analysis of Periodic Breathing and Very Long Apnea in Preterm Infants". W&M ScholarWorks, 2016. https://scholarworks.wm.edu/etd/1593092111.
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Johnson, Pamela Lesley. "Sleep and Breathing at High Altitude". University of Sydney, 2008. http://hdl.handle.net/2123/3531.
Testo completoAbstract (sommario):
Doctor of Philosphy (PhD)This thesis describes the work carried out during four treks, each over 10-11 days, from 1400m to 5000m in the Nepal Himalaya and further work performed during several two-night sojourns at the Barcroft Laboratory at 3800m on White Mountain in California, USA. Nineteen volunteers were studied during the treks in Nepal and seven volunteers were studied at White Mountain. All subjects were normal, healthy individuals who had not travelled to altitudes higher than 1000m in the previous twelve months. The aims of this research were to examine the effects on sleep, and the ventilatory patterns during sleep, of incremental increases in altitude by employing portable polysomnography to measure and record physiological signals. A further aim of this research was to examine the relationship between the ventilatory responses to hypoxia and hypercapnia, measured at sea level, and the development of periodic breathing during sleep at high altitude. In the final part of this thesis the possibility of preventing and treating Acute Mountain Sickness with non-invasive positive pressure ventilation while sleeping at high altitude was tested. Chapter 1 describes the background information on sleep, and breathing during sleep, at high altitudes. Most of these studies were performed in hypobaric chambers to simulate various high altitudes. One study measured sleep at high altitude after trekking, but there are no studies which systematically measure sleep and breathing throughout the whole trek. Breathing during sleep at high altitude and the physiological elements of the control of breathing (under normal/sea level conditions and under the hypobaric, hypoxic conditions present at high altitude) are described in this Chapter. The occurrence of Acute Mountain Sickness (AMS) in subjects who travel form near sea level to altitudes above 3000m is common but its pathophysiology not well understood. The background research into AMS and its treatment and prevention are also covered in Chapter 1. Chapter 2 describes the equipment and methods used in this research, including the polysomnographic equipment used to record sleep and breathing at sea level and the high altitude locations, the portable blood gas analyser used in Nepal and the equipment and methodology used to measure each individual’s ventilatory response to hypoxia and hypercapnia at sea level before ascent to the high altitude locations. Chapter 3 reports the findings on the changes to sleep at high altitude, with particular focus on changes in the amounts of total sleep, the duration of each sleep stage and its percentage of total sleep, and the number and causes of arousals from sleep that occurred during sleep at increasing altitudes. The lightest stage of sleep, Stage 1 non-rapid eye movement (NREM) sleep, was increased, as expected with increases in altitude, while the deeper stages of sleep (Stages 3 and 4 NREM sleep, also called slow wave sleep), were decreased. The increase in Stage 1 NREM in this research is in agreement with all previous findings. However, slow wave sleep, although decreased, was present in most of our subjects at all altitudes in Nepal; this finding is in contrast to most previous work, which has found a very marked reduction, even absence, of slow wave sleep at high altitude. Surprisingly, unlike experimental animal studies of chronic hypoxia, REM sleep was well maintained at all altitudes. Stage 2 NREM and REM sleep, total sleep time, sleep efficiency and spontaneous arousals were maintained at near sea level values. The total arousal index was increased with increasing altitude and this was due to the increasing severity of periodic breathing as altitude increased. An interesting finding of this research was that fewer than half the periodic breathing apneas and hypopneas resulted in arousal from sleep. There was a minor degree of upper airway obstruction in some subjects at sea level but this was almost resolved by 3500m. Chapter 4 reports the findings on the effects on breathing during sleep of the progressive increase of altitude, in particular the occurrence of periodic breathing. This Chapter also reports the results of changes to arterial blood gases as subjects ascended to higher altitudes. As expected, arterial blood gases were markedly altered at even the lowest altitude in Nepal (1400m) and this change became more pronounced at each new, higher altitude. Most subjects developed periodic breathing at high altitude but there was a wide variability between subjects as well as variability in the degree of periodic breathing that individual subjects developed at different altitudes. Some subjects developed periodic breathing at even the lowest altitude and this increased with increasing altitude; other subjects developed periodic breathing at one or two altitudes, while four subjects did not develop periodic breathing at any altitude. Ventilatory responses to hypoxia and hypercapnia, measured at sea level before departure to high altitude, was not significantly related to the development of periodic breathing when the group was analysed as a whole. However, when the subjects were grouped according to the steepness of their ventilatory response slopes, there was a pattern of higher amounts of periodic breathing in subjects with steeper ventilatory responses. Chapter 5 reports the findings of an experimental study carried out in the University of California, San Diego, Barcroft Laboratory on White Mountain in California. Seven subjects drove from sea level to 3800m in one day and stayed at this altitude for two nights. On one of the nights the subjects slept using a non-invasive positive pressure device via a face mask and this was found to significantly improve the sleeping oxyhemoglobin saturation. The use of the device was also found to eliminate the symptoms of Acute Mountain Sickness, as measured by the Lake Louise scoring system. This finding appears to confirm the hypothesis that lower oxygen saturation, particularly during sleep, is strongly correlated to the development of Acute Mountain Sickness and may represent a new treatment and prevention strategy for this very common high altitude disorder.
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Mebrate, Yoseph. "Mathematical modelling of periodic breathing in chronic heart failure to design novel real-time dynamic therapy". Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/51091.
Testo completoAbstract (sommario):
Periodic breathing (PB) is common in chronic heart failure (CHF) and has poor prognosis. The most commonly used therapy option involve continuous positive airway pressure, which is not acceptable to all patients. In this thesis I present a mathematical model providing a novel approach to treat PB with carefully controlled dynamic administration of supplementary CO2. I explored the consequences of phasic CO2 administration, with different timing and dosing algorithms. I found an optimal time window within the ventilatory cycle in which therapy reduces ventilation oscillations by more than 95%. Outside this window therapy increases ventilatory oscillations by more than 30%. A quadratic grading of CO2 dose (combined gradation of both concentration and duration) increased treatment efficiency. The undesired increase in mean CO2 caused by dynamic therapy was negligible compared with static therapy, to achieve the same degree of ventilatory stabilisation. Similarly, the increase in average ventilation was much smaller with dynamic than static therapy. In collaboration with my clinical and engineering colleagues we tested my model findings on seven healthy subjects simulating voluntary PB and seven heart failure (HF) patients with day time spontaneous PB. Dynamic CO2 administered at hyperventilation phase achieved the greatest reduction in ETCO2 oscillations caused by voluntary PB, and practically abolished spontaneous PB in the HF patients. During dynamic CO2 administration the mean ETCO2 and ventilation levels were not different to baseline and much lower than during continuous CO2 administration, in both groups of subjects. I developed the model further to investigate the effect of random physiological fluctuations on dynamic CO2 therapy and investigated, which is the best single parameter to guide dynamic CO2 therapy. I found that if alveolar CO2 could be measured to guide therapy, it would be as effective as using ventilation. However ETCO2, the clinically observable variable, is less effective because during severe hypopnoea it markedly diverges from alveolar CO2. Dynamic CO2 therapy ameliorated both sustained PB in unstable systems and intermittent PB in stable systems, although both guidance methods became less effective with a large noise component, regardless of the underlying system stability. I investigated further the emergence of intermittent ventilatory periodic patterns, on normally stable systems (loop gain < 1), following the introduction of random physiological fluctuations into the model. This was due to the amplification of the added noise by the delay feedback system, at its natural frequency. The development of this intermittent periodic breathing pattern is dependent on the proximity of the feedback system's loop gain to its tipping point (loop gain=1.0). To investigate the possibility of modulating heart rate by using implantable pacemaker in HF patients with PB, as a tool to manipulate ETCO2 and subsequently ventilation, I devised a novel analytical model equation that demonstrated how a change in cardiac output alters alveolar CO2. We implemented this model equation and found that ETCO2 and ventilation developed consistent oscillations with period 60s during the heart rate alternations. Furthermore, we verified the mathematical prediction that the amplitude of these oscillations would depend on those in cardiac output.
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Campbell, Leah Catherine. "Exploring Differences in Pediatric and Adult Sleep: Two Mathematical Investigations". The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338312080.
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Loadsman, John Anthony. "Perioperative Sleep and Breathing". University of Sydney. College of Health Sciences, 2005. http://hdl.handle.net/2123/689.
Testo completoAbstract (sommario):
Sleep disruption has been implicated in morbidity after major surgery since 1974. Sleep-related upper airway obstruction has been associated with death after upper airway surgery and profound episodic hypoxaemia in the early postoperative period. There is also evidence for a rebound in rapid eye movement (REM) sleep that might be contributing to an increase in episodic sleep-related hypoxaemic events later in the first postoperative week. Speculation regarding the role of REM sleep rebound in the generation of late postoperative morbidity and mortality has evolved into dogma without any direct evidence to support it. The research presented in this thesis involved two main areas: a search for evidence of a clinically important contribution of REM sleep rebound to postoperative morbidity, and a re-examination of the role of sleep in the causation of postoperative episodic hypoxaemic events. To assess the latter, a relationship between airway obstruction under anaesthesia and the severity of sleep-disordered breathing was sought. In 148 consecutive sleep clinic patients, 49% of those with sleep-disordered breathing (SDB) had a number of events in non-rapid eye movement sleep (NREM) that was greater than or equal to that in REM and 51% had saturation nadirs in NREM that were equal to or worse than their nadirs in REM. This suggests SDB is not a REM-predominant phenomenon for most patients. Of 1338 postoperative deaths occurring over 6.5 years in one hospital only 37 were unexpected, most of which were one or two days after surgery with no circadian variation in the time of death, casting further doubt on the potential role of REM rebound. Five of nine subjects studied preoperatively had moderately severe SDB. Unrecognised and significant SDB is common in middle-aged and elderly patients presenting for surgery suggesting overall perioperative risk of important adverse events from SDB is probably small. In 17 postoperative patients, sleep macro-architecture was variably altered with decreases in REM and slow wave sleep while stage 1 sleep and a state of pre-sleep onset drowsiness, both associated with marked ventilatory instability, were increased. Sleep micro-architecture was also changed with an increase in power in the alpha-beta electroencephalogram range. These micro-architectural changes result in ambiguity in the staging of postoperative sleep that may have affected the findings of this and other studies. Twenty-four subjects with airway management difficulty under anaesthesia were all found to have some degree of SDB. Those with the most obstruction-prone airways while anaesthetised had a very high incidence of severe SDB. Such patients warrant referral to a sleep clinic.
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Nespoulet, Hugo. "Oxygénation en conditions hypoxiques : rôle de la chémosensibilité sur la tolérance à l'altitude, plasticité et amélioration par pression positive expiratoire". Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENS041/document.
Testo completoAbstract (sommario):
A l'éveil comme au cours du sommeil, en plaine comme en haute altitude, le maintien d'une oxygénation artérielle stable et élevée est un marqueur essentiel d'une bonne réponse physiologique de l'organisme. L'intolérance à l'altitude regroupe des pathologies graves voire fatales dont le développement est en lien direct avec le taux d'oxygénation artériel des sujets. D'autre part, en plaine, la prévalence élevée du syndrome d'apnées obstructives du sommeil (SAOS) incite les chercheurs au développement de modèles d'études spécifiques, permettant d'investiguer les conséquences du principal stimulus du SAOS : l'hypoxie intermittente. La chémosensibilité pourrait avoir un impact important dans ces deux pathologies, ayant pour rôle le maintien des gaz du sang à des valeurs normales, en adaptant la ventilation aux conditions externes ou internes à l'organisme.Les objectifs de ce travail étaient de comprendre l'impact de la chémosensibilité (avec d'autres mécanismes décrits dans la littérature) sur l'oxygénation et la tolérance à l'altitude, d'étudier les effets de la résistance expiratoire sur l'amélioration de l'oxygénation, ainsi que les conséquences de l'hypoxie intermittente chronique sur la plasticité du chémoréflexe.Il en ressort que la chémosensibilité périphérique à l'hypoxie a un impact majeur sur le développement de l'intolérance à l'altitude. Cela semble en outre être un facteur prédictif de la survenue de ces pathologies. En hypoxie, une amélioration efficace de l'oxygénation a été obtenue par l'utilisation d'une résistance expiratoire calibrée à 10 cm H2O permettant l'amélioration de la diffusion alvéolo-capillaire. L'exposition à l'hypoxie intermittente chronique nocturne a provoqué une fragmentation du sommeil ainsi qu'une intensification de la chémosensibilité à l'hypoxie et à l'hypercapnie.Ainsi, une altération de la réponse des corps carotidiens à l'hypoxémie participerait au développement du mal aigu des montagnes et de ses complications, tout en facilitant sa prédiction avant ascension. L'utilisation d'une résistance expiratoire pourrait permettre de combler la désaturation exagérée retrouvée chez les sujets sensibles à l'altitude lors d'un séjour en haute montagne. Il apparaît également que la chémosensiblité périphérique et centrale (CO2 et O2) fasse preuve d'une plasticité importante en réponse à l'hypoxie intermittente nocturne chez des sujets sainsAt awakening and during sleep, at sea level or in high altitude, maintaining a high level in arterial blood oxygenation is a marker for an adaptated physiological response external and internal factors.High altitude illness encompasses pathologies, that sometimes could be fatal, and which seems to be correlated with the level of arterial oxygenation in hypoxia.Secondly, at sea level and in general population, the high prevalence of obstructive sleep apnea syndrome (OSAS) encourage scientists to develop new models for studying consequences of the main OSAS' stimulus: intermittent hypoxia.Chemosensitivity could play an important role in those two different diseases, with regulation of blood gases and homeostasis by controlling ventilation.Our objectives was to investigate (1) impact of chemosensitivity on blood oxygenation and tolerance to high altitude, comparatively to other physiological factors commonly involved, (2) effects of using positive expiratory pressure in order to improve oxygenation in hypoxia, and (3) consequences of chronic exposure to nocturnal intermittent hypoxia on chemoreflexe plasticity.We found that peripheral chemoresponse to hypoxia play a crucial role in high altitude illness development. Moreover, this variable seems to be a predictive factor for those diseases. In hypoxic conditions, using a positive expiratory pressure (10 cmH2O) lead to a significant improve in arterial oxygenation, by increasing pulmonary diffusion. Finally, nocturnal intermittent hypoxia induced significant sleep disturbances and major changes in chemoresponse to hypoxia and hypercapnia
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Sandström, Anders. "IMPROVING SELF-RESCUE EQUIPMENT : Can a self-contained self-rescue unit be more comfortable to wear over long periods of time, not damage other equipment and be donned easily?" Thesis, Umeå universitet, Designhögskolan vid Umeå universitet, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-107995.
Testo completoAbstract (sommario):
A self-contained self-rescue unit is a device that is used in the mining industry in case of fires or release of toxic gases that depletes or contaminates breathable oxygen in the surrounding atmosphere. These units are the first line of defense by providing oxygen in a closed breathing cycle, allowing personnel to get themselves to safety. The goal of this project was to design a unit that is more comfortable to carry during the daily operations in and outside the mines. A unit that is easier to done and less likely to damage the users and/or surrounding mining equipment. It is developed in close collaboration with Atlas Copco, as the main sponsor, as well as Dräger and personnel working at Zink Gruvan Mining. The result is a unit with an operational time of twenty minutes and a reduced size and weight. It’s position can be adjusted to be worn around the waist or the chest, depending on the tasks the user performs, as well as simplifying the donning procedure.
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John, Angela Beatriz. "Determinação de padrões ventilatórios e avaliação de estratégias de rastreamento de transtornos respiratórios durante o sono em pacientes candidatos à cirurgia bariátrica". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/139775.
Testo completoAbstract (sommario):
Introdução: A obesidade é um problema de saúde pública em crescimento, sendo o principal fator de risco para os transtornos respiratórios durante o sono (TRS), como a apneia obstrutiva do sono (AOS) e a hipoventilação noturna. A cirurgia bariátrica se consolidou como possibilidade terapêutica para a obesidade significativa. A identificação precoce dos TRS na fase pré-operatória é essencial, pois acarretam um risco aumentado de complicações perioperatórias. Diversas propostas de triagem dos TRS com abordagens mais simplificadas em relação à polissonografia (PSG) têm surgido na literatura nos últimos anos, nem todas avaliadas em uma população de pacientes obesos. Objetivo: Determinar os padrões ventilatórios em obesos candidatos à cirurgia bariátrica e avaliar três estratégias de rastreamento de TRS nessa população. Métodos: Os critérios de inclusão foram pacientes com idade ≥18 anos com obesidade graus III [índice de massa corporal (IMC) ≥40 kg/m2] ou II (IMC ≥35 kg/m2) com comorbidades relacionadas à obesidade encaminhados para avaliação para cirurgia bariátrica. Foram excluídos pacientes com cardiopatia e/ou pneumopatia graves ou descompensadas. Foram avaliados 91 pacientes através de três estratégias: (1) Clínica [Escala de Sonolência de Epworth e questionários STOP-Bang, Berlim e Sleep Apnea Clinical Score (SACS), acrescidos de gasometria arterial (GA)]; (2) Oximetria (holter de oximetria durante o sono e GA) e (3) Portátil [monitorização portátil (MP) durante o sono e capnografia)]. Todos os testes realizados foram comparados com o teste padrão, a PSG, para o diagnóstico de AOS. Resultados: A amostra estudada foi composta por 77 mulheres (84,6%) com média de idade de 44,7 ± 11,5 anos e de IMC de 50,1 ± 8,2 kg/m2. Os padrões ventilatórios identificados foram ronco, hipoxemia isolada durante o sono, AOS e hipoventilação noturna em associação com AOS. Os dados polissonográficos evidenciaram AOS em 67 de 87 pacientes (77%), sendo 26 com transtorno leve, 19 moderado e 22 grave. Vinte pacientes (23%) tiveram diagnóstico de ronco e dois deles também apresentaram hipoxemia isolada durante o sono sem AOS ou hipoventilação concomitantes. Hipoventilação noturna associada com AOS foi identificada por capnografia em um paciente. Na Estratégia Clínica, o melhor resultado alcançado foi com o escore STOP-Bang ≥6 em pacientes com índice de apneia hipopneia (IAH) ≥30 (acurácia total de 82,8%). Na Estratégia Oximetria, os pontos de corte com maior sensibilidade e especificidade para IAH ≥5, ≥10, ≥15 e ≥30 foram tempo total de registro com saturação periférica de oxigênio (SpO2) <90% por, pelo menos, 5 minutos; índice de dessaturação (ID)3% ≥22 dessaturações/hora de registro e ID4% ≥10 e ≥15 dessaturações/hora de registro. Todas as áreas sobre a curva (ASC) situaram-se acima de 0,850. Para um IAH ≥5, o ID4% ≥10 apresentou sensibilidade de 97%, especificidade de 73,7%, valor preditivo positivo de 92,8% e negativo de 87,5% e acurácia total de 91,8%. Na Estratégia Portátil, o índice de distúrbios respiratórios (IDR) foi um bom preditor de AOS nos variados pontos de corte de IAH (ASC de 0,952 a 0,995). As melhores sensibilidades e especificidades foram alcançadas em pontos de corte semelhantes de IDR e IAH, especialmente nos extratos de IAH ≥10 e ≥30. A acurácia total máxima foi de 93,9% para IDR ≥5, ≥10 e ≥30 nos seus correspondentes IAH. Baseados nesses resultados, foram testadas estratégias combinadas compostas pelo questionário STOP-Bang ≥6 com ID4% ≥10 ou ≥15. O melhor equilíbrio entre sensibilidade e especificidade e a maior acurácia foram obtidos com a estratégia STOP-Bang ≥6 com ID4% ≥15 em AOS grave. Conclusões: A frequência de ocorrência de TRS nos obesos em avaliação para cirurgia bariátrica foi alta, sendo a AOS o transtorno mais encontrado. Os questionários disponíveis até o momento, isoladamente, parecem ser insuficientes para o rastreamento de AOS nessa população, à exceção do STOP-Bang ≥6 em pacientes com AOS grave. O uso de uma medida fisiológica objetiva expressa pelo holter de oximetria foi útil para rastrear AOS em pacientes obesos. A MP apresentou acurácia aumentada, especialmente nos extremos de valores de IAH, com resultados comparáveis aos da PSG. A PSG poderia ser reservada apenas para confirmação diagnóstica em casos selecionados.Introduction: Obesity is a growing public health problem and the main risk factor for sleep-disordered breathing (SDB), including obstructive sleep apnea (OSA) and nocturnal hypoventilation. Bariatric surgery has become an option for the treatment of significant obesity. Early detection of SDB preoperatively is essential, since these disorders are associated with an increased risk of perioperative complications. Several screening tools for SDB, with a more simplified approach than polysomnography (PSG), have been proposed in recent years, but not all of them have been evaluated in a population of obese patients. Objective: To determine ventilatory patterns in obese candidates for bariatric surgery and evaluate three SDB screening strategies in this population. Methods: Eligible participants were all patients aged ≥18 years with grade III (body mass index [BMI] ≥ 40kg/m2) or grade II (BMI ≥35 kg/m2) obesity and obesity-related comorbidities who were referred for evaluation for bariatric surgery. Exclusion criteria were heart disease and/or severe or decompensated pulmonary disease. Ninety-one patients were evaluated by three strategies: (1) Clinical (Epworth Sleepiness Scale and STOP-Bang questionnaire, Berlin questionnaire and Sleep Apnea Clinical Score [SACS] plus blood gas analysis [BGA]); (2) Oximetry (overnight Holter-oximeter monitoring and BGA); and (3) Portable (overnight portable monitoring and capnography). All tests were compared with the gold standard, PSG, for the diagnosis of OSA. Results: The sample consisted of 77 women (84.6%) with a mean (SD) age of 44.7 (11.5) years and BMI of 50.1 (8.2) kg/m2. The ventilatory patterns identified were snoring, isolated nocturnal hypoxemia, OSA, and nocturnal hypoventilation associated with OSA. Polysomnographic data showed OSA in 67 of 87 patients (77%), 26 with mild, 19 with moderate and 22 with severe disorder. Twenty patients (23%) had a diagnosis of snoring, and two of them also had isolated nocturnal hypoxemia without concomitant OSA or hypoventilation. Nocturnal hypoventilation associated with OSA was detected by capnography in one patient. In the Clinical Strategy, the best result was obtained with the STOP-Bang score ≥6 in patients with an apnea-hypopnea index (AHI) ≥30 (overall accuracy of 82.8%). In the Oximetry Strategy, the cutoff values with the highest sensitivity and specificity for AHI ≥5, ≥10, ≥15, and ≥30 were total recording time with peripheral oxygen saturation (SpO2)< 90% for at least 5 minutes, 3% oxygen desaturation index (ODI) ≥22 desaturations/hour of recording, and 4%ODI ≥10 and ≥15 desaturations/hour of recording. All areas under the curve (AUC) were above 0.850. For AHI ≥5, 4%ODI ≥10 had a sensitivity of 97%, specificity of 73.7%, positive predictive value of 92.8%, negative predictive value of 87.5%, and overall accuracy of 91.8%. In the Portable Strategy, the respiratory disturbance index (RDI) was a good predictor of OSA in various cutoff values of AHI (AUC of 0.952 to 0.995). The highest sensitivity and specificity were obtained at similar cutoff values for RDI and AHI, especially for AHI ≥10 and ≥30. The maximum overall accuracy was 93.9% for RDI ≥5, ≥10, and ≥30 in their corresponding AHI. Based on these results, combined strategies were tested consisting of the STOP-Bang score ≥6 combined with 4%ODI ≥10 or ≥15. The best balance between sensibility and specificity and the maximum accuracy were achieved with the strategy composed by STOP-Bang ≥6 and 4%ODI ≥15 in patients with severe OSA. Conclusions: The frequency of occurrence of SDB in obese individuals undergoing evaluation for bariatric surgery was high, and OSA was the most frequent occurrence. Currently available questionnaires were insufficient to screen for OSA in this population, with the exception for the STOP-Bang score ≥6 in patients with severe OSA. The use of an objective physiological measure, such as Holter-oximetry monitoring, was useful as a screening tool for OSA in obese patients. Portable monitoring showed increased accuracy, especially in extreme AHI values, with results comparable to those obtained with PSG. The PSG could be reserved only for certain cases where diagnostic confirmation is necessary.
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Limongi, Vivian 1988. "Estudo do perfil e dos efeitos de um programa de intervenção fisioterapêutica respiratória em candidatos à transplante de fígado = Study of the profile and the effects of a respiratory physiotherapeutic intervention program in candidates for liver transplantation". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/313007.
Testo completoAbstract (sommario):
Orientadores: Raquel Silveira Bello Stucchi, Ilka de Fátima Santana Ferreira BoinDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-26T05:37:24Z (GMT). No. of bitstreams: 1 Limongi_Vivian_M.pdf: 4966241 bytes, checksum: 5286830ea48e718dfac3a565a7b7f54a (MD5) Previous issue date: 2014
Resumo: Os candidatos à transplante de fígado podem apresentar desnutrição, fadiga, perda de massa e função muscular. A associação desses fatores induz à deficiência motora global e à inatividade física. O objetivo do estudo foi avaliar o perfil dos candidatos à transplante de fígado acompanhados no Gastrocentro - UNICAMP, bem como os efeitos de um programa de intervenção respiratória fisioterapêutica nesta população. Foram avaliados a PImáx e PEmáx por manovacuometria, atividade elétrica muscular do reto abdominal e diafragma por eletromiografia de superfície e anotados os valores de RMS quando solicitado uma respiração forçada a cada três segundos. A função pulmonar foi avaliada pela espirometria e a qualidade de vida pela aplicação do questionário SF-36. Participaram do estudo do perfil 62 pacientes, 74,2% do sexo masculino, idade 55,5±9,5 anos e MELD corrigido 18,6±5,1. A maioria com diagnóstico de cirrose por HVC (24,2%). Mais da metade (56,4%) eram ex-tabagistas, 72,6% ex-etilistas, 46,8% relataram dispneia, e a ascite esteve presente em 40,3% dos indivíduos. Houve diferença significante (p=0,017) entre a PImáx mensurada e PImáx predita para idade e gênero. Os pacientes apresentaram em média valores acima de 80% do predito para as variáveis obtidas por meio da espirometria e baixa pontuação em todos os domínios do questionário SF-36. Dos 62 pacientes, foram randomizados 37 pacientes para constituírem os grupos controle e intervenção, sendo que 23 participaram do grupo controle e 14 do grupo intervenção. As avaliações foram realizadas antes da intervenção, e após três meses desta. Os exercícios foram supervisionados à distância, mensalmente sempre pelo mesmo observador. A intervenção consistiu de um manual ilustrativo e explicativo a ser seguido em casa, com os exercícios de respiração diafragmática; exercício isométrico diafragmático, Threshold IMT®; elevação de membros superiores com bastão e fortalecimento dos abdominais. Todos os exercícios foram realizados em três séries, 15 repetições. Para treinamento com o Threshold IMT® foi utilizada uma carga de 23 a 40 cmH2O, ajustada para cada paciente de acordo com a sua tolerância. Durante os três meses, o indivíduo treinou com a mesma carga estabelecida na avaliação inicial. Houve aumento significativo (p=0,017) da PImáx no grupo controle e grupo intervenção após três meses; bem como nos domínios do SF-36, Estado Geral de Saúde (p=0,019) e Saúde Mental (p=0,004). O RMS do diafragma diminuiu no grupo intervenção (p=0,001) e houve aumento do escore de Capacidade Funcional (p=0,006) no tempo final, comparado ao grupo controle. Concluindo, o estudo do perfil dos pacientes em lista de espera para transplante de fígado revelou que eles apresentavam força muscular inspiratória diminuída em comparação ao predito para idade e gênero, função pulmonar preservada e a qualidade de vida prejudicada. A intervenção proposta foi capaz de melhorar a força muscular inspiratória dos pacientes, e consequentemente, reduzir a atividade elétrica do diafragma. Além disso, o grupo intervenção apresentou melhora na qualidade de vida, principalmente no escore Capacidade Funcional do SF-36
Abstract: Candidates for liver transplantation may have malnutrition, fatigue, loss of muscle mass and function. The combination of these factors leads to global motor impairment and physical inactivity. The aim of the study was to evaluate the profile of candidates for liver transplantation followed at Gastrocentro - UNICAMP, and evaluate the effects of a program of respiratory physiotherapy intervention in this population. MIP and MEP were assessed by manometer, electrical muscle activity of the rectus abdominis and diaphragm was measured by surface electromyography, the RMS values were noted every three seconds, in this period the patient made forced breath. The pulmonary function was evaluated by spirometry and the SF-36 questionnaire was applied. The study of profile evaluated 62 patients, 74,2% males, age 55,5±9,5 and corrected MELD 18,6±5,1. Cirrhosis due to HCV was found in most patients (24,2%). More than half of the patients (56,4%) were former smokers, 72,6% were ex-alcoholics, 46,8% reported dyspnea, and ascites was present in 40,3% of patients. There was a significant difference (p=0,017) between the measured MIP and MIP predicted for age and gender. Patients had a mean values above 80% of predicted for the variables obtained by spirometry and low scores in all domains of the SF-36. Of the 62 patients, 37 patients were randomized to constitute the control and intervention groups, of which 23 participated in the control group and 14 in the intervention group. Evaluations were performed before the intervention, and three months after that. The exercises were supervised from a distance, monthly by the same observer. The evaluations were conducted before the intervention, and after three months of it. The intervention consisted of an explanatory and illustrative manual to be followed at home with diaphragmatic breathing exercises, diaphragmatic isometric exercise, Threshold IMT®, lifting upper with bat and strengthening the abdominals. All exercises were performed in three sets, 15 repetitions. For training with Threshold IMT®, a load 23-40 cmH2O adjusted for each patient according to their tolerance was used. During the three months, the subject trained with the same charge established in the initial evaluation. A significant increase of MIP (p=0,017) was found in bouth groups after three months; as well as in domains of SF-36, General Health (p=0,019) and Mental Health (p=0,004). The RMS of the diaphragm decreased in the intervention group (p=0,001) and the score of Functional Capacity increased (p=0,006) at the end of time, compared to the control group. In conclusion, the study of the profile of patients on the waiting list for liver transplantation revealed that they had decreased inspiratory muscle strength compared to the predicted for age and gender, lung function preserved and impaired quality of life. The proposed intervention was able to improve inspiratory muscle strength of patients, and hence reduce the electrical activity of the diaphragm. In addition, the intervention group showed improvement in quality of life, especially in the Functional Capacity, a SF-36 domain
Mestrado
Fisiopatologia Cirúrgica
Mestra em Ciências
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Castro, Renata Rodrigues Teixeira de. "Variabilidade ventilatória durante exercício dinâmico em indivíduos saudáveis e com insuficiência cardíaca". Universidade do Estado do Rio de Janeiro, 2010. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4770.
Testo completoAbstract (sommario):
A presença de ventilação periódica durante o exercício confere pior prognóstico a pacientes com insuficiência cardíaca. Existem divergências quanto aos critérios para
identificação deste fenômeno. Além disso, a interpretação dicotômica (presença ou ausência) quanto a este fenômeno dificulta a estratificação de risco mais detalhada dos
pacientes com insuficiência cardíaca. Desta forma, esta tese avalia a utilização de técnicas estabelecidas para análise de variabilidade de sinais para quantificar as oscilações ventilatórias que ocorrem durante o teste cardiopulmonar de exercício, em indivíduos saudáveis, atletas e com insuficiência cardíaca. Um protocolo mais curto para realização de teste cardiopulmonar de exercício em cicloergômetro de braço foi proposto e validado. Tal protocolo foi utilizado em estudo posterior, onde se comprovou que, apesar dos tempos respiratórios não serem influenciados pelo tipo de exercício realizado, a variabilidade ventilatória é maior durante a realização de exercício dinâmico com membros superiores do que com membros inferiores. A capacidade aeróbica de indivíduos sadios também influencia a variabilidade ventilatória durante o teste
cardiopulmonar de exercício. Isto foi comprovado pela menor variabilidade ventilatória no domínio do tempo em atletas do que sedentários durante exercício. A análise destes
voluntários com o método da análise dos componentes principais revelou que em atletas a variabilidade do volume corrente é a principal responsável pela variabilidade da ventilação-minuto durante o exercício, ao passo que em sedentários a variabilidade da freqüência respiratória apresenta-se como principal responsável por tais variações. Em estudo randomizado e controlado comprovamos que, mesmo indivíduos sadios apresentam redução da variabilidade ventilatória ao exercício após 12 semanas de
treinamento físico. Comprovamos que a reabilitação cardíaca reverteu a ocorrência de ventilação periódica em um paciente com insuficiência cardíaca e, finalmente, encontramos que a variabilidade ventilatória correlaciona-se inversamente com a fração de ejeção ventricular esquerda em pacientes com insuficiência cardíaca. Estudos futuros deverão analisar o poder prognóstico da variabilidade ventilatória nestes
pacientes.Exercise periodic breathing confers a bad prognosis in patients with heart failure. There is no agreement among proposed criteria to diagnose exercise periodic breathing. The dichotomic interpretation (presence or absence) when diagnosing this phenomenon impairs a more detailed risk stratification in heart failure. Thus, this thesis evaluates the use of established signal variability techniques to quantify ventilatory oscillations during cardiopulmonary exercise test, in healthy individuals, athletes and patients with heart failure. A short protocol used to perform cardiopulmonary exercise test in arm crank was proposes and validated. This protocol was used in the next study, which found that, although timing of breathing was not altered by exercise type, ventilatory variability was greater during arm dynamic exercise when compared to leg exercise. Aerobic capacity of healthy individuals also influences ventilatory variability during cardiopulmonary exercise test. This was proven by the lower time-domain ventilatory variability in athletes when compared to sedentary individuals. The evaluation of these individuals with principal components analysis showed that tidal volume variability is the principal component o minute-ventilation variability in athletes, whilst in sedentary men, respiratory frequency variability is the responsible for minute-ventilation variability. In a randomized controlled study we have found that even healthy individuals reduce their exercise ventilatory variability after 12 weeks exercise training. We have shown that cardiac rehabilitation reverted exercise periodical breathing in a patient with heart failure and, finally, found that exercise ventilatory variability inversely correlates to left ventricle ejection fraction in patients with heart failure. Future studies should evaluate the prognostic value of ventilatory variability in these patients.
Libri sul tema "Periodic breathing"
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Nussbaumer-Ochsner, Yvonne, e Konrad E. Bloch. Sleep at high altitude and during space travel. A cura di Sudhansu Chokroverty, Luigi Ferini-Strambi e Christopher Kennard. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199682003.003.0054.
Testo completoAbstract (sommario):
This chapter summarizes data on sleep–wake disturbances in humans at high altitude and in space. High altitude exposure is associated with periodic breathing and a trend toward reduced slow-wave sleep and sleep efficiency in healthy individuals. Some subjects are affected by altitude-related illness (eg, acute and chronic mountain sickness, high-altitude cerebral and pulmonary edema). Several drugs are available to prevent and treat these conditions. Data about the effects of microgravity on sleep are limited and do not allow the drawing of firm conclusions. Microgravity and physical and psychological factors are responsible for sleep–wake disturbances during space travel. Space missions are associated with sleep restriction and disruption and circadian rhythm disturbances encouraging use of sleep medication. An unexplained and unexpected finding is the improvement in upper airway obstructive breathing events and snoring during space flight.
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Randerath, Winfried J., e Shahrokh Javaheri. Sleep and the heart. A cura di Sudhansu Chokroverty, Luigi Ferini-Strambi e Christopher Kennard. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199682003.003.0040.
Testo completoAbstract (sommario):
Heart function and sleep are closely associated. While NREM sleep reduces cardiac workload, phasic REM sleep increases sympathetic activity and cardiac vulnerability. Heart failure (HF) patients suffer from disturbed sleep due to frequent awakenings, periodic limb movements, sleep apnea, and depression. Insomnia seems to be associated with incident HF, and, when comorbid, results in a vicious circle. There is much evidence of a relationship between breathing disturbances during sleep and heart diseases. At least 50% of HF patients suffer from obstructive (OSA) or central (CSA) sleep apnea, both associated with impaired prognosis. OSA is a risk factor for arterial hypertension, atrial fibrillation, and HF. Continuous positive airway pressure devices reduce adverse cardiac events and improve outcome in severe OSA in compliant subjects. Adaptive servoventilation (ASV) is superior to other therapeutic options for CSA. However, the use of ASV is contraindicated in severe HF with reduced, but not preserved, ejection fraction.
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Finn, Patrick C., e Michael C. Reade. Bleeding Emergencies (DRAFT). A cura di Raghavan Murugan e Joseph M. Darby. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190612474.003.0010.
Testo completoAbstract (sommario):
This chapter is concerned with coagulopathic and non-coagulopathic bleeding in the perioperative period, after trauma, and spontaneously, as a result of hematologic and other disease. The initial assessment and management of all potentially bleeding patients is to stop any obvious bleeding through mechanical first aid measures, then address airway or breathing compromise, and obtain intravenous (or intraosseous) access. Obvious external hemorrhage is easily identified, but most patients with bleeding emergencies who are already hospitalized will have occult blood loss. Physical examination should identify signs of shock and identify or exclude potential bleeding locations. This chapter will cover initial assessment and management, laboratory and bedside testing, as well as disease-specific therapies in the context of rapid response team (RRT) calls.
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Mills, Gary H. Pulmonary disease and anaesthesia. A cura di Philip M. Hopkins. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199642045.003.0082.
Testo completoAbstract (sommario):
Respiratory adverse events are the commonest complications after anaesthesia and have profound implications for the recovery of the patient and their subsequent health. Outcome prediction related to respiratory disease and complications is vital when determining the risk:benefit balance of surgery and providing informed consent. Surgery produces an inflammatory response and pain, which affects the respiratory system. Anaesthesia produces atelectasis, decreases the drive to breathe, and causes muscle weakness. As the respiratory system ages, closing capacity increases and airway closure becomes an increasing issue, resulting in atelectasis. Increasing comorbidity and polypharmacy reduces the patient’s ability to eliminate drugs. The proportion of major operations on older frailer patients is rising and postoperative recovery becomes more complicated and the demand for critical care rises. At the same time, the population is becoming more obese, producing rapid decreases in end-expiratory lung volume on induction, together with a high incidence of sleep-disordered breathing. Despite this, many high-risk patients are not accurately identified preoperatively, and of those that are admitted to critical care, some are discharged and then readmitted to the intensive care unit with complications. Respiratory diseases may lead to increases in pulmonary vascular resistance and increased load on the right heart. Some lung diseases are primarily fibrotic or obstructive. Some are inflammatory, autoimmune, or vasculitic. Other diseases relate to the drive to breathe, the nerve supply to, or the respiratory muscles themselves. The range of types of respiratory disease is wide and the physiological consequences of respiratory support are complex. Research continues into the best modes of respiratory support in theatre and in the postoperative period and how best to protect the normal lung. It is therefore essential to understand the effects of surgery and anaesthesia and how this impacts existing respiratory disease, and the way this affects the balance between load on the respiratory system and its capacity to cope.
Capitoli di libri sul tema "Periodic breathing"
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Burgess, Keith, Katie Burgess, Prajan Subedi, Phil Ainslie, Zbigniew Topor e William Whitelaw. "Prediction of Periodic Breathing at Altitude". In Integration in Respiratory Control, 442–46. New York, NY: Springer New York, 2008. http://dx.doi.org/10.1007/978-0-387-73693-8_77.
Testo completo
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Gottschalk, A., M. C. K. Khoo e A. I. Pack. "Multiple Modes of Periodic Breathing during Sleep". In Advances in Experimental Medicine and Biology, 105–10. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4615-1933-1_22.
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Caples, S. M., e V. K. Somers. "Central Sleep Apnea, Hypoventilation Syndromes and Periodic Breathing Disorders". In Sleep Apnea, 180–91. Basel: KARGER, 2006. http://dx.doi.org/10.1159/000093167.
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LONGOBARDO, GUY, Carlo J. Evangelisti e Neil S. Cherniack. "Effects of Controller Dynamics on Simulations of Irregular and Periodic Breathing". In Advances in Experimental Medicine and Biology, 389–99. Boston, MA: Springer US, 2003. http://dx.doi.org/10.1007/978-1-4419-9280-2_50.
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Eleuteri, Michela, Erica Ipocoana, Jana Kopfová e Pavel Krejčí. "Breathing as a Periodic Gas Exchange in a Deformable Porous Medium". In Trends in Mathematics, 131–35. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-25261-8_20.
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Fordyce, Wayne E., e Robert K. Kanter. "Factors Inducing Periodic Breathing in Man During Acclimatization to Chronic Hypoxia". In Respiratory Control, 317–26. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4613-0529-3_34.
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Wolff, C. B., M. Bell, C. D. Thake e D. J. Collier. "Oscillations in Cardiac Output in Hypoxia with Periodic Breathing and Constant End-Tidal PCO2 at High Altitude (5,000 m)". In Oxygen Transport to Tissue XXXIII, 197–206. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4614-1566-4_29.
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Painter, Rosemary, Saeed Khamnei e Peter Robbins. "A Mathematical Model of the Ventilatory Response to a Period of Sustained Isocapnic Hypoxia in Humans". In Control of Breathing and Its Modeling Perspective, 123–26. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4757-9847-0_21.
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Brock-Utne, John G. "Case 25: Difficulty with Breathing in the Postoperative Period". In Case Studies of Near Misses in Clinical Anesthesia, 69–71. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-1179-7_25.
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Mandolini, Marco, Manila Caragiuli, Daniele Landi, Antonio Gracco, Giovanni Bruno, Alberto De Stefani e Alida Mazzoli. "Evaluation of the Effects Caused by Mandibular Advancement Devices Using a Numerical Simulation Model". In Lecture Notes in Mechanical Engineering, 101–7. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-70566-4_17.
Testo completoAbstract (sommario):
AbstractObstructive sleep apnea syndrome (OSAS) is a sleep disorder that causes pauses in breathing or periods of shallow breathing during sleep. Mandibular advancement devices (MADs) represent a non-invasive treatment for OSAS that has had the highest development in recent years. Nevertheless, literature has not primarily investigated the effects of mandibular advancement. This paper presents a finite element method numerical simulation model for evaluating the stress/strain distribution on the temporomandibular joint (TMJ) and periodontal ligaments caused by advancement devices used for the treatment of OSAS. Results highlight that the mandible lift phase generates significant stress values on TMJ, which cannot be neglected for extended usage of MADs. Furthermore, mandible molar teeth are more loaded than incisor ones.
Atti di convegni sul tema "Periodic breathing"
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Garde, Ainara, Beatriz F. Giraldo, Raimon Jane, Ivan Diaz, Sergio Herrera, Salvador Benito, Maite Domingo e Antonio Bayes-Genis. "Characterization of periodic and non-periodic breathing pattern in chronic heart failure patients". In 2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 2008. http://dx.doi.org/10.1109/iembs.2008.4649891.
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Ghirardo, Sergio, Alessandro Amaddeo, Sonia Khirani, Lucie Griffon e Brigitte Fauroux. "Description of central apnea and periodic breathing in children". In ERS International Congress 2020 abstracts. European Respiratory Society, 2020. http://dx.doi.org/10.1183/13993003.congress-2020.1226.
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Herkenrath, Simon, Catarina Lacerda, Alessandra Castrogiovanni, Marcel Treml, Ilona Kietzmann, Kerstin Richter e Winfried Randerath. "Loop Gain in Heart Failure Patients with Periodic Breathing". In ERS International Congress 2017 abstracts. European Respiratory Society, 2017. http://dx.doi.org/10.1183/1393003.congress-2017.oa3205.
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Fletcher, Hannah, Arif Khokhar, Peter Siu Pan Cho e James Hull. "Exercise-related periodic ventilatory irregularities in dysfunctional breathing disorder>". In ERS International Congress 2017 abstracts. European Respiratory Society, 2017. http://dx.doi.org/10.1183/1393003.congress-2017.pa2233.
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Stone, Jordan R., Jennifer A. Black e Scott B. Papp. "Subharmonic Synchronization of Soliton Microcomb Breathing Oscillations to Periodic Forces". In CLEO: Science and Innovations. Washington, D.C.: OSA, 2021. http://dx.doi.org/10.1364/cleo_si.2021.sw2h.4.
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Pusalavidyasagar, Snigdha, Reena Kartha e Adnan Abbasi. "Effect of periodic limb movements on plasma nitric oxide levels in patients with obstructive sleep apnoea". In ERS/ESRS Sleep and Breathing Conference 2017 abstracts. European Respiratory Society, 2017. http://dx.doi.org/10.1183/23120541.sleepandbreathing-2017.p87.
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Dongol, Eptehal, Panagis Drakatos, Rexford Tapiwa Muza, Mohamed Shahat Badawy, Brian Kent, Ahmed Younis e Adrian Williams. "Periodic limb movement disorder: a Trojan horse for residual sleepiness in patients with OSAS while on CPAP?" In ERS/ESRS Sleep and Breathing Conference 2017 abstracts. European Respiratory Society, 2017. http://dx.doi.org/10.1183/23120541.sleepandbreathing-2017.p29.
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Dubey, Ashutosh, e M. Bandyopadhyay. "DNA breathing dynamics under periodic forcing: Study of first passage time". In PROF. DINESH VARSHNEY MEMORIAL NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM 2018. Author(s), 2019. http://dx.doi.org/10.1063/1.5098619.
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Matsumoto, Shiho, Satoshi Kasagi, Takatoshi Kasai, Fusae Kawana e Koji Narui. "Periodic Leg Movements In Heart Failure Patients With Sleep Disordered Breathing". In American Thoracic Society 2010 International Conference, May 14-19, 2010 • New Orleans. American Thoracic Society, 2010. http://dx.doi.org/10.1164/ajrccm-conference.2010.181.1_meetingabstracts.a6531.
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Weinreich, Gerhard, Philip de Chazal, Yi Wang e Helmut Teschler. "Non-contacting Detection Of Sleep-disordered Breathing And Periodic Limb Movement". In American Thoracic Society 2010 International Conference, May 14-19, 2010 • New Orleans. American Thoracic Society, 2010. http://dx.doi.org/10.1164/ajrccm-conference.2010.181.1_meetingabstracts.a6752.
Testo completoRapporti di organizzazioni sul tema "Periodic breathing"
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White, David P., Kevin Gleeson, John T. Reeves, Cheryl K. Pickett e Anne M. Rannels. Predictors of Periodic Breathing at Altitude. Fort Belvoir, VA: Defense Technical Information Center, aprile 1986. http://dx.doi.org/10.21236/ada167947.
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Clausen, Jay, D. Moore, L. Cain e K. Malinowski. VI preferential pathways : rule or exception. Engineer Research and Development Center (U.S.), luglio 2021. http://dx.doi.org/10.21079/11681/41305.
Testo completoAbstract (sommario):
Trichloroethylene (TCE) releases from leaks and spills next to a large government building occurred over several decades with the most recent event occurring 20 years ago. In response to a perceived conventional vapor intrusion (VI) issue a sub-slab depressurization system (SSDS) was installed 6 years ago. The SSDS is operating within design limits and has achieved building TCE vapor concentration reductions. However, subsequent periodic TCE vapor spikes based on daily HAPSITE™ measurements indicate additional source(s). Two rounds of smoke tests conducted in 2017 and 2018 involved introduction of smoke into a sanitary sewer and storm drain manholes located on effluent lines coming from the building until smoke was observed exiting system vents on the roof. Smoke testing revealed many leaks in both the storm sewer and sanitary sewer systems within the building. Sleuthing of the VI source term using a portable HAPSITE™ indicate elevated vapor TCE levels correspond with observed smoke emanation from utility lines. In some instances, smoke odors were perceived but no leak or suspect pipe was identified suggesting the odor originates from an unidentified pipe located behind or enclosed in a wall. Sleuthing activities also found building roof materials explain some of the elevated TCE levels on the 2nd floor. A relationship was found between TCE concentrations in the roof truss area, plenum space above 2nd floor offices, and breathing zone of 2nd floor offices. Installation of an external blower in the roof truss space has greatly reduced TCE levels in the plenum and office spaces. Preferential VI pathways and unexpected source terms may be overlooked mechanisms as compared to conventional VI.
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Point-of-use assessment of emergency escape breathing devices for the U.S. Navy - sample period: 2010-2014. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, ottobre 2018. http://dx.doi.org/10.26616/npptlrepp20180105.
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