The role of mean inspiratory effort on daytime sleepiness.

This study has investigated the role of average maximum inspiratory effort in excessive daytime sleepiness in patients with obstructive sleep apnoea syndrome (OSAS) and upper airway resistance syndrome (UARS). Fifteen patients diagnosed with UARS and 32 patients with OSAS, with >5.5 h total sleep time (TST) during 8 h of nocturnal polygraphic recordings, were included in the study. Demographical data, polysomnographical data and data about daytime sleepiness, including Epworth sleepiness scale (ESS) and multiple sleep latency test (MSLT), were evaluated. In order to compute the average maximum inspiratory effort from oesophageal pressure (Poes) measurements, maximum Poes was obtained from 20 representative obstructive respiratory events (obstructive apnoeas, hypopnoeas or flow limitations) for each sleep stage in both supine and side positions. From Poes measurements during sleep, the increase in Poes (deltaPoes) during respiratory events was also calculated. The average maximum Poes, deltaPoes, respiratory disturbance index (RDI) and arousal index were significantly correlated with ESS in OSAS patients. In patients with UARS, the only significant correlation was obtained between average maximum Poes and ESS. The MSLT score did not show any significant correlation with arousal index, number of stage variations, RDI, average Poes, deltaPoes, minimum oxygen saturation (Sa,O2) and percentage of TST with an Sa,O2 <90% in both UARS and OSAS patients. The results of multiple regression analysis showed that average maximum Poes correlates best with the variance in ESS for OSAS patients. In conclusion, the data from this study indicate the possible important role of average inspiratory effort in determining subjective sleepiness in both obstructive sleep apnoea syndrome and upper airway resistance syndrome patients.     

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.     

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.     

Low sleep quality and daytime sleepiness in obese patients without obstructive sleep apnoea syndrome

OBJECTIVES: To evaluate sleep quality, sleep-related symptoms, and degree of excessive daytime sleepiness (EDS) in severe obesity, independently of obstructive sleep apnoea syndrome (OSAS). DESIGN: A cross-sectional study. SETTING: Primary-care setting. SUBJECTS, MAIN OUTCOME MEASURES: Anthropometric parameters, respiratory function data and sleep related symptoms were evaluated in 78 severely obese patients (aged 16-75 years) without OSAS and in 40 healthy sex- and age-matched normal weight subjects, who underwent a full-night polysomnography. RESULTS: Obese patients and control subjects had similar sleep latency and rapid eye movement (REM) latency, but they showed lower percentage of REM (P < 0.01) and sleep efficiency (P < 0.05) than controls. All sleep-related symptoms (observed or reported apnoea, awakenings, choking and unrefreshing sleep) were significantly more frequent in obese patients than in control subjects. Loud snoring was present in 46.7% of the obese patients and in 8.1% of the control individuals (P < 0.01). Excess daytime sleepiness was reported by 34.7% of the obese patients and by 2.7% of the normal weight subjects (P < 0.01). The Epworth Sleepiness Scale (ESS) was higher in the obese group than in the control group (P < 0.01), whereas arousals were not different between the two groups. CONCLUSIONS: This study clearly shows that severe obesity, even in the absence of OSAS, is associated with sleep-related disorders and EDS. All these alterations may be partly responsible for a lower quality of life, a higher prevalence of medical complications, an increased risk of occupational injury, and both social and family problems characterizing obese patients, independently of the presence of OSAS.     

老年心血管疾病患者阻塞性睡眠呼吸暂停综合征的评价

目的 评价老年心血管疾病患者阻塞性睡眠呼吸暂停综合征(OSAS)的患病情况和特点,为临床决策提供参考. 方法 采用便携式睡眠监测仪对入住在老年心内科的患者,进行睡眠呼吸监测,了解其阻塞性睡眠呼吸暂停(OSA)的患病情况. 结果 共监测了317例老年心血管疾病患者的夜间睡眠呼吸紊乱情况,得出符合OSA[睡眠呼吸紊乱指数(AHI)≥5]的有281例,占88.6%;符合阻塞性睡眠呼吸暂停综合征(OSAS)[AHI≥5,Epworth量表(ESS)≥9分]的有47例,占14.8%.多元回归分析结果 提示,以OSA严重程度作为因变量,对它影响有显著性意义的是最低血氧饱和度和血氧饱和度下降指数(简称氧减指数),而年龄、习惯性打鼾、嗜睡评分、体质指数(BMI)、血氧饱和度平均值和低于90%的时间对其影响无显著性意义. 结论 老年心血管疾病患者中OSAS具有高的患病率,而且无白天嗜睡症状的OSA的老年人患病率更高.对睡眠呼吸暂停严重程度的独立预测因子是最低血氧饱和度氧减指数,而老年人的年龄、BMI、是否经常打鼾、是否白天嗜睡与OSA的严重程度关系不密切.     

Predictors of objective level of daytime sleepiness in patients with sleep-related breathing disorders

Excessive daytime sleepiness, the most prevalent symptom associated with the OSAS, is hypothesized to result from either fragmentation of sleep or hypoxemia during sleep. Measures of nocturnal sleep, respiration during sleep, and daytime sleepiness in 466 patients with apnea were collected to evaluate these two hypotheses. The various parameters were submitted to correlation and multiple regression analyses to predict daytime sleepiness as measured by the MSLT. The RAI, which measures the number of arousals from sleep associated with respiratory disturbances (best fragmentation correlation), produced a higher correlation with MSLT scores than did TMES (best hypoxemia correlation); however, the measures were highly intercorrelated, and multiple regression analyses to determine which parameters independently predicted MSLT showed the single best predictor to be the RAI. Additional independent variance in MSLT score was explained by TST and PSG1. Measures of hypoxemia provided little or no independent predictive information. These data support the hypothesis that sleep fragmentation is an important determinant of daytime sleepiness in patients with apnea.     

Hypoxemia vs sleep fragmentation as cause of excessive daytime sleepiness in obstructive sleep apnea

To determine the effects of intermittent hypoxemia on daytime sleepiness in the clinical setting of obstructive sleep apnea syndrome, we enrolled seven patients in a prospective, randomized, crossover study. We had two experimental conditions with NCPAP treatment as follow: (1) to correct apneas, sleep fragmentation, and hypoxemia; and (2) to correct apneas and sleep fragmentation and at the same time, induce intermittent hypoxemia. The outcome variable, daytime sleepiness, was measured objectively with the multiple sleep latency test following completion of baseline and each treatment condition. Compared with sleep latencies in the untreated condition, both experimental treatment arms prolonged sleep latencies (p less than 0.05). We found no statistically significant differences between mean MSLT scores obtained after NCPAP treatment under hypoxemic and nonhypoxemic conditions. In summary, two nights of intermittent nocturnal hypoxemia during NCPAP treatment for OSAS did not diminish the objective improvement in daytime somnolence seen with NCPAP treatment in the absence of nocturnal hypoxemia. Results lend further support to the hypothesis relating excessive daytime sleepiness to sleep fragmentation.     

The sleep apnoea/hypopnoea syndrome depresses waking vagal tone independent of sympathetic activation.

The modest daytime hypertension and sympathetic upregulation associated with the sleep apnoea/hypopnoea syndrome (SAHS), does not explain the relatively large increased risk of cardiac morbidity and mortality in the SAHS patients population. Therefore, efferent vagal and sympathetic activity was evaluated during wakefulness in SAHS subjects and matched healthy controls, in order to determine if vagal downregulation may play a role in the aetiology of cardiac disease in the SAHS. The awake autonomic nervous system function of 15 male subjects, with mild-to-moderate SAHS was compared to that of 14 healthy controls matched for age, body mass index, gender and blood pressure. All subjects were free from comorbidity. Vagal activity was estimated from measurements of heart rate variability high frequency power (HF) and sympathetic activity was measured from urine catecholamine excretion. The %HF power was significantly (p < 0.03) reduced in SAHS patients (10+/-1.6 (mean+/-SEM)) as compared to controls (17 +/- 3). In addition, HF power correlated with the apnoea/hypopnoea index in the SAHS subjects (R = -0.592, p = 0.02). There was no statistically significant difference in the daytime excretion of nonadrenaline between control (242 +/- 30 nmol x collection(-1)) and SAHS (316 +/- 46 nmol x collection(-1)) subjects (p = 0.38). In these sleep apnoea/hypopnoea syndrome patients there was limited evidence of increased waking levels of urine catecholamines. The principal component altering waking autonomic nervous system function, in the sleep apnoea/hypopnoea syndrome subjects, was a reduced daytime efferent vagal tone.     

The impact of ageing and sex on the association between sleepiness and sleep disordered breathing

The aim of our study was to investigate age-related changes in sleepiness symptoms associated with sleep disordered breathing (SDB). Wisconsin Sleep Cohort participants were assessed using polysomnography, the Epworth Sleepiness Scale (ESS) and the multiple sleep latency test (MSLT). SDB was defined as an apnoea/hypopnoea index ≥15 events·h(-1), and sleepiness as ESS ≥10 and MSLT ≤5 min. Odds ratios were calculated using generalised estimating equations associating sleepiness with SDB, and conditional logistic regression examining changes in longitudinal sleepiness status (ESS only). Models were a priori stratified by sex. ESS was measured in 1,281 participants and MSLT in 998 at multiple time-points (ESS n=3,695; MSLT n=1,846). Significant interactions were found between SDB and age in males, but not females. The odds ratios modelled for sleepiness in a 40-yr-old male with SDB were significant compared to a male without SDB (ESS 2.1 and MSLT 2.9); however, these associations were not significant at 60 yrs of age. The within-subject odds ratio for sleepiness was also significant at 40 yrs of age (OR 3.4), but not at 60 yrs of age. The age-related reductions in the association between sleepiness and SDB may have clinical implications for the diagnosis and treatment of SDB in older people as sleepiness is often used as a therapeutic target.     

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.     

Frequency and mechanism of daytime pulmonary hypertension in patients with obstructive sleep apnoea syndrome

In order to study the frequency and the mechanisms of daytime pulmonary hypertension (PH) in obstructive sleep apnoea syndrome (OSAS) lung function tests, blood gas analysis and right-heart catheterization were performed in 46 consecutive patients. OSAS was assessed by polysomnography. 9 patients only (20%) had PH (mean pulmonary artery pressure (Ppa) greater than or equal to 20 mmHg). Patients with PH had lower daytime PaO2 (60.8 +/- 7.6 vs. 76.2 +/- 9.4 mmHg; p less than 0.001), higher daytime PaCO2 (44.8 +/- 4.2 vs. 38.0 +/- 4.0 mmHg; p less than 0.001), lower forced vital capacity (FVC) and forced expiratory volume (FEV1) (p less than 0.001), but the severity of OSAS was not different whether PH was present or not (apnoea index: 62 +/- 34 hour in the PH group vs. 65 +/- 40 hour, apnoea + hypopnoea index 102 +/- 33 hour in the PH group vs. 86 +/- 36 hour, lowest sleep SaO2: 59 +/- 21% in the PH group vs. 66 +/- 18%). There were significant correlations between Ppa and: daytime PaO2 (r = -0.61; p less than 0.001), PaCO2 (r = 0.55; p less than 0.001), FEV1 (r = -0.52; p less than 0.001) but not between Ppa and apnoea index, apnoea + hypopnoea index, lowest sleep SaO2. PH and daytime hypoxaemia were associated either with chronic airway obstruction or with severe obesity.     

Performance vigilance task and sleepiness in patients with sleep-disordered breathing.

Altered vigilance performance has been documented in patients with sleep-related breathing disorders (SRBDs). Sleep fragmentation, sleepiness, respiratory disturbances and nocturnal hypoxaemia have been suggested as the pathogenesis of these deficits, yet it remains difficult to find a good correlation between performance deficits and the above factors. In the present study, which performance measure better characterised SRBD patients and the main factors implicated in these disturbances were examined. The study group consisted of 152 patients and 45 controls, all examined using a performance vigilance task and subjective sleepiness assessment. Speed and accuracy in the psychomotor vigilance task (PVT) were measured in patients and controls. Objective daytime sleepiness was assessed in the patient group using the maintenance of wakefulness test. In comparison with controls, PVT accuracy rather than speed seems to be affected in SRBD patients, with lapses and false responses significantly greater in patients with more severe objective sleepiness and higher apnoea/hypopnoea index. Although slowing and increased variability in reaction time were associated with shorter sleep latency in the maintenance of wakefulness test, subjective sleepiness, sleep fragmentation, nocturnal hypoxaemia and apnoea/hypopnoea index influenced mainly PVT accuracy. It is concluded that vigilance impairment, sleep fragmentation and severity of disease may partially and differentially contribute to the diurnal performance consequences found in sleep-related breathing disorders. Since the psychomotor vigilance task worsening is more marked in accuracy that in speed, measurement of lapses and false responses would better characterise the degree of diurnal impairment in these patients.     

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.     

Assessment of excessive day-time sleepiness in professional drivers with suspected obstructive sleep apnea syndrome

Excessive daytime sleepiness is a common symptom of obstructive sleep apnea syndrome (OSAS) and can be a cause of traffic accidents, creating a problem of particular importance for professional drivers given the associated death, disability and professional repercussions. We assessed whether the Epworth sleepiness scale (ESS), which is a subjective measure of daytime sleepiness, correlates well with multiple sleep latency (MSL) testing, which gives an objective measure of daytime sleepiness. We also compared each method with the results of polysomnography (apnea-hypopnea index, arousal index and minimum oxygen saturation). We studied 55 professional drivers suspected of OSAS. All answered the ESS questionnaire and underwent polysomnographic and MSL testing. We found a significant, though not relevant, correlation between the degree of excessive daytime sleepiness estimated by the ESS and by MSL testing (r = -0.41; p = 0.002). A significant, though weak, correlation was found between the ESS score and the arousal index (r = 0.26; p < 0.05). Our results do not clarify which method is best for measuring excessive daytime sleepiness in professional drivers suspected of OSAS.     

Metabolic syndrome, insulin resistance and sleepiness in real-life obstructive sleep apnoea

The metabolic syndrome shows a variable prevalence in obstructive sleep apnoea (OSA), and its association with insulin resistance or excessive daytime sleepiness in OSA is unclear. This study assessed the following in consecutive patients with newly diagnosed OSA: 1) the prevalence of metabolic syndrome; and 2) its association with insulin resistance and daytime sleepiness. Metabolic syndrome (National Cholesterol Education Program Adult Treatment Panel (NCEP-ATP) III criteria), insulin resistance (Homeostatic Model Assessment (HOMA) index, n = 288) and daytime sleepiness (Epworth Sleepiness Scale) were assessed in 529 OSA patients. The prevalence of metabolic syndrome was 51.2%, which increased with OSA severity. Each metabolic syndrome component correlated with apnoea/hypopnoea index, but only blood pressure retained significance after correction for confounders. Both obesity and OSA contributed to metabolic abnormalities, with different sex-related patterns, since diagnosis of metabolic syndrome was significantly associated with neck circumference, age, body mass index and lowest arterial oxygen saturation in males, and with age and arousal index in females. The number of metabolic syndrome components increased with HOMA index (p<0.001). Prevalence of sleepiness was the same in patients with and without metabolic syndrome. The metabolic syndrome occurs in about half of "real-life" OSA patients, irrespective of daytime sleepiness, and is a reliable marker of insulin resistance.     

Impaired glucose-insulin metabolism in males with obstructive sleep apnoea syndrome.

The aim of this cross-sectional study was to evaluate the frequency of type-2 diabetes and impaired glucose tolerance (IGT) in a large clinic-based male population presenting various degrees of obstructive sleep apnoea syndrome (OSAS) and to analyse the relationship between OSAS and glucose-insulin metabolism. Male patients (n=595) with suspected OSAS underwent both nocturnal polysomnography and a 2-h oral glucose-tolerance test with measurements of fasting and postload blood glucose and plasma insulin. Insulin sensitivity was evaluated by the ratio of fasting glucose to fasting insulin. OSAS was diagnosed in 494 patients, while 101 patients were nonapnoeic snorers. Type-2 diabetes was present in 30.1% of OSAS patients and 13.9% of nonapnoeic snorers. IGT was diagnosed in 20.0% of OSAS patients and 13.9% of nonapnoeic snorers. Fasting and postload blood glucose increased with severity of sleep apnoea. Insulin sensitivity decreased with increasing severity of sleep apnoea. In addition to body mass index and age, the apnoea/hypopnoea index independently influenced postload blood glucose and insulin sensitivity. The authors conclude that in a clinic-based sample of patients, obstructive sleep apnoea syndrome is associated with a high frequency of type-2 diabetes and impaired glucose tolerance. The relationship between sleep-disordered breathing and impaired glucose-insulin metabolism is independent of obesity and age.     

Influence of sampling interval on the evaluation of nocturnal blood pressure in subjects with and without obstructive sleep apnoea.

Blood pressure (BP) variability during sleep is high in obstructive sleep apnoea syndrome (OSAS). How BP sampling interval affects the estimate of mean nocturnal BP in OSAS and control subjects was investigated. Nine subjects with apnoea/hypopnoea index (AHI) <5 and 18 OSAS patients with AHI >30 underwent nocturnal polysomnography with beat-by-beat BP monitoring. Mean nocturnal BP was evaluated averaging: a) all systolic (Ps) and diastolic (Pd) BP values; b) Ps and Pd sampled every 5, 10, 15, 20, and 30 min. The sampling starting point was repeatedly shifted, and several mean BP estimates for each sampling interval were obtained. Differences (deltaPs and deltaPd) between means obtained by sampling BP and by averaging all BP values were calculated. In both groups deltaPs and deltaPd scatter increased as sampling interval increased; their variance was always higher in OSAS subjects (p<0.001). Over 95% of deltaPs and deltaPd were <5% of the beat-by-beat mean values at all sampling intervals in controls, but this occurred only at sampling intervals < or =10 min in OSAS subjects. To conclude, for each blood pressure sampling time, a larger number of inaccurate nocturnal mean blood pressure estimates are obtained in obstructive sleep apnoea syndrome than in control subjects. Obstructive sleep apnoea syndrome subjects require more frequent blood pressure measurements to obtain a similar accuracy in nocturnal blood pressure evaluation.     

Predicting sleep apnoea syndrome from heart period: a time-frequency wavelet analysis.

Heart rate fluctuations are a typical finding during obstructive sleep apnoea, characterised by bradycardia during the apnoeic phase and tachycardia at the restoration of ventilation. In this study, a time-frequency domain analysis of the nocturnal heart rate variability (HRV) was evaluated as the single diagnostic marker for obstructive sleep apnoea syndrome (OSAS). The predictive accuracy of time-frequency HRV variables (wavelet (Wv) decomposition parameters from level 2 (Wv2) to level 256 (Wv256)) obtained from nocturnal electrocardiogram Holter monitoring were analysed in 147 consecutive patients aged 53.8+/-11.2 yrs referred for possible OSAS. OSAS was diagnosed in 66 patients (44.9%) according to an apnoea/hypopnoea index > or = 10. Using receiver-operating characteristic curves analysis, the most powerful predictor variable was Wv32 (W 0.758, p<0.0001), followed by Wv16 (W 0.729, p<0.0001) and Wv64 (W 0.700, p<0.0001). Classification and Regression Trees methodology generated a decision tree for OSAS prediction including all levels of Wv coefficients, from Wv2 to Wv256 with a sensitivity reaching 92.4% and a specificity of 90.1% (percentage of agreement 91.2%) with this nonparametric analysis. Time-frequency parameters calculated using wavelet transform and extracted from the nocturnal heart period analysis appeared as powerful tools for obstructive sleep apnoea syndrome diagnosis.     

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.