Effect of continuous positive airway pressure on gastroesophageal reflux in patients with obstructive sleep apnea: a meta-analysis

Sleep and Breathing - Gastroesophageal reflux disease (GERD) often occurs in patients with obstructive sleep apnea (OSA). Although continuous positive airway pressure (CPAP) is considered...     

Efficacy of nasal masks versus nasal pillows masks during continuous positive airway pressure titration for patients with obstructive sleep apnea

Purpose

Nasal masks are usually the first choice for CPAP therapy, but patients may experience side effects. There are limited data regarding the efficacy of nasal pillows masks during CPAP titration. This study aimed to compare the polysomnography outcomes during CPAP titration while comparing two types of masks (nasal and pillows) and to assess whether or not the patient characteristics differed between mask preferences.

Methods

In a sleep-disorders clinic, we prospectively analyzed all patients undergoing CPAP titration for three consecutive months. CPAP pressures were manually titrated. Anthropometric data (age, sex, body mass index, and neck and waist circumferences) and OSA severity were documented. Patients completed a self-administered questionnaire that measured nasal obstruction (NOSE scale). Before titration, both types of masks were presented to patients, and each of them chose the one they preferred.

Results

Of 157 patients, 55% (n = 86) used nasal masks, and 45% (n = 71) used nasal pillows masks. There was no difference according to mask type chosen by age, sex, body mass index, neck and waist circumferences, and NOSE scale. Polysomnography outcomes were similar between the mask groups. The mean CPAP level was 9.4 ± 1.8 cm H₂O for nasal masks and 9.1 ± 2.0 cm H₂O for nasal pillows (p = 0.61). Residual apnea-hypopnea index was 3.0 ± 2.8 events/h for nasal mask and 3.5 ± 4.1 events/h for pillow mask (p = 0.28). Baseline AHI, body mass index, neck and waist circumferences, and residual AHI were independent predictors of a higher CPAP pressure for both groups (p < 0.0001).

Conclusions

Nasal pillows masks seem to be as effective as nasal masks and may be considered to be an initial choice for CPAP titration.

     

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     

Central sleep apnea reversed by continuous positive airway pressure

Continuous positive airway pressure (CPAP) is an accepted and highly effective method used in the treatment of obstructive sleep apnea (OSA). We have explored the potential utility of CPAP in a patient with sleep apnea without a major contribution of airway obstruction as measured by the usual criteria. The patient showed dramatic clinical and laboratory improvement in central apnea when treated with CPAP. A low level of CPAP (7.5 cm H2O) resulted in the reduction of central apneas from 281 to 32 per night with no significant change in obstructive apneas, which increased from 43 to 59 per night. On a separate night, a higher level of CPAP (12.5 cm H2O) resulted in virtually complete removal of all apneas. Measurement of pharyngeal properties revealed pharyngeal cross-sectional area in the low normal range, but increased pharyngeal compliance. This case illustrates that pharyngeal abnormalities may be present in patients with central sleep apnea, and CPAP may be beneficial in the treatment of this disorder. Although the exact mechanism of action of CPAP in this disorder is unclear, we propose several possibilities that may account for the beneficial effect of CPAP in this patient.     

Auto-titrating continuous positive airway pressure for treating adult patients with sleep apnea syndrome

PURPOSE OF REVIEW: The treatment of sleep apnea syndrome (SAS) is continuous positive airway pressure (CPAP) as the first line of therapy. The current standard is for an attendant technician to titrate CPAP by means of an in-laboratory polysomnography to obtain a fixed single pressure. Over the past decade and a half, some devices able to modify the pressure delivered to the patient overnight and from night to night have become available. The efficacy of such devices to manage SAS has been demonstrated, however the question of their use either as unattended APAP to determine pressures for fixed CPAP or for self-adjusting APAP treatment on a long-term basis is still matter of debate. RECENT FINDINGS: However, if cost considerations may render reluctant to APAP, off note, using APAP could allow initiation of treatment more quickly, reduce in-laboratory time, and reduce healthcare costs. SUMMARY: Auto-titrating continuous positive airway pressure and CPAP are to date equivalent in terms of efficacy to treat SAS, but APAP could allow quick initiation of treatment and therefore reduce healthcare costs.     

Clinical characteristics of periodic limb movements during sleep categorized by continuous positive airway pressure titration polysomnography in patients with obstructive sleep apnea

Sleep and Breathing - The presence of periodic limb movements during sleep (PLMS) varies among patients with obstructive sleep apnea (OSA) undergoing treatment with continuous positive airway...     

Sleep structure correlates of continuous positive airway pressure variations during application of an autotitrating continuous positive airway pressure machine in patients with obstructive sleep apnea syndrome

STUDY OBJECTIVES: To evaluate the relationship between sleep structure and continuous positive airway pressure (CPAP) delivered by an automatic CPAP (auto-CPAP) machine in patients with obstructive sleep apnea syndrome (OSAS). DESIGN: Nocturnal polysomnography was performed during CPAP administration by an auto-CPAP machine (Autoset Clinical 1; ResMed; Sydney, Australia). SETTING: Sleep-disorders center in a research institute. PATIENTS: Fifteen subjects with newly diagnosed OSAS deserving home CPAP treatment. Measurements and results: During the night, in most cases, the lowest CPAP level was recorded during a prolonged nonrapid eye movement (NREM) sleep period uninterrupted by arousals, whereas the highest level during wake-sleep transitions or NREM sleep fragmented by arousals. In four subjects, rapid eye movement sleep was always associated with increasing CPAP. Sleep efficiency was negatively correlated with CPAP variability, evaluated as the SD of the mean nocturnal CPAP level averaged epoch by epoch (r = 0.63, p < 0.02). Eighty-eight percent of rapid CPAP augmentations (increases by at least 2 cm H(2)O in less-than-or-equal 2 min) were observed during sleep-wake transitions or after arousals/awakenings (Ar/Aw); 63% of such Ar/Aw were not preceded by any detectable respiratory abnormality. CONCLUSIONS: CPAP levels and variations during auto-CPAP application may be mainly related to sleep continuity and efficiency. The recording of a highly variable pressure during auto-CPAP administration in an unattended environment must raise the question whether the patient's sleep quality was acceptable. A poor sleep quality during an autotitration night could lead to an undesirable overestimation of the CPAP level needed for use with fixed-level CPAP machines.     

经鼻持续气道正压通气治疗睡眠呼吸暂停综合征的依从性及其影响因素

目的　调查睡眠呼吸暂停综合征 (SAS)患者接受经鼻持续气道正压通气 (nCPAP)治疗的依从性、主观疗效和不良反应 ,了解影响依从性的相关因素。方法　对我院 1994年 2月～ 2 0 0 0年 8月间接受nCPAP治疗的 118例SAS患者进行有关依从性的问卷调查并分析其影响因素。结果　 118例SAS患者中 5 7%应用nCPAP依从性良好 ,影响nCPAP治疗依从性的因素主要有治疗前睡眠呼吸暂停 /低通气指数 (AHI) (P =0 0 35 )、治疗前夜间最低血氧饱和度 (LSaO2 ) (P =0 0 0 6 )、治疗前及后Epworth嗜睡评分 (ESS) (P值均 <0 0 0 1)及CPAP呼吸机的性能 (P <0 0 0 1)。结论　 5 7%的SAS患者能长期坚持应用nCPAP治疗 ,nCPAP可作为SAS长期治疗的重要手段 ;影响nCPAP治疗依从性的因素主要有治疗前AHI、治疗前夜间LSaO2 、治疗前及后ESS及CPAP呼吸机的性能。     

Influence of continuous positive airway pressure on sleep apnea-related desaturation in sleep apnea patients

To investigate the influence of nasal continuous positive airway pressure (CPAP) on apnea-related desaturation, we compared the sleep apnea-related desaturations obtained during a poly somnographic study before and during nasal CPAP in 15 sleep apnea patients. An individual desaturation curve was determined with a regression analysis by plotting the lowest SaO₂ value reached during each apnea against its duration; these data were collected throughout the night. At baseline, we only considered the apneas with a preapneic SaO₂ value greater than 90% and a minimal SaO₂ value above or equal to 60%. For the CPAP study, the preapneic Sa0₂ value also had to be within 2% the baseline value for the apneas to be retained. Due to the restriction criteria imposed to characterize apnea-related Sa0₂ falls, residual apneas still had to be recorded with CPAP. These data were analyzed separately for obstructive apnea for non-rapid eye movement (REM) and REM sleep stages. A desaturation curve was obtained from 10 sec to a variable upper limit that corresponded to the longest apnea duration commonly reached during both baseline and CPAP for a given apnea-type and sleep stage. The individual apnea-related Sa0₂ fall was characterized by measuring a desaturation area corresponding to the area under the curve. It was expressed in % Sa0₂/sec of apnea. CPAP reduced the number of apneas per hour of sleep from 37.5 ± 6.5 (mean ± SEM) to 14.3 3.7 (p = 0.001), and improved the whole night SaO₂, level as estimated by a cumulative SaO₂ curve. The mean apnea duration was reduced from 22.9 ± 1.5 sec at baseline to 16.8 ± 0.5 sec during CPAP therapy (p = 0.005). The preapneic SaO₂ value was 94.8 ± 0.3% at baseline and 95.5 ± 0.2% during CPAP (p = 0.5). The desaturation area decreased from 267 ± 48% SaO₂/sec at baseline to 152 ± 41% Sa0₂/sec during CPAP (p < 0.001). We conclude that CPAP improves the apnea-related desaturation independently of the shortening of apneas and of any difference in the preapneic SaO₂ value.     

Autotitration positive airway pressure therapy in patients with obstructive sleep apnea who are intolerant of fixed continuous positive airway pressure

Compliance with continuous positive airway pressure (CPAP) therapy is one of the most difficult management problems for patients with obstructive sleep apnea (OSA). We postulated that autotitration positive airway pressure (APAP) may be effective in some patients who have an intolerance of fixed CPAP. The study was done to estimate how often patients who cannot tolerate fixed CPAP can tolerate APAP. We identified 25 patients seen in the Sleep Disorders Center who had been treated with fixed CPAP for OSA and were intolerant of CPAP therapy despite multiple efforts to improve tolerance. We substituted APAP therapy and measured subjective and objective compliance with treatment 1 month later. The primary end point was the number of patients who successfully tolerated the use of APAP at the end of 30 days, measured objectively by the device's compliance monitor. A positive outcome was defined as an average use of APAP that was greater than 3 h per night on more than 70% of possible nights. Of the 25 patients (mean age, 68 years; mean apnea-hypopnea index, 35), 11 were able to tolerate APAP therapy. The mean number of hours of use in these responders was 6.2; the mean percentage of nights of use among responders was 89%. Determinants of successful APAP use were an apnea-hypopnea index (AHI) less than 18, male sex, OSA related to rapid eye movement, and a high body mass index. APAP therapy may be an effective option in patients who do not tolerate fixed-CPAP therapy.     

持续正压通气治疗阻塞性睡眠呼吸暂停低通气综合征伴高血压的护理

目的研究持续气道正压通气(CPAP)治疗阻塞性睡眠呼吸暂停低通气综合征(OSAHS)伴高血压的作用及护理。方法45例OSAHS伴高血压患者使用CPAP,每晚治疗8h。定时测量血压,并辅以积极的护理措施,观察患者治疗前后的血压变化。结果治疗后血压有所下降(P<0.05),下降时间为3～14d,平均(5±2.5)d。结论CPAP治疗OSAHS伴高血压是一种有效方法,护理有其特殊性和重要性。     

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.     

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.     

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.     

Prognosis of patients with heart failure and obstructive sleep apnea treated with continuous positive airway pressure

BACKGROUND: Therapy with continuous positive airway pressure (CPAP) provides several benefits for patients with heart failure (HF) complicated by obstructive sleep apnea (OSA). However, the effect on the prognosis of such patients remains unknown. Aims: To determine whether CPAP therapy and compliance affects the prognosis of HF patients with OSA. METHODS: We classified 88 patients with HF and moderate-to-severe OSA into a CPAP-treated group (n = 65) and an untreated group (n = 23), and then those treated with CPAP were further subclassified according to CPAP therapy compliance. The frequency of death and hospitalization was analyzed using multivariate analysis. RESULTS: During a mean (+/- SD) period of 25.3 +/- 15.3 months, 44.3% of the patients died or were hospitalized. Multivariate analysis showed that the risk for death and hospitalization was increased in the untreated group (hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.07 to 3.68; p = 0.030) and in less compliant CPAP-treated patients (HR, 4.02; 95% CI, 1.33 to 12.2; p = 0.014). CONCLUSION: Therapy with CPAP significantly reduced the risk of death and hospitalization among patients with HF and OSA. However, reduced compliance with CPAP therapy was significantly associated with an increased risk of death and hospitalization.     

Oxidative and carbonyl stress in patients with obstructive sleep apnea treated with continuous positive airway pressure

Purpose  

The pathogenesis of cardiovascular complications of obstructive sleep apnea syndrome (OSAS) can be explained by oxidative and carbonyl stress due to oxygenation and reoxygenation injury during sleep. This hypothesis has yet to be proved experimentally, although several clinical observations have found increased oxidative damage in plasma. Continuous positive airway pressure (CPAP) improves symptoms and prognosis of patients with OSAS.     

Obstructive sleep apnea in amyloidosis treated with nasal continuous positive airway pressure

Obstructive sleep apnea can occur in patients with a variety of upper airway anatomic abnormalities including macroglossia. We present a case of macroglossia secondary to amyloidosis causing obstructive sleep apnea that was successfully treated with low pressures of nasal continuous positive airway pressure (5 cm of water).     

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.