RESUMO
PURPOSE: The effects of the mobile phone speaker function, which makes it possible to communicate continuously and to allows the free use of two hands, during the early phase of cardiopulmonary resuscitation (CPR) by dispatcher-assisted laypersons were investigated through a mannequin-based simulation study. METHODS: Fifty volunteers were randomly assigned to "non-speaker function CPR" (NSFCPR) (n=25) and "speaker function CPR" (SFCPR) (n=25). Fifty compressions of "Hands-only CPR" were performed according to telephone-instructed CPR by dispatchers with or without the speaker function. The quality of CPR administered and interviews from laypersons on the difficulties of performing CPR were examined. RESULTS: There were no significant differences in compression rate, depth, incomplete chest recoil, and time to first compression between the two groups. However, fourteen participants in the NSFCPR group (56.0%) and five participants in the SFCPR group (20.0%) reported interrupted chest compression (p=0.042). There were twenty-eight events of interruption in the NSFCPR group and twelve in the NSFCPR group (p=0.008). The most common cause of interrupted chest compression were difficulties in hearing the dispatcher's instructions (23, 57.5%). All 13 cases for position correction (32.5%) were observed in the NSFCPR group. There were significant differences between the two groups in causes and counts of compression interruption (p=0.004). CONCLUSION: There was difference in the interruption of compression and there were no differences in CPR performance between two groups. Still, the speaker function may reduce the interruption of chest compression due to phone holding, permitting a clearer hearing of instructions.