Abstract P168: Early Markers of Rescuer’s Fatigue
Purpose: Suboptimal CPR quality is usually attributed to the development of fatigue. Identifying early markers of rescuer’s fatigue may improve CPR quality. We therefore, assessed rescuer’s heart rate and saturation of peripheral oxygen (SpO2) along with compression quality as potential markers of fatigue.
Materials and Methods: Using a hand-held CPR audiovisual accelerometer-based feedback device (PocketCPR™, ZOLL Medical), 12 non-critical care hospital nurses performed 6 minutes chest compression (CC) on a Laerdal manikin according to AHA guideline. Compression depth (CD) and rate, heart rate (HR) and pulse oximetry were continuously monitored during CC. Each subject rated perceived fatigue (PF). CPR labor intensity was calculated using Karvonen method. One participant who did not exercise regularly was excluded in data analysis.
Results: CD during the 0 –1 minute interval was significantly higher than in the 1–2 minute interval (2.06in vs. 1.99in, p=0.048); however, it remained unchanged thereafter. Study participants were unaware of this initial decrease in CD. The calculated averaged CPR labor intensity was 44.2%. HR increased and reached the peak at approximately 2 minutes and decreased gradually thereafter before stabilized at 4 minutes. SpO2 decreased and reached the minima approximately 2 minutes and increased gradually thereafter. The PF was significantly increased from 1st two minutes to 2nd two minutes (20.8%±14.4% vs. 40.4%±18.3%, p=0.0002). The quality compressions were provided until 4 minutes on average.
Conclusions: The initial decrease in CD in 1st two minutes was not caused by participant’s fatigue. HR peak and SpO2 minima coincided with onset of PF, though; they did not predict CPR performance. The CPR feedback device provided with the objective and reliable measurement of compression quality, which could be a more accurate marker for rescuer’s fatigue.