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

In summary, the evaluation of the tired patient requires an awareness of the various meanings of tiredness. Furthermore, it is important to differentiate normal sleepiness that is a product of circadian rhythm variation in vigilance from pathologic sleepiness. Sleepiness that results from faulty habits, e.g., altered sleep scheduling, drugs, or sleep restriction, can be readily discerned with the aid of a sleep-wake diary. Because subjective sleepiness is often unappreciated, especially in patients with sleep apnea, methods that rely on self-ratings of the severity of sleepiness, e.g., visual analogue scale, 10-cm line, or SSS may not coincide with performance tasks, observer assessments, or such physiologic methods as the MSLT. Less commonly employed neurophysiologic methods include pupillometry and averaged evoked potentials. On the other hand, the MSLT is commonly used for the detection of physiologic sleepiness. Moreover, it is helpful in evaluating response to treatment. A variation of the MSLT, the MWT, which instructs the individual to remain awake, does not discriminate between sleep onset times for wakefulness and the MSLT for sleepiness in normal subjects. The MWT may be useful for the assessment of treatment responses for excessive daytime sleepiness, e.g., narcolepsy, and for determining the frequency of daytime sleep episodes. The differences that have been observed between behavioral measures and physiologic measures of sleepiness suggest that these techniques assess different aspects of sleepiness. HLA typing (DR2, DQw1) has been shown to be a useful method for corroborating narcolepsy-cataplexy, but the antigens are neither specific for the disorder nor for sleepiness alone.
Clin Chest Med 1992 Sep
PMID:Evaluation of daytime sleepiness. 152 10

Patients with untreated obstructive sleep apnea have poorer driving performance than patients without sleep apnea. This poor driving has been demonstrated by studies on a wide variety of driving simulators. Patients with sleep apnea show a significant improvement in driving performance after successful treatment of their apnea with nasal CPAP. After treatment with CPAP, their driving performance is similar to control subjects. Several studies show that patients with untreated sleep apnea are poor drivers and have two to three times more auto accidents than other drivers. These studies reveal that almost one quarter of these patients report frequently falling asleep while driving. Patients with severe sleep apnea or those who perform poorly on driving simulators may be at highest risk of auto accidents. Automobile accidents involving patients with sleep apnea may lead to severe injury or death. Patients, individual physicians, and the medical profession have responsibilities to help prevent these accidents. Finally, more study is needed to improve patient care, protect drivers, and formulate a fair and rational policy concerning drivers with sleep apnea.
Clin Chest Med 1992 Sep
PMID:Driving performance and automobile accidents in patients with sleep apnea. 152 11

Obstructive sleep apnea may contribute to the development of pulmonary hypertension and RVF primarily through pulmonary vasoconstriction secondary to hypoxia. Several recent studies indicate, however, that intermittent apnea-related hypoxia is not sufficient to cause sustained pulmonary hypertension. These studies have been consistent in showing that pulmonary hypertension and RVF are almost invariably seen in the presence of diurnal hypoxia. Sustained pulmonary hypertension, therefore, appears to be associated with sustained hypoxia as is the case in COPD. Patients with OSA who have hypoxia while awake are, as a rule, obese and have mild-to-moderate diffuse obstructive airways disease. Thus, most cases of pulmonary hypertension in association with OSA result from a combination of OSA, obesity, and diffuse obstructive airways disease, a so-called overlap syndrome. However, from the therapeutic viewpoint, it is apparent that treatment of OSA by NCPAP or tracheostomy, in such cases, is usually sufficient to reverse pulmonary hypertension and RVF. More recent work has provided strong evidence that OSA can play a role in the pathogenesis of LV heart failure in patients with CHF of otherwise unknown etiology. It is likely that this occurs through a combination of increased LV afterload related to exaggerated negative Pit swings during obstructive apneas, to intermittent hypoxia, and to chronically elevated sympathoadrenal activity. Reversal of OSA by NCPAP in these patients may relieve LV heart failure. These findings add a new dimension to our understanding of the pathophysiologic effects of OSA on the cardiovascular system by demonstrating that the LV is a structure that may suffer functional impairment secondary to the stresses imposed by OSA. Finally, it has now become apparent that CSR in patients with CHF can cause symptoms of a sleep apnea syndrome when associated with intermittent hypoxia and arousals from sleep. Reversal of CSR during sleep by NCPAP can lead to alleviation of these symptoms and possibly to reduced cardiac dyspnea and LV systolic function as well. Taken together, this suggests that much more extensive use of polysomnography may be warranted in the investigation of cardiovascular disease. The reasons are compelling: sleep apnea disorders are common and eminently treatable conditions whose reversal can result in improved right and left heart function and symptomatic improvement in patients with impaired myocardial function.
Clin Chest Med 1992 Sep
PMID:Right and left ventricular functional impairment and sleep apnea. 152 13

Acromegaly is an uncommon disorder and may present in a variety of ways, leading to considerable delay in diagnosis. Unlike other pituitary tumors, tumors associated with acromegaly tend to be fairly large in most patients. Thus, symptoms may be commonly due to the tumor mass as well as to hormone oversecretion. Mortality is two- to threefold increased due to cardiovascular, respiratory, and neoplastic causes. An increase in diabetes mellitus and hypertension may contribute to the first of these. Early treatment may reverse the diabetes, soft tissue changes, sleep apnea, cardiovascular disease, and neuromuscular disease. The effect of early treatment on neoplasia is unclear, and patients probably should continue to be screened, especially for colon neoplasia, even after appropriate therapy for the acromegaly. Hypopituitarism may be present initially as a result of tumor mass but may also develop as a result of ablative therapy.
Endocrinol Metab Clin North Am 1992 Sep
PMID:Clinical manifestations of acromegaly. 152 14

To investigate the temporal organization of EEG sleep activity in the second and minute ranges we developed a method which, based on Fourier transformation, allows the presentation of periodic oscillations of spectral power and coherence. The application of this method is demonstrated in 3 subjects with different types of alpha activity during sleep: (a) alpha-sleep pattern (a physiological variant of NREM sleep activity); (b) abnormally increased arousal alpha activity. The results show that differences in the temporal organization of these alpha activities can be determined with the following parameters: period length, duration of sequences with periodic activity, number and rate of these sequences, and proportion of periodicities generated simultaneously in the left and right hemispheres. The physiologically modulated periodicities of the alpha-sleep pattern are contrary to a stereotyped 40-60 sec periodicity of abnormal arousal alpha activity. Such abnormal periodicity corresponds to periodicities occurring in association with other sleep disturbances, such as sleep apnea or periodic movements in sleep. Periodicity analysis gives additional criteria for a more refined evaluation of normal as well as abnormal sleep structure.
Electroencephalogr Clin Neurophysiol 1990 Sep
PMID:Periodicity analysis of sleep EEG in the second and minute ranges--example of application in different alpha activities in sleep. 169 54

Children, who were tonsillectomized because of sleep apnea were examined with respect to facial growth and dental arch morphology. Dental casts and lateral roentgencephalograms were analysed before surgery and two years after tonsillectomy. The findings were compared to data from children without tonsillary obstruction. A higher proportion of malocclusion than normal, especially open bite and crossbite, was noticed before surgery. Two years after surgery, 77% of the open bites were normalised and 50-65% of the buccal and anterior crossbites. The best results were seen in children operated before the age of 6.
Int J Pediatr Otorhinolaryngol 1991 Sep
PMID:The influence of tonsillar obstruction and tonsillectomy on facial growth and dental arch morphology. 174 73

Sleep disorders, including a high incidence of sleep apnea, have been recognized as a significant problem in chronic renal failure (CRF) patients. In a preliminary study, we examined CRF patients on maintenance hemodialysis for three nights; one control night, and thereafter randomized to infusion of saline (placebo) for one night and 4% branch-chain amino acid (BCAA) solution for one night. Polysomnographic and respiratory data [respiratory rate, oxygen saturation and end-tidal CO2 (ETCO2)] was recorded continuously throughout the nights and data from each hour compared with baseline (awake) values. The patients studied were characterized by reduced sleep quality and decreased amount of rapid eye movement (REM) sleep. The BCAA infusion was associated with a return of REM sleep to normal and a significant decrease in ETCO2 during both REM and non-REM sleep (P less than 0.05). Our findings demonstrate respiratory stimulation during sleep with infusion of BCAA; this stimulatory effect on respiration (in contrast to many respiratory stimulants) is associated with an increased amount of REM sleep.
Kidney Int 1991 Sep
PMID:Branched-chain amino acid in chronic renal failure patients: respiratory and sleep effects. 178 51

Previous investigators have demonstrated in patients with obstructive sleep apnea that weight reduction results in a decrease in apnea severity. Although the mechanism for this decrease is not clear, we hypothesize that decreases in upper airway collapsibility account for decreases in apnea severity with weight loss. To determine whether weight loss causes decreases in collapsibility, we measured the upper airway critical pressure (Pcrit) before and after a 17.4 +/- 3.4% (mean +/- SD) reduction in body mass index in 13 patients with obstructive sleep apnea. Thirteen weight-stable control subjects matched for age, body mass index, gender (all men), and non-REM disordered breathing rate (DBR) also were studied before and after usual care intervention. During non-REM sleep, maximal inspiratory airflow was measured by varying the level of nasal pressure and Pcrit was determined by the level of nasal pressure below which maximal inspiratory airflow ceased. In the weight loss group, a significant decrease in DBR from 83.3 +/- 31.0 to 32.5 +/- 35.9 episodes/h and in Pcrit from 3.1 +/- 4.2 to -2.4 +/- 4.4 cm H2O (p less than 0.00001) was demonstrated. Moreover, decreases in Pcrit were associated with nearly complete elimination of apnea in each patient whose Pcrit fell below -4 cm H2O. In contrast, no significant change in DBR and a minimal reduction in Pcrit from 5.2 +/- 2.3 to 4.2 +/- 1.8 cm H2O (p = 0.031) was observed in the "usual care" group. We conclude that (1) weight loss is associated with decreases in upper airway collapsibility in obstructive sleep apnea, and that (2) the resolution of sleep apnea depends on the absolute level to which Pcrit falls.
Am Rev Respir Dis 1991 Sep
PMID:Effect of weight loss on upper airway collapsibility in obstructive sleep apnea. 189 85

Chubby Puffer syndrome produces symptoms such as sleep apnea, cor pulmonale and upper airway obstruction due to adenotonsillar enlargement. We gave anesthesia for adenotonsillectomy in a 6-year-old boy with this syndrome. The child was massively obese. Anesthesia was induced with thiamylal, nitrous oxide and enflurane by monitoring SaO2. Tracheostomy was performed following orotracheal intubation because of possible difficult postoperative course. At the beginning of operation arterial blood studies showed hypoxemia. Positive end-expiratory pressure ventilation was effective to improve oxygenation. After adenotonsillectomy the symptoms were relieved.
Masui 1991 Sep
PMID:[Anesthetic management of a patient with Chubby Puffer syndrome]. 194 17

Obstructive sleep apnoea is a common disorder in western societies and has a strong association with obesity and alcohol use. The condition has not previously been recorded in Papua New Guinea. The clinical details of 2 patients from Papua New Guinea with obstructive sleep apnoea are described, and the principles of treatment of this condition are outlined. Sleep apnoea is likely to become an increasing problem in Papua New Guinea.
P N G Med J 1990 Sep
PMID:Obstructive sleep apnoea: a new disease for Papua New Guinea? 208 Jun 74


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