Abstract P83: CPR Rescuer Fatigue: Oxygen Consumption (VO2) Is Static While Chest Compression Quality Deteriorates Over Time
BACKGROUND: Rescuer fatigue during CPR impacts quality of chest compressions (CC) and survival. AHA recommends switching CC provider every 2 min. Little data exists relating CC quality and fatigue during CPR.
OBJECTIVE: Determine the relationship between minute oxygen consumption (VO2), a physiologic measure of energy expenditure, and CC quality during 1-rescuer manikin CPR.
DESIGN/METHODS: Prospective randomized trial of trained in-hospital rescuers. Each performed continuous CC on adult manikins until fatigue or max 10 min. Breath-by-breath VO2 measures were assessed by calibrated metabolic cart (SensorMedics V29). CC rate, depth and leaning force were recorded with a CC sensor (HeartStart MRx, Philips). % CC meeting quality criteria (rate 90 –120/min, depth >38mm) were averaged over 30 sec epochs. Data were analyzed by ANOVA and t-test.
RESULTS: For 25 BLS certified providers, mean VO2 rose from 0.59L/min to 0.85L/min after 90 sec, without further increase over 10 min (p = 0.42) (Figure 1⇓). Over 10 min, mean CC rate increased 103/min to 120/min and mean CC depth decreased 43.9mm to 34.9mm. % adequate CC (depth >38mm, rate 90 –120/min) decreased from 94% to 32% over 10 min, was less than 75% within 2 min, and continued to deteriorate steadily. (ANOVA, p<0.001)
CONCLUSIONS: Oxygen consumption (VO2), a physiologic measure of energy expenditure, increases to plateau within 90 sec, and remains high for 10 min. CC quality declined within 2 min, and continued to deteriorate steadily during simulated in-hospital 1-rescuer manikin CPR.