A randomized control trial to evaluate pressure-reducing seat cushions for elderly wheelchair users.

Objective: To determine if the use of pressure-reducing wheelchair cushions for elderly nursing home resident wheelchair users who are at high risk for developing sitting-acquired pressure ulcers would result in a lower incidence rate of pressure ulcers, a greater number of days until ulceration, and lower peak interface pressures compared with the use of convoluted foam cushions over a 12-month period. To determine the feasibility of conducting a subsequent full-scale definitive trial to evaluate the use of pressure-reducing seat cushions for elderly nursing home resident wheelchair users.

Design: Randomized control trial

Setting: 2200-bed skilled nursing facilities (1 suburban and 1 urban academic medical center)

Patients: 32 male and female at-risk nursing home residents who were wheelchair users > or = 65 years of age. Participants had Braden Scale scores < or = 18, Braden Activity and Mobilitysubscale scores < or = 5, no sitting surface pressure ulcers, and a daily wheelchair sitting tolerance of more than 6 hours. All met criteria for using the ETAC Twin wheelchair.

Interventions: Seating evaluation with pressure-mapping and subsequent seating prescription. Subjects were assigned to either a foam (n=17) or pressure-reducing cushion (n=15) group and weekly assessments of skin and pressure ulcer risk were made.

Main Outcome Measures: Incidence of pressure ulcers, days to ulceration, and peak interface pressure.

Main Results: At a 95% confidence interval, a 2-tailed analysis showed no differences between the FOAM and pressure-reducing cushion groups for pressure ulcer incidence, total days to pressure ulcer, or initial peak interface pressure. Pressure-reducing cushions were more effective in preventing sitting-acquired (ischial) pressure ulcers (P<.005). Higher interface pressures were associated with a higher incidence of pressure ulcers (P<.001).

Conclusions: A definitive randomized control multicenter cushion trial is feasible with a sample size of 50 to 100 per study group. In the definitive trial, the definition of sitting-acquired pressure ulcers should be limited to lesions occurring over the ischial tuberosities.