CPAP or placebo-effect?

Neurobehavioral Impairment and CPAP Treatment Response in Mild-Moderate Obstructive Sleep Apneas

STUDY OBJECTIVES

The degree of neurobehavioral impairment and treatment response in mild-moderate obstructive sleep apnea (OSA) compared to that of an appropriate control group are unclear. This study compared neurobehavioral function and response to continuous positive airway pressure (CPAP) treatment in patients with mild to moderate OSA with those of a non-sleep apneic community sample of similar demography.

METHODS

One hundred ten patients with OSA and 31 asymptomatic community dwellers underwent overnight polysomnography and neurobehavioral testing. Participants with OSA (n = 88) were treated with CPAP for 3 months, and repeat evaluations were performed at the end of the treatment period.

RESULTS

Compared to the community sample, participants with OSA were significantly sleepier, had impaired mood and quality of life, and showed decrements in neuropsychological function, specifically psychomotor function, working memory and vigilance. Some neuropsychological and mood outcomes were normalized with CPAP, but significant decrements persisted in most outcomes even in those participants with adequate device usage.

CONCLUSIONS

Patients with mild to moderate OSA have significant neurobehavioral morbidity. During "gold standard" treatment, normal function was not achieved, even with adequate device usage. CPAP efficacy for improving sleepiness and neuropsychological function in this milder end of the OSA spectrum may be poor, which may affect CPAP adherence. These findings suggest that there may be neurological changes related to OSA that do not respond to CPAP treatment, the etiology of which requires further investigation.

Effect of Home Noninvasive Ventilation With Oxygen Therapy vs Oxygen Therapy Alone on Hospital Readmission or Death After an Acute COPD Exacerbation: A Randomized Clinical Trial

IMPORTANCE

Outcomes after exacerbations of chronic obstructive pulmonary disease (COPD) requiring acute noninvasive ventilation (NIV) are poor and there are few treatments to prevent hospital readmission and death.

OBJECTIVE

To investigate the effect of home NIV plus oxygen on time to readmission or death in patients with persistent hypercapnia after an acute COPD exacerbation.

DESIGN, SETTING, AND PARTICIPANTS

A randomized clinical trial of patients with persistent hypercapnia (Paco2 >53 mm Hg) 2 weeks to 4 weeks after resolution of respiratory acidemia, who were recruited from 13 UK centers between 2010 and 2015. Exclusion criteria included obesity (body mass index [BMI] >35), obstructive sleep apnea syndrome, or other causes of respiratory failure. Of 2021 patients screened, 124 were eligible.

INTERVENTIONS

There were 59 patients randomized to home oxygen alone (median oxygen flow rate, 1.0 L/min [interquartile range {IQR}, 0.5-2.0 L/min]) and 57 patients to home oxygen plus home NIV (median oxygen flow rate, 1.0 L/min [IQR, 0.5-1.5 L/min]). The median home ventilator settings were an inspiratory positive airway pressure of 24 (IQR, 22-26) cm H2O, an expiratory positive airway pressure of 4 (IQR, 4-5) cm H2O, and a backup rate of 14 (IQR, 14-16) breaths/minute.

MAIN OUTCOMES AND MEASURES

Time to readmission or death within 12 months adjusted for the number of previous COPD admissions, previous use of long-term oxygen, age, and BMI.

RESULTS

A total of 116 patients (mean [SD] age of 67 [10] years, 53% female, mean BMI of 21.6 [IQR, 18.2-26.1], mean [SD] forced expiratory volume in the first second of expiration of 0.6 L [0.2 L], and mean [SD] Paco2 while breathing room air of 59 [7] mm Hg) were randomized. Sixty-four patients (28 in home oxygen alone and 36 in home oxygen plus home NIV) completed the 12-month study period. The median time to readmission or death was 4.3 months (IQR, 1.3-13.8 months) in the home oxygen plus home NIV group vs 1.4 months (IQR, 0.5-3.9 months) in the home oxygen alone group, adjusted hazard ratio of 0.49 (95% CI, 0.31-0.77; P = .002). The 12-month risk of readmission or death was 63.4% in the home oxygen plus home NIV group vs 80.4% in the home oxygen alone group, absolute risk reduction of 17.0% (95% CI, 0.1%-34.0%). At 12 months, 16 patients had died in the home oxygen plus home NIV group vs 19 in the home oxygen alone group.

CONCLUSIONS AND RELEVANCE

Among patients with persistent hypercapnia following an acute exacerbation of COPD, adding home noninvasive ventilation to home oxygen therapy prolonged the time to readmission or death within 12 months.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00990132.