Pressure ulcers prevention efficacy of an alternating pressure air mattress in elderly patients: E²MAO a randomised study

Abstract

Objective: Our aim was to compare Axtair One, an alternating pressure air mattress (APAM), with a viscoelastic foam mattress (VFM) in elderly patients at moderate to high risk of developing pressure ulcers (PUs).

Method: A randomised, controlled, superiority, parallel-group, open-label, multicentre study, was conducted, between February 2012 and March 2015, in nine French, medium- and long-term stay facilities. Eligible patients were aged 70 and over, had no PUs on enrolment, were bedridden for at least 15 hours per day, had reduced mobility, an absent or minimal positioning capability, a Braden score <14, a nutritional status score >12 and a Karnofsky score <40%. The primary endpoint was the appearance of PUs over a 30-day monitoring period. The primary objective was to demonstrate a 50% reduction in instantaneous risk of PUs in the APAM versus the VFM group. Secondary objectives were to determine if preventive care was less frequent in the APAM group, the instantaneous relative risk of PUs (hazard ratio) was constant over time and the comfort experienced was higher in the APAM group and to verify the uniformity of the preventive benefit of an APAM, regardless of the level of exposure to major risk factors for PUs.

Results: We randomised 76 patients (39 in the APAM group and 37 in the VFM group). The groups were comparable on enrolment and throughout the study. The cumulative risk of PUs was estimated at 6.46% [95% confidence interval (CI): 1.64; 23.66] in the APAM group and at 38.91% [95% CI: 24.66; 57.59] in the VFM group, p=0.001 (log-rank test). The adjusted hazard ratio according to the Cox model with four prognostic factors for the appearance of PUs was 7.57 [95% CI: 1.67; 34.38, p=0.009]. Preventive care proved to be equivalent in both groups. The only risk factor significantly associated with an increased risk of PUs was the type of mattress (VFM). The comfort and tolerance perceived by the patients were both high and similar in the two groups. The constancy over time of the preventive benefit of an APAM could not be verified because of the lack of a sufficient number of events (appearance of PUs) in the APAM group.

Conclusion: The APAM was superior to a VFM for preventing PUs in elderly patients, bedridden for more than 15 hours per day, severely dependent, at moderate-to high-risk of PUs, with an instantaneous risk for the appearance of PUs 7.57 times greater in the VFM group than in the APAM group. This study provides descriptive information and evidence for practice.

Keywords: alternating pressure air mattress; elderly patients; pressure ulcers; viscoelastic foam mattress.