Medline ® Abstracts for References 61-65

Whether computerized autoadjusted continuous positive airway pressure (aCPAP) is effective or even superior to constant continuous positive airway pressure (cCPAP) in the treatment of obstructive sleep apnea syndrome (OSAS) is still controversial. We performed a randomized, double-blind, controlled, cross-over trial comparing efficacy of sleep apnea home therapy by a novel aCPAP machine (REMStarAuto; Respironics; Murrysville, PA) operated in autoadjusted or constant mode. Thirty sleep apnea patients were recruited consecutively. Mean baseline Epworth sleepiness scale (ESS) score was 12.7 +/- 0.6 (+/- SD), mean sleep resistance time was 26 +/- 2 min (Osler test; Stowood Scientific Systems; Oxford, UK), and mean apnea-hypopnea index (AHI) was 41.1 +/- 3.6 h. Patients were randomly assigned to 1 month of home therapy with aCPAP followed by 1 month with cCPAP, or vice versa. After 1 month with treatment, the mean ESS score, sleep resistance time, and AHI were significantly improved (6.6 +/- 0.6, 37 +/- 1 min, and 4.6 +/- 0.7 h, respectively; all p<0.05 vs baseline). Similar effects were achieved with cCPAP (p = not significant vs aCPAP). Twenty-six patients preferred aCPAP, and 4 patients preferred cCPAP (p<0.001). We conclude that patients with OSAS preferred aCPAP over cCPAP in the initial phase of therapy. The effectiveness aCPAP in improving major outcomes was equivalent to cCPAP. Since aCPAP does not require initial titration, it is a simple and promising modality for sleep apnea home therapy.

BACKGROUND: The optimal approach to initiate positive-pressure therapy in patients with obstructive sleep apnea is still debated. Current options are autotitrating positive airway pressure (APAP) or manual titration with continuous positive airway pressure (CPAP). Procedures differ by parameters and by algorithms used for adapting pressure.

OBJECTIVES: To evaluate the efficacy of attended automatic titration in a randomized crossover study compared with manual titration over 2 nights where the sequence of the titration mode was changed. Therapy outcome was controlled after 6 weeks.

METHODS: 21 sleep apnea patients were treated using manual CPAP versus automatic APAP titration. The mode used during the 2nd night was continued for 6 weeks. Cardiorespiratory polysomnography, Epworth Sleepiness Scale (ESS), SF-36 score and compliance were assessed.

RESULTS: Apnea-hypopnea index reduction was equally effective at similar effective pressure independent of the titration mode. If APAP was applied during the 1st night, total sleep time was longer (384 vs. 331 min, p<0.01) and sleep efficacy was higher (91 vs. 81%, p<0.01) than after starting with manual titration with CPAP. Compliance was comparable in both groups (4.6 +/- 1.9 h). The ESS improved in both groups (from 12.9 to 6.5). SF-36 scores and therapeutic pressure did not much change.

CONCLUSIONS: Taking the sequence of titration into account, we found equal effectiveness of CPAP and APAP. Sleep quality was better with initial application of APAP - which favors attended automatic titration if only 1 titration night is possible. Both modes are comparable after 6 weeks regarding therapeutic pressure, efficacy, compliance and quality of life.

STUDY OBJECTIVE: To compare the effectiveness of auto-titrating continuous positive airway pressure (APAP) versus conventional continuous positive airway pressure (CPAP) in reducing the apnea-hypopnea index (AHI), reducing the mean airway pressure, improving subjective sleepiness, and improving treatment adherence in patients with obstructive sleep apnea (OSA).

DESIGN: Meta-analysis and metaregression of published randomized trials comparing APAP to CPAP.

SETTING: N/A.

PARTICIPANTS: N/A.

INTERVENTIONS: N/A.

RESULTS: We identified 9 randomized trials studying a total of 282 patients. Compared to CPAP, there was no significant advantage of APAP in reducing AHI or sleepiness (pooled APAP-CPAP posttreatment AHI and Epworth Sleepiness Scale score = -0.20 events per hour, 95% confidence interval:[-0.74,0.35], and -0.56 [-1.4,0.3]respectively). The use of APAP reduced the mean applied pressure across the night by 2.2 cm water [1.9,2.5]compared to CPAP. Adherence with therapy was not substantially improved with APAP; pooled estimate of improvement was 0.20 hours per night ([-0.16,0.57], P = .28) using a random-effects model.

CONCLUSIONS: Compared to standard CPAP, APAP is associated with a reduction in mean pressure. However, APAP and standard CPAP were similar in adherence and their ability to eliminate respiratory events and to improve subjective sleepiness. Given that APAP is more costly than standard CPAP, APAP should not be considered first-line chronic therapy in all patients with OSA. However, APAP may be useful in other situations (eg, home titrations, detection of mouth leak) or in certain subgroups of patients with OSA. Identifying circumstances in which APAP is a definite improvement over CPAP in terms of costs or effects should be the focus of future studies.

BACKGROUND: Ventilation with continuous positive airway pressure (CPAP) is the gold standard therapy for obstructive sleep apnea (OSA). However, it was recently suggested that a novel mode of ventilation, Bilevel-auto, could be equally effective in treating patients unable to tolerate CPAP. The aim of this study was to investigate the ability of Bilevel-auto to treat OSA patients whose nocturnal ventilatory disturbances are not completely corrected by CPAP.

METHODS: We enrolled 66 consecutive OSA patients, not responsive to (group A) or intolerant of (group B) CPAP treatment, after a full night of manual CPAP titration in a laboratory. Full polysomnography data and daytime sleepiness score were compared for each group in the three different conditions: basal, during CPAP, and during Bilevel-auto.

RESULTS: The apnea-hypopnea index decreased significantly during CPAP in both groups; however, in the group A, there was a further significant improvement during Bilevel-auto. The same trend was observed for oxygenation indices, while the distribution and the efficiency of sleep did not differ following the switch from CPAP to Bilevel-auto.

CONCLUSIONS: This study confirmed the role of Bilevel-auto as an effective therapeutic alternative to CPAP in patients intolerant of this latter mode of ventilation. Moreover, extending the use of Bilevel-auto to those OSA patients not responsive to CPAP, we showed a significantly better correction of nocturnal respiratory disturbances.

BACKGROUND: Millions of individuals with obstructive sleep apnoea (OSA) are treated by CPAP aimed at reducing blood pressure (BP) and thus cardiovascular risk. However, evidence is scarce concerning the impact of different CPAP modalities on BP evolution.

METHODS: This double-blind, randomised clinical trial of parallel groups of patients with OSA indicated for CPAP treatment compared the efficacy of fixed-pressure CPAP (FP-CPAP) with auto-adjusting CPAP (AutoCPAP) in reducing BP. The primary endpoint was the change in office systolic BP after 4 months. Secondary endpoints included 24 h BP measurements.

RESULTS: Patients (322) were randomised to FP-CPAP (n=161) or AutoCPAP (n=161). The mean apnoea+hypopnoea index (AHI) was 43/h (SD, 21); mean age was 57 (SD, 11), with 70% of males; mean body mass index was 31.3 kg/m(2) (SD, 6.6) and median device use was 5.1 h/night. In the intention-to-treat analysis, office systolic blood pressure decreasedby 2.2 mm Hg (95% CI -5.8 to 1.4) and 0.4 mm Hg (-4.3 to 3.4) in the FP-CPAP and AutoCPAP group, respectively (group difference: -1.3 mm Hg (95% CI -4.1 to 1.5); p=0.37, adjusted for baseline BP values). 24 h diastolic BP (DBP) decreased by 1.7 mm Hg (95% CI -3.9 to 0.5) and 0.5 mm Hg (95% CI -2.3 to 1.3) in the FP-CPAP and AutoCPAP group, respectively (group difference: -1.4 mm Hg (95% CI -2.7 to -0.01); p=0.048, adjusted for baseline BP values).

CONCLUSIONS: The result was negative regarding the primary outcome of office BP, while FP-CPAP was more effective in reducing 24 h DBP (a secondary outcome).

TRIAL REGISTRATION NUMBER: NCT01090297.