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.     

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.     

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。     

经鼻无创正压通气治疗阻塞性睡眠呼吸暂停综合征血栓前状态效果评价

目的评价经鼻无创正压通气(nCPAP)对阻塞性睡眠呼吸暂停综合征(OSAS)血栓前状态(PTS)的治疗效果。方法收集北京世纪坛医院2003年9月至2005年9月确诊的OSAS患者30例及同期健康对照者30名,血样采取均在经过前一夜睡眠监测及睡眠监测并nCPAP治疗后(OSAS组)仰卧位时立即进行。结果OSAS组与健康对照组比较,OSAS患者血液中血小板α颗粒膜蛋白-140(GMP-140)升高;部分凝血活酶时间(APTT)、抗凝血酶Ⅲ复合物(AT-Ⅲ)以及血浆组织型纤溶酶原激活物(t-PA)降低,血浆组织型纤溶酶原抑制物(PAI)升高,与健康对照组比较各个指标在两组之间的差异均有统计学意义。nCPAP治疗后OSAS组呼吸紊乱指数由(63.21±23.23)/h降至(0.56±0.84)/h,夜间最低血氧饱和度由0.68±0.07上升至0.90±0.02,GMP-140和PAI分别降至(17.07±7.97)%、(95.83±5.91)%,AT-Ⅲ和t-PA分别升高至(95.20±6.67)%、(5.45±1.61)μg/L。结论OSAS患者存在PTS,nCPAP治疗可部分或全部逆转PTS,减少与OSAS相关的心脑血管栓塞性疾病的发生。     

Changes in cerebral hemoglobin indices in obstructive sleep apnea syndrome with nasal continuous positive airway pressure treatment

Introduction  

This study examined both the relationship between the changes in the brain tissue hemoglobin indices and SpO₂ during sleep in patients with obstructive sleep apnea syndrome (OSAS) and the effect of nasal continuous positive airway pressure (CPAP) treatment on hemoglobin indices.     

The effects of nasal continuous positive airway pressure on platelet activation in obstructive sleep apnea syndrome

OBJECTIVE: A case-controlled study to assess the effects of nasal continuous positive airway pressure (CPAP) on platelet activation in patients with obstructive sleep apnea (OSAS) syndrome. METHODS: We recruited 65 patients with suspected OSAS for this study. Blood samples were taken with the patient in the supine position in the morning immediately after polysomnography, and 1 night and 3 months after the start of nasal CPAP therapy to measure an index of platelet activation (IPA+), which reflected both the quantity and quality of platelet activation. Significant OSAS was defined as an apnea-hypopnea index (AHI) of > or = 10 events per hour. RESULTS: There were 42 patients with significant OSAS and 23 control subjects with AHI < 10 events per hour. The mean (+/- SD) age for the OSAS patients was 48 +/- 9 years, the mean body mass index was 30.7 +/- 4.8, the mean AHI was 47 +/- 25 events per hour, the mean arousal index (AI) was 37 +/- 23 events per hour, and the mean minimum arterial oxygen saturation was 74 +/- 11%. Following multiple linear regression analyses of the clinical and polysomnography parameters, AI was the independent factor that correlated best with the baseline IPA+ (beta-coefficient, 0.386; p = 0.006). Following nasal CPAP treatment with a mean objective CPAP compliance of 3.9 +/- 1.9 h per night, there was a significant decrease in IPA+ from 15.1 +/- 12.2 U (at baseline) to 12.2 +/- 5.2 U (p < 0.001) and 9.8 +/- 4.3 U (p = 0.005), respectively, after 1 night and 3 months, whereas no significant change was noted among the control subjects. Using univariate analysis of variance to compare the changes in IPA+ between the two groups at 3 months with adjustment for the baseline value, nasal CPAP reduced IPA+ by 5.63 (SE, 1.85), whereas IPA+ increased in control subjects by 1.33 (SE, 1.27) [least-squared mean difference between groups, 3.34; 95% confidence interval, 0.42 to 6.26; p = 0.026]. CONCLUSIONS: OSAS, through repeated episodes of arousals, may lead to platelet activation, which can be reduced by nasal CPAP therapy.     

Effect of nocturnal nasal continuous positive airway pressure on blood pressure in obstructive sleep apnea

Obstructive sleep apnea (OSA) is a very common risk factor for hypertension, and continuous positive airway pressure (CPAP) has been widely used to treat OSA. We conducted a meta-analysis of randomized, controlled trials to evaluate the effects of CPAP on blood pressure, reported as either a primary or secondary end point, among patients with OSA. Studies were retrieved by searching Medline (January 1980 to July 2006), the Cochrane Database of Systematic Reviews, conference abstracts, and bibliographies of review and original articles. From 255 relevant reports, 16 randomized clinical trials were selected that compared CPAP to control among participants with OSA, had a minimum treatment duration of 2 weeks, and reported blood pressure changes during the intervention or control period. Data on sample size, participant characteristics, study design, intervention methods, duration, and treatment results were independently abstracted by 2 investigators using a standardized protocol. Data from 16 trials representing 818 participants were examined using a random-effects model. Mean net change in systolic blood pressure for those treated with CPAP compared with control was -2.46 mm Hg (95% CI: -4.31 to -0.62); mean net change in diastolic blood pressure was -1.83 mm Hg (95% CI: -3.05 to -0.61); and mean net change in mean arterial pressure was -2.22 mm Hg (95% CI: -4.38 to -0.05). Net reductions in blood pressure were not statistically different between daytime and nighttime. These results indicate that CPAP decreases blood pressure among those with OSA and may help prevent hypertension.     

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。     

Neuropsychologic symptoms in obstructive sleep apnea improve after treatment with nasal continuous positive airway pressure

To describe the affective changes associated with sleep restoration we assessed psychologic symptoms using the Profile of Mood States questionnaire before and two months after treatment with nasal continuous positive airway pressure (NCPAP) in seven men with obstructive sleep apnea (OSA). The results were compared with those of a control group of patients with OSA who did not receive NCPAP. Two of six mood factors, depression and fatigue, improved significantly following treatment with NCPAP. Total Mood Disturbance (TMD) score was used to assess global mood differences. The mean TMD score for the patients before treatment was 1.7 and during treatment decreased to -7.6 (p less than 0.05). This mean decrease of 9.3 in the TMD score implies generalized improvement in mood. These findings support the opinion that sleep fragmentation and abnormalities of respiration during sleep are at least partially responsible for affective changes seen in sleep apnea. These psychologic disturbances improve after treatment with NCPAP.     

Periodic leg movements in sleep following treatment of obstructive sleep apnea with nasal continuous positive airway pressure

Periodic leg movements in sleep are shown to be a common finding in patients with OSA and may become evident or increase in severity after treatment of the OSA with NCPAP. Periodic leg movements in sleep were measured during baseline polysomnography, a NCPAP treatment trial, and a repeat NCPAP recording in 33 patients treated with NCPAP for OSA. During baseline PSG, nine patients had five or more PLMS per hour of sleep (index), while 14 patients had a PLMSI of 5 or more during the NCPAP trial and the repeat NCPAP recording. Among those patients with a PLMSI of 5 or more during repeat NCPAP studies, the PLMSI showed a significant increase from baseline to initial NCPAP (16.9 +/- 25.3 vs 39.3 +/- 29.4; p less than 0.001) and from baseline to repeat NCPAP (16.9 +/- 25.3 vs 42.9 +/- 39.8; p less than 0.05). The number of PLMS associated with electroencephalographic arousal also increased significantly from baseline to initial NCPAP (4.3 +/- 7.4 vs 9.7 +/- 8.9; p less than 0.05) and from baseline to repeat NCPAP (4.3 +/- 7.4 vs 16.5 +/- 18.6; p less than 0.05). The 14 patients with a PLMSI of 5 or more on the repeat NCPAP had significantly more stage 1 sleep and less REM sleep than 19 patients with a PLMSI of less than 5. Bilateral anterior tibialis EMG must be measured during NCPAP recordings in order to recognize sleep disruption caused by PLMS.     

Long-term effects of nasal continuous positive airway pressure on vasodilatory endothelial function in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is associated with a dysfunction of vascular endothelial cells. The aim of this study was to investigate long-term improvement of endothelial dysfunction in OSAS with nasal continuous positive airway pressure (nCPAP) treatment. We investigated endothelium-dependent and endothelium-independent vasodilatory function in patients with OSAS using the hand vein compliance technique. Dose–response curves to endothelium-dependent vasodilator bradykinin were obtained in 16 subjects with OSAS before and after 6 months of nCPAP therapy and in 12 control subjects without OSAS. Maximum dilation (Emax) to bradykinin, being impaired in all OSAS patients, was completely restored with nCPAP. Mean Emax to bradykinin rose from 54.9±18.5 to 108.2±28.7% with 164.4±90.0 nights of nCPAP therapy (p<0.0001; Emax healthy controls, 94.8±9.5%). At treatment follow-up, endothelium-dependent vasodilatory capacity was not significantly different in nCPAP-treated OSAS patients vs healthy controls. Mean vasodilation with endothelium independently acting nitroglycerin was not altered initially and did not change with nCPAP therapy indicating that nCPAP restored endothelial cell function and not unspecific, endothelium-independent factors. These results suggest that regular nocturnal nCPAP treatment leads to a sustained restoration of OSAS-induced impaired endothelium-dependent nitric oxide-mediated vasodilation, suggesting an improvement of systemic endothelial dysfunction in patients studied.     

Cerebral hemodynamic changes in obstructive sleep apnea syndrome after continuous positive airway pressure treatment

Background

Patients with obstructive sleep apnea syndrome (OSAS) are at increased risk for cerebrovascular diseases. The underlying mechanisms remain obscure. It may occur through a reduction in cerebral vascular reactivity. Continuous positive airway pressure (CPAP) is effective in reducing the occurrence of apneas. We hypothesized that treatment with CPAP improves cerebral vascular reactivity.

Methods

This is a prospective study with OSAS patients. The apnea test (ApT) was calculated as an increase of mean artery velocity during apnea: [Artery velocity in apnea minus Resting artery velocity]/Resting artery velocity expressed as percentage. After 2 years of CPAP treatment, the test was repeated.

Results

Seventy-six patients represented the study pool. After 2 years of treatment with CPAP, we were able to conduct a reassessment in 65 patients. Of the 65 patients who finished the clinical study, 56 were men, and 9 were women, with an average age of 48.1?±?10.4 years. There was an improvement in the ApT after CPAP treatment (30.8?±?12.1 vs 39.8?±?15.1; p:0.000). The values of cerebral blood flow velocities, diastolic blood pressure in apnea, and basal heart rate decreased.

Conclusions

Cerebral vascular reactivity in OSAS patients measured by ApT improved after 2 years of CPAP.     

持续气道内正压治疗阻塞性睡眠呼吸暂停低通气综合征

持续气道内正压（CPAP）通气是治疗阻塞性睡眠呼吸暂停低通气综合征（OSAHS）的主要方法。OSAHS患者经CPAP治疗后嗜睡改善、血压下降、心脑血管病变的发生率降低，生活质量提高。CPAP治疗OSAHS的主要机制是气道内正压使上气道撑开^[1]，并且由于呼气时气道内正压使肺残气增高，也有助于维持上气道的畅通。