Continuous positive airway pressure (CPAP) with fixed mask pressure is the current standard treatment for obstructive sleep apnoea (OSA). Auto-CPAP devices apply at any time the minimally required pressure to normalise breathing and may improve patient comfort and compliance. We present an open descriptive study of auto-CPAP treatment at home in patients previously managed with conventional CPAP.

Fifteen patients with obstructive sleep apnoea (OSA), previously treated for at least one year with standard CPAP, were followed prospectively for a two month period on auto-CPAP. Outcome measures were both subjective evaluation by the patients and objective (polysomnographic) data obtained at one and two months of follow up.

The Epworth sleepiness score did not change significantly between baseline and follow up after one and two months and no systematic changes in CPAP related side effects were reported. Compared with the baseline polysomnographic values without treatment, a significant improvement in both respiratory and sleep parameters was observed during auto-CPAP. These results were not significantly different from those obtained with standard CPAP. A significant correlation was found between the effective CPAP pressure (Peff) and the amount of time spent below Peff during auto-CPAP treatment (r = 0.6, p = 0.01).

Long term auto-CPAP treatment in these patients with severe OSA appears to provide comparable efficacy to that of standard CPAP treatment.