The impact of a step stool on cardiopulmonary resuscitation: a cross-over mannequin study.

Abstract

Shallow chest compressions and incomplete recoil are common during cardiopulmonary resuscitation (CPR) and negatively affect outcomes. A step stool has the potential to alter these parameters when performing CPR in a bed but the impact has not been quantified. We conducted a cross-over design, simulated study of in-hospital cardiac arrest. Rescuers performed a total of four 2-min segments of uninterrupted chest compressions, half of which were on a step stool. Compression characteristics were measured using a CPR-sensing defibrillator and subjective impressions were obtained from rescuer surveys. Paired analyses were performed to measure the impact of the step stool, taking into account rescuer characteristics, including height. Fifty subjects, of whom 36% were men, with a median height of 169.8 cm (range 148.6-190.5) volunteered to participate. Use of a step stool resulted in an average increase in compression depth of 4 mm (p<0.001) and 18% increase in incomplete recoil (p<0.001). However, unlike with incomplete recoil, the effect was more pronounced in rescuers in the lowest height tertile (9±9 mm vs 2±6 mm for those rescuers taller than 167 cm, p=0.006). Using a step stool when performing CPR in a bed results in a trade-off between increased compression depth and increased incomplete recoil. Given the nonlinear relationship between the increase in compression depth and rescuer height, the benefit of a step stool may outweigh the risks of incomplete release for rescuers ≤167 cm in height. The benefit is less clear in taller rescuers.