Evaluation of chest compression depth during nine minutes of hands-only cardiopulmonary resuscitation performed by a lone rescuer and its effect by age group: a pilot simulation study using a manikin

Objective: There have been few studies on the use of long-standing hands-only cardiopulmonary resuscitation (CPR) by a lone rescuer. This study aimed to evaluate the long-standing (nine minutes) hands-only CPR by a lone rescuer, and the change of chest compression depth over time. The effect of age of rescuer on chest compression depth was also studied. Methods: From a total of 404 adult lay-persons who participated in CPR training, 91 subjects were enrolled in the simulation trial of nine minutes of hands-only CPR using a manikin with a Skill-Reporter (TM). The quality of the chest compression over time and the effects of rescuer age were analysed. Results: Of the 91 participants, 74 (81%) fully completed the nine minutes of CPR. No significant differences of incomplete CPR rate between each age group were observed. No significant differences in the degree of reduction in effective chest compressions were observed based on the time course among the different age groups. The total number of compressions decreased abruptly from the six-minute time point onwards (five minutes vs. six minutes, p=0.038). Conclusions: Most trained lay-persons could complete the 9 minutes of hands-only CPR. The rate of chest compression shows a significant decrease after 6 minute. We do not find a significant difference in the decrease of adequate chest compressions over time among various age groups in this pilot simulation study. (Hong Kong j.emerg.med. 2013;20:9-17)