Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0037315 (sleep apnea)
 8,000 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 32 patients with sleep apnea syndrome (SAS), pulmonary function, blood gases and the ventilatory response to CO2 (CO2 VR) were studied before and 6 months after uvulopalatopharyngoplasty. Nine of the SAS patients had airway obstruction (AO-SAS), defined as FEV1.0 < or = 72% of the predicted value. They had a significantly higher PaCO2, lower PaO2 and a lower CO2 VR than the remaining SAS patients. Preoperatively 4 SAS patients were hypercapnic (PaCO2 > 5.8 kPa) and compared with the normocapnic ones they were more obese; in 3 of them FEV1.0 was < or = 72%. The hypercapnic SAS patients had a significantly lower CO2 VR. The CO2 VR was significantly correlated to AO and the degree of oxygen desaturation during sleep, but not to the number of episodes of apnea and hypopnea nor their length. The VR to CO2 did not predict the postoperative outcome. Postoperatively 2 hypercapnic obese AO-SAS patients showed a large decrease in episodes of apnea and hypopnea and an increase in CO2 VR, and became normocapnic. Other patients showed no consistent changes in CO2 VR postoperatively.
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PMID:Airway obstruction, obesity and CO2 ventilatory responsiveness in the sleep apnea syndrome. 147 13

Voluntary end-expiratory apnoea in a 23-year-old asymptomatic mild hypertensive patient consistently elicited bradyarrhythmias (complete heart block and sinus pause) and sympathetic activation to muscle blood vessels, indicating simultaneous sympathetic and parasympathetic activation during apnoea. The sympathetic bradyarrhythmic response to apnoea was potentiated by hypoxia and eliminated by atropine. Baroreflex activation also attenuated the bradycardic response to apnoea. A 43-year-old hypertensive patient with sleep apnoea also exhibited bradyarrhythmias (sinus arrest for up to 10 s) and a fall in perfusion pressure to less than 50 mmHg during episodes of sleep apnoea. These cardiovascular changes were associated with a reduction in oxygen saturation to levels as low as 35%. Neither patient was on any medication. Simultaneous sympathetic and parasympathetic activation during episodes of apnoea may predispose to cardiovascular catastrophe. These chemoreflex mediated autonomic changes are inhibited by baroreflex activation. We propose that patients with impaired baroreflexes (patients with hypertension or heart failure and premature infants) may be especially susceptible to excessive autonomic responses to chemoreflex stimulation during periods of apnoea. In these patient groups, bradyarrhythmias, hypoxia, hypoperfusion and sympathetic activation during apnoea may predispose to sudden death.
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PMID:Parasympathetic hyperresponsiveness and bradyarrhythmias during apnoea in hypertension. 149 63

Two patients with obstructive sleep apnoea syndrome are reported where the initial presenting complaint was of lingual ulceration. This unusual presentation has not been reported previously. Both patients experienced frequent apnoeic episodes during sleep with a profound fall in the arterial oxygen saturation. It is postulated that the lingual ulceration resulted from repeated trauma to the tongue by the teeth as the patient made violent inspiratory efforts at the termination of an apnoeic episode. The diagnosis of sleep apnoea syndrome was based upon suggestive symptoms of snoring, morning fatigue and day-time somnolence plus a minimum of 15 apnoeic episodes per hour of sleep. The first-line investigations of this condition are available in all district general hospitals and a diagnosis of sleep apnoea syndrome obtained. Referral to a regional sleep study centre may be appropriate prior to the commencement of therapy. Management is predominantly medical, consisting of weight loss and the administration of nocturnal nasal continuous positive airways pressure.
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PMID:Obstructive sleep apnoea syndrome presenting as lingual ulceration. 151 Sep 3

Infants experiencing apparent life-threatening events (ALTE) have been reported to have elevated frequencies of periodic breathing and obstructive apnea when compared to presumably normal control groups. Whether these characteristics extend to the siblings of ALTE infants remains unknown. This study compared, retrospectively, the apnea indices of 13 first-born infants experiencing an ALTE with their subsequent asymptomatic siblings who had undergone polygraphic sleep apnea evaluations (including electrocardiogram, chest wall movements, expired CO2, and transcutaneous pulse oximetry). Gestation, birthweight, age at study, apnea and periodic breathing indices, and oxygen desaturations were compared. Regression analyses revealed that adjustments for gestational and postnatal age eliminated differences in apnea indices. ALTE infants and their subsequent siblings experienced similar rates of apnea. Neither group had elevated rates of prolonged central apneas (greater than 10 seconds duration) or periodic breathing (greater than 5% sleep time). Neither group had subsequent severe apneas. The use of polygraphic study and cardiac/apnea monitors in subsequent siblings of ALTE are unnecessary and should be considered only when there is parental disagreement.
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PMID:Apnea in subsequent asymptomatic siblings of infants who had an apparent life-threatening event. 152 29

The usefulness of a 40-min per trial version of the maintenance of wakefulness test was assessed in 322 patients with obstructive sleep apnea. This test is a variant of the multiple sleep latency test in which patients are asked to remain awake in a quiet darkened room, and then monitored for electroencephalographic sleep onset. The four trials of the test are each stopped after 40 min. The mean sleep latency for all patients was 26.0 +/- 11.8 (SD) min. In a group of 24 patients who underwent treatment with nasal continuous positive airway pressure, the mean sleep latency increased from 18.0 +/- 12.3 to 31.9 +/- 10.4. The strongest nocturnal correlates of the MWT sleep latency were respiratory arousal index (r = -.35), mean oxygen saturation (r = .30), and weight/height ratio (r = -.25). These correlations were comparable to other studies using the MSLT. There were strong intercorrelations among the variables. In the more severe groups, measures of hypoxemia were more strongly correlated with MWT sleep latency. A two-factor analysis of variance using respiratory arousal index and several measures of oxyhemoglobin saturation indicated that both arousals from sleep and degree of hypoxemia contribute interactively to daytime dysfunction in patients with sleep apnea. The MWT appears useful in evaluating disability from daytime sleepiness.
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PMID:Maintenance of wakefulness test in obstructive sleep apnea syndrome. 155 55

In order to assess the complications of sleep apnea, we have reviewed a data base of 619 consecutive admissions to a university sleep disorders center. Although patients with obstructive sleep apnea (OSA) described more subjective sleepiness than patients with central sleep apnea (CSA) or primary snoring (PS), the multiple sleep latency test (MSLT) indicated similar levels of physiologic sleepiness in the two apneic groups, which was greater than among those with PS. There was no significant relationship between individual subjective estimates of habitual sleepiness and the MSLT values. Among the OSA patients the mean minimum arterial oxygen desaturation during REM sleep accounted for 65 percent of the variance of the mean sleep latency on the MSLT, with an additional, smaller, contribution of the disordered breathing rate per hour. Subjective reports of sleepiness were associated with sleep efficiency and the number of disordered breathing events in NREM sleep. Patients with OSA or CSA had similar diastolic blood pressures and frequencies of history of treatment for hypertension, which were significantly higher in OSA than in the PS group. In the OSA group the absolute minimum arterial oxygen desaturation during NREM sleep was the most significant contributor to waking diastolic blood pressure, with an additional small contribution by weight. A history of treatment for hypertension was most strongly associated with weight, without significant additional contributions by measures of disordered breathing events or oxygen desaturation; however, weight was highly intercorrelated with measures of the apnea/hypopnea index and minimum arterial oxygen desaturation. In summary, these data support recent findings which show a close relation of obesity to a history of hypertension in OSA, and extend to this group a previous observation that in regular heavy snorers, there may be a disparity between levels of physiologic and subjective sleepiness.
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PMID:Sleepiness and hypertension in obstructive sleep apnea. 155 54

The effect of transtracheal oxygen administration by means of a 9-French (2.7 mm) percutaneous catheter was assessed in five patients with severe obstructive sleep apnea. We hypothesized that the delivery of oxygen below the site of airway obstruction should reduce the arterial oxygen desaturation during apneas and hypopneas, thereby increasing respiratory stability. Standard sleep and respiratory measurements were recorded in these subjects with all-night polysomnography on nonconsecutive nights during four experimental conditions: room air (BL), nasal continuous positive airway pressure (CPAP), nasal O2 (NC O2), and transtracheal O2 (TT O2). In three of these subjects, room air was infused (TT RA) at flow rates comparable to TT O2. Compared with baseline room air measurements, TT O2 not only significantly increased the SaO2 nadir from 70.4 percent to 89.7 percent (p less than 0.01), but it also reduced the frequency of sleep apnea/hypopnea from 64.6 to 26.2/h sleep (p less than 0.01). NC O2 ameliorated desaturation during apnea/hypopnea (mean SaO2 nadir, 86.2 percent; p less than .01) but did not significantly alter frequency (59.0/h sleep). Nasal CPAP was the most effective means of reducing sleep apnea/hypopnea (13.8/h sleep) but did not abolish desaturations when apneas occurred (mean SaO2 nadir, 80.0 percent). Compared with oxygen, transtracheal infusion of room air appeared to be somewhat effective; however, the small number of studies with TT RA precluded statistical analysis. We believe that TT O2 is superior to NC O2 for some patients with obstructive sleep apnea because continuous oxygen flow below the site of airway obstruction more reliably prevents alveolar hypoxia and respiration is stabilized. Infusion of air or oxygen through the tracheal catheter flow may also increase mean airway pressure and reduce obstructive apnea similar to nasal CPAP. We conclude that TT O2 may be an effective alternative mode of therapy for some patients with severe sleep apnea/hypopnea when nasal CPAP is not tolerated or when combined oxygen and nasal CPAP are required.
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PMID:Transtracheal oxygen, nasal CPAP and nasal oxygen in five patients with obstructive sleep apnea. 158 76

A polysomnographic study was undertaken in nine patients with unexplained polycythaemia and nine age- and sex-matched controls. Circulating plasma levels of immunoreactive erythropoietin (IrEPO) were analysed before and after sleep. Seven out of nine polycythaemia patients were found to have sleep-disordered breathing and fulfilled the criteria for the sleep apnoea syndrome. Erythrocyte volume fraction was by definition higher among polycythaemia patients, and showed a weak positive correlation with minimum oxygen saturation during sleep (P less than 0.05). However, plasma IrEPO did not differ between the two groups or between morning and evening samples within the respective groups. In a separate study, IrEPO was repeatedly analysed during sleep in a group of six patients with severe obstructive sleep apnoea and six matched controls. No correlation with severity of sleep-disordered breathing was found. None of these patients had polycythaemia, and there was no obvious diurnal variation in IrEPO levels. A nocturnal sleep study may be warranted in patients with unexplained polycythaemia. Obstructive sleep apnoea does not appear to be related to increased IrEPO levels, although polycythaemia has been reported as a relatively common finding in this disease.
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PMID:Secondary polycythaemia associated with nocturnal apnoea--a relationship not mediated by erythropoietin? 158 63

An association between chronic high blood pressure and obstructive sleep apnea has been described. We hypothesized that repetitive episodic hypoxia patterned after the hypoxia seen in sleep apnea could contribute to diurnal elevation of blood pressure. Using 12-second infusions of nitrogen into daytime sleeping chambers, four groups of male rats (250-375 g) were subjected to intermittent hypoxia (3-5% nadir ambient oxygen) every 30 seconds, 7 hours per day for up to 35 days. In one group, blood pressure was measured weekly by the tail-cuff method in conscious animals during 5 weeks of episodic hypoxia. In the other three groups, blood pressure was measured in conscious animals via femoral artery catheters at baseline and after 20, 30, or 35 days of exposure. Additional groups served as controls: two sham groups housed in identical "hypoxia" chambers received compressed air instead of nitrogen (35 days) while two other groups remained unhandled in their usual cages (35 days). Both groups challenged with 35 days episodic hypoxia showed significant increases in blood pressure compared with controls: the tail-cuff rats showed a 21 mm Hg increase in systolic pressure (p less than 0.05) and the intra-arterially measured rats a 13.7 mm Hg increase in mean arterial pressure (p less than 0.05). The 30-day exposed rats also showed a 5.7 mm Hg increase in mean pressure over baseline (p less than 0.05). Blood pressure did not change significantly from baseline in the control groups. Left ventricle-to-body weight ratio was higher in both 35-day exposed groups than in unhandled or sham controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Repetitive, episodic hypoxia causes diurnal elevation of blood pressure in rats. 159 51

The authors review the literature on the oculo-mandibulo-facial syndrome and present the case of a six-year-old boy with congenital cataracts, microphthalmos, nystagmus, failure to thrive, dysmorphic features with a tiny pinched nose, mandibular hypoplasia, microstomia, double chin, chronic snoring, recurrent respiratory infections and dental problems. Chronic obstructive sleep apnoea with decreased oxygen saturation was present. Optimal medical management of OMFS-patients is described.
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PMID:A new look at the management of the oculo-mandibulo-facial syndrome. 159 91


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