Comparison of two repositioning schedules for the prevention of pressure ulcers in patients on mechanical ventilation with alternating pressure air mattresses

The objective was to compare the effectiveness of repositioning every 2 or 4 h for preventing pressure ulcer development in patients in intensive care unit under mechanical ventilation (MV). This was a pragmatic, open-label randomized clinical trial in consecutive patients on an alternating pressure air mattress (APAM) requiring invasive MV for at least 24 h in a university hospital in Spain. Eligible participants were randomly assigned to groups for repositioning every 2 (n = 165) or 4 (n = 164) h. The primary outcome was the incidence of a pressure ulcer of at least grade II during ICU stay. A pressure ulcer of at least grade II developed in 10.3 % (17/165) of patients turned every 2 h versus 13.4 % (22/164) of those turned every 4 h (hazard ratio [HR] 0.89, 95 % confidence interval [CI] 0.46-1.71, P = 0.73). The composite end point of device-related adverse events was recorded in 47.9 versus 36.6 % (HR 1.50, CI 95 % 1.06-2.11, P = 0.02), unplanned extubation in 11.5 versus 6.7 % (HR 1.77, 95 % CI 0.84-3.75, P = 0. 13), and endotracheal tube obstruction in 36.4 versus 30.5 %, respectively (HR 1.44, 95 % CI 0.98-2.12, P = 0.065). The median (interquartile range) daily nursing workload for manual repositioning was 21 (14-27) versus 11 min/patient (8-15) (P < 0.001). A strategy aimed at increasing repositioning frequency (2 versus 4 h) in patients under MV and on an APAM did not reduce the incidence of pressure ulcers. However, it did increase device-related adverse events and daily nursing workload.