Chest
Volume 126, Issue 1, July 2004, Pages 31-37
Journal home page for Chest

Clinical Investigations
SLEEP AND BREATHING
Constant vs Auto-Continuous Positive Airway Pressure in Patients With Sleep Apnea Hypopnea Syndrome and a High Variability in Pressure Requirement

https://doi.org/10.1378/chest.126.1.31Get rights and content

Study objectives:

Auto-continuous positive airway pressure (CPAP) has been reported to have no more efficacy than constant CPAP in unselected patients with sleep apnea hypopnea syndrome (SAHS). The aim of this study was to evaluate patients judged to be good candidates for auto-CPAP because of a high within-night variability in pressure requirement.

Design:

Single-blind, randomized, cross-over study (2 × 8 weeks) to compare auto-CPAP with constant CPAP.

Patients:

Outpatients with moderate-to-severe SAHS attending the chest clinic.

Interventions:

Patients were equipped at home in the auto-CPAP mode (model GK418A; Malinckrodt; Nancy, France), using a 4- to 14-cm H2O pressure range. Those individuals having a high within-night variability in pressure requirement, assessed at the end of a 14-day run-in period, were included in the cross-over study. Auto-CPAP was compared with constant CPAP (according to a titration night in the sleep laboratory) in terms of compliance, efficacy on apneas (assessed from the pressure monitor), and sleepiness (assessed on the Epworth sleepiness scale).

Measurements and results:

Of 90 consecutive patients with SAHS, 27 patients were selected for a within-night variability in pressure requirement exceeding a given threshold. After completion of the cross-over, 24 patients were evaluable. The median percentage of nights the machine was used was 95.5% (range, 45 to 100%) on constant CPAP, and 96.5% (range, 40 to 100%) on auto-CPAP; the median apnea index recorded by the device was 0.40/h (range, 0 to 2.40/h) on constant CPAP, and 0.45/h (range, 0 to 5.80/h) on auto-CPAP (differences not significant). The mean Epworth sleepiness score was significantly (p < 0.01) lower on auto-CPAP (5.1; SD, 2.8) than on constant CPAP (6.1; SD, 2.8).

Conclusions:

In patients selected for a high within-night variability in pressure requirement, auto-CPAP administered via a GK418A device was equivalent to constant CPAP based on a titration night in the sleep laboratory. Subjective ratings for sleepiness were slightly lower on auto-CPAP.

Section snippets

Study Design

The study protocol was approved by the Ethics Committee of the Hôpital Erasme, and all patients gave informed consent. All patients went to the sleep laboratory for baseline polysomnography and a classical CPAP titration, in order to assess an effective pressure. Treatment with CPAP at home was initiated at the chest clinic by a respiratory physician (A.N.). In the run-in period, all patients were given a machine in the auto-CPAP mode with a 4- to 14-cm H2O pressure range. The recorded data

Patients

Ninety-three patients attending the chest clinic were eligible for the study on the basis of their polysomnographic results and absence of exclusion criteria. Three patients refused CPAP as treatment at home. Of the remaining 90 patients, 27 patients had at the end of the run-in period a within-night pressure variability exceeding the required threshold (VI > 2.75 cm H2O) and were randomized. All but one were men. Their anthropometric features were as follows: age, 49 years (SD, 10); height,

Discussion

In the present study, we evaluated the GK418A device with a nose mask for home treatment, using a single-blind, randomized, cross-over design to compare auto-CPAP with constant CPAP, in 24 patients with SAHS selected on the basis of a high within-night variability in pressure requirement. We have found that a short run-in period on auto-CPAP with a large 4- to 14-cm H2O pressure range showed markedly different individual patterns in pressure requirement, and allowed for the selection of a

ACKNOWLEDGMENT

The authors thank Mrs. F. Martinez Vadillo for secretarial assistance.

References (20)

There are more references available in the full text version of this article.

Cited by (0)

View full text