Randomised trial of compliance with flexible (C-Flex) and standard continuous positive airway pressure for severe obstructive sleep apnea. [Expiratory pressure reduction (C-Flex Method) versus fix CPAP in the therapy for obstructive sleep apnoea]. A long-term randomized, cross-over comparison of auto-titrating and standard nasal continuous airway pressure. Comparison between automatic and fixed positive airway pressure therapy in the home. A randomized cross-over study of auto-continuous positive airway pressure versus fixed-continuous positive airway pressure in patients with obstructive sleep apnoea. Constant vs auto-continuous positive airway pressure in patients with sleep apnea hypopnea syndrome and a high variability in pressure requirement. Pressure-relief continuous positive airway pressure vs constant continuous positive airway pressure: a comparison of efficacy and compliance. Constant vs. automatic continuous positive airway pressure therapy: home evaluation. Preference for fixed or automatic CPAP in patients with obstructive sleep apnea syndrome. Efficacy of automatic continuous positive airway pressure therapy that uses an estimated required pressure in the treatment of the obstructive sleep apnea syndrome. Comparative study of autotitrating and fixed-pressure CPAP in the home: a randomized, single-blind crossover trial. Two months auto-adjusting versus conventional nCPAP for obstructive sleep apnoea syndrome. Autoadjusting CPAP therapy based on impedance efficacy, compliance and acceptance. Fixed and autoadjusting continuous positive airway pressure treatments are not similar in reducing cardiovascular risk factors in patients with obstructive sleep apnea. Continuous versus bilevel positive airway pressure for obstructive sleep apnea. Evaluation of autoCPAP devices in home treatment of sleep apnea/hypopnea syndrome. Effects of fixed compared to automatic CPAP on sleep in Obstructive Sleep Apnoea Syndrome. Efficacy of auto-CPAP in the treatment of obstructive sleep apnea/hypopnea syndrome. Comparison of three ways to determine and deliver pressure during nasal CPAP therapy for obstructive sleep apnoea. Randomised study of three non-surgical treatments in mild to moderate obstructive sleep apnoea. Auto-adjusting versus fixed positive pressure therapy in mild to moderate obstructive sleep apnoea. A randomized trial of auto-titrating CPAP and fixed CPAP in the treatment of obstructive sleep apnea-hypopnea. Randomized, prospective trial of bilevel versus continuous positive airway pressure in acute pulmonary edema. Noninvasive positive airway pressure and risk of myocardial infarction in acute cardiogenic pulmonary edema: continuous positive airway pressure vs noninvasive positive pressure ventilation. Helmet continuous positive airway pressure vs oxygen therapy to improve oxygenation in community-acquired pneumonia: a randomized, controlled trial. Auto-CPAP therapy based on the forced oscillation technique. Randomized short-term trial of two autoCPAP devices versus fixed continuous positive airway pressure for the treatment of sleep apnea. The efficacy of early continuous positive airway pressure therapy in patients with acute cardiogenic pulmonary edema. Continuous positive airway pressure vs. pressure support ventilation in acute cardiogenic pulmonary edema: a randomized trial. Randomised controlled crossover trial of humidified continuous positive airway pressure in mild obstructive sleep apnoea.
Obstructive sleep apnea (OSA) is often treated with continuous positive airway pressure (CPAP) but the effectiveness of treatment is probably limited by poor compliance. CPAP manufacturers are thus attempting to devise more comfortable PAP devices in an effort to improve compliance. An example of such a novel device is Flexible expiratory-modulated PAP (C-Flex mode Respironics REMstar Pro, Murraysville, PA, USA).
                We aimed to compare compliance between C-Flex and standard CPAP in patients with severe OSA in a randomised controlled trial. Nineteen patients with severe OSA (mean +/- SD Apnea Hypopnea Index = 78 +/- 33/h, Epworth 14 +/- 4, PAP 8-17 cm H2O, BMI = 39 +/- 10 kg/m2) and aged 20-63 years were randomly assigned to 4 weeks of either C-Flex (setting II, n = 9) or CPAP (n = 10).
                Patients treated with C-Flex exhibited a trend toward higher compliance with their PAP devices compared to patients treated with standard CPAP (4.7 +/- 2.9 vs. 3.0 +/- 2.1 h/night, p = 0.15, effect size = 0.68). Paradoxically, improvements in subjective sleepiness (Epworth Sleepiness Scale) were greater in those who received CPAP than C-Flex (8.1 + 4.9 vs. 2.1 + 4.0 points, p = 0.014, effect size = 1.46). Improvements in objective wakefulness (Modified Maintenance of Wakefulness Test) and simple reaction times (Psychomotor Vigilance Task) were not significantly different between treatments. This randomised trial provides some evidence that C-Flex might increase initial treatment compliance, compared to CPAP, in patients with severe OSA. However, this trend toward greater compliance was not associated with better short-term treatment outcomes for patients. These findings need to be confirmed in a larger, longer-term trial. The REM star C-Flex (Fa. Respironics) was introduced in 2003. In contrast to the conventionel fix CPAP mode, the C-Flex mode is characterised by a pressure reduction at the beginning of expiration. In a randomised cross-over design, we investigated if this C-Flex-mode has advantages compared to the fix CPAP mode in terms of treatment quality and patient satisfaction.
                In this prospective randomised single-blinded cross-over study we investigated 20 patients with obstructive sleep apnoea treated with fix CPAP versus treatment with the C-Flex mode (level 2) for 6 weeks, respectively. We compared the polysomnographically measured quality of treatment and the subjective satisfaction of either form of therapy. Additionally, we measured long-term compliance of the C-Flex therapy in a 3-year follow-up with the integrated counter of the C-Flex devices.
                The mean levels of pressure of the fix CPAP and the C-Flex therapies were 8.4 +/- 2.9 mbar in both groups. There was an identical quality of treatment in terms of respiratory events, arousal index, slow wave sleep and Epworth sleepiness scale. The compliance of nocturnal use of the C-Flex and the fix CPAP was identical (6.0 +/- 0.67 C-Flex use vs. 5.8 +/- 0.98 CPAP use [h/night]). The subjective satisfaction was higher in the C-Flex mode at the end of the study since 18 of 20 patients (90%) subjectively prefered the C-Flex mode because of the easier expiration. 19 patients received a C-Flex device for long-term therapy. The 3-year-follow-up showed a regular utilisation of the C-Flex by 16 of 19 (84.2%) of these patients (mean nocturnal use 6.0 +/- 0.9 h/night). 3 of the 19 patients (15.8%) did not use their C-Flex regulary. None of the patients has terminated therapy completely.
                C-Flex mode and the conventional fix CPAP therapies show an equivalent treatment quality according to polysomnographic data. The expiratory pressure reduction compared to conventional CPAP was felt to be more comfortable by 90% of patients. The long-term-compliance as measured by regular use of the C-Flex device was 84.2% (16 out of 19 patients) after 3 years, these numbers are higher than published data on compliance with conventional CPAP therapy. This study is a 12-week randomized, cross-over, single-blind comparison of the tolerance, compliance, and symptomatic improvement obtained with standard nasal continuous positive airway pressure (CPAP) vs. an auto-titrating, self-adjusting device (APAP). Sixty newly diagnosed patients, 53 with obstructive sleep apnea (OSA) and seven with upper airway resistance syndrome were studied. Thirty-nine patients (65%) completed the 24-week protocol. Data were complete in 33. In these 33 patients CPAP and APAP reduced the Epworth Sleepiness score from 15+/-1 (+/-SEM) to 8+/-1 and 9+/-1 respectively (both <0.0001 from baseline but NS between modes). The APAP average pressure was lower than the CPAP pressure, 6.4+/-0.4 and 10.6+/-0.4 cm H20, respectively. The average daily machine use was greater with APAP, 6.0+/-0.3 hrs. versus 5.5+/-0.3 hrs. with CPAP (P < 0.04). The number of days of machine use, and the pattern of use were not different between CPAP and APAP. A higher proportion of patients who did not complete the study was randomized to CPAP for their initial treatment period. This study showed that: 1) CPAP and APAP produced an equivalent improvement in daytime sleepiness, 2) APAP pressure was lower than CPAP pressure, 3) patients wore the APAP device longer during nights they used the pressure support system, and 4) patients who began the study with APAP were more prone to continue treatment. We conclude that APAP was better tolerated and used a greater number of hours than CPAP, but the extent of improvement in excessive daytime sleepiness was similar between the two modes of therapy. We tested the hypothesis that continuous positive airway pressure (CPAP) use and outcomes can be improved by an autotitrating CPAP device in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) who require higher CPAP (10 cm H2O or more). In this multisite randomized single-blind cross-over study, 44 patients (mean age, 49 +/- 10 years) were randomized to 6 weeks at laboratory-determined fixed pressure and 6 weeks on autotitrating CPAP. Average nightly use was greater in automatic mode (306 versus 271 minutes, p = 0.005); median and 95th centile pressures in automatic mode were lower (p < 0.002). Automatic CPAP resulted in better SF-36 Vitality scores (65 +/- 20 versus 58 +/- 23, p < 0.05) and mental health scores (80 +/- 14 versus 75 +/- 18, p < 0.05), but no significant difference in Epworth score (p = 0.065). During automatic therapy, patients reported more restful sleep, better quality sleep, less discomfort from pressure, and less trouble getting to sleep for both the first week of therapy and for the averaged scores for Weeks 2-6 (all p values < 0.006). Patients who require higher fixed CPAP use autotitrating CPAP more and report greater benefit from this therapy. To compare the efficacy of auto-CPAP (AutoSet Spirit, ResMed) versus fixed-CPAP (S6 Elite, ResMed) in improving daytime sleepiness, health status, objective compliance and the ultimate treatment preference in patients with severe OSA.
                The study recruited 43 subjects aged 18-65 years with newly diagnosed severe OSA (AHI >30/h). Patients were initially treated with either auto-CPAP or fixed-CPAP for 2 months and then crossed over after a washout period of 1 week for another 2 months.
                The study was completed by 41 patients. Results are presented as mean (SE). Use of auto-CPAP in the first and the second month was significantly higher than that of fixed-CPAP [129.7 (9.9) and 130.5 (10.7) h vs 115.2 (9.5) and 113.2 (9.4) h, P = 0.04 and 0.01], whereas mean hourly use per night was 4.3 and 4.4 h versus 3.8 and 3.7 h, respectively. The Epworth sleepiness scores improved after 1 month in both treatments (13.4 to 8.5 and 8.2, P < 0.01 for both). The Sleep apnoea quality of life index improved in the first month in both compared with baseline [4.6 (0.2) to 5.0 (0.2) for auto-CPAP and 4.9 (0.2) for fixed-CPAP, P = 0.01 and 0.04, respectively], with no difference between the two treatments. Nine and 30 patients preferred auto-CPAP and fixed-CPAP, respectively, at the end of the trial, whereas 14 and 25 patients would have chosen the same treatments if cost had not been a consideration.
                Auto-CPAP and fixed-CPAP were equally effective in improving symptoms and health status in patients with severe OSA. Usage was higher with auto-CPAP, but more patients ultimately chose fixed-CPAP. Auto-continuous positive airway pressure (CPAP) has been reported to have no more efficacy than constant CPAP in unselected patients with sleep apnea hypopnea syndrome (SAHS). The aim of this study was to evaluate patients judged to be good candidates for auto-CPAP because of a high within-night variability in pressure requirement.
                Single-blind, randomized, cross-over study (2 x 8 weeks) to compare auto-CPAP with constant CPAP.
                Outpatients with moderate-to-severe SAHS attending the chest clinic.
                Patients were equipped at home in the auto-CPAP mode (model GK418A; Malinckrodt; Nancy, France), using a 4- to 14-cm H(2)O pressure range. Those individuals having a high within-night variability in pressure requirement, assessed at the end of a 14-day run-in period, were included in the cross-over study. Auto-CPAP was compared with constant CPAP (according to a titration night in the sleep laboratory) in terms of compliance, efficacy on apneas (assessed from the pressure monitor), and sleepiness (assessed on the Epworth sleepiness scale).
                Of 90 consecutive patients with SAHS, 27 patients were selected for a within-night variability in pressure requirement exceeding a given threshold. After completion of the cross-over, 24 patients were evaluable. The median percentage of nights the machine was used was 95.5% (range, 45 to 100%) on constant CPAP, and 96.5% (range, 40 to 100%) on auto-CPAP; the median apnea index recorded by the device was 0.40/h (range, 0 to 2.40/h) on constant CPAP, and 0.45/h (range, 0 to 5.80/h) on auto-CPAP (differences not significant). The mean Epworth sleepiness score was significantly (p < 0.01) lower on auto-CPAP (5.1; SD, 2.8) than on constant CPAP (6.1; SD, 2.8).
                In patients selected for a high within-night variability in pressure requirement, auto-CPAP administered via a GK418A device was equivalent to constant CPAP based on a titration night in the sleep laboratory. Subjective ratings for sleepiness were slightly lower on auto-CPAP. To compare polysomnographic data and compliance in sleep apnea patients receiving continuous positive airway pressure (CPAP) and pressure-relief CPAP (PRCPAP) [C-flex; Respironics; Murrysville, PA] as first treatment in the sleep laboratory and subsequently at home.
                A prospective, randomized, crossover design was used in the sleep laboratory, and a prospective randomized design was used at home.
                Data were collected from 52 sleep apnea patients for whom CPAP was used for the first time.
                Treatment with constant CPAP and PRCPAP.
                Patients with a first-time diagnosis of obstructive sleep apnea syndrome (OSAS) underwent conventional CPAP titration. Thereafter, polysomnography was performed at the titrated pressure using both the fixed CPAP pressure mode and the PRCPAP mode in a randomized crossover approach. The patients were then discharged home for 7 weeks of treatment with the last-applied treatment mode, and compliance data were established at the end of that time. The average apnea-hypopnea index was 53.3/h in the "diagnostic night," 5.8/h with CPAP, and 7.0/h with PRCPAP. The native arousal index was 35.2/h, 12.6/h with CPAP, and 12.9/h with PRCPAP (not significant [NS]). The central apnea index was 0.7/h with CPAP and 1.2/h with PRCPAP (p < 0.05). Compliance after 7 weeks was, on average, 9.4 min longer with PRCPAP than with CPAP (NS). Evaluation of a 13-item questionnaire showed scores of 16.4 for PRCPAP and 18.1 for constant CPAP (NS) [the fewer the complaints, the lower the score]. With regard to oral dryness, the score with PRCPAP (1.4) was significantly lower than with constant CPAP (1.9) [p < 0.05]. This difference was no longer detectable after 7 weeks.
                In terms of the effectiveness in treating obstructive sleep apnea, PRCPAP and constant CPAP are comparable. During the first night of treatment, patients receiving PRCPAP had less dryness of mouth; over a period of 7 weeks, this difference disappeared. Nightly use of the device was comparable in both groups. PRCPAP is therefore a new ventilation mode that enables effective treatment of OSAS patients. Further studies should be done to investigate the effects of expiratory pressure lowering in low-compliance patients and patients requiring CPAP > 9 cm H(2)O or experiencing dry mouth with CPAP. To compare the efficacy and patient tolerance, compliance, and preference between auto-continuous positive airway pressure (CPAP) and constant CPAP.
                Single-blinded, crossover, cohort study of consecutive patients with obstructive sleep apnea syndrome, with two treatment periods of 2 months each.
                Twenty-five patients (22 men, 3 women) with sleep apnea syndrome confirmed by ambulatory polysomnography.
                After baseline polysomnography, patients underwent in-laboratory polysomnography for titration of constant CPAP. The order of treatment was randomly allocated, either auto-CPAP and then constant CPAP, or vice versa. The auto-CPAP pressure range was 6 to 16 cm H(2)O. At the end of each 2-month period, patients underwent a control ambulatory polysomnography and received a questionnaire on subjective well-being and device evaluation. Duration of use was checked through CPAP device monitoring.
                No differences were found in apnea/hypopnea index (constant CPAP, 9.7+/-1.9 events/h vs auto-CPAP, 10.6+/-9.3 events/h), awakening/arousal index (constant CPAP, 13.7 +/- 8.0 events/h vs auto-CPAP, 15.5 +/- 8.9 events/h), slow-wave sleep duration, nocturnal saturation, or complaint of daytime sleepiness. The mean pressure required was significantly lower during auto-CPAP than during constant CPAP (8.8+/-1.8 cm H(2)O vs. 9.7+/-2.6 cm H(2)O, respectively). Patient tolerance, compliance, and duration of use were similar with both treatments.
                Auto-CPAP is as effective as constant CPAP. A wide pressure range for auto-CPAP can be used in all patients, suggesting that, in the future, use of a broad pressure range in the auto-CPAP mode could obviate the need for the titration night. The aims of this study were to compare compliance to treatment with fixed CPAP and with autoCPAP, subjective preference for type of CPAP treatment, and factors associated to preference for autoCPAP in patients with OSAS.
                Twenty-two subjects were studied in a randomized, single blind cross-over fashion. They were treated for one month by fixed CPAP (Elite Sullivan V, ResMed, Sydney, Australia) and one month by autoCPAP (Autoset T, ResMed, Sydney, Australia).
                Four subjects who stated a preference for fixed CPAP and four who expressed no preference were pooled together; fourteen preferred autoCPAP. Compliance to treatment using the two machines did not differ in the first group (3.8 (1.9) vs. 3.8 (1.5)h/day, fixed vs autoCPAP), but was higher with autoCPAP in the second group (4.8 (1.8) vs 5.5 (1.5)h/day, P<0.05). Baseline apnea/hypopnea index (AHI) was high in both groups, but was higher in the second group P<0.02. First treatment was always fixed CPAP in patients who preferred fixed CPAP, while it was either in the other subjects.
                Compliance to autoCPAP differs among OSAS patients. As long as factors predicting higher compliance to autoCPAP are not found, a trial with autoCPAP in patients poorly compliant to fixed CPAP may be warranted. Continuous positive airway pressure (CPAP) is effective therapy for the obstructive sleep apnea syndrome (OSAS). Automatic CPAP devices continuously adjust the positive pressure to the required levels.
                To determine the efficacy of an automatic CPAP machine used with an estimated reference pressure value.
                A before-and-after, single-blind trial in which patients were randomly allocated to one of three modes of CPAP administration.
                Referral-based sleep center in a public health care institution.
                36 outpatients with OSAS.
                Continuous positive airway pressure was given at a conventional fixed pressure (group 1), automatic CPAP was given at a measured reference pressure (group 2), and automatic CPAP was given at an estimated reference pressure (group 3). In group 1, the effective pressure was determined during a titration sleep study. In groups 2 and 3, the pressure interval was allowed to vary from 4 cm H2O below reference pressure to 3 cm H2O above reference pressure. In group 3, the estimated value of the reference pressure was determined according to individual anthropometric characteristics.
                Sleep studies were performed and measurements of diurnal sleepiness were obtained at each visit.
                Sleep and breathing disorders and hypersomnolence were alleviated similarly in the three groups. The apnea + hypopnea index remained abnormal in one patient in group 3 for whom the reference pressure had been underestimated. A strong negative correlation was found between the percentage of time spent below reference pressure during CPAP and the difference between the effective and estimated pressures.
                Automatic CPAP can be used with an estimated reference pressure without doing a titration sleep study. The positive pressure trend can be used to determine whether treatment failure is caused by an inadequate pressure setting and to determine the amount of pressure to apply. To compare compliance and treatment response between continuous positive airway pressure (CPAP) and auto-titrating positive airway pressure (APAP) and to develop selection criteria for the use of APAP.
                Randomized, single-blinded, parallel crossover study.
                Tertiary referral sleep disorders center.
                Consecutive patients with obstructive sleep apnea syndrome requiring treatment with CPAP.
                2-month treatment each of conventional CPAP and APAP in random order comparing objective compliance, Epworth Sleepiness Score, SF-36 Health Survey, visual-analog measures of ease of and attitude to treatment, side effects, and treatment pressures or system leaks obtained from the Autoset T device.
                There were no differences between treatment modes in overall compliance (CPAP 4.86 +/- 2.65, APAP 5.05 +/- 2.38 hours per night, P = .14), Epworth Sleepiness Scale scores (baseline 12.4 +/- 5.1, CPAP 8.4 +/- 5.2, APAP 7.9 +/- 4.8, P < .001 relative to baseline, NS between modes), SF-36 scores (significant improvements in Role Physical and Vitality domains relative to baseline, P < .001 but NS between modes). There were fewer reported side effects in APAP mode (CPAP 28, APAP 15 reports, P = .02) and compliance was greater with APAP in those reporting any side effect (95% confidence interval CPAP 0-6.8, APAP 2.9-7.8 hours per night, P < .001). APAP delivered significantly lower median and 95th centile airway pressures and fewer system leaks.
                Compliance, subjective sleepiness, and quality of life are similar between patients who used CPAP and APAP. APAP delivers lower pressures and results in lower-pressure leaks and fewer reported side effects. Compliance is higher with APAP in subjects reporting any side effect. APAP may be indicated in patients reporting side effects with conventional CPAP. Autoadjusting nasal continuous positive airway pressure (CPAP) greatly reduces the apnoea/hypopnoea index (AHI), and affords a significant reduction in median pressure (P50) compared-with manually titrated conventional nasal CPAP. The aim of the present study was to test whether these benefits were maintained in the medium term at home, in a double-blind crossover study. Ten sequential subjects (mean AHI 52.9 x h(-1)) were enrolled. After a manual titration, subjects were randomly allocated to 2 months autoadjusting nasal CPAP (AutoSet), followed by 2 months with the AutoSet device in fixed pressure mode at the manually titrated pressure, or vice versa. The machine-scored AHI, P50, and median leak were recorded on 12 nights in each arm, and averaged. Mean+/-SEM AHI was 4.0+/-0.3 x h(-1) in auto mode, and 3.7+/-0.3 x h(-1) in manual mode (NS). Mean+/-SEM P50 was 7.2+/-0.4 cmH2O auto, 9.4+/-0.6 cmH2O manual, average reduction 23+/-4% (p<0.0001). Auto "recommended" pressure was (mean+/-SEM) 10.1+/-0.5 cmH2O (p=0.04 with respect to manual) and peak pressure typically 1 cmH2O higher. Median (+/-SEM) leak was 0.181+/-0.006 L x s(-1) auto (and uncorrelated with AHI or pressure), 0.20+/-0.006 L x s(-1) manual (p=0.003). Compliance was 6.3+/-0.4 h in auto mode and 6.1+/-0.5 h in fixed mode (NS). Apnoea/hypopnoea index during 2 months of home autoadjusting nasal continuous positive airway pressure is comparable to that during conventionally titrated fixed pressure continuous positive airway pressure, while affording a 23% reduction in median pressure but no increase in compliance. Leak did not importantly affect autoadjustment. Constant continuous positive airway pressure (CPAP) is the treatment of choice for the obstructive sleep apnea syndrome (OSAS). To enable the pressure to be matched more accurately to actual requirements, and thus increase patient acceptance, an autoadjusting device based on the measurement of upper airway impedance was developed (APAP(FOT)). We investigated the efficacy and compliance in continuous use at home. Fifty-two patients were treated (randomized crossover) with CPAP and APAP(FOT) for 6 wk each. Respiratory disturbances, sleep profile, and arousals improved significantly with both modes (AHI: baseline, 35.1 +/- 26/h; APAP(FOT), 5.0 +/- 5.2; CPAP, 4.3 +/- 6.3; p < 0.001 baseline versus each mode). The mean pressure with APAP(FOT) was significantly reduced as compared with CPAP (CPAP, 7.8 +/- 1.5 cm H2O; APAP(FOT), 5.7 +/- 1.8 cm H2O; p < 0.001). Under APAP(FOT) the pressure was lower than that under CPAP for 81.5 +/- 21% of the time. Although overall use did not differ, 75% of the patients preferred APAP(FOT) for home treatment. We conclude that APAP(FOT) is as efficacious as constant CPAP in the treatment of OSAS. The treatment pressure can be reduced significantly, and sleep microstructure improved with APAP(FOT). These might be the reasons for patient preference of automatic therapy. A strong association between obstructive sleep apnea (OSA) and the risk for cardiovascular and cerebrovascular diseases has been reported. Continuous positive airway pressure (CPAP) is the first-line therapy for OSA, able not only to reduce daytime sleepiness but also to improve cardiovascular and metabolic outcomes. Autoadjusting CPAP (APAP), an alternative treatment to CPAP, can reduce OSA symptoms while increasing long-term CPAP compliance without the high costs of CPAP titration. However, no data are available on the effects of APAP on cardiovascular risk factors
                We performed standard full polysomnography; obtained plasma levels of glucose, insulin, and C-reactive protein (CRP); and measured systolic BP (SBP) and diastolic BP (DBP) in 31 patients with newly diagnosed, severe OSA. After standard CPAP titration, all subjects were randomized to CPAP or APAP treatment. Measurements were obtained at baseline and after 3 months of treatment.
                The two groups were similar in terms of age, sex, body mass index (BMI), and severity of OSA. SBP, DBP, heart rate (HR), homeostasis model assessment index (HOMA-IR), and CRP were similar in the two groups. After 3 months of treatment, BMI, HR, and compliance to therapy were also comparable. OSA indexes were significantly reduced in both groups. Significant reductions in SBP, DBP, and HOMA-IR were observed in the CPAP group but not in the APAP group, while CRP plasma levels were similarly reduced.
                Our results suggest that CPAP and APAP, despite significant effects on OSA indexes and symptoms, do not improve cardiovascular risk factors in the same fashion. Recent objective studies demonstrate relatively low hours of nightly use during nasal continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea (OSA). Patients frequently complain of dyspnea or discomfort during CPAP use, especially during expiration (against the continuous pressure), which may be a reason for the low hours of use. We hypothesized that with decreased expiratory pressure, hours of nightly use would increase. Therefore, we randomized 83 OSA patients to receive either continuous or bilevel positive airway pressure when expiratory pressure is lower. To document objectively the effective use of either therapy, we built and installed elapsed-time and mask pressure sensors in the patients' positive airway pressure units. A total of 62 patients were evaluable and followed for 1 yr. Of these, 26 received bilevel and 36 CPAP pressures. The machine timers measured accumulated "machine-on" time, and the mask pressure sensor recorded the total time in which the mask pressure was within 2 cm H2O of the effective pressure (pressure shown to eliminate 95% of the obstructive apneas during a full night of polysomnography). The mean machine timer hours of CPAP were 5.0 +/- 0.19 SEM and 4.9 +/- 0.23 SEM during bilevel therapy (p NS) over a 12-mo period. The pressures required during CPAP or bilevel therapy were not different between high and low hourly users. Effective use, the percentage of time that the machine was running and the prescribed pressure was being delivered, was 80% in CPAP and 82% in the bilevel users (p NS). Both groups had equal complaints with regard to mask discomfort, machine noise, and nasal stuffiness.(ABSTRACT TRUNCATED AT 250 WORDS) Quality of life (QOL) and sleepiness for patients with sleep apnea/hypopnea syndrome (SAHS) might improve with continuous positive airway pressure devices working in auto-adjust mode (autoCPAP) by allowing pressure modulations following patient needs. Clinical comparisons between devices driven by different algorithms are needed.
                We compared the clinical effectiveness of fixed pressure CPAP and four different autoCPAP devices by assessing compliance and QOL (36-item short-form health survey [SF-36]). SAHS patients were randomly allocated to five groups. Polysomnography (PSG) was performed to titrate the effective pressure in the constant CPAP group and evaluate residual apnea/hypopnea index (AHI) under autoCPAP. Follow-up consisted of clinical visits at three and six months by homecare technicians who assessed compliance, symptom scores and SF-36 scores. A laboratory-based PSG using the same CPAP/autoCPAP device as at home was performed at six months.
                Eighty-three patients (mean age 56+/-10 yrs) with mean body mass index (BMI) 30.8+/-5.3 kg/m(2) and severe SAHS (mean AHI: 52.3+/-17.8/h) were included. There were no differences in clinical symptoms or QOL scores, and similar clinical and PSG improvements were seen in all groups. CPAP use was >5 h per night, without any significant difference between groups.
                AutoCPAP is equally as effective as fixed CPAP for long-term home treatment in severe SAHS patients. Automatic CPAP has been developed to improve CPAP efficiency and compliance. Continually matching the effective pressure may be associated to more frequent arousals that could disturb sleep. The aim of the present study was to compare sleep architecture after one month's home therapy with CPAP or with an AutoCPAP device.
                Twenty OSAS patients (18 M / 2 F) after polysomnographic study with CPAP titration received either an automatic (AutoSet T, ResMed, Sydney, Australia) or a fixed level CPAP machine in a random, single blind fashion for one month. At the end of the home treatment period polysomnography was repeated while CPAP was administered by the same machine used at home.
                There was no significant difference between groups in terms of age (50.0 vs 45.5, NS), sex, BMI (38.3 vs 35.1, NS), RDI (45.4 vs 48.0, NS), and CPAP effective level (9.8 vs 10.8, NS). After one month of therapy the correction of sleep respiratory disturbances and of sleep structure was satisfactory in both groups. No difference in any polysomnographic variable or in subjective sleepiness was found at re-evaluation.
                The results of this study demonstrate that on average CPAP administered by a fixed CPAP machine and by the AutoSet T autoCPAP device has similar effects in improving respiratory function during sleep, nocturnal sleep architecture, and subjective daytime sleepiness after a one-month therapy. As autoCPAP devices are more expensive than fixed CPAP machines, their prescription should be considered only after a clear demonstration of an increase in compliance to treatment by these devices. The auto-CPAP (Morphée Plus) is characterized by its ability to modify the positive-pressure level applied during the night for the presence or absence of sleep-induced respiratory disorders. The aim of the study was to compare the efficacy of this new mode of CPAP therapy with that of conventional constant-CPAP in the treatment of sleep apnea/hypopnea syndrome (SAHS). Sixteen patients with SAHS were randomly allocated to two groups that were paired for age, apnea/hypopnea index, and mean sleep latency. In the auto-CPAP group, the pressure level could change within fixed limits in both directions (+2 to -4 cm H2O) of the previously determined effective pressure level (Peff). In the constant-CPAP group, patients used the same apparatus (Morphée Plus) in a constant mode at Peff level. At the beginning of the study, the Peff level was determined during a polysomnographic recording. Day-time vigilance was measured subjectively by a standardized questionnaire and objectively by the maintenance of wakefulness test (MWT); Trailmaking tests (TMT) were used to evaluate cognitive functions. After 3 wk of home CPAP therapy, a control sleep study was done with the CPAP machine used in the protocol, and daytime vigilance and cognitive function tests were obtained. Baseline sleep and nocturnal breathing disorders characteristics did not differ between the two groups, and daytime vigilance and cognitive function abnormalities were similarily altered. In both groups, the apnea/hypopnea index was within normal range at the final CPAP sleep study. In the auto-CPAP group, 49.3 +/- 14.9% (mean +/- SD) of home treatment time was spent at a pressure < or = Peff. Home amount of use estimated by the number of sleeping hours with a positive pressure applied was 6.5 +/- 1.0 h in the auto-CPAP group and 5.1 +/- 1.1 h in the constant-CPAP group (p = 0.02). During the control CPAP sleep study, the positive pressure level was significantly lower during Stage III-IV than during the other sleep stages (p = 0.004). The improvement in the MWT and the TMT observed with CPAP therapy was identical in both groups. We conclude that (1) the amount of use during CPAP treatment is higher with auto-CPAP than with constant-CPAP, and (2) Morphée+auto-CPAP is an efficient as conventional CPAP in correcting nocturnal breathing disorders, daytime sleepiness, and cognitive impairment in SAHS. The simplest method of initiating and maintaining therapeutic continuous positive airways pressure (CPAP) therapy for obstructive sleep apnoea (OSA) has not been established.
                Ninety eight subjects with OSA requiring CPAP treatment (more than 10 dips in oxygen desaturation of >4% per hour of sleep study and Epworth Sleepiness Score (ESS) >9) were randomised prospectively to three different methods of CPAP delivery for 6 months: (1) autotitration pressure throughout; (2) autotitration pressure for 1 week followed by fixed pressure (95th centile) thereafter; and (3) fixed pressure determined by algorithm (based on neck size and dip rate). Patients and investigators were blind to group allocation. One week after initiation the patients were routinely reviewed by sleep nurses. Study assessments took place before starting CPAP treatment and 1 and 6 months after to assess ESS, maintenance of wakefulness test, 24 hour blood pressure, general health (SF-36), and sleep apnoea related quality of life. CPAP internal monitoring data were also collected.
                There were no significant differences in any of the outcome measures or CPAP monitoring data between the three groups. The 95th centile CPAP pressures delivered in the 6 month and 1 week autotitration groups were higher than in the algorithm group, but the median pressures were lowest in the 6 month autotitration group.
                The method of determining CPAP pressure for treatment of moderate to severe OSA makes no significant difference to clinical outcome measures. The autotitration CPAP machine used has no advantage in this setting over simpler methods of pressure determination. Patients with mild to moderate obstructive sleep apnoea (OSA) may be managed with different treatment options. This study compared the effectiveness of three commonly used non-surgical treatment modalities.
                Subjects with mild to moderate OSA were randomised to one of three treatment groups for 10 weeks: conservative measures (sleep hygiene) only, continuous positive airways pressure (CPAP) in addition to conservative measures or an oral appliance in addition to conservative measures. All overweight subjects were referred to a weight-reduction class. OSA was assessed by polysomnography. Blood pressure was recorded in the morning and evening in the sleep laboratory. Daytime sleepiness was assessed with the Epworth Sleepiness Scale. Health-related quality of life (HRQOL) was assessed with the 36-Item Short-Form Health Survey (SF-36) and Sleep Apnoea Quality of Life Index (SAQLI).
                101 subjects with a mean (SEM) apnoea-hypopnoea index (AHI) of 21.4 (1.1) were randomised to one of the three groups. The severity of sleep-disordered breathing was decreased in the CPAP and oral appliance groups compared with the conservative measures group, and the CPAP group was significantly better than the oral appliance group. Relief from sleepiness was significantly better in the CPAP group. CPAP was also better than the oral appliance or conservative measures in improving the "bodily pain" domain, and better than conservative measures in improving the "physical function" domain of SF-36. Both CPAP and the oral appliance were more effective than conservative measures in improving the SAQLI, although no difference was detected between the CPAP and oral appliance groups. CPAP and the oral appliance significantly lowered the morning diastolic blood pressure compared with baseline values, but there was no difference in the changes in blood pressure between the groups. There was also a linear relationship between the changes in AHI and body weight.
                CPAP produced the best improvement in terms of physiological, symptomatic and HRQOL measures, while the oral appliance was slightly less effective. Weight loss, if achieved, resulted in an improvement in sleep parameters, but weight control alone was not uniformly effective. To determine if auto-adjusting positive airway pressure (APAP) would be better tolerated on the basis of delivering a lower mean pressure in patients with mild to moderate obstructive sleep apnoea syndrome (OSAS).
                Patients spent 8 weeks on continuous positive airway pressure (CPAP) and 8 weeks on APAP in a randomized crossover design.
                Respiratory Sleep Disorders Unit in a University Hospital and the patient's home.
                Twenty-nine patients with newly diagnosed mild to moderate OSAS (apnoea-hypopnoea frequency of 5-30 events/hour) were studied.
                N/A.
                Overnight polysomnography and Epworth Sleepiness Scale were recorded at baseline and at the end of each treatment period in addition to patient preference for device, side effects, and objective compliance. No differences were found in polysomnographic variables or Epworth Sleepiness Scale scores between the 2 treatment modes, but all variables were significantly improved from baseline values. Mean APAP pressure levels were significantly lower than CPAP (6.3 +/- 1.4 vs 8.1 +/- 1.7 cm H2O, p < .001). Patient compliance was similar with both treatments. More patients requiring higher fixed pressure (> or = 8cm H2O) preferred APAP, whereas those requiring lower pressure (< 8 cm H2O) preferred CPAP (p = .03). Follow-up after 18 months of therapy indicated that 76% of subjects continued to be compliant, with a nightly use of 5.8 +/- 1.9 hours per night, despite high levels of minor side effects.
                APAP and CPAP are equally effective in managing patients with mild to moderate OSAS, but device preference may be influenced by fixed pressure requirements. Continuous positive airway pressure (CPAP) remains the treatment of choice for obstructive sleep apnea hypopnea (OSAH). Auto-titrating CPAP (APAP) devices automatically adjust pressure and may improve treatment compliance compared to fixed CPAP (F-CPAP).
                Randomized, prospective, single-blind, crossover trial to compare efficacy, side effects, compliance, patient satisfaction and preference between APAP and F-CPAP therapy in patients with moderate to severe OSAH. There were two treatment periods of 4 weeks each (APAP and F-CPAP), separated by a 2-week washout period.
                Ten CPAP-naive OSAH patients (9 males) completed the study. They had Mean +/- SD age of 44.9 +/- 9.7 years; body mass index of 35.9 +/- 12.9 kg/m2 and apnea/hypopnea index (AHI) of 47.2 +/- 35.6. Both forms of therapy were equally effective in improving the symptoms and in reducing the AHI. Both forms of therapy were associated with frequent side effects and had similar patient compliance. At the end of the study, more patients (6-1) preferred F-CPAP to A-CPAP therapy.
                A-PAP was as effective as F-CPAP in the treatment of OSAH but was not associated with fewer side effects, better compliance, better satisfaction or increased patient preference. To evaluate whether bilevel positive airway pressure, by actively assisting inhalation, more rapidly improves ventilation, acidemia, and dyspnea than continuous positive airway pressure (CPAP) in patients with acute pulmonary edema.
                Randomized, controlled, double-blind trial.
                Emergency department in a university hospital.
                Twenty-seven patients, presenting with acute pulmonary edema, characterized by dyspnea, tachypnea, tachycardia, accessory muscle use, bilateral rales, and typical findings of congestion on a chest radiograph.
                In addition to standard therapy, 13 patients were randomized to receive nasal CPAP (10 cm H2O), and 14 patients were randomized to receive nasal bilevel positive airway pressure (inspiratory and expiratory positive airway pressures of 15 and 5 cm H2O, respectively) in the spontaneous/timed mode that combines patient flow-triggering and backup time-triggering.
                After 30 mins, significant reductions in breathing frequency (32 +/- 4 to 26 +/- 5 breaths/min), heart rate (110 +/- 21 to 97 +/- 20 beats/min), blood pressure (mean 117 +/- 28 to 92 +/- 18 mm Hg), and Paco2 (56 +/- 15 to 43 +/- 9 torr [7.5 +/- 2 to 5.7 +/- 1.2 kPa]) were observed in the bilevel positive airway pressure group, as were significant improvements in arterial pH and dyspnea scores (p < .05 for all of these parameters). Only breathing frequency improved significantly in the CPAP group (32 +/- 4 to 28 +/- 5 breaths/min, p < .05). At 30 mins; the bilevel positive airway pressure group had greater reductions in Paco2 (p = .057), systolic blood pressure (p = .005), and mean arterial pressure (p = .03) than the CPAP group. The myocardial infarction rate was higher in the bilevel positive airway pressure group (71%) compared with both the CPAP group (31%) and historically matched controls (38%) (p = .05). Duration of ventilator use, intensive care unit and hospital stays, and intubation and mortality rates were similar between the two groups.
                Bilevel positive airway pressure improves ventilation and vital signs more rapidly than CPAP in patients with acute pulmonary edema. The higher rate of myocardial infarctions associated with the use of bilevel positive airway pressure highlights the need for further studies to clarify its effects on hemodynamics and infarction rates, and to determine optimal pressure settings. The addition of both noninvasive continuous positive airway pressure (n-CPAP) or noninvasive intermittent positive pressure ventilation (n-IPPV) to medical treatment has been shown to improve the outcome of patients with acute cardiogenic pulmonary edema (ACPE). Previous studies indicated a potential risk of new-onset acute myocardial infarction (AMI) associated with the use of n-IPPV. Although further studies did not confirm this observation, a few recent metaanalyses could not eliminate all the doubts at this regards because of the paucity of data available and the presence of confounding factors. This study aims to assess whether the application of n-IPPV, as opposed to n-CPAP, increases the rate of AMI in ACPE patients.
                Fifty-two patients with severe hypoxemia consequent to ACPE were randomized to receive n-CPAP (n = 27) or n-IPPV (n = 25) in addition to medical therapy. Patients with signs of acute coronary syndrome on hospital admission were excluded from the study. Cardiac markers, ECG, and clinical/physiologic parameters were assessed at study entry, after 30 and 60 min, and every 6 h for the first 2 days.
                No significant difference was observed in the rate of AMI (26.9% and 16% with n-CPAP and n-IPPV, respectively, p = 0.244). Rate of intubation (p = 0.481), death (p = 0.662), and hospital stay (p = 0.529) were not different between the two groups. Both techniques were effective in improving gas exchange and vital signs in patients with ACPE.
                The AMI rate was not different with n-CPAP and n-IPPV, which resulted to be equally effective in the treatment of ACPE. Trial registration: Clinicaltrials.gov Identifier: NCT00453947. Our objective was to evaluate the efficacy of noninvasive continuous positive airway pressure (CPAP) delivered by helmet in improving oxygenation in comparison with oxygen therapy in community-acquired pneumonia (CAP).
                This was a multicenter, randomized, controlled trial enrolling patients with CAP admitted to an ED with moderate hypoxemic acute respiratory failure (ARF) (Pa(O(2))/Fi(O(2)) ratio > or = 210 and < or = 285). Patients were randomized to helmet CPAP or standard oxygen therapy (control group). The primary end point was the time to reach a Pa(O(2))/Fi(O(2)) ratio > 315. After reaching this value, patients randomized to CPAP were switched to oxygen, and the proportion of subjects who could maintain a Pa(O(2))/Fi(O(2)) ratio > 315 at 1 h was recorded.
                Forty-seven patients were recruited: 20 randomized to CPAP and 27 to controls. Patients randomized to CPAP reached the end point in a median of 1.5 h, whereas controls reached the end point in 48 h (P < .001). The proportion of patients who reached the primary end point was 95% (19/20) among the CPAP group and 30% (8/27) among controls (P < .001). One hour after reaching the primary end point, 2/14 patients in the CPAP group maintained a Pa(O(2))/Fi(O(2)) value > 315.
                CPAP delivered by helmet rapidly improves oxygenation in patients with CAP suffering from a moderate hypoxemic ARF. This trial represents a proof-of-concept evaluation of the potential usefulness of CPAP in patients with CAP. Autoadjusting CPAP devices (APAP) are designed to continuously adjust the positive pressure to the required levels, and thus increase treatment quality and patient compliance. The results of APAP treatment strongly depend on the control mechanism of the respective APAP device. In agreement with other working groups, we have recently shown that the forced oscillation technique (FOT) is capable of detecting incipient upper airway obstruction prior to physiological reactions such as the onset of increasing esophageal pressure swings or microarousals. Therefore we studied efficacy and acceptance of a novel APAP device controlled exclusively by FOT. 100 consecutive patients with OSAS confirmed by polysomnography (mean AHI 47.9 +/- 22.6) and daytime sleepiness (Epworth sleepiness scale, ESS 12.6 +/- 3.9) were randomized to either APAP treatment (n = 50) or conventional CPAP treatment (n = 50). Polysomnographies were performed at the second treatment night and subjective sleepiness (modified ESS) was established in the morning. The respiratory disturbance was largely normalized in both treatment groups in the second treatment night (AHI 4.7 +/- 5.3 vs. 3.7 +/- 3.4; n.s.). Both groups showed largely improved sleep profiles and had markedly reduced ESS-scores (6.6 +/- 3.6 vs. 7.0 +/- 3.4; n.s.). The mean treatment pressure during APAP was significantly lower than during CPAP treatment (6.0 +/- 2.0 vs. 9.0 +/- 1.8 mbar; p < 0.001). There were no significant differences between APAP and CPAP treatment in any parameter of efficacy or acceptance. APAP treatment with this device controlled exclusively by FOT is well accepted by the patients and permits an adequate treatment of OSAS without the need for invidiual CPAP titration. We evaluated the efficacy of two different continuous positive airway pressure devices with automatic mask pressure adjustment (autoCPAP) in comparison with fixed CPAP in treating obstructive sleep apnea syndrome in 29 patients. The mean (+/- SE) apnea-hypopnea index was 46 +/- 4 per hour and the Epworth score was 14.2 +/- 0.7. Patients were treated over three consecutive 1-month periods with three regimens in random order: an autoCPAP device responding to apnea-hypopnea and snoring, another autoCPAP device responding to snoring and changes in flow contour, and fixed CPAP at the 90th pressure percentile titrated by autoCPAP over 2 weeks. Allowed pressure in the autoCPAP mode was 4 to 15 cm H2O. At the end of each treatment period, symptoms, quality of life, vigilance, and nocturnal breathing disturbances were evaluated. All three treatment modalities improved symptoms, quality-of-life domains, and apnea-hypopnea index significantly and to a similar degree. Mean (+/- SE) maintenance-of-wakefulness time increased by 4.5 +/- 1.8, 6.0 +/- 1.5, and 6.1 +/- 1.4 minutes with DeVilbiss AutoAdjust LT, AutoSet T, and fixed-pressure CPAP, respectively (p<0.001 vs. baseline, p=not significant for comparisons among the three modalities). We conclude that both autoCPAP devices were equally effective as fixed-pressure CPAP in improving major outcomes during short-term therapy of sleep apnea. Although continuous positive airway pressure (CPAP) therapy using a face mask is known to improve oxygenation, the intrapulmonary shunt reduction remains unsettled. Our study was designed to explore this issue. From 1985 to 1987 80 patients with acute cardiogenic pulmonary edema were randomly chosen to receive either serial CPAP therapy or high-flow face mask oxygen therapy without CPAP (control) for the purpose of evaluating the efficacy of CPAP therapy. After screening for exclusion, only 55 patients were included in the first 3-hour investigation period. PaO2 in the CPAP group showed a significant increase by the end of the initial study; whereas intrapulmonary shunt and alveolar-arterial oxygen tension gradient AaDO2 revealed simultaneously a significant reduction. Conversely, neither PaO2 nor intrapulmonary shunt (or AaDO2) in the control group demonstrated any significant beneficial changes. As for cardiovascular function, only the CPAP therapy achieved a significant reduction in rate pressure product in contrast to the control (face mask) therapy alone. In terms of therapeutic failure, 10 patients in the control group failed. However, in the CPAP group only 5 patients had failed at the end of the first 3-hour study period. Overall, the cumulative therapeutic failure rate was 28% in the CPAP group and 60% in the control group during a 6-hour observation study. However, there was no significant difference between the two groups in 24-hour hospital mortality.(ABSTRACT TRUNCATED AT 250 WORDS) Both non-invasive continuous positive airway pressure (nCPAP) and non-invasive pressure support ventilation (nPSV) have been shown to be effective treatment for acute cardiogenic pulmonary edema (ACPE). In patients with severe ACPE who are treated with standard medical treatment, the baseline intubation rate is approximately 24%.
                This study was conducted to compare the endotracheal intubation (ETI) rate using two techniques, nCPAP vs. nPSV. In addition, mortality rate, improvement in gas exchange, duration of ventilation, and hospital length of stay were also assessed.
                This prospective, multi-center, randomized study enrolled 80 patients with ACPE who were randomized to receive nCPAP or nPSV (40 patients in each group) via an oronasal mask. Inclusion criteria were severe dyspnea, respiratory rate > 30 breaths/min, use of respiratory accessory muscles, or PaO(2)/FiO(2) < 200.
                ETI was required in 0 (0%) and in 3 (7.5%) patients in the nCPAP group and in the nPSV group, respectively (p = 0.241). No significant difference was observed in in-hospital mortality: 2 (5%) vs. 7 (17.5%) in nCPAP and nPSV groups, respectively (p = 0.154). No difference in hospital length of stay was observed between the two groups, nor was there a difference observed in duration of ventilation, despite a trend for reduced time with nPSV vs. nCPAP (5.91 ± 4.01 vs. 8.46 ± 7.14 h, respectively, p = 0.052). Both nCPAP and nPSV were effective in improving gas exchange, including in the subgroup of hypercapnic patients.
                Both methods are effective treatment for patients with ACPE. Non-invasive CPAP should be considered as the first line of treatment because it is easier to use and less expensive than non-invasive PSV.
                Copyright © 2010 Elsevier Inc. All rights reserved. It is unclear whether continuous positive airway pressure (CPAP), the treatment of choice for severe obstructive sleep apnoea (OSA), is effective at improving outcomes in mild OSA.
                To help define the role of humidified CPAP in mild OSA, a randomised crossover study was undertaken of patients with an apnoea hypopnoea index (AHI) of 5-30/hour. Subjective sleepiness, objective wakefulness, mood, reaction time, and quality of life were measured at baseline, after 3 weeks treatment with humidified CPAP and 3 weeks sham CPAP (2 week washout).
                Twenty nine of 31 enrolled patients (age 25-67 years, seven women, mean (SD) body mass index 31.5 (6) kg/m2) completed the protocol. Humidified CPAP improved polysomnographic indices of OSA and Epworth Sleepiness Scale (2.4 points (95% CI 0.6 to 4.2)). Objective wakefulness (modified maintenance of wakefulness test) showed a trend towards improvement (5.2 minutes (95% CI -0.6 to 11)). Mood (Hospital Anxiety and Depression Scale), quality of life (SF 36, Functional Outcomes of Sleep Questionnaire), and reaction times (Psychomotor Vigilance Task) were not improved more than sham CPAP. Compliance with humidified and sham CPAP both averaged 4.9 hours/night. Placebo effects were evident in many outcomes and there was no clear treatment preference.
                Humidified CPAP improves subjective sleepiness and possibly objective wakefulness but not reaction times, quality of life, or mood. These results do not support the routine use of CPAP in all patients with mild OSA, but offers some support for the trialling of CPAP in those with severe sleepiness.
Improvement in average machine use of auto-CPAP was superior in studies with a cross-over design; the point estimate in parallel group trials was similar, but did not reach statistical significance. It is uncertain how use of machines in study settings relates to 'real world' use. Where preference was measured participants preferred auto-CPAP to fixed pressure CPAP. Further studies are required to assess the evidence for Bi-PAP, C-FlexTM and humidification. The studies assembled were characterised by high machine usage in the control groups, and low withdrawal rates. Future studies need to consider the effects of treatment in participants with more mild disease, and those who struggle to accept therapy despite persistent symptoms.