Daytime sleepiness and polysomnographic variables in sleep apnoea patients.

Excessive daytime sleepiness (EDS) is not invariably present in patients with obstructive sleep apnoea syndrome (OSAS). The aim of the present study was to investigate polysomnographic determinants of EDS in patients with OSAS. EDS was assessed using the Epworth Sleepiness Scale (ESS) and the multiple sleep latency test (MSLT). Patients showed EDS whenever the ESS score was >10 and the MSLT score <5 min. Absence of EDS was defined as having an ESS score of <10 and an MSLT score of >10 min. In total, 23 male patients with EDS (mean+/-sd ESS and MSLT score 17+/-3 and 4+/-1 min, respectively) and 17 without EDS (ESS and MSLT score 5+/-2 and 16+/-3 min, respectively), were studied. Both groups exhibited a similar apnoea/hypopnoea index (62+/-18 versus 60+/-20 events.h(-1)). Patients with EDS exhibited shorter sleep latency (11+/-16 versus 18+/-18 min) and greater sleep efficiency (90+/-7 versus 82+/-13%) than those without EDS. Patients with EDS showed lower oxygenation (lowest arterial oxygen saturation 69+/-12 versus 79+/-8%; mean arterial oxygen saturation 87+/-6 versus 90+/-5%). Sleep stage distribution and arousal index did not differ between the groups. Patients with obstructive sleep apnoea syndrome and excessive daytime sleepiness are characterised by shorter sleep latency, increased sleep efficiency and worse nocturnal oxygenation than those without excessive daytime sleepiness. Nocturnal hypoxaemia can be a major determinant of excessive daytime sleepiness in patients with obstructive sleep apnoea syndrome.     

Daytime sleepiness and EEG spectral analysis in apneic patients before and after treatment with continuous positive airway pressure

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is characterized by recurrent apneas during sleep, resulting in repetitive hypoxemic episodes and interruptions of the normal sleep pattern. A previous study showed EEG slowing (ie, a higher ratio of delta + theta frequencies to alpha + beta frequencies on EEG) during rapid eye movement (REM) sleep and wakefulness in untreated OSAS patients. STUDY AND OBJECTIVES: To determine whether EEG slowing is reversible with continuous positive air pressure (CPAP) treatment and to verify whether the persistence of excessive daytime sleepiness (EDS) is correlated with residual slowing of the EEG. PATIENTS: Ten healthy subjects (9 men and 1 woman) and 14 patients with moderate-to-severe OSAS (13 men and 1 woman) were studied before and after 6 months of treatment with CPAP. RESULTS: Untreated OSAS patients showed EEG slowing in frontal and central cortical regions during both wakefulness and during REM sleep compared to healthy control subjects. This EEG slowing was found to be independent of time spent with arterial oxygen saturation < 90%, severity of OSAS, or mean sleep latency as determined by the multiple sleep latency test. CPAP treatment was found to correct the EEG slowing for both REM sleep and wakefulness. Daytime sleepiness also greatly improved with treatment, but some degree of somnolence remained. CONCLUSION: CPAP treatment was found to correct the EEG slowing that was observed in untreated OSAS patients. Persistent EDS may be related to persistent obesity after CPAP treatment.     

Sleep and daytime sleepiness in upper airway resistance syndrome compared to obstructive sleep apnoea syndrome.

This study has investigated differences in the nocturnal sleep and daytime sleepiness among patients with obstructive sleep apnoea syndrome (OSAS), upper airway resistance (UARS), sleep hypopnoea syndrome, and normal control subjects, using sleep scoring and spectral activity analysis of the electroencephalogram (EEG). Twelve nonobese males with UARS aged 30-60 yrs were recruited. These subjects were strictly matched for age and body mass index with twelve OSAS patients, 12 sleep hypopnoea syndrome patients, and 12 normal controls, all male. Daytime sleepiness was evaluated using the Epworth Sleepiness Scale (ESS) and the Multiple Sleep Latency Test (MSLT). The macrostructure of sleep was determined using international criteria and spectral analysis of the sleep EEG was obtained from a central lead. The sleep macrostructure of OSAS and UARS patients was significantly different from that of controls. These patients were also sleepier during the daytime than controls. Complaints of tiredness and daytime sleepiness, ESS and MSLT scores were similar in the different patient groups. Mild dysmorphia was present in all three patient groups. However, nocturnal sleep was significantly different among the different groups. OSAS patients had significantly more awake time during sleep than the UARS patients. The spectral activity of the total sleep time of the patient groups also differed significantly from that of controls. When the sleep spectral activity of UARS and OSAS patients were compared, OSAS patients had less slow wave sleep activity than UARS patients. UARS patients had a significantly higher absolute power in the 7-9 Hz bandwidth than OSAS patients. The absolute delta power over the different sleep cycles was also different between controls and patients, and between UARS and OSAS patients. There are clear differences in the macrostructure and spectral activity of sleep between upper airway resistance and obstructive sleep apnoea syndrome patients, demonstrated by differences in the cortical activity recorded in the central lead during sleep. Despite these nocturnal sleep differences, the tests of subjective daytime sleepiness are not significantly different.     

Excessive daytime sleepiness in sleep disorders

Excessive daytime sleepiness is a significant public health problem, with prevalence in the community estimated to be as high as 18%. Sleepiness is caused by abnormal sleep quantity or sleep quality. Amongst others, multiple neurological, psychological, cardiac and pulmonary disorders may contribute. Risk factors for excessive sleepiness include obesity, depression, extremes of age and insufficient sleep. In the clinical setting, two of the most commonly encountered causes are obstructive sleep apnoea and periodic limb movement disorder. There is continuing discussion of the mechanisms by which these disorders cause daytime symptoms, with intermittent nocturnal hypoxia, sleep fragmentation and autonomic dysregulation identified as important factors. The increased prevalence of obstructive sleep apnoea in obese subjects does not fully account for the increased rates of daytime sleepiness in this population and there is evidence to suggest that it is caused by metabolic factors and chronic inflammation in obese individuals. Sleepiness is also more common in those reporting symptoms of depression or anxiety disorders and significantly impacts their quality of life. Clinicians should be aware of factors which put their patients at high risk of daytime sleepiness, as it is a debilitating and potentially dangerous symptom with medico-legal implications. Treatment option should address underlying contributors and promote sleep quantity and sleep quality by ensuring good sleep hygiene. However, stimulant medication may be indicated in some cases to allow for more normal daytime functioning.KEY WORDS : Sleep, sleep apnoea, obstructive, nocturnal myoclonus syndrome, obesity, depression     

Determinants of daytime sleepiness in obstructive sleep apnea

To investigate determinants of daytime sleepiness in obstructive sleep apnea syndrome (OSAS), we studied 100 unselected OSAS patients by nocturnal polygraphic recording and the Multiple Sleep Latency Test (MSLT). Data obtained were submitted to three types of analysis. Respiratory disturbance index, oxygen saturation indices, body mass index, and total nocturnal sleep time did not significantly correlate with daytime sleepiness, as measured by the MSLT. Analysis of subgroups based on weight and degree of alertness also showed a nonsignificant correlation with daytime sleepiness. The best predictor of the excessive daytime sleepiness (EDS) frequently found in OSAS patients was the nocturnal polygraphic recording of the sleep disturbances and sleep structure anomalies that reflect the brain's overall dysfunction in OSAS. Understanding why an electroencephalogram arousal response occurs during sleep in association with abnormal breathing and how this response can become blunted may help us to better predict the development of EDS.     

Alternatives to CPAP in the treatment of the obstructive sleep apnea syndrome

The obstructive sleep apnoea syndrome (OSAS) results in excessive daytime sleepiness, impaired quality of life, and is associated with an increased risk of traffic accidents and cardiovascular disease. Nasal continuous positive airway pressure (CPAP), the standard treatment for OSAS provides immediate relief of symptoms and has only minor side effects. Nevertheless, an alternative treatment is needed if CPAP is not feasible for medical or psychological reasons. Removable oral appliances that advance the mandible when fitted to the teeth during sleep also improve nocturnal breathing disturbances, symptoms, quality of life, vigilance and blood pressure in OSAS patients. Their long-term effectiveness and side effects require further study. In morbidly obese patients suffering from OSAS bariatric surgery should be considered as a treatment that reduces obesity and at the same time improves OSAS. In selected patients including those with adeno-tonsillar hypertrophy, and cranio-facial malformations various surgical techniques that enlarge the upper airway may be a treatment option for OSAS.     

Metabolic disturbances in obesity versus sleep apnoea: the importance of visceral obesity and insulin resistance

Obstructive sleep apnoea (OSA) is a very prevalent disorder particularly amongst middle-aged, obese men, although its existence in women as well as in lean individuals is increasingly recognized. Despite the early recognition of the strong association between OSA and obesity, and OSA and cardiovascular problems, sleep apnoea has been treated as a 'local abnormality' of the respiratory track rather than as a 'systemic illness'. In 1997, we first reported that the pro-inflammatory cytokines interleukin (IL)-6 and tumour necrosis factor-alpha (TNF alpha) were elevated in patients with disorders of excessive daytime sleepiness (EDS) and proposed that these cytokines were mediators of daytime sleepiness. Also, we reported a positive correlation between IL-6 or TNF alpha plasma levels and the body mass index (BMI). In subsequent studies, we showed that IL-6, TNF alpha, leptin and insulin levels were elevated in sleep apnoea independently of obesity and that visceral fat, was the primary parameter linked with sleep apnoea. The association of OSA with insulin resistance and diabetes type 2 has been confirmed since then in several epidemiological and clinical studies. Furthermore, our findings that women with polycystic ovary syndrome (PCOS, a condition associated with hyperandrogenism and insulin resistance) were much more likely than controls to have sleep disordered breathing (SDB) and daytime sleepiness support the pathogenetic role of insulin resistance in OSA. Other findings that support the view that sleep apnoea and sleepiness may be manifestations of a serious metabolic disorder, namely the Metabolic or Visceral Obesity Syndrome, include: obesity without sleep apnoea is associated with daytime sleepiness; PCOS and diabetes type 2 are independently associated with EDS after controlling for SDB, obesity and age; and increased prevalence of sleep apnoea in postmenopausal women, with hormonal replacement therapy associated with a significantly reduced risk for OSA. In conclusion, accumulating evidence provides support to our model of the bi-directional, feedforward, pernicious association between sleep apnoea, sleepiness, inflammation and insulin resistance, all promoting atherosclerosis and cardiovascular disease.     

Inflammatory proteins in patients with obstructive sleep apnea with and without daytime sleepiness

Excessive daytime sleepiness (EDS) is one of the most frequent symptoms in patients with obstructive sleep apnea syndrome (OSAS). However, not all patients with OSAS manifest EDS. The aim of this study was to assess whether differential circulatory levels of inflammatory mediators would account for differences in somnolence among patients with OSAS. Patients were prospectively recruited from referral patient cohort to the university hospital sleep center. A total of 50 consecutive patients with OSAS undergoing overnight polysomnography with or without EDS and 20 controls were evaluated. EDS was assessed using the Epworth sleepiness scale (ESS) and the multiple sleep latency test after overnight polysomnography. EDS was defined when the ESS was >10 and the mean sleep latency <10 min. Fasting blood was drawn in the morning after polysomnography. Circulating levels of tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6), intercellular adhesion molecule 1 (ICAM-1), 8-isoprostaglandin F2α (8-iso-PGF2α), and P-selectin were measured with commercially available high sensitivity kits. Although patients with OSAS have elevated levels of ICAM-1, IL-6, and TNFα, there were no statistically significant differences in any of the inflammatory mediators between patients with EDS and without EDS. Emergence of EDS in the context of OSA does not appear to result from the selective increase of any particular somnogenic substance, i.e., TNFα, IL-6, ICAM-1, 8-iso-PGF2α, and P-selectin in the context of sleep-disordered breathing. The work was performed in Hospital Universitario Son Dureta and Kosair Children’s Hospital Research Institute.     

Relationship between serum substance P levels and daytime sleepiness in obstructive sleep apnea syndrome

OBJECTIVE: We hypothesized that intermittent hypoxia might influence serum substance P levels, and that this effect might in turn contribute in excessive daytime sleepiness (EDS) in patients with obstructive sleep apnea syndrome (OSAS). PATIENTS AND METHODS: Fifty-five patients with newly diagnosed OSAS and 15 age-matched nonapneic control subjects were enrolled in this study. Full polysomnography was performed in all patients. Single blood samples were drawn between 8:00 am and 9:00 am after the sleep study. Substance P levels were analyzed with a competitive enzyme immunoassay (substance P EIA kit; Cayman Chemical; Ann Arbor, MI). RESULTS: There were no significant differences in age, gender, body mass index, smoking habit, and snoring between the two groups. Serum substance P levels in the OSAS group were significantly lower than that in the control group (p < 0.0001). Serum substance P levels were positively correlated with rapid eye movement sleep (r = 0.330, p = 0.049) and slow-wave sleep (r = 0.324, p = 0.049) phases. Serum substance P levels were negatively correlated with Epworth sleepiness scale score (r = - 0.253, p = 0.048), number of total apneas during the night (r = - 0.247, p = 0.036), number of respiratory events during the night (r = - 0.266, p = 0.024), apnea-hypopnea index (r = - 0.287, p = 0.015), respiratory arousal index (r = - 0.267, p = 0.026), time spent in apnea and hypopnea (r = - 0.307, p = 0.01), average oxygen desaturation (r = - 0.265, p = 0.026), and oxygen desaturation index (r = - 0.254, p = 0.031). CONCLUSION: We concluded that EDS seen in some of the OSAS patients might be associated with various pathophysiologic mechanisms including substance P levels.     

Afternoon serum-melatonin in sleep disordered breathing

OBJECTIVES: To study afternoon serum-melatonin values in patients with sleep disordered breathing. Melatonin has a strong circadian rhythm with high values during the night-time and low values in the afternoon. Sleep disordered breathing may change the circadian rhythm of melatonin which may have diagnostic implications. SETTING: The Sleep Laboratory, The Department of Internal Medicine, Avesta Hospital, Sweden, and the Department of Anaesthesiology, Glostrup University Hospital, Copenhagen, Denmark. SUBJECTS: We examined 60 consecutive patients admitted for sleep disordered breathing and 10 healthy non snoring controls. The patients underwent a sleep apnoea screening test having a specificity of 100% for the obstructive sleep apnoea syndrome (OSAS) using a combination of static charge sensitive bed and oximetry. Obstructive sleep apnoea syndrome was found in 49 patients, eight patients had borderline sleep disordered breathing (BSDB) and three patients were excluded due to interfering disease. MAIN OUTCOME MEASURES: Patients and controls had an afternoon determination of serum-melatonin. The Epworth Sleepiness Scale was used to score day-time sleepiness. RESULTS: In comparison with normal controls patients suffering from OSAS had significantly higher serum-melatonin levels in the afternoon. However, as a diagnostic test for OSAS in patients with sleep disordered breathing serum-melatonin showed a low sensitivity but a high specificity. The results indicate that breathing disorders during sleep in general affect pineal function. CONCLUSIONS: Sleep disordered breathing seems to disturb pineal function. Determination of afternoon serum-melatonin alone or together with a scoring of daytime sleepiness does not identify OSAS-patients in a heterogeneous population of patients complaining of heavy snoring and excessive daytime sleepiness.     

Obstructive sleep apnoea syndrome: current status

Introduction: Obstructive sleep apnoea syndrome (OSAS) is a prevalent condition that covaries with cardiovascular complications and most likely with arterial hypertension and diabetes mellitus. Objective: The present paper is a review of the current status of OSAS. Results: Definitions and diagnostic criteria as well as known risk factors, prevalence, symptoms, covariance with other diseases and consequences as traffic accidents are described. OSAS is characterised by daytime sleepiness symptoms that range from mild to severe. Risk factors such as anatomical upper airway abnormalities, overweight, smoking, excessive alcohol intake and use of muscle relaxants are related to the development of sleep apnoea. Various diagnostic procedures and treatment modalities are considered. Overnight polysomnography is the reference standard for sleep apnoea recording. Treatment modalities include mechanical [continuous positive airway pressure (CPAP), oral appliances], surgical, pharmacological and ‘conservative’ lifestyle modifications. Finally, Nordic accrediation guidelines for sleep medicine clinics and sleep medicine specialists are described. Conclusion: The diagnosis of OSAS should be performed with a polygraph, and the first‐line treatment of moderate to severe OSAS is CPAP. Lastly, compliance for this treatment should be optimised with regular clinical controls. Please cite this paper as: Berg S. Obstructive sleep apnoea syndrome: current status. The Clinical Respiratory Journal 2008; 2: 197–201.     

A comparative study of patients with chronic obstructive pulmonary disease with and without obstructive sleep apnea syndrome

We aimed to study whether the presence of obstructive sleep apnea syndrome (OSAS) in patients with chronic obstructive pulmonary disease (COPD) led to differences in clinical picture, gas exchange during awake and sleep states and mechanical ventilation, in comparison with patients with COPD alone. We enrolled 48 COPD patients. In 26 (54.1%), OSAS was ruled out (non-OSAS COPD group) by polysomnography, and in 22 (45.8%) associated OSAS was diagnosed (OSAS COPD group). Patients in the OSAS COPD group experienced greater daytime sleepiness and less dyspnea. Body mass index was not significantly difference. The OSAS COPD group had significantly lower daytime PaO2 (66.4 +/- 10.4 mmHg in the OSAS COPD group and 75.5 +/- 11.2 mmHg in the non-OSAS COPD group; p = 0.01); there were no differences in PaCO2.Pimax in the OSAS-COPD group was 70.6 +/- 23.8 cmH2O, a level that was significantly lower than in the non-OSAS COPD group (Pimax 90.5 +/- 26.1 cmH2O; p = 0.04). Patients in the non-OSAS COPD group experienced longer periods of REM sleep. Nighttime saturation parameters were significantly different in the group with OSAS. We conclude that patients with both OSAS and COPD experience greater oximetric changes than those without OSAS, during both sleep and awake states. The deterioration of respiratory muscle pressures in such patients may play an important role in the changes. The groups also present differences in the intensity of some symptoms, such as degree of daytime sleepiness and dyspnea.     

The sleep apnoea syndrome in obesity: risk of sudden death.

A total of 34 severely obese men with a history of heavy snoring and excessive daytime sleepiness indicative of obstructive sleep apnoea syndrome (OSAS) were studied prospectively. Their mean age was 46 years, and mean body mass index was 41.6 kg m-2. During a 4-year follow-up, 15% (5/34) of these subjects died (three cases of acute myocardial infarction and two cases of pulmonary oedema), all of them suddenly and unexpectedly, outside hospital. On autopsy the degree of atherosclerosis was found to be moderate in all cases. In 68% (15/22) of the men a pathological apnoea index (mean value 46 +/- 20) confirmed the OSAS diagnosis. Exercise tests and neurological examinations did not reveal any other causes of daytime sleepiness. Mean blood pressure at rest and during exercise was normal, and mean serum lipid and blood glucose levels were normal. Spirometry revealed intrapulmonary restrictive changes that could not be attributed to the heavy thoracic wall. Compliance was reduced to about 50% of reference values, and the mean pCO2 level (5.8 kPa) was close to the upper reference limit. Blood tests suggested that high alcohol consumption may be an important factor contributing to OSAS. These results demonstrate that morbidly obese men with a history of OSAS have a high risk of sudden cardiovascular death, despite the absence of other conventional risk factors.     

Relationship between quality of life and mood or depression in patients with severe obstructive sleep apnea syndrome

STUDY OBJECTIVES: To assess the quality of life (QOL) in patients with severe obstructive sleep apnea (OSAS), and the relationship between the QOL and severity of OSAS, excessive daytime sleepiness (EDS), and mood. METHODS: Sixty patients with OSAS and 34 normal control subjects were assessed for QOL using the Medical Outcomes Study Short-Form 36 Health Survey questionnaire (SF-36), for EDS using the Epworth sleepiness scale (ESS), and for mood using the Zung self-rated depression scale (SDS). The associations between each domain and the total score on the SF-36 and the baseline characteristics, polysomnographic parameters, ESS score, and SDS score were examined by simple regression analysis and stepwise multiple regression analysis. RESULTS: Six of eight domains and the total score on the SF-36 were significantly lower than those in the control subjects. The ESS and SDS scores were also more impaired in the patients than in the control subjects. There was no relationship between each domain on the SF-36 and the severity of OSAS and ESS score. Five of eight domains and the total score on the SF-36 were significantly correlated with the SDS score. Stepwise multiple regression analysis selected three variables, the SDS score (partial R(2) = 0.505), the lowest arterial oxygen saturation during sleep (partial R(2) = 0.064), and ESS score (partial R(2) = 0.053), as independent factors for predicting the total score on the SF-36. These three variables accounted for 62.2% of the total variance in the total score on SF-36 (R(2) = 0.622, p < 0.0001) CONCLUSIONS: The QOL of patients with severe OSAS was decreased compared with normal control subjects. The QOL of patients was strongly correlated with the depression scale on simple regression analysis. However, EDS score and oxygen desaturation during sleep also affected the QOL, although the magnitude of its effect was small.     

Changes in left ventricular ejection fraction during REM sleep and exercise in chronic obstructive pulmonary disease and sleep apnoea syndrome.

Nine patients, 4 with chronic obstructive pulmonary disease (COPD) and 5 with obstructive sleep apnoea syndrome (OSAS) were monitored during sleep, rest and exercise. Left ventricular ejection fraction (LVEF) was investigated using gated equilibrium 99mtechnetium ventricular scintigraphy during rapid eye movement (REM) sleep, during exercise, and during wakeful rest. Control wakeful rest periods used for comparison with a study state (either REM sleep or exercise) were always selected during the same circadian segment as that state. Myocardial stress thallium-201 scintigraphy was performed during, and 4 h after, exercise, and results were compared to a daytime rest period. Several patients had myocardial hypoperfusion despite a normal electrocardiographic (ECG) treadmill test. During REM sleep, all patients exhibited a significant change in LVEF (greater than 5%) compared to wakefulness. During exercise, 5 subjects increased their LVEF normally (greater than 5%) and 4 (1 COPD, 3 OSAS) decreased it. All patients had a similar change (increase or decrease) during REM and at maximal exercise. Our results suggest that REM sleep in COPD and in OSAS can produce a myocardial stress as great as that produced by exercise. We conclude that REM sleep, like exercise, is a state in which morbidity may become higher and that it may account for mortality in COPD and OSAS patients with compromised myocardial circulation.     

Obstructive sleep apnoea among HIV patients

The development of body weight gain and lipodystrophy due to antiretroviral therapy may lead to disturbances in sleep, particularly the obstructive sleep apnoea (OSA) syndrome. A retrospective review of the medical records of consecutively identified HIV-infected subjects who were diagnosed with OSA by overnight polysomnography between January 1, 2003 and December 31, 2004 was performed. Twelve HIV-infected subjects with OSA confirmed by polysomnography (total apnoea/hypopnoea index > or = 5) were identified. Daytime somnolence, fatigue, and snoring were the most common symptoms identified. Eleven (92%) subjects were overweight/obese, and seven (58%) had lipodystrophy. Eleven (92%) had a neck size > or =40.0 cm. Increased neck circumference, overweight or obese body mass index, and lipodystrophy are therefore potential risk factors for OSA among HIV patients. Clinicians caring for HIV patients with these characteristics should inquire about daytime somnolence, fatigue, and snoring and consider evaluation for a sleep-related disorder such as OSA. Overnight polysomnography can aid in the diagnosis of sleep disturbances.     

Subjective efficacy of nasal CPAP therapy in obstructive sleep apnoea syndrome: a prospective controlled study.

The response to nasal continuous positive airways pressure (nCPAP) of a wide variety of symptoms recognized to be associated with obstructive sleep apnoea syndrome (OSAS) was examined. Fifty-six consecutive patients with OSAS, confirmed by polysomnography (mean (SD) apnoea-hypopnoea index (AHI) 49.6 (22.6) events x h(-1), Epworth score 15.4 (5.0)), were asked to complete paired symptom evaluation questionnaires, before treatment and again after 4 months of nCPAP. The response rate was 80%. A control group of 21 consecutive OSAS patients of similar age, body mass index (BMI), AHI and Epworth score to the treated group but managed with conservative measures, completed the same questionnaires on two occasions, 4 months apart. The nCPAP-treated group showed significant reductions (Wilcoxon matched pairs test) in the symptoms of daytime sleepiness, restless sleep, heartburn, nocturia, enuresis, headache and nocturnal sweating, whereas controls showed no significant changes in these symptoms. There were no changes in BMI, smoking, alcohol consumption or exercise habits in either group. It was concluded that, in addition to improvements in symptoms of daytime sleepiness and restless sleep, a wide range of other symptoms may improve significantly with nasal continuous positive airways pressure therapy.     

Polysomnographic characteristics of daytime sleepiness in obstructive sleep apnea syndrome

Purpose  

The study is intended to explore the nocturnal sleep determinants for excessive daytime sleepiness (EDS) in patients with obstructive sleep apnea syndrome (OSAS).     

阻塞性睡眠呼吸暂停综合征患者睡眠状态下呼吸中枢控制功 …

目的 探讨阻塞性睡眠呼吸暂停综合征（ＯＳＡＳ）患者上气道阻塞与睡眠状态下呼吸中枢控制功能的低下是否有关，方法 通过经鼻气管插管建立鼻咽通气道测定了１６例重度ＯＳＡＳ患者在清楚状态，非快动眼（ＮＲＥＭ）Ｉ＋Ⅱ睡眠期，Ⅲ＋Ⅳ睡眠期，快速眼（ＲＥＭ）睡眠期的口腔阻断压（Ｐ０．１）低氧反应指标（△Ｐ０．１／△ＳａＯ２，△ＶＥ／△ＳａＯ２）及高二氧化碳反应指标（△Ｐ０．１／△ＳａＯ２，△ＶＥ／△ＳａＯ２）。