Hand vs. leg-heel: Evaluating a viable second line approach for chest compressions to bridge the 'bystander's window'

High quality bystander cardiopulmonary resuscitation (CPR) substantially improves outcomes from cardiac arrest. However, chest compression (CC) quality may be impaired in situations of physical incapacitation, low body weight or rescuer fatigue. For such situations, the leg-heel'-approach has been proposed as an alternative. No study, however, has yet explored this method in a standardized setting over a realistic time span, e.g., until professional rescue teams arrive.

In a cross-over design, final year medical students performed continuous CC on a manikin using conventional (C-CPR) and 'leg-heel'-CPR (LH-CPR) for five minutes each with no pause between methods. Students were randomly assigned to the order of approaches. For the LH-CPR, a chair was provided for the rescuer to stabilize the upper body.

121 students were included, and all participants completed the whole ten-minute-task.Mean absolute CC depth (C-CPR: 49.8 mm [SD 8.7, CI 48.2-51.4] vs. LH-CPR: 49.9 mm [SD 9.4, CI 48.2-51.5], p = 0.974) and mean leaning depth (C-CPR: 10.9 mm [SD 7.4, CI 9.6-12.3] vs. LH-CPR: 10.9 [SD 7.6, CI 9.6-12.3]), were similar, while mean CC frequency was higher in C-CPR (120/min [SD 13, CI 118-123] vs. 113/min [SD 16, 110-116], p < 0.01). With C-CPR, CC rate steadily increased over time up to 125/min whereas with LH-CPR it remained within the guideline target of 100-120/min. Over time, rescuer fatigue was slightly less pronounced in LH-CPR.

In a standardized setting over a realistic time span, the 'leg-heel'-approach led to equal CPR quality as the conventional approach. Application of the 'leg-heel'-approach however, has to be considered with caution as its effects on haemodynamics and resuscitation-related injuries are unknown. Cases should therefore be carefully observed.

This finding may justify developing training algorithms for 'leg-heel'-CPR as a second line alternative in situations of fatigue, low body weight or physical incapacitation.