RESUMO
PURPOSE: The study evaluated changes in the quality of chest compressions over 2 min in 30:2 cardio-pulmonary resuscitation (CPR) by lay-persons and analyzed rescuer factors affecting the quality of chest compressions over time. METHODS: CPR training courses attended by 538 adult hospital and university workers (lay-person) were conducted at a university hospital. After 4-hour CPR training, tests were performed using a manikin with Skill-ReporterTM. Data of 459 subjects were analyzed concerning the quality of chest compressions over time and rescuer factors such as age, gender, body mass index, prior CPR training and CPR experience were also analyzed to determine their effect on the change in the quality of chest compressions. RESULTS: Compression depth (p=0.002) showed significant change over 2 min, but the rate (p=0.133), chest recoil (p=0.442) and hand placement (p=0.991) were insignificant. Ineffective compression depth (mean proportions of correct depth<70%) was not observed during the 2 min CPR. Female gender (p<0.001; OR, 5.882, 95% CI, 3.098-11.167) and no CPR training (p=0.004; OR, 2.163, 95% CI, 1.277-3.663) were associated with decline of compression depth. Time-dependent analysis revealed significant ineffective compression depth (<70%) in females and underweight patients (p<0.001). CONCLUSION: Switching compressors at an interval of 2 min is reasonable for 30:2 CPR by lay-persons. But, significant decline of correct compression depth over time in female and underweight rescuers was evident.