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

To assess the accuracy of the respiratory inductive plethysmograph (RIP) during sleep in obese patients with obstructive sleep apnea (OSA), we monitored 13 patients with OSA during wakefulness and nocturnal sleep with simultaneous measurements of tidal volume from RIP and integrated airflow. Patients wore a tightly fitting face mask with pneumotachograph during wakefulness and sleep. Calibrations were performed during wakefulness prior to sleep and compared with subsequent wakeful calibrations at the end of the study. Patients maintained the same posture during sleep (supine, 11; lateral, two) as during calibrations. There were no significant differences in calibrations before sleep and after awakening. The mean error in 13 patients undergoing RIP measurements of tidal volume during wakefulness was -0.7 +/- 3.4 percent while that during sleep was 2.1 +/- 14.9 percent (p < 0.001). The standard deviation (SD) of the differences between individual breaths measured by RIP and integrated airflow was 9.8 +/- 5.5 percent during wakefulness and 25.5 +/- 18.6 percent during sleep (p < 0.001). During both wakefulness and sleep, errors in RIP tidal volume were not significantly correlated with body mass index. In 12 patients with at least 10 percent time in each of stages 1 and 2 sleep, SD was greater in stage 2 sleep compared with wakefulness and stage 1 (p < 0.001). In three patients who manifested all stages of sleep, SD was greater in REM sleep than in wakefulness and all stages of non-REM sleep (p < 0.001). In three patients who manifested all stages of sleep, SD was greater in REM sleep than in wakefulness and all stages of non REM sleep (p < 0.001). This was associated with paradoxic motion of the rib cage in two patients during REM. We conclude that, despite increased errors in individual breath measurements during sleep, more marked during stages 2 and REM sleep, RIP is clinically useful to measure ventilation quantitatively in obese patients with sleep apnea. The criterion of a decrease of 50 percent in tidal volume assessed by RIP is appropriate to define hypopneas in such patients.
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PMID:Accuracy of respiratory inductive plethysmography during wakefulness and sleep in patients with obstructive sleep apnea. 139 58

Nasal continuous positive airway pressure (nCPAP) improved arterial oxygenation in patients with sleep apnoea as well as those with acute pulmonary processes such as Pneumocystis carinii pneumonia. Despite an expanding pool of clinical information, little if any attempt seems to have been made to see whether nCPAP alters ventilatory patterns. The effect of nCPAP was assessed by respiratory inductance plethysmography in 14 healthy males. nCPAP reduced respiratory rate (14.3 +/- 1.47 to 9.7 +/- 1.98, p less than 0.0001) but increased tidal volume (0.483 +/- 0.090 to 0.602 +/- 0.140 l, p = 0.01). Accordingly, minute ventilation decreased (6.91 +/- 1.20 to 5.64 +/- 0.93 l.min-1, p = 0.0002). Duty cycle (TI/TTOT) decreased from 0.43 +/- 0.04 to 0.35 +/- 0.05 s during nCPAP (p less than 0.0001). Mean inspiratory time and mean expiratory time increased with nCPAP (1.79 +/- 0.19 to 2.20 +/- 0.41 and 2.44 +/- 0.38 to 4.27 +/- 1.07 s, respectively, p less than 0.02), but there were no significant changes in mean inspiratory flow rate or partitioning of rib cage and abdominal/diaphragmatic contributions to tidal volume. We conclude that nCPAP effects ventilatory pattern in a manner similar to that described for expiratory threshold loading; that is, by decreasing respiratory frequency and minute ventilation. nCPAP does not appear to stimulate healthy subjects to increase their level of ventilation.
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PMID:Ventilatory effects of nasal continuous positive airway pressure. 219 64

To establish a natural model of sleep-disordered breathing, we investigated respiration during wakefulness and sleep in the English bulldog. This breed is characterized by an abnormal upper airway anatomy, with enlargement of the soft palate and narrowing of the oropharynx. During sleep, the animals had disordered respiration and episodes of O2 desaturation. These were worst in rapid-eye-movement (REM) sleep, with most bulldogs having O2 saturations of less than 90% for prolonged durations. In contrast, control dogs never desaturated. In REM sleep, the bulldogs had episodes of both central and obstructive apnea, the latter being associated with paradoxical movements of the rib cage and abdomen. During wakefulness, the bulldogs were hypersomnolent as evidenced by a shortened sleep latency (mean of 12 min compared with greater than 150 min for controls). This animal model should facilitate studies of the natural history of the sleep apnea syndrome and its complications.
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PMID:The English bulldog: a natural model of sleep-disordered breathing. 369 67

We have evaluated the reliability of the transcutaneous (t.c.) method of measurement of arterial PO2 and PCO2 in adult man. In 33 simultaneous measurements of 9 normals and 12 patients with a wide range of hypoxemia, we found: t.c. PCO2 = 3.62 + 1.29 PaCO2 +/- 7.3 (r = 0.96) and t.c. PO2 = 11.14 + 0.86 PaO2 +/- 9.89 (r = 0.92). Recalculating t.c. PCO2 to 37 degrees C we can obtain: t.c. PCO2 = 2.7 + 0.97 X PaCO2, stating that there is no significant difference between t.c. PCO2 and PaCO2. The t.c. apparatus detects 10 and 90% O2 pressure changes with a delay of time of about 15 s and 1 min, respectively; the t.c. method is therefore not suitable for detecting changes in PaO2 caused by sleep apnea of short duration. On the contrary the t.c. method provided a useful monitoring of arterial PO2 and PCO2 changes during the night in chronic obstructive pulmonary disease (COPD) and non-COPD patients. A nocturnal monitoring of t.c. PO2 and PCO2 seems: (a) absolutely necessary in non-COPD hypoxemics, especially if total lung capacity (TLC) and/or residual volume (RV) are significantly reduced; (b) not absolutely necessary in COPD hypoxemics, provided they have an enlarged TLC and/or a very expanded RV; (c) advisable in intermediate situations, e.g., in COPD hypoxemics with an associated restrictive disorder caused by heart failure, congestion of pulmonary bed, parenchymal or rib cage disease, in order to establish the optimal concentration of oxygen for each patient and to avoid severe nocturnal hypoxemia without producing a dangerous rise in PaCO2.
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PMID:Value of nocturnal monitoring of transcutaneous O2 and CO2 pressures in adults with respiratory failure. 392 61

Patterns of rib cage (RC) and abdomen (ABD) motion obtained from a respiratory inductive plethysmograph were studied during disordered breathing events - obstructive apnea, obstructive hypopnea, mixed apnea, and central apnea - in 54 patients with sleep apnea. The type of disordered breathing event was verified by esophageal pressure and bias-flow mask recordings. Obstructive apnea occurred to a variable extent in all patients and was characterized by stereotyped paradoxical motion of the RC or ABD or both in 49 patients (91%). There was no paradox in 2 patients with "feeble" inspiratory effort during obstructions and in 3 patients with normal inspiratory effort during obstructed breaths. The more obese patients displayed paradox of the ABD rather than of the RC. Paradox did not occur in central apnea or in the central component of mixed apnea. Obstructive hypopnea was characterized by paradox during part of the breath. We conclude that RC and ABD motion can adequately characterize apnea in most patients and thus avoid invasive monitoring techniques that can adversely affect sleep. However, if chest wall motion suggests that all apneas are central, a direct measurement of respiratory effort is necessary to exclude obstruction.
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PMID:Chest wall motion in sleep apnea. 674 13

We present a case of severe breathing abnormality during sleep in a young man who had had poliomyelitis 20 yr before. His sleep disorder led to respiratory failure and cor pulmonale, which were greatly improved by oxygen therapy. A study of this case and those previously described supports the notion that brainstem damage during acute poliomyelitis is important in the later appearance of sleep-disordered breathing. In addition, such patients usually have mechanical abnormalities involving the thoracic cage and respiratory muscles. These ventilatory restrictions amplify the pathophysiologic effects of abnormal central nervous system control of breathing during sleep, and we suggest that their presence has a key role in the development of sleep apnea syndrome in these patients.
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PMID:Sleep apnea syndrome after poliomyelitis. 684 37

Seventeen patients with sleep apnea were studied with reference to the frequency and duration of apneic episodies, the mechanism of the apnea and the extent to which oxygen saturation was depressed by the apnea. In all patients, esophageal pressure was recorded simultaneously with respiratory magnetometer records of rib cage and abdominal motion. Thermistor records from the nose and mouth indicated the presence of apnea. Nine patients had purely obstructive apnea and eight a mixture of central and obstructive apnea. In all instances the magnetometer records alone permitted distinction between obstructive and central apnea. Inspiratory efforts against an occluded airway produced a very different pattern of motion when compared to unobstructed breathing or to central apnea. We propose that magnetometer monitoring of thoracoabdominal motion indicates upper airway obstruction reliably and provides a noninvasive and thus more acceptable alternative to esophageal pressure recording for detecting upper airway obstructive apnea.
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PMID:Use of the respiratory magnetometer in diagnosis and classification of sleep apnea. 735 37

Sleep has a physiological influence on respiration, which can have major adverse effects on gas exchange in patients with respiratory insufficiency. These effects relate largely to a reduction in various stimulant inputs to the brainstem respiratory centre. Conditions that may be associated with sleep-related respiratory insufficiency range from pulmonary disorders (such as chronic obstructive pulmonary disease (COPD)), to central respiratory insufficiency (such as central alveolar hypoventilation), neurological and neuromuscular disorders (such as polio and muscular dystrophy), and thoracic cage disorders (such as kyphoscoliosis). All these conditions have in common the finding of hypoxaemia and hypercapnia, which become more pronounced during sleep. The relative hypoventilation, which is common to each condition, is due to varying combinations of an inadequate respiratory drive and an increase in the work of breathing. Management of respiratory insufficiency during sleep should be directed first at optimizing the underlying disorder, then at correcting hypoxaemia with controlled low-flow supplemental oxygen. Pharmacological therapy may be effective in some instances, but the choice of agent varies with the underlying disorder. Assisted ventilation is an important part of the management of advanced cases, and the recent development of intermittent positive pressure ventilation by nasal mask (NIPPV) has been an important advance in this area. Use of NIPPV during the night is associated with beneficial effects during the day, particularly improved awake gas exchange and respiratory muscle strength, in addition to less dyspnoea and improved quality of life. Electrophrenic pacing of the diaphragm is helpful in highly selected cases, particularly patients with central respiratory insufficiency and high quadriplegia, but is frequently complicated by the development of obstructive sleep apnoea.
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PMID:Impact of sleep in respiratory failure. 915 Mar 36

Twenty patients of interstitial lung disease (ILD) and same number of healthy adults were selected to monitor arterial hemoglobin oxygen saturation (SaO2) breathing pattern and arrhythmias during sleep. The maximum fall in SaO2 during sleep was 13.1% (10-16%) in ILD patients as compared to 4.8% (3-6%) in controls and the difference was significant (p < 0.005). The ILD patients spent 16.9% of mean total sleep time (TST) below 85% SaO2 and 0.7% of mean TST below 80% SaO2 whereas none of the healthy subjects had SaO2 below 90% during sleep. These patients had more disturbed sleep than controls. Abnormally high breathing frequency demonstrated by ILD patients while awake, was not altered during sleep. Both tidal volume (VT) and minute ventilation (Vmin) decreased by 6.6% and 11.5%, respectively in ILD patients during sleep though it was not significant (p > 0.25) statistically. The respiratory drive was declined during sleep in ILD patients. The percent of tidal volume contributed by rib cage (% RC) lessened during sleep in all the subjects. The ratio of the total excursion of the rib cage and abdomen during inspiration without considering the direction of movement, divided by tidal volume (TCD/VT) revealed asynchronous breathing in ILD patients during sleep. Arrhythmias were found in 6 (30%) of ILD patients and 4 (20%) of control subjects. Observed apnea-hypopnea did not qualify for sleep apnea syndrome in any case.
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PMID:Study of oxygen saturation, breathing pattern and arrhythmias in patients of interstitial lung disease during sleep. 935 49

Paradoxical inward rib cage movement in children is quantified by the labored breathing index (LBI) on the respiratory inductive plethysmography. Labored breathing index during rapid eye movement sleep (REMS) in 59 children without obvious sleep disordered breathing (SDB) declined with age, and decreased to the mature low level at 35 months of age. The LBI was also found to reflect well the severity of SDB. Paradoxical inward rib cage movement, which was quantified by LBI, is concluded to be an important finding in diagnosing SDB in child patients.
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PMID:Quantitative analysis of paradoxical inward rib cage movement during sleep in children. 1118 98


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