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Query: UMLS:C0037315 (sleep apnea)
 8,000 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a case of sleep apnea syndrome (SAS) with nocturnal pulmonary hypertension (NPH) in a 71-year-old man suffering from dyspnea during sleep. Severe snoring at night and daytime sleepiness were noticed before admission by his wife. Nocturnal oxygen desaturation (NOD) was documented with a pulse oximeter and severe sleep apnea syndrome was diagnosed on the basis of results of respiratory inductive plethysmography, an apnea index (AI) > 20, minimum SpO2 56%. NPH was diagnosed by Swan-Ganz catheter. The levels of NPH were severe. Elevation of systolic pulmonary arterial pressure (PAP) above 40 mmHg was observed 137 episodes at night. Both NPH and NOD were improved by 1 L/min of nasal oxygen therapy. A number of episodes of systolic PAP above 40 mmHg with oxygen therapy was 55 episodes. Peak mean PAP was 36 mmHg in room air vs 33 mmHg in oxygen therapy. Minimum SpO2 with oxygen therapy was improved to 69%. Total time of SpO2 < 90% at night was 153 minutes in room air vs 37 minutes in oxygen therapy. In this case, NPH and NOD due to severe SAS were remarkably improved by oxygen therapy.
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PMID:[Nocturnal pulmonary hypertension in an elderly patient with sleep apnea syndrome]. 859 33

"Cor pulmonale" is a classic feature of the "Pickwickian syndrome". Earlier studies have reported a high prevalence of pulmonary hypertension (PH) in obstructive sleep apnoea (OSA) patients, but this has not been confirmed by recent studies with a more adequate methodology, including larger groups of patients. The first part of this review is devoted to the prevalence of PH in OSA; most recent studies agree on prevalence of 15-20%. The second (and major) part of the study deals with the causes and mechanisms of PH in OSA. Pulmonary hypertension is rarely observed in the absence of day-time hypoxaemia, and the severity of nocturnal events (apnoea index (AI), apnoea+ hypopnoea index (AHI) does not appear to be the determining factor of PH. Diurnal arterial blood gas disturbances and PH are most often explained by the presence of severe obesity (obesity-hypoventilation syndrome) and, principally, by association of OSA with chronic obstructive pulmonary disease (the so called "overlap syndrome"). Bronchial obstruction is generally of mild-to-moderate degree and may be asymptomatic. The final part of the review analyses the therapeutic consequences of the presence of PH in OSA patients. Pulmonary hypertension, which is generally mild-to-moderate, does not need a specific treatment. When nasal continuous positive airway pressure (CPAP) fails to correct sleep-related hypoxaemia, supplementary oxygen must be administered. In patients with marked daytime hypoxaemia (arterial oxygen tension (Pa,O2), < or = 7.3 kPa (55 mmHg) conventional O2 therapy (nocturnal + diurnal) is required.
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PMID:Pulmonary hypertension in the obstructive sleep apnoea syndrome: prevalence, causes and therapeutic consequences. 872 47

Sleep apnea, defined as the cessation of breathing for at least 10 seconds during sleep, can have detrimental effects on the critically ill. Three types of sleep apnea exist, the most common being obstructive sleep apnea. Though its prevalence is only 1% to 3% in adults, it is very important to diagnose it and treat it early in the critically ill because it causes respiratory failure and difficult weaning from mechanical ventilation. Its most characteristic manifestations are repetitive apneic episodes during sleep, snoring, and diurnal hypersomnolence. Complications of sleep apnea include dysrhythmias, systemic and pulmonary hypertension, hypoxia, hypoventilation, left ventricular dysfunction, and stroke. Treatment methods depend on the cause and include medications, surgery, and nasal continuous positive airway pressure. The main nursing role is astute assessment and early detection, proper respiratory management, provision of psychologic support, and patient and family teaching.
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PMID:Sleep apnea: a challenge in critical care. 877 69

The increased mortality among patients with obstructive sleep apnea syndrome has been explained in part by the increased incidence of arterial and pulmonary hypertension. A decreased heart rate variability (HRV) has been shown to be associated with an increased mortality as well. We investigated 53 patients, admitted to the hospital for chest pain for sleep-related breathing disorders (SRBD) with an ambulatory screening device (MESAM-IV). HRV was recorded simultaneously. All patients received coronary artery catheterization and 36 had significant coronary artery disease (CAD; 67.9%). Standard time domain parameters were compared by a 4-way Anova for patients with an oxygen desaturation index of more and less than 5/hour and the factors CAD, diabetes and beta-blocker use. The percentage of differences between RR intervals that differ more than 50 ms (pNN > 50: 9.0 +/- 11.1 vs. 19.2 +/- 22.2%: p < 0.05) as well as the root mean square of these differences (38.0 +/- 29.0 vs. 59.2 +/- 51.5 ms; p < 0.05) were significantly decreased in patients with SRBD. In an hourly breakdown the number of desaturations was not correlated with a change in HRV. Mean oxygen saturation was significantly decreased in patients with SRBD (95.2 +/- 1.8 vs. 96.2 +/- 1.42%, p < 0.05), and positively correlated with the pNN > 50 (r = 0.34, p < 0.01). This correlation might suggest a more profound pathophysiological interaction between HRV and SRBD than short-term vagal activation alone. The results favor HRV for inclusion in future risk stratification models in patients with sleep apnea syndrome.
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PMID:Heart rate variability in patients with sleep-related breathing disorders. 890 76

We reviewed clinical data, autopsy reports, and microscopic slides on 10 patients with sleep apnea/obesity hypoventilation syndrome (SA/OHS) to define the cardiopulmonary pathological features and establish clinicopathologic correlations. Ten obese (>136 kg) patients without SA/OHS were studied as controls. Patients with SA/OHS exhibited biventricular cardiac failure and pulmonary hypertension with a higher prevalence of moderate/severe pulmonary hemosiderosis (8 v 0 patients), alveolar hemorrhage (7 v 4 patients), capillary proliferation (4 v 0 patients), iron encrustation of elastica (1 v 0 patients) and medial hypertrophy of muscular pulmonary arteries (11.9 +/- 2.4 v 9.7 +/- 1.6%) (P < .05). In two patients capillary proliferation resembled capillary hemangiomatosis. Mean right ventricular thickness was higher in the SA/OHS group (0.71 +/- 0.17 v 0.42 +/- 0.1 cm) (P < .01). Four patients with SA/OHS and three controls had moderate/severe myocardial fibrosis. Biventricular cardiac failure caused death in seven patients with SA/OHS. Hypoxia is probably the most important cause of pulmonary hypertension, arterial muscularization, and right ventricular hypertrophy in SA/ OHS. Left ventricular failure in some SA/OHS patients may be the result of hypertensive cardiac disease. In others, the etiology of left ventricular failure was not determined morphologically, suggesting functional abnormalities related to obesity and/or apneic episodes.
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PMID:Cardiopulmonary pathology in patients with sleep apnea/obesity hypoventilation syndrome. 938 47

To date, a paucity of information is available on the optimal management of obstructive sleep apnea in Down syndrome, which may have particularly important implications in this already vulnerable patient population. The objective of this study was to evaluate prospectively the results of a new surgical approach for the treatment of obstructive sleep apnea. Patients with Down syndrome and obstructive sleep apnea underwent preoperative and postoperative polysomnography and clinical and radiologic evaluation to determine prospectively the efficacy of sleep apnea surgery. Statistical testing of apnea index, respiratory disturbance index, and lowest oxygen saturation were compared by means of paired t tests. Seven children (five boys, two girls) from 3 to 12 years of age were subjected to a management protocol that included an aggressive surgical approach to the treatment of obstructive sleep apnea. Clinical symptoms and signs of obstructive sleep apnea, apnea index, respiratory disturbance index, lowest oxygen saturation, and surgical morbidity were the main outcome measures. Surgical treatment consisted of a combination of soft-tissue and skeletal alterations including tongue reduction (n = 6), tongue hyoid advancement (n = 4), uvulopalatopharyngoplasty (n = 7), and maxillary or midface advancement (n = 2). Polysomnography was obtained preoperatively and postoperatively in six patients. One patient was intubated preoperatively. Mean preoperative apnea index and respiratory disturbance index were 34.00 and 52.46 compared with mean postoperative values of 1.62 and 6.46, respectively. Clinically, all patients were improved symptomatically in terms of snoring, noisy breathing, and oxygen requirements. The one patient who had been intubated preoperatively for respiratory failure was extubated successfully but later developed recurrent tricuspid regurgitation and was found to have fixed pulmonary hypertension with cor pulmonale. This patient represented the only treatment failure and underwent tracheostomy. An aggressive surgical approach aimed at correcting all anatomic abnormalities associated with upper airway obstruction was applied successfully to the treatment of obstructive sleep apnea in Down syndrome. We suggest periodic polysomnography in patients with Down syndrome, especially if there is unexplained deterioration in mental capacity or other signs and symptoms of obstructive sleep apnea. Surgical treatment should address both the soft-tissue abnormalities and the skeletal deformities such as midface retrusion. Preoperative cardiac ultrasonography is important to determine the presence of right-sided heart failure, which may be an indication for cardiac catheterization to determine pulmonary venous pressures.
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PMID:Down syndrome: identification and surgical management of obstructive sleep apnea. 904 80

Even if different mechanisms of various interactions during sleep are known, it is still unsolved by which mechanisms physiological reactions during sleep may start a pathophysiological course. Hypoxia, Hypercapnia and repetitive sympathetic elevations are well known elements in the control of the arterial resistance. Furthermore investigations in patients with sleep apnea showed changes of the pulsatile secretion pattern within the renin-angiotensin-system and the antinatriuretic peptides. These changes were reversible under nasal CPAP-therapy, nycturia as a frequent symptom disappeared. Nevertheless neither hypoxia nor intrathoracic pressure changes nor the arousals can assert the longterm influence on the blood pressure alone, a multifactorial confluence must be assumed. Further it is unclear how a tonic increase of the arterial blood pressure may occur in dependence of the REM- and NREM-sleep cycle changes as well as during daytime. First investigations in sleeping man seem to indicate, that a disturbance of the physiological coupling of breathing and circulation may present a pathogenetic element. Finally it remains open, whether the changes of the cardiorespiratory coupling during sleep of control persons and of patients with OSA are comparable, and whether they may be procured for an explanation of the pathogenesis of arterial and pulmonary hypertension. Further investigations in the control mechanisms of breathing and circulation related to the circuits of chemo- and baroreception, thresholds during wakefulness and sleep may be of decisive help to process the question, to what extent clinical states find a correlate in a disturbed cardiorespiratory coupling and, much more significantly, whether a disturbance in the physiological cardiorespiratory coupling appears already in early states of a disease. Sleep with ist complex physiology as well as with its characteristic pathophysiological phenomenon of sleep related breathing disorders has opened a new interdisciplinary field where tools like the polysomnography and electronic data analysis are used by physiologists, pathophysiologists as well as by physicians.
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PMID:[Cardiorespiratory coupling in obstructive sleep apnea (OSA)]. 924 90

Obstructive sleep apnoea (OSA) produces immediate effects on pulmonary haemodynamics during sleep in all subjects. In addition, in some subjects, OSA is accompanied by chronic abnormalities of the pulmonary circulation. During sleep, pressure in the main pulmonary artery oscillates within each apnoea, in synchrony with intrathoracic pressure changes; in addition, it may increase progressively as a consequence of prolonged severe hypoxaemia. Pulmonary capillary wedge pressure may increase during inspiratory efforts, possibly reflecting a mechanical limitation of left ventricular function. Cardiac output decreases at apnoea resolution as an effect of a decreased right ventricular stroke volume, despite increased cardiac frequency. During wakefulness, postcapillary pulmonary hypertension occurs on exercise in many OSA patients, whilst pulmonary hypertension at rest is precapillary and occurs in patients with an altered daytime respiratory function. Development of right ventricular hypertrophy and a decrease in right ventricular ejection fraction appear to be related to the severity of respiratory alterations during sleep, whilst an overt right heart failure requires an altered daytime respiratory function. Long-term treatment of the obstructive sleep apnoea syndrome is more effective in increasing right ventricular ejection fraction than in decreasing pulmonary artery pressure during wakefulness.
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PMID:Acute and chronic influences of obstructive sleep apnoea on the pulmonary circulation. 927 Feb 54

It has been hypothesized but not firmly established that sleep-related hypoxaemia could favour the development of pulmonary hypertension in chronic obstructive pulmonary disease (COPD) patients without marked daytime hypoxaemia. We have investigated the relationships between pulmonary function data, sleep-related desaturation and daytime pulmonary haemodynamics in a group of 94 COPD patients not qualifying for conventional O2 therapy (daytime arterial oxygen tension (Pa,O2) in the range 7.4-9.2 kPa (56-69 mmHg)). Nocturnal desaturation was defined by spending > or = 30% of the recording time with a transcutaneous O2 saturation < 90%. An obstructive sleep apnoea syndrome was excluded by polysomnography. Sixty six patients were desaturators (Group 1) and 28 were nondesaturators (Group 2). There was no significant difference between Groups 1 and 2 with regard to pulmonary volumes and Pa,O2 (8.4+/-0.6 vs 8.4+/-0.4 kPa (63+/-4 vs 63+/-3 mmHg)) but arterial carbon dioxide tension (Pa,CO2) was higher in Group 1 (6.0+/-0.7 vs 53+/-0.5 kPa (45+/-5 vs 40+/-4 mmHg); p<0.0001). Mean pulmonary artery pressure (Ppa) was very similar in the two groups (2.6+/-0.7 vs 2.5+/-0.6 kPa (19+/-5 vs 19+/-4 mmHg)). No individual variable or combination of variables could predict the presence of pulmonary hypertension. It is concluded that in these patients with chronic obstructive pulmonary disease with modest daytime hypoxaemia, functional and gasometric variables (with the noticeable exception of arterial carbon dioxide tension) cannot predict the presence of nocturnal desaturation; and that mean pulmonary artery pressure is not correlated with the degree and duration of nocturnal hypoxaemia. These results do not support the hypothesis that sleep-related hypoxaemia favours the development of pulmonary hypertension.
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PMID:Sleep-related O2 desaturation and daytime pulmonary haemodynamics in COPD patients with mild hypoxaemia. 927 11

There is conclusive evidence that obstructive sleep apnoea syndrome (OSAS) influences right heart haemodynamics and can also induce pulmonary hypertension. It is not known, however, whether right ventricular dysfunction can occur in patients with OSAS in the absence of lung disease. We studied 107 patients (94 males, 13 females, mean age 55 +/- 11 yrs) with polysomnographically verified OSAS in whom clinically significant lung disease was excluded. Right ventricular ejection fraction (RVEF) was determined by radionuclide ventriculography. In addition, pulmonary function tests, arterial blood gas analysis and right heart catheterization were performed. RVEF was impaired in 19 patients (18%). Eighteen (95%) had signs or symptoms consistent with mild right ventricular failure. Patients with or without impaired RVEF did not differ with respect to body mass index, age or lung function. Stepwise multiple logistic regression analysis revealed that RVEF was significantly associated with the apnoea/hypopnoea index (r = -0.68; p = 0.0009) and the extent of nocturnal oxyhaemoglobin saturation (r = 0.42; p = 0.035), but not with age, body mass index, blood gas analysis, gender, lung function, pulmonary artery pressure and left ventricular ejection fraction. We conclude that in patients with otherwise unexplained right ventricular failure, obstructive sleep apnoea syndrome may underlie the right ventricular dysfunction.
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PMID:Right ventricular dysfunction in patients with obstructive sleep apnoea syndrome. 931 6


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