AUTO-CPAP TREATMENT OF OBSTRUCTIVE SLEEP- APNEA SYNDROME - A PROSPECTIVE, RANDOMIZED STUDY DURING INITIATION OF TREATMENT

Objective: The efficacy and acceptance of self-regulated continuous po sitive airway pressure (auto-CPAP) ventilation was compared with conve ntional CPAP administration in the treatment of patients with obstruct ive sleep apnoea. Patients and methods: Using a cross-over design, und er polysomnographic monitoring in a sleep laboratory, 25 patients with obstructive sleep apnoea underwent conventional CPAP or auto-CPAP tre atment. Using a questionnaire, patients gave their assessment of its a cceptability and efficacy after each treatment session. Results: The m ean pressure during treatment was the same in the two groups (7.2 +/- 1.9 versus 7.1 +/- 1.9 mbar; no significant difference). Maximal press ure during auto-CPAP averaged 3.7 +/- 2.1 mbar higher than during conv entional CPAP ventilation. The mean apnoea-hypopnoea index (AHI) durin g auto-CPAP, 4.4 +/- 4.3 mbar, during auto-CPAP was significantly high er than during conventional CPAP treatment (2.8 +/- 2.8 mbar; P = 0.04 4). In eight patients on auto-CPAP-an AHI of 5 or less could not be re ached, while an AHI of 5 or less was obtained in all but three patient s under conventional CPAP. In a subgroup of 17 patients, in whom a red uction of AHI to at most 5 was achieved with both conventional and aut o-CPAP, analysis of sleep pattern and of arousals was similar with the two forms of ventilation. Several patients reported that with auto-CP AP falling in sleep was more difficult and they slept less well. None of the patients preferred auto-CPAP. Conclusion: By means of the auto- CPAP neither a pressure reduction nor an improvement in compliance cou ld be achieved. Therapeutic effectiveness was significantly less as wi th conventional CPAP therapy.