Arbitrary-pressure continuous positive airway pressure for obstructive sleep apnea syndrome

Current resources are inadequate to meet the demand for polysomnography, resulting in long waiting lists. This study aimed to evaluate the role of arbitrary-pressure continuous positive airway pressure (CPAP) as a method to reduce delays in commencing treatment. The study was of an open, randomized, parallel design. Ninety-one subjects with obstructive sleep apnea syndrome were randomized to either arbitrary-pressure CPAP based on body mass index before treatment polysomnography or to CPAP at settings determined by polysomnography. Both interventions resulted in similar improvements in clinical outcomes as determined by Epworth Sleepiness Score, Short Form-36 Quality of Life questionnaire, objective compliance, and subjective attitudes to treatment. There was higher sleep efficiency at treatment polysomnography in the group commenced at arbitrary pressure (81.8 +/- 10.1% [mean +/- SD] compared with 72.2 +/- 18.0%, p = 0.01). Subjects unable to tolerate CPAP were identified by the use of arbitrary pressure, leading to a reduction in the proportion of "wasted" treatment polysomnograms (studies performed in subjects not persisting with treatment) relative to commencing therapy after treatment polysomnography (3 of 39 compared with 12 of 35, p = 0.01). This approach to initiating treatment with CPAP appears feasible when there are long waiting lists for polysomnography.     

经鼻持续气道正压通气对阻塞性睡眠呼吸暂停综合征的综合疗效

经鼻持续气道正压通气（CPAP）是目前治疗阻塞性呼吸暂停综合征（OSAS）最有效的内科治疗方法,通过向气道内增加一定程度的正压,保持上气道通畅,消除患者夜间缺氧,改善患者夜间打鼾,白天嗜睡等临床症状,恢复睡眠结构,并治疗与此相关的各系统疾病,提高患者长期的生活质量。     

Positional treatment vs continuous positive airway pressure in patients with positional obstructive sleep apnea syndrome

OBJECTIVES: The aim of this study was to compare the relative efficacy of continuous positive airway pressure (CPAP) and positional treatment in the management of positional obstructive sleep apnea (OSA), using objective outcome measures. DESIGN: A prospective, randomized, single blind crossover comparison of CPAP and positional treatment for 2 weeks each. SETTING: A university teaching hospital. PATIENTS: Thirteen patients with positional OSA, aged (mean+/-SD) 51+/-9 years, with an apnea-hypopnea index (AHI) of 17+/-8. MEASUREMENTS: (1) Daily Epworth Sleepiness Scale scores; (2) overnight polysomnography, an objective assessment of sleep quality and AHI; (3) maintenance of wakefulness testing; (4) psychometric test battery; (5) mood scales; (6) quality-of-life questionnaires; and (7) individual patient's treatment preference. RESULTS: Positional treatment was highly effective in reducing time spent supine (median, 0; range, 0 to 32 min). The AHI was lower (mean difference, 6.1; 95% confidence interval [CI], 2 to 10.2; p = 0.007), and the minimum oxygen saturation was higher (4%; 95% CI, 1% to 8%; p = 0.02) on CPAP as compared with positional treatment. There was no significant difference, however, in sleep architecture, Epworth Sleepiness Scale scores, maintenance of wakefulness testing sleep latency, psychometric test performance, mood scales, or quality-of-life measures. CONCLUSION: Positional treatment and CPAP have similar efficacy in the treatment of patients with positional OSA.     

Nasal continuous positive airway pressure therapy in obstructive sleep apnea syndrome]

Sixteen patients (male: 14, female: 2, 41-72 yrs, mean 57.5 yrs) with OSAS were treated by nCPAP in our hospital since 1987. Respiratory disturbance index ranged from 16.5 to 83.1. The longest apnea duration was 35.0-120.5 seconds before the treatment. Two patients were treated with Sleep Easy III (Respironics Inc.) and others with a home made instruments. nCPAP was set at a pressure of 5 to 10 cm H2O. 12 patients (75%) tolerated the device but 4(25%) did not. Polysomnographic parameters before and after nCPAP therapy were compared. The longest apnea duration was 63.1 +/- 23.5 to 40.9 +/- 27.4 seconds (P less than 0.001) and the lowest saturation oxygen was 55.1 +/- 20.4% to 71.4 +/- 18.6% (P less than 0.05). The sleep structure improved but not significant statistically. One of them used nCPAP at home for more than two. years and showed a good long term effect. We concluded that nCPAP is an effective and safe treatment for OSAS. However, patients may be uncomfortable because of the wearing of the nasal mask during sleep.     

Influence of gender on continuous positive airway pressure requirements in patients with obstructive sleep apnea syndrome

Introduction  

Gender differences have been noted in key aspects of upper airway physiology and pathophysiology of obstructive sleep apnea (OSA). We postulate that these will lead to disparities in pharyngeal collapsibility and, consequently, positive airway pressure requirements of patients with OSA.     

Prediction of continuous positive airway pressure in obstructive sleep apnea

Continuous positive airway pressure (CPAP) prediction formulas can potentially simplify the treatment of obstructive sleep apnea (OSA). However, they can be difficult to derive and validate. We tested a statistical method to derive and validate a CPAP prediction formula using the same sample population. Seventy-six OSA patients underwent polysomnography and CPAP titration. Anthropometric measures, sleep parameters, and the Epworth sleepiness scale (ESS) were evaluated as predictors. All subsets regression was used to determine the optimum number of variables in the model. The Bayes information criterion was used to find the best-fit model. The model was then evaluated by a tenfold cross-validation procedure. Subjects were obese (BMI 31.3 ± 5.4) and had significant daytime somnolence (ESS 11.9 ± 5). Mean respiratory disturbance index (RDI) was 53.5 ± 31.3. The ESS was not predictive of titrated CPAP. The best-fit model included three variables (CPAP_pred = 30.8 + RDI × 0.03 − nadir saturation × 0.05 − mean saturation × 0.2). This model explained 67% of the variance. Our data and the literature suggest that a combination of two to three factors is predictive of titrated CPAP: RDI, oxyhemoglobin saturation, and obesity. Except for RDI, the specific factors vary in each population. A CPAP prediction formula that explains a high proportion of the titrated CPAP variance can be easily derived from parameters measured during the diagnostic work-up of OSA patients using a unique statistical model that allows derivation and validation of the formula in the same test population.     

Effect of continuous positive airway pressure vs placebo continuous positive airway pressure on sleep quality in obstructive sleep apnea

STUDY OBJECTIVES: Continuous positive airway pressure (CPAP) therapy has become the treatment of choice for obstructive sleep apnea (OSA). However, the efficacy of CPAP therapy has not been evaluated against a suitable control. We investigated the effectiveness of CPAP therapy in improving sleep quality in patients with OSA. We hypothesized that CPAP improves sleep quality. PATIENTS: Forty-eight CPAP-naive OSA patients were evaluated. None were receiving antihypertensive medications, and none had major medical illnesses. DESIGN: Patients were randomized to receive either CPAP or placebo CPAP (CPAP at an ineffective pressure) for 7 days in a double-blind fashion. Forty-one patients completed the protocol. Sleep quality variables, arousals, sleep arterial oxygen saturation (SaO(2)), and respiratory disturbance index (RDI) were assessed at baseline, after 1 day of treatment, and after 7 days of treatment. Repeated measures analysis of variance was used to evaluate the effects of treatment, time, and the interaction of the two. RESULTS: As expected, CPAP lowered RDI and number of arousals, and increased SaO(2) over time (p = 0.001). Contrary to expectations, both CPAP and placebo CPAP had comparable effects on sleep quality as assessed by sleep architecture, sleep efficiency, total sleep time, and wake after sleep onset time. CONCLUSIONS: This study confirms the effectiveness of CPAP in lowering the number of arousals and the RDI, and in raising SaO(2). However, our data suggest that short-term CPAP is no different than placebo in improving sleep architecture. Further evaluation of the effectiveness of CPAP using a suitable placebo CPAP in prospective randomized studies is needed     

持续气道正压通气治疗对OSAHS患者血液流变学的影响

目的探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者经鼻持续气道正压通气(ncpap)治疗对其血液流变学指标的影响。方法随机选择我科确诊为中度或重度OSAHS的患者30例,其中男20例,女10例,年龄45~68岁,平均年龄(58±3)岁,治疗前14d内未服用过非甾体类消炎药及阿斯匹林,潘生丁等抗凝剂,并排除其它呼吸系疾病、紫绀性先心病、肾脏疾病及原发性红细胞增多症,分别于治疗前及治疗30d后检测血细胞比容、全血比粘度(高切度、中切度、低切度),红细胞聚集指数。结果治疗后血细胞比容、全血比粘度(高切度、中切度、低切度)、红细胞聚集指数较治疗前显著降低(P<0.01)。结论OSAHS存在显著血栓栓塞高危因素,ncpap对其有明显防治作用。     

Effect of nasal continuous positive airway pressure in uncontrolled nocturnal asthmatic patients with obstructive sleep apnea syndrome

The mechanisms of nocturnal asthma are intimately related to circadian rhythms, which influence inflammatory cells and mediators, hormone levels and cholinergic tone. Nocturnal airway narrowing in asthma is sometimes associated with sleep disorders, such as obstructive sleep apnea syndrome (OSAS). The aims of this study were to evaluate the association of nocturnal asthma and OSAS, and investigate the influence of continuous positive airway pressure (CPAP) therapy to improve nighttime symptoms in asthmatic patients with OSAS. Forty-three asthmatic patients who had nocturnal symptoms in spite of the optimal medical treatment according to the Global Initiative for Asthma guidelines and associated with snoring were studied. Pulmonary function tests (PFTs), asthma nighttime symptom scores, and polysomnography were performed on all patients. We treated the patients with an apnea-hypopnea index (AHI) 15 (moderate-severe OSAS) (n=16) with CPAP during 2 months. After 2 months, PFT, asthma nighttime symptom scores were reperformed. There was no significant difference in PFT values before and after CPAP treatment in OSAS patients. Asthma nighttime symptom scores were improved significantly (P<0.05) after CPAP treatment. In conclusion, in some patients with nocturnal asthma, OSAS may be responsible disease for nocturnal symptoms. In this condition, CPAP improves nocturnal symptoms without amelioration in PFT abnormalities.     

Efficacy of continuous positive airway pressure on arrhythmias in obstructive sleep apnea patients

The purpose of this study was to determine the relationship between obstructive sleep apnea (OSA) and cardiovascular disorders in a large Japanese population, and to assess the efficacy of continuous positive airway pressure (CPAP) in the treatment of OSA-associated arrhythmias. The study population comprised 1394 Japanese subjects (1086 men and 308 women) who were divided into four groups on the basis of polysomnography (PSG) analysis as follows: the no sleep apnea (N-SA) group (n = 44, apnea-hypopnea index [AHI] < 5), the mild OSA (Mi-OSA) group (n = 197, 5 < AHI < 15), the moderate OSA (Mo) group (n = 368, 15 < AHI < 30), and severe OSA (SOSA) group (n = 785, AHI < 30). The following baseline characteristics were significantly associated with OSA: age (P < 0.001), gender (P < 0.001), body mass index (P < 0.001), hypertension (P < 0.001), diabetes (P = 0.009), and hyperlipidemia (P = 0.013). In the OSA group, PSG revealed the predominance of paroxysmal atrial fibrillation (PAF) (P = 0.051), premature atrial complex short run (P < 0.005), premature ventricular complex (PVC, P = 0.004), sinus bradycardia (P = 0.036), and sinus pause (arrest >2 s, P < 0.001) during the PSG recording. A total of 316 patients from the group underwent CPAP titration and were then re-evaluated. Continuous positive airway pressure therapy significantly reduced the occurrences of PAF (P < 0.001), PVC (P = 0.016), sinus bradycardia (P = 0.001), and sinus pause (P = 0.004). The results of this study demonstrate a significant relationship between OSA and several cardiac disorders, and also demonstrate the efficacy of CPAP in preventing OSA-associated arrhythmias in a large population of Japanese patients.     

持续气道正压通气对阻塞性睡眠呼吸暂停患者睡眠结构的影响

目的探讨患者白天嗜睡等症状的原因,评估经鼻持续气道内正压通气(nCRAP)治疗对阻塞性睡眠呼吸暂停患者睡眠结构的影响。方法选择2001-2004年广东省佛山市第一人民医院呼吸科34例OSAS病人在睡眠多导生理记录仪监测下,进行nCPAP治疗,观察治疗前后呼吸紊乱指数、血氧饱和度和睡眠结构的变化。结果治疗后呼吸紊乱指数下降,最低血氧饱和度上升,睡眠结构明显改善。结论nCRAP能有效地改善OSAS病人的睡眠结构和呼吸紊乱。     

Effect of continuous positive airway pressure therapy on 24-hour blood pressure in patients with obstructive sleep apnea syndrome

BACKGROUND: Patients with obstructive sleep apnea syndrome (OSAS) are subject to an increased cardiovascular morbidity including systemic hypertension. Little is known about the effects of treatment with nasal continuous positive airway pressure (CPAP) on systemic hypertension. METHODS: Automated ambulatory 24-h blood pressure (BP) monitoring was performed in 88 consecutive patients who were referred for evaluation of snoring or suspected OSAS. In addition, the long-term effects of CPAP therapy on 24-h BP were assessed. RESULTS: A total of 62 patients had OSAS and 26 habitual snoring. Patients with OSAS had significantly higher mean arterial BP values than snorers (102.7 +/- 10.7 v 94.0 +/- 10.2 mm Hg; P < .01). Multiple stepwise linear regression analysis disclosed that the degree of systemic hypertension was independently associated with the severity of OSAS as determined by the apnea/hypopnea index (R = 0.43; P < .001), but not with age, body mass index, or smoking habits. Of the 62 patients with OSAS, 52 were treated with CPAP and reevaluated after 9 months. The CPAP resulted in a significant decrease in mean arterial BP (from 103.7 +/- 10.4 to 99.1 +/- 10.8 mm Hg; P < .05). For those patients with systemic hypertension whose BP improved with CPAP therapy, 24-h mean pulse pressure at baseline (r = -0.36; P < .05) as well as average heart rate during the day (r = -0.35; P < .05) turned out as predictors. CONCLUSIONS: Obstructive sleep apnea syndrome contributes, at least in part, to the development of systemic hypertension, and CPAP may improve BP values in treated OSAS patients. Predictors of a beneficial CPAP effect on BP are a high heart rate and a high pulse pressure before treatment.     

Long-term acceptance of continuous positive airway pressure in obstructive sleep apnea

We studied the long-term acceptability of nasal continuous positive airway pressure (CPAP) treatment in 168 consecutive patients, 147 with obstructive sleep apnea (OSA) and 21 with snoring. Follow-up was between 1.5 and 78 months. At latest follow-up 107 of 168 (64%) were still using CPAP. Acceptance of CPAP was least for patients with snoring alone (6 of 21 persisted) and best for patients with both excessive daytime somnolence and severe hypoxemia (minimum SaO2 less than 75%), of whom 40 of 45 (89%) persisted with treatment. Patients with excessive daytime somnolence but without severe hypoxemia were less tolerant of CPAP (39 of 71, 55%, persisted) than patients with no symptoms of excessive somnolence but with severe hypoxemia (21 of 30, 70%, persisted). The most common reasons for discontinuing CPAP were intolerance of the mask (26 of 61), the inconvenience of treatment (16 of 61), and the lack of symptomatic benefit from treatment (10 of 61). We concluded that long-term acceptance of CPAP was difficult to predict in advance but that it was most likely in patients with the most severe sleep apnea. Because intolerance of the mask and inconvenience were the most common reasons for ceasing treatment, improvements in the design of CPAP systems and careful patient training may improve the acceptability of CPAP substantially.     

Effects of exercise training associated with continuous positive airway pressure treatment in patients with obstructive sleep apnea syndrome

Purpose

The aim of this study was to evaluate the effects of a 2-month exercise training associated with continuous positive airway pressure (CPAP) treatment on the subjective and objective sleep measurements, quality of life, and mood in moderate to severe obstructive sleep apnea syndrome (OSAS) patients.

Methods

Male patients were randomized into two treatment groups: CPAP (n?=?19) and CPAP?+?exercise (n?=?13). All patients completed 1?month of sleep hygiene, 2?months of treatment (CPAP or CPAP?+?exercise), and 1?week of washout (no treatment). Fletcher and Luckett sleep questionnaire, Epworth sleepiness scale, sleep diaries, polysomnography, SF-36 inventory of quality of life, Profile of Mood States (POMS) questionnaire, neck circumference, and body composition were evaluated. CPAP?+?exercise group also underwent cardiopulmonary exercise test before and after treatment.

Results

Both treatments were effective in improving subjective sleepiness but CPAP?+?exercise treatment was more effective in maintaining this improvement after washout. No significant differences were found in most of the sleep parameters studied in both groups. CPAP?+?exercise group showed lower values of tension and fatigue on POMS and higher values of physical functioning, general health perception, and vitality on SF-36 after treatment.

Conclusions

A 2-month exercise training associated with CPAP treatment for OSAS patients has a positive impact on subjective daytime sleepiness, quality of life (physical functioning and general health perception), and mood state (tension and fatigue).