Commencing one-handed chest compressions while activating emergency medical system using a handheld mobile device in lone-rescuer basic life support: a randomised cross-over simulation study.

Introduction: In conventional basic life support (c-BLS), a lone rescuer is recommended to start chest compressions (CCs) after activating the emergency medical system. To initiate earlier CCs in lone-rescuer BLS, we designed a modified BLS (m-BLS) sequence in which the lone rescuer commences one-handed CCs while calling for help using a handheld cellular phone with the other free hand. This study aimed to compare the quality of BLS between c-BLS and m-BLS.

Methods: This was a simulation study performed with a randomised cross-over controlled trial design. A total of 108 university students were finally enrolled. After training for both c-BLS and m-BLS, participants performed a 3-minute c-BLS or m-BLS on a manikin with a SkillReporter at random cross-over order. The paired mean difference with SE between c-BLS and m-BLS was assessed using paired t-test.

Results: The m-BLS had reduced lag time before the initiation of CCs (with a mean estimated paired difference (SE) of -35.0 (90.4) s) (p<0.001). For CC, a significant increase in compression fraction and a higher number of CCs with correct depth were observed in m-BLS (with a mean estimated paired difference (SE) of 16.2% (0.6) and 26.9% (3.3), respectively) (all p<0.001). However, no significant paired difference was observed in the hand position, compression rate and interruption time. For ventilation, the mean tidal volumes did not differ. However, the number of breaths with correct tidal volume was higher in m-BLS than in c-BLS.

Conclusion: In simulated lone-rescuer BLS, the m-BLS could deliver significantly earlier CCs than the c-BLS while maintaining high-quality cardiopulmonary resuscitation.