Flexible positive airway pressure improves treatment adherence compared with auto-adjusting PAP

Abstract

Study objectives: There are no clinical data comparing adherence and quality of life between auto-adjusting positive airway pressure (APAP) and two different flex positive airway pressure (PAP) devices (A-Flex, C-Flex) in patients with obstructive sleep apnea (OSA).

Design and setting: Ninety-three patients in whom OSA was newly diagnosed were randomly assigned to receive 3 mo of APAP (n = 31), APAP with C-Flex (n = 31), or APAP with A-Flex (n = 31). Objective adherence was determined after 3 mo of CPAP treatment, and the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Calgary Sleep Apnea Quality of Life Index (SAQLI) were examined at baseline and after 3 mo. After 3 mo, patients in the APAP with A-Flex group and those in the APAP with C-Flex group were crossed over and those in the APAP group were switched to A-Flex for an additional 3 mo.

Measurements and results: The groups were similar demographically. Treatment adherence during the first 3 mo was significantly greater in the APAP with C-Flex group (APAP with C-Flex: 5.19 ± 1.84 h/night versus APAP: 3.96 ± 1.66 h/night versus APAP with A-Flex: 4.27 ± 2.12 h/night, P = 0.04). There was a significant improvement in two of four of the SAQLI domain scores and in the ESS and PSQI in the APAP with C-Flex group. Adherence significantly improved among the poor compliers (< 4 h/night of use) in the APAP group after change to APAP with A-Flex (P = 0.01).

Conclusions: Of these three modes of PAP delivery, adherence was greatest with APAP with C-Flex.

Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00873977.

Figure 1

(A) C-Flex pressure relief reduced pressure at the beginning of exhalation and returned to the therapeutic pressure just before inhalation. The level of pressure relief varies based on the patient’s expiratory flow and which of the three C-Flex settings (1, 2, and 3) has been selected. (B-D) A-Flex has the same function as C-Flex during expiration. At 4 cm H₂O CPAP, the A-Flex PAP machine is same as the C-Flex machine PAP (B). At 5 cm H₂O CPAP, the A-Flex PAP machine can provide 1 cm H₂O pressure support at the inspiration (C). From 6 or more cm H₂O CPAP, A-Flex machine can make 2 cm H₂O pressure supports at the inspiration (D).

Figure 2

Flow chart of the study population. APAP, auto-adjusting positive airway pressure; CPAP, continuous positive airway pressure.

Figure 3

CPAP adherence with APAP with C-Flex, APAP, and APAP with A-Flex after 3 mo of treatment. Data are shown as a bow-whisker plot with median and 25th percentile of CPAP adherence. APAP, auto-adjusting positive airway pressure.

Figure 4

Analysis of poor compliers (< 4 h/night of CPAP use) between 3 and 6 mo. Individual data are presented.