Abstract 11591: Physiological CPR Quality Parameters and ROSC Indicators
Introduction: Survival of cardiac arrest depends on CPR quality with blood flow as the main parameter. Blood flow is affected (among others) by compression depth. AHA guidelines advise the same depth range for all patients while their individual optimum may vary widely. An individual and time dependent optimum, guided by a non-invasive measure of blood flow may result in an increased survival chance. We investigated surrogate parameters that reflect invasive blood flow.
Methods: VF was induced in seven anesthetized pigs of ± 30 kg. CPR was performed at 100 cpm with a proprietary automated CPR device. Compression depth was altered every 2 minutes (sequence: 4.0, 3.25, 4.0, 5.0, 6.0, 5.0 and 4.0 cm) to obtain a large range of blood flows. After 14 minutes of CPR defibrillation was performed. After a stable ROSC period the complete sequence was repeated.
Correlation coefficients between net carotid blood flow and potential surrogate parameters were calculated for the compression period in order to see what parameters could be used to reflect CPR quality. The same analysis was done for a 6 min period around the last compression (see figure 1) to investigate what parameters could be used to detect ROSC.
Results: Average correlation coefficients between carotid flow and surrogate parameters are shown in figure 1.
Conclusion: DBP and CPP were the best CPR quality and ROSC indicators. Contrary to CPP, DBP has the potential to be measured non-invasively (e.g. with a cuff) which in the future might be used to steer CPR and detect ROSC.
PPG signals (i.e. a pulse oximetry sensor) had a negative correlation with flow as PPG reflects blood volume inversely. The baseline channels showed some potential to be used as ROSC detector and as CPR surrogate, especially in the infrared channel. The amplitudes of the PPG were not of use to detect ROSC or to steer CPR.
SBP, MAP, PP, ETCO2 and VCO2 have the potential to detect ROSC but are not of great use as a measure of CPR quality. For ETCO2 the low correlation is remarkable.
Author Disclosures: P. Aelen: Employment; Significant; Philips. S. Ordelman: Employment; Significant; Philips. P. Woerlee: Employment; Significant; Philips. G. Noordergraaf: Consultant/Advisory Board; Significant; Philips.
- © 2015 by American Heart Association, Inc.