Performer fatigue and CPR quality comparing 30:2 to 15:2 compression to ventilation ratios in older bystanders: A randomized crossover trial.

Objectives: We sought to compare bystander fatigue and CPR quality after 5min of CPR using the 30:2 vs. the 15:2 chest compression:ventilation ratios in a population of older participants.

Methods: This randomized cross-over study included independent-living participants aged ≥55. Participants completed two 5-min CPR sessions (using 30:2 and 15:2 ratios) on a recording manikin, separated by a 5-min rest. We measured changes in heart rate (HR), mean arterial pressure (MAP), venous lactate (VL; in selected participants), and perceived level of exhaustion (Borg Scale and subjective). CPR quality measures included total number of chest compressions and number of adequate compressions.

Results: The 42 enrolled participants were: mean age 66.0 (range 55-84), female 69.0%, and previously CPR trained 66.7%. Measures of bystander fatigue were similar for each CPR ratio: mean difference in increased HR 1.5 (95%CI -1.5 to 4.5), MAP 1.5 (-1.8 to 4.8), VL 0.2 (-1.1 to 1.4), Borg 0.2 (-0.2 to 0.8), but subjectively reported fatigue level was higher after the 30:2 session. Participants attempted more chest compressions per session using the 30:2 vs. the 15:2 ratio: mean diff. 78.6 (69.5-87.7), but did not complete more adequate compressions: mean diff. 1.9 (-18.9 to 22.9). The decline in number of adequate compressions/min over time was significant but similar in each group.

Conclusions: In this study of older volunteers, the 30:2 CPR ratio resulted in similar objective measures of fatigue, but higher perceived fatigue than the 15:2 ratio. The 30:2 ratio resulted in proportionally more inadequate compressions.