ABSTRACTS
A Comparison of Subjective and Objective Fatigue Factors Affecting Cardiopulmonary Resuscitation (CPR) OutcomesAuthor: Jennifer Longo | | Associate Authors: Katie J. Lyman | Thomas A. Hanson
Introduction
The most recent CPR guidelines released by the American Heart Association (AHA) continue to recommend compression-only CPR for lay rescuers. While some evidence supports the notion that lay rescuers are unable to perform adequate ventilations, there is also a lack of data supporting the recommendation of continuous chest compressions. Thus, the purpose of this study was to analyze subjective and objective variables related to four compressions to 10-second Methods A convenience sample of 23 participants (M = 22.3 years + 3.8) was used in a cross-sectional design. Participants were randomized and counterbalanced to complete four separate chest compression conditions, each lasting 9 minutes. Independent variables included four compressions to 10-second break ratio conditions (30:10, 50:10, 100:10, and continuous compressions [CC]). Dependent variables included Borg Rating of Perceived Exertion (RPE), VO2, hand grip dynamometry, heart rate (HR), and all aspects of CPR performance (depth percentage, depth mm, and rate percentage). CPR variables were analyzed via one-way ANOVA and Tukey’s post hoc test, while fatigue variables were analyzed using repeated measures ANOVA with a between-subject factor of ratio condition. Results As compared to CC, compression depth percent was significantly greater in the 30:10 (P < .001) and 50:10 (P = .05) conditions. Similarly, participants allowed full chest recoil significantly more often in the conditions including breaks as compared to CC (30:10 [P = .002], 50:10 [P = .036], and 100:10 [P = .032]). RPE increased with number of compressions and over time (P < .001). VO2 and HR significantly increase over time (P < .001); however, the entirety of the significance occurs between the start and remaining three observations, which do not differ significantly from each other. The RPE to VO2 and HR relationship is not significant suggesting perceived fatigue is greater than physiological measures. Conclusion As compression ratio increases, CPR performance decreases. While physiological measures do not indicate continual increases in fatigue, subjective data is, perhaps, more relevant when determining CPR performance. The results of this study do not support the recommendation for continuous chest compressions. Rather, they indicate the need for breaks during administration of compression-only CPR for rescuers to provide quality compressions.
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