Constant vs. automatic continuous positive airway pressure therapy: home evaluation

Chest. 2000 Oct;118(4):1010-7. doi: 10.1378/chest.118.4.1010.


Study objectives: To compare the efficacy and patient tolerance, compliance, and preference between auto-continuous positive airway pressure (CPAP) and constant CPAP.

Design: Single-blinded, crossover, cohort study of consecutive patients with obstructive sleep apnea syndrome, with two treatment periods of 2 months each.

Patients: Twenty-five patients (22 men, 3 women) with sleep apnea syndrome confirmed by ambulatory polysomnography.

Measurements and interventions: 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.

Results: 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.

Conclusions: 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.

Publication types

  • Clinical Trial
  • Comparative Study
  • Evaluation Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Circadian Rhythm / physiology
  • Cross-Over Studies
  • Female
  • Home Care Services / standards*
  • Humans
  • Male
  • Middle Aged
  • Patient Compliance
  • Polysomnography
  • Positive-Pressure Respiration / methods*
  • Single-Blind Method
  • Sleep / physiology
  • Sleep Apnea Syndromes / diagnosis
  • Sleep Apnea Syndromes / physiopathology
  • Sleep Apnea Syndromes / therapy*
  • Surveys and Questionnaires
  • Treatment Outcome