The effect of differing support surfaces on the efficacy of chest compressions using a resuscitation manikin model

External chest compression (ECC) efficacy is influenced by factors including the surface supporting the patient. Air-filled support surfaces are deflated for cardiopulmonary resuscitation, with little evidence to substantiate this. We investigated the effect that differing support surfaces had on ECC efficacy using a CPR manikin model.

Four participants carried out four cycles of ECC with an assistant ventilating. The subjects were blinded to the seven support surfaces and the order was randomised. For each participant/surface combination, ECC variables and the participants' perceptions were measured.

Participants produced effective ECC with the manikin on the floor (mean proportion correct, 94.5%; mean depth, 42.5 mm). Compared with the floor: the proportion of correct ECC was less for the overlay inflated (P<0.05); the depth of ECC was less effective (30-37 mm) for the overlay inflated/deflated and low-air-loss inflated and foam mattresses (P<0.05). The foam mattress, overlay inflated/deflated, and low-air-loss inflated were perceived as being less stable and as having reduced ECC efficacy compared with the floor. There was no difference or agreement, regarding subjects' perceptions or ECC variables, between the support surfaces or between inflated/deflated air-filled support surfaces.

The efficacy of ECC is affected by the support surfaces. There seems little evidence to substantiate deflating all air-filled support surfaces for CPR.