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Showing papers on "Hypoventilation published in 2002"


Journal ArticleDOI
01 Aug 2002-Thorax
TL;DR: Progressive ventilatory restriction in neuromuscular diseases correlates with respiratory muscle weakness and results in progressive SDB which, by pattern and severity, can be predicted from daytime lung and respiratory muscle function.
Abstract: Background: Sleep disordered breathing (SDB) is common in neuromuscular diseases but its relationship to respiratory function is poorly defined. A study was undertaken to identify distinct patterns of SDB, to clarify the relationships between SDB and lung and respiratory muscle function, and to identify daytime predictors for SDB at its onset, for SDB with continuous hypercapnic hypoventilation, and for diurnal respiratory failure. Methods: Upright and supine inspiratory vital capacity (IVC, % predicted), maximal inspiratory muscle pressure (PImax), respiratory drive (P0.1), respiratory muscle effort (P0.1/PImax), and arterial blood gas tensions were prospectively compared with polysomnography and capnometry (PtcCO2) in 42 patients with primary myopathies. Results: IVC correlated with respiratory muscle function and gas exchange by day and night. SDB evolved in three distinct patterns from REM hypopnoeas, to REM hypopnoeas with REM hypoventilation, to REM/non-REM (continuous) hypoventilation, and preceded diurnal respiratory failure. SDB correlated with IVC and PImax which yielded highly predictive thresholds for SDB onset (IVC <60%, PImax <4.5 kPa), SDB with continuous hypoventilation (IVC <40%, PImax <4.0 kPa), and SDB with diurnal respiratory failure (IVC <25%, PImax <3.5 kPa). Conclusion: Progressive ventilatory restriction in neuromuscular diseases correlates with respiratory muscle weakness and results in progressive SDB which, by pattern and severity, can be predicted from daytime lung and respiratory muscle function.

235 citations


Patent
24 Sep 2002
TL;DR: In this paper, an active medical device was used to diagnose a patient respiratory profile of the Cheyne-Stokes type by detecting an alternation of respiratory cycles of hyperventilation separated by periods of respiratory pause or periods of hypoventilation or normal ventilation.
Abstract: An active medical device to diagnose a patient respiratory profile. This device is able to measure respiratory activity and deliver a signal ( 26 ) representative of the periodicity and amplitude of the successive respiratory cycles of the patient, in particular, a of minute ventilation (MV) signal. The device is able to analyze the aforementioned signal and discriminate between various types of respiratory profiles, in particular, to diagnose a respiratory profile of the Cheyne-Stokes type. This is achieved by detecting an alternation of respiratory cycles of hyperventilation ( 20 ) separated by periods of respiratory pause ( 22 ) or periods of hypoventilation or normal ventilation ( 24 ) and, in the latter case, to discriminate between periods of respiratory pause, corresponding to a profile of the Cheyne-Stokes (CSR) type, and periods of hypoventilation or normal ventilation, corresponding to a profile of the periodic breathing (PB) type.

102 citations


Journal ArticleDOI
TL;DR: It is concluded that CCHS may be an inherited disorder, and increased endogenous progesterone during pregnancy has no effect on the ventilatory response, and diaphragm pacing can successfully provide adequate ventilation throughout pregnancy.
Abstract: The cause of congenital central hypoventilation syndrome (CCHS) is unknown, but a genetic etiology is strongly suspected. We report a 25-year-old woman with CCHS (no Hirschsprung's disease) who gave birth to a daughter who also has CCHS. This suggests a dominant mode of inheritance for CCHS in this family. Pregnancy can be associated with physiologic challenges in CCHS. The increase in endogenous progesterone may stimulate breathing and may possibly improve symptoms of hypoventilation. Although this patient did not have any worsening in symptoms, her hyperoxic hypercapnic rebreathing ventilatory response was not different when pregnant versus when not pregnant. Ventilatory support for the patient was successfully managed with diaphragm pacing throughout the pregnancy without the need to adjust settings, despite the enlarged abdomen during pregnancy. We conclude that CCHS may be an inherited disorder. Increased endogenous progesterone during pregnancy has no effect on the ventilatory response, and diaphrag...

69 citations


Journal ArticleDOI
TL;DR: This randomized trial suggested no beneficial effect of reduction of tidal volume on bleeding during hepatic resection.
Abstract: Hypothesis Blood loss in hepatic resection is an important determinant of operative outcome. Objective To clarify whether reducing the tidal volume would be effective in decreasing blood loss during liver transection. Design Randomized controlled trial. Setting University hospital. Patients Eighty patients scheduled to undergo hepatic resection were randomly assigned to receive liver transection under normoventilation (n = 40) or hypoventilation (n = 40). Interventions During liver transection, in the normoventilation group, the tidal volume was 10 mL/kg and the respiratory rate was 10/min; in the hypoventilation group, the tidal volume was reduced to 4 mL/kg and respiratory rate was increased to 15/min. Liver transection was performed under total or selective inflow occlusion. Main Outcome Measure Blood loss. Results Between the normoventilation and hypoventilation groups, no significant difference was found in total blood loss (median [range]: 630 mL [72-3600 mL] vs 630 mL [120-3520 mL];P= .44) or blood loss per transection area (median [range]: 7.3 mL/cm2[1.2-55.4 mL/cm2] vs 9.8 mL/cm2[0.9-79.9 mL/cm2];P= .55). During liver transection, the central venous pressure was significantly reduced in the hypoventilation group than in the normoventilation group (median [range]: –0.7 cm H2O [–3.0 to 1.8 cm H2O] vs –0.2 cm H2O [–4.0 to 2.0 cm H2O];P= .007). The maximum end-tidal carbon dioxide level in the hypoventilation group was significantly higher than that in the normoventilation group (maximum [range]: 50 mm Hg [28-66 mm Hg] vs 37 mm Hg [27-60 mm Hg];P Conclusion This randomized trial suggested no beneficial effect of reduction of tidal volume on bleeding during hepatic resection.

59 citations


Journal ArticleDOI
TL;DR: It is hypothesized that the consistent negative correlation of COUGH-evoked pain with PEF is, in part, caused by avoidance of coughing, which ultimately limits deep inspiration, lung reexpansion, and clearance of secretions.
Abstract: The pathogenesis of postoperative lung dysfunction implies a role for movement-evoked pain (e.g., splinting/hypoventilation because of pain avoidance). However, interactions between evoked pain and respiratory physiology are poorly understood. Thus, we examined the relationship between evoked versus

39 citations


Journal ArticleDOI
TL;DR: It is crucial to provide controlled hypoventilation, longer expiratory time, and titrated extrinsic positive end-expiratory pressure to avoid dynamic hyperinflation and its attendant consequences.
Abstract: Ventilatory intervention is often life-saving when patients with asthma or chronic obstructive pulmonary disease (COPD) experience acute respiratory compromise. Although both noninvasive and invasive ventilation methods may be viable initial choices, which is better depends upon the severity of illness, the rapidity of response, coexisting disease, and capacity of the medical environment. In addition, noninvasive ventilation often relieves dyspnea and hypoxemia in patients with stable severe COPD. On the basis of current evidence, the general principles of ventilatory management common to patients with acutely exacerbated asthma/COPD are these: noninvasive ventilation is suitable for a relatively simple condition, but invasive ventilation is usually required in patients with more complex or more severe disease. It is crucial to provide controlled hypoventilation, longer expiratory time, and titrated extrinsic positive end-expiratory pressure to avoid dynamic hyperinflation and its attendant consequences. Controlled sedation helps achieve synchrony of triggering, power, and breath timing between patient and ventilator. When feasible, noninvasive ventilation often facilitates the weaning of ventilator-dependent patients with COPD and shortens the patient's stay in the intensive care unit.

39 citations


Journal ArticleDOI
TL;DR: Although long-term oxygen therapy (LTOT) improves survival, it has little effect on hypoventilation and other outcomes in patients with hypercapnic respiratory failure due to chronic obstructive pulmonary disease (COPD).
Abstract: Although long-term oxygen therapy (LTOT) improves survival, it has little effect on hypoventilation and other outcomes in patients with hypercapnic respiratory failure due to chronic obstructive pulmonary disease (COPD). Recent studies have shown that the use of noninvasive positive-pressure ventilation, when used in combination with LTOT in selected stable COPD patients, controls hypoventilation and improves daytime arterial blood gases, sleep quality, health status and may have a benefit in reducing exacerbation frequency and severity. Patients who show the greatest reduction in overnight carbon dioxide tension in arterial blood with ventilation are most likely to benefit from long-term ventilatory support. Some benefits have also been shown in patients with chronic respiratory failure due to bronchiectasis and cystic fibrosis, though survival is inferior in this patient group. As most studies of noninvasive positive-pressure ventilation in chronic obstructive pulmonary disease have been relatively short term, large multicentre studies with survival, exacerbations and hospital admissions as the primary end points are required to evaluate longer term effects.

37 citations


Journal ArticleDOI
TL;DR: It is concluded that aortic chemoreceptors contribute to eupneic breathing in piglets that were carotid denervated at 5 days of age and there are multiple sites of residual peripheral chemosensitivity after CBD.
Abstract: The objective of the present study was to test the hypothesis that in neonatal piglets there would be no hypoventilation after sham denervation or aortic denervation (AOD) alone, but there would be transient hypoventilation after carotid body denervation (CBD) and the hypoventilation would be greatest after combined carotid and aortic denervation (CBD+AOD). There was a significant (P < 0.05) hypoventilation in CBD and CBD+AOD piglets denervated at 5, 15, and 25 days of age. The hypoventilation in CBD+AOD piglets denervated at 5 days of age was greater (P < 0.05) than that of all other groups. Conversely, sham-denervated and AOD piglets did not hypoventilate after denervation. Injections of sodium cyanide showed that aortic chemoreceptors were a site of recovery of peripheral chemosensitivity after CBD. This aortic sodium cyanide response was abolished by prior injection of a serotonin 5a receptor blocker. Residual peripheral chemosensitivity after CBD+AOD was localized to the left ventricle. We conclude that 1) aortic chemoreceptors contribute to eupneic breathing in piglets that were carotid denervated at 5 days of age and 2) there are multiple sites of residual peripheral chemosensitivity after CBD.

34 citations


Journal ArticleDOI
TL;DR: Investigation of quality of life in patients with chronic alveolar hypoventilation due to neuromuscular or restrictive chest wall disorders found patients with untreated CAH had significantly impaired HRQL compared to historical data from a healthy reference population.
Abstract: Measurements of health-related quality of life (HRQL) have not been reported in patients with chronic alveolar hypoventilation (CAH) before starting home mechanical ventilation. The purpose of this study was to investigate quality of life in a population of such patients. Forty-four consecutive patients with CAH due to previous polio, scoliosis, healed pulmonary tuberculosis or neuromuscular disease answered a battery of condition specific and generic (Sickness Impact Profile, Hospital Anxiety and Depression scale, Mood Adjective Check List) self-report questionnaires. Spirometry, arterial blood gases and overnight oxygen saturation were measured. Patients with untreated CAH had significantly impaired HRQL compared to historical data from a healthy reference population. Sleep-related problems were frequent. Age, underlying disease, and standard bicarbonate correlated significantly with HRQL measures, albeit with modest levels of explained variance (8-37%). Patients with chronic alveolar hypoventilation due to neuromuscular or restrictive chest wall disorders had severely impaired health-related quality of life. Age, the underlying disease and severity of hypoventilation are each related to the health-related quality of life decrements. Health-related quality of life measurements add important information to traditional clinical observations.

33 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of abnormal ventilation on the nervous system are discussed, where the authors deal with the effect of abnormal ventilations on the respiratory and central nervous systems.

22 citations


Journal ArticleDOI
TL;DR: A mixed breed dog presented with generalized weakness, hypoventilation and hypoxemia and had persistent cervical ventroflexion for a total of 4 weeks.
Abstract: Objective: To discuss a new clinical presentation of organophosphate toxicity called the intermediate syndrome in a dog Case summary: A mixed breed dog presented with generalized weakness, hypoventilation and hypoxemia The weakness was most marked in the thoracic limbs, cervical and respiratory muscles The history revealed a likely exposure to an organophosphate compound The other dog in the household demonstrated mild clinical signs of organophosphate toxicity A blood cholinesterase level was markedly reduced Therapy included placement of a tracheostomy tube and mechanical ventilation The dog gradually improved over the following 8 days but had persistent cervical ventroflexion for a total of 4 weeks New or unique information provided: Organophosphate toxicity can present as a paralysis following the acute cholinergic crisis The muscular weakness predominantly affects the thoracic limb and neck muscles but cranial nerve deficits can also occur Dogs can die from the associated respiratory depression Oxime therapy is indicated in the treatment of this syndrome

Journal ArticleDOI
TL;DR: This article characterizes the unique features of neonatal respiratory control mechanisms and clarifies how immature respiratory control contributes to neonatal apnea, including the contribution of upper airway obstruction to episodes of mixed apnea.
Abstract: After completing this article, readers should be able to: 1. Characterize the unique features of neonatal respiratory control mechanisms. 2. Clarify how immature respiratory control contributes to neonatal apnea. 3. Identify the contribution of upper airway obstruction to episodes of mixed apnea. Idiopathic apnea of prematurity is a common disorder that requires therapeutic intervention to avoid potential morbidity in preterm infants who require neonatal intensive care. Severe, recurrent apneic episodes may lead to multiple investigations to rule out secondary disorders leading to apnea (see accompanying article in this issue). Although the incidence of neonatal apnea is inversely related to gestational age and is probably as high as 100% in the most immature preterm infants, the onset may be delayed by the presence of lung disease in the first days of life. Apnea of prematurity, especially if severe or persistent, has been associated with poor developmental outcome in school-age children, although a cause-and-effect relationship is difficult to establish. The definition of apnea varies among studies. Apnea of prematurity has been defined most widely as cessation of breathing in excess of 15 seconds’ duration, typically accompanied by desaturation and bradycardia. However, shorter episodes of apnea, and even periodic breathing, may be accompanied by bradycardia or hypoxemia. Prolonged desaturation episodes also have been reported in the absence of apnea or bradycardia, both in healthy preterm infants and in infants who have chronic lung disease. These episodes might represent obstructive apnea, hypoventilation, or possibly intrapulmonary right-to-left shunting, although episodes of desaturation and bradycardia almost always are preceded by apnea or hypoventilation. Apnea is classified traditionally into three categories based on the presence or absence of upper airway obstruction: central, obstructive, and mixed apneas. Central apnea is characterized by total cessation of inspiratory efforts with no evidence of obstruction. In obstructed apnea, the infant tries to breathe against …

Journal ArticleDOI
01 Sep 2002
TL;DR: More-rapidly changing heart rate variation from spontaneous or reflexively-induced sources is diminished in CCHS but remains intact from voluntary expiratory efforts, as does slower variation.
Abstract: Question of the Study Congenital central hypoventilation syndrome (CCHS) subjects exhibit diminished respiratory-related heart rate variation in addition to defining characteristics of CO2 insensitivity and reduced ventilatory drive during sleep. Loss of cardiovascular and breathing coupling may diminish blood pressure influences on breathing; such influences may be determined by evaluating cardiorespiratory responses to different pressor challenges.

Book ChapterDOI
01 Jan 2002
TL;DR: A rare and unique form of familial parkinsonist with autosomal dominant inheritance that is characterized by all cardinal features of parkinsonism, apathy, depression, central hypoventilation, weight loss, and rapid progression was first described by Perry et al.
Abstract: A rare and unique form of familial parkinsonism with autosomal dominant inheritance that is characterized by all cardinal features of parkinsonism, apathy, depression, central hypoventilation, weight loss, and rapid progression was first described by Perry et al.1 Thereafter, four additional families from different ethnic background have been reported (Table 1).2–6 In most of these affected individuals, disease presented between ages of 40–55, with symptoms of apathy, psychomotor slowness and/or depression, usually accompanied or followed by moderate degrees of parkinsonism and weight loss. Central type of hypoventilation developed eventually and caused death in most of the patients due to sudden apnea or complications of respiratory insufficiency. Pathology differs from idiopathic Parkinson’s disease by severe neuronal loss and gliosis in substantia nigra with no or very few Lewy-body formation,1,2,4,5 and in some patients, by extension of neuronal loss to locus ceruleus, caudate, pallidum and medulla. 2’4

Journal ArticleDOI
01 Sep 2002-Thorax
TL;DR: This case documents the treatment of chronic type II respiratory failure secondary to central hypoventilation with medroxyprogesterone with a new treatment option.
Abstract: Hypoventilation secondary to brainstem stroke resulting in chronic respiratory failure is extremely uncommon. This case documents the treatment of chronic type II respiratory failure secondary to central hypoventilation with medroxyprogesterone, a new treatment option.

01 Oct 2002
TL;DR: Sleep has well recognised effects on respiratory muscle function, most of which are detrimental, which contribute to hypoventilation and worsening ventilation-perfusion mismatching, particularly in patients with chronic lung disease such as COPD, with resulting oxygen desaturation.
Abstract: Sleep has well recognised effects on respiratory muscle function, most of which are detrimental. Upper airway dilator muscle function is compromised, which predisposes to obstruction, particularly during rapid-eye-movement sleep (REM). The diaphragm and accessory muscles of respiration are differently affected by sleep. Diaphragmatic function is largely preserved, which is essential for the maintenance of adequate ventilation during sleep. However, accessory muscle function is reduced, particularly during REM sleep, which may have adverse effects on lung mechanics. These changes contribute to hypoventilation and worsening ventilation-perfusion mismatching, particularly in patients with chronic lung disease such as COPD, with resulting oxygen desaturation.

Journal ArticleDOI
TL;DR: The mechanisms of action and monitoring of neuromuscular blocking agents are reviewed, as well as a basic overview of postoperative complications involving hypoventilation and motor weakness are provided.

Journal ArticleDOI
TL;DR: A rule of thumb used to assess need for mechanical ventilation is a PaO2 of less than 50 mm Hg despite aggressive oxygen therapy, or a PaCO2 of greater than 50mm HgDespite treatment for causes of hypoventilation as discussed by the authors.
Abstract: There are many causes of respiratory failure in veterinary patients. Assessment of oxygenation is imperative for the diagnosis and monitoring of these patients. Oxygen therapy should be instituted when hypoxemia is diagnosed to prevent tissue hypoxia, end-organ damage, and death. Methods of administering oxygen include commercial oxygen cages, mask oxygen, nasal cannulation (for dogs), and intubation. Mechanical ventilation is an option in many referral hospitals for patients who are severely hypoxemic and are not responding to inspired oxygen concentrations achieved with other methods of oxygen administration. One rule of thumb used to assess need for mechanical ventilation is a PaO2 of less than 50 mm Hg despite aggressive oxygen therapy, or a PaCO2 of greater than 50 mm Hg despite treatment for causes of hypoventilation. A mechanical ventilator has the ability to vary the FiO2 by increments of one, from 21% to 100% (0.21-1) oxygen in inspired gas. Positive end-expiratory pressure (PEEP) is also available on most ventilators. PEEP allows the alveoli to remain open on expiration, allowing gas exchange to occur in both inspiration and expiration. PEEP also helps diseased alveoli to inflate, increasing the available surface area for gas exchange and improving arterial blood oxygen tension. Because patients requiring mechanical ventilation have severe respiratory failure that did not respond to conventional oxygen therapy, the prognosis is guarded for most of these patients unless ventilation is instituted due to primary hypoventilation and lung parenchyma is normal. Hypoxemia caused by respiratory failure is a common problem in small animal veterinary patients. Assessment of blood oxygenation and continual monitoring of respiratory rate and effort are essential in management of these patients. Oxygen therapy should be instituted if hypoxemia is diagnosed. The prognosis depends on the underlying disease process and response to treatment with an enriched oxygen environment.

Journal ArticleDOI
TL;DR: In humans, duration and recovery times of vecuronium are prolonged in respiratory acidosis and shortened in respiratory alkalosis, and the closest significant correlation in this study was observed between recovery time and arterial blood pH.

Journal ArticleDOI
TL;DR: The physiopathologic background of this findings are discussed, which has important impact on intensive care medicine, which usually takes only pO 2 into account for therapeutic decisions, which sometimes leads to "overtreatment", with possible harm to the patient.
Abstract: Extreme mountain climbers and patients with stable but severe ventilatory insufficiency (e.g. obesitas hypoventilation-syndrome, scoliosis) sometimes experience a state of severe hypoxemia without any or only mild subjective disturbances. Organ failure is never observed in these periods. On the other hand there are two well documented studies concerning long term oxygen therapy (LTOT) that have shown in hypoxemic COPD-patients (pO 2 lower then 55 mm Hg) a doubling the life expectancy under oxygen. This contradiction can be elucidated if the influence of oxygen on the ventilation is taken into account. These study patients treated with LTOT all had more or less hypercapnia (hypoventilation) due to an overload of their respiratory pump. Oxygen reduces the ventilation (seen as hypercapnia) which leads to an unloading of the respiratory muscles. Later studies to LTOT found a positive correlation between the extent of stable hypercapnia and life expectancy. In this article the physiopathologic background of this findings are discussed. The main parameter of the regulator for the oxygen transport is not pO 2 but the oxygen content. The oxygen content multiplied by cardiac output determines the extent of oxygen delivery. Many regulatory systems (e.g. polyglobuly or expression of oxygen resistant isoenzymes of the respiratory chain) are involved to compensate the hypoxemia associated with hypoventilation which prevents an organ threatening hypoxia. This pathophysiologic finding has important impact on intensive care medicine, which usually takes only pO 2 into account for therapeutic decisions (e. g. high FiO 2 and high pressure support). This sometimes leads to "overtreatment", with possible harm to the patient.


Journal Article
TL;DR: Use of endotracheal ventilation may be necessary to control a state of shock or consciousness disorders incompatible with the patient cooperation necessary for non-invasive ventilation, particularly with a ventilator capable of maintaining positive expiratory and pressure.
Abstract: Obstructive sleep apnea, obesity-related hypoventilation - a hypoventilation which is independent of apneas and increased by sleep -, and hypoxemia related to local ventilation-perfusion disorders are the main mechanisms of respiratory failure occurring during acute respiratory decompensation following an often minimal triggering event. Non-invasive ventilation has been found to be an effective treatment, particularly with a ventilator capable of maintaining positive expiratory and pressure. The level of the expiratory positive airway pressure must be adapted to cure episodes of obstructive apnea or hypopnea. The level of the inspiratory positive airway pressure (pressure support ventilator), or the tidal volume (volume-controlled ventilator) must be adapted to correct the residual hypoventilation. These adaptations can be made by proper assessment of nocturnal SaO(2) recordings. In particularly severe cases, use of endotracheal ventilation may be necessary to control a state of shock or consciousness disorders incompatible with the patient cooperation necessary for non-invasive ventilation.

Journal Article
TL;DR: Evaluation of noninvasive nasal IMV effectiveness along with a risk of abdominal distension caused by air trapping resulted in decreased incidence of apnoe of prematurity, avoiding the risks of nosocomial pneumonia and bronchopulmonary dysplasia.
Abstract: Early extubation of ELBW and VLBW premature infants treated with IMV results in decreased incidence of tracheal and laryngeal injury, lowers the risk of nosocomial infection, decreases the severity and frequency of bronchopulmonary dysplasia (BPD). Due to prematurity this group of patients is especially susceptible to extubation failure because of apnoe, hypoventilation and atelectasis. In clinical practice attempt was made to provide adequate noninvasive ventilation by the use of nasal intermittent mandatory ventilation in the case of apnoe of prematurity. Advantages of noninvasive nasal IMV oppose the risk of stomach distension and regurgitation due to high tension of pylorus combined with inadequate cardia tension. The aim of study was the evaluation of noninvasive nasal IMV effectiveness along with a risk of abdominal distension caused by air trapping. 32 patients were examined during one year of studies. In all but one the use of nasal intermittent mandatory ventilation resulted in decreased incidence of apnoe of prematurity. Satisfactory levels of SaO2 and pCO2 were achieved without endotracheal tube placement, avoiding the risks of nosocomial pneumonia and bronchopulmonary dysplasia.

Journal ArticleDOI
TL;DR: Two patients with high spinal cord lesions in whom the use of flow triggering was unsuccessful are reported, indicating severe muscle weakness in these patients made them sensitive to small changes in ventilator trigger characteristics.
Abstract: Flow triggering in ventilators is an alternative to pressure triggering. Differences between these two trigger mechanisms may not be clinically significant in most patients. We report two patients with high spinal cord lesions in whom the use of flow triggering was unsuccessful. Severe muscle weakness in these patients made them sensitive to small changes in ventilator trigger characteristics.

Journal Article
Z Tomori, V Donic, R Benacka, M Kuchta, S Koval, Jan Jakus 
TL;DR: Four basic control mechanisms of breathing, as well as their sleep-related disorders, are analysed and augmented ventilatory effort and hypoxaemia evoke reflex dilation of airways and arousal from sleep, stimulating the sympatho-adrenal system which provokes autoresuscitation by gasping preventing fatal asphyxia.
Abstract: Four basic control mechanisms of breathing (brainstem respiratory centre, peripheral and central chemoreceptors, intero- and exteroceptive reflexes and suprapontine influences), as well as their sleep-related disorders are analysed. A decrease in central chemoreceptor sensitivity to CO2 and an increase in upper airway resistance during sleep result in hypoventilation and mild hypoxaemia already in physiological conditions. Compensatory increase in ventilatory effort with synchronous inhibition of pharyngeal dilators during sleep reduces the upper airway lumen manifesting with snoring, upper airway resistance syndrome, and OSA. The resulting hypoxaemia may cause marked cardiovascular, neuro-psychic, endocrine-metabolic and behavioural disorders. The augmented ventilatory effort and hypoxaemia evoke reflex dilation of airways and arousal from sleep, stimulating the sympatho-adrenal system, which provokes autoresuscitation by gasping preventing fatal asphyxia. Failure of this autoresuscitation mechanism seems to cause SIDS. Elimination of voluntary breathing by sleep either in Ondine's curse induced by lesions of respiratory centre, or in congenital central hypoventilation syndrome caused by insufficient central chemoreceptors result in respiratory failure and death. Nocturnal attacks of bronchial and cardiac asthma, lung oedema and other consequences of pulmonary congestion are also discussed. The pathomechanism of extreme daytime sleepiness, chronic fatigue, and disorders of memory, cognitive and other brain functions, are also analysed. Severe cardiovascular consequences of SAS may manifest acutely as angina pectoris, myocardial infarction. dysrhythmias, transient ischaemic attacks and even stroke or sudden cardiac death. OSAS may result also in development of hypertension, central obesity, diabetes mellitus, erectile dysfunction, depression, and various behavioural disorders.

Journal ArticleDOI
TL;DR: It is concluded that myocardial vulnerability to the ventricular arrhythmias is influenced by ventilatory disorders in the circadian dependence in in-vivo rat models.

Patent
20 Jul 2002
TL;DR: In this paper, a method involves subjecting testees to seven functional respiratory tests, which involve hyperventilation, hypoventilation, retained respiration, gas exchange, pneumogram, electrocardiogram and electroencephalogram.
Abstract: medicine. SUBSTANCE: method involves subjecting testees to seven functional respiratory tests. Characteristic features like external breathing, gas exchange, pneumogram, electrocardiogram, electroencephalogram, arterial blood pressure, latent period of motor response are recorded. Respiratory tests involve hyperventilation, hypoventilation and retained respiration. EFFECT: enhanced effectiveness in detecting sensitive patients to humoral and neurogenic factors. 2 cl

01 Jan 2002
TL;DR: The influence of the breathing technique (hypo- and hyperventilation) used in breath alcohol measurement using the Alcotest(registered trademark) 7110 MKIII Evidential is significantly reduced if not ruled out altogether by correcting the breath alcohol concentration to a standard temperature.
Abstract: The influence of the breathing technique (hypo- and hyperventilation) used in breath alcohol measurement using the Alcotest(registered trademark) 7110 MKIII Evidential is significantly reduced if not ruled out altogether by correcting the breath alcohol concentration (BrAC) to a standard temperature of 34(degrees)C (hyperventilation from - 11% to - 2%; hypoventilation from + 13% to + 7%). The BrAc deviation on hypoventilation correlates significantly with the time of hypoventilation (p lt 0.001). Besides temperature related alteration of alcohol saturation in breath, the time of alveolar contact seems to play an additional role. In hyperventilation compared to normoventilation the time of alveolar contact is only marginally reduced, therefore being of secondary importance in this context.


Journal ArticleDOI
TL;DR: The obesity hypoventilation or Pickwickian syndrome comprises of extreme obesity, alveolar hypovENTilation, somnolence, plethora, pulmonary hypertension and right heart failure.
Abstract: 비만성 자환기 증후군은 Pickwickian 증후군이라고도 불리우는 환기장애질환으로 폐쇄성 수면무호홉 증후군파 함께 비만과 관련된 대표적인 호흡기 질환이다. 비만환자가 급증하고 있는 현실로 보아 향후 임상에서 보다 자주 접하게 될 가능성이 많은 질환이지만 국내에는 현재까지 1예만이 보고되어 있다. 저자들은 과도한 주간 졸리움 등의 증상을 주소로 내원한 비만환자 3명에서 비만성 저환기 증후군을 진단하고 치료하였기에 문헌고찰과 함께 보고하는 바이다. 【Severe obesity can produce a marked impairment of respiratory function. The obesity hypoventilation or Pickwickian syndrome comprises of extreme obesity, alveolar hypoventilation, somnolence, plethora, pulmonary hypertension and right heart failure. It is sometimes associated with obstructive sleep apnea but can be distinguished from obstructive sleep apnea by the presence of awake $CO_2$ retention. Alt hough uncommon, it is important to recognize this syndrome because due to its potential life threatening nature and because can be reversed by appropriate treatment. Here, we report 3 cases of obesity hypoventilation syndrome.】