Abstract 2274: Hemodynamic Effects of Epinephrine during Cardiopulmonary Resuscitation in Pigs Depend on Chest Compression Quality.
Background: Epinephrine is used during CPR based on animal experiments without supportive clinical data. The quality of clinical CPR was recently shown to be much poorer than expected and what is generally done in laboratory experiments. We have studied the hemodynamic effects of epinephrine during CPR with good laboratory quality and with quality simulating clinical findings and the feasibility of monitoring these effects through VF waveform analysis (Slope). We hypothesized that hemodynamic effects of epinephrine depend on chest compression quality.
Methods: After four minutes of cardiac arrest followed by four minutes of BLS, 14 pigs (27±2.6 kg) were randomized to ClinicalCPR (manual chest compressions with 50% hands-off time and compression depth 30 –34 mm) or LabCPR (continuous mechanical chest compressions with compression depth 45 mm). Epinephrine 0.02 mg kg−1 was administered 30 seconds thereafter in a peripheral vein followed by a saline flush. We monitored coronary perfusion pressure (CPP), cerebral cortical blood flow (CCBF), femoral blood flow (FBF) and Slope.
Results: Plasma epinephrine concentration peaked earlier with LabCPR than with ClinicalCPR, median (range), 90 (30,150) vs. 150 (90,270) sec (P=0.007), respectively. CPP and CCBF increased while FBF decreased after epinephrine administration during LabCPR. CPP peaked median (IQR) 69 (53, 83) seconds after administration of epinephrine in the LabCPR group with mean difference (95% CI) vs. control 17 (6, 29) mmHg, P=0.01, FBF −5 (−9, −1) ml min−1, P=0.02, median difference CCBF 12% of baseline, P=0.04. There were no significant effects of epinephrine during ClinicalCPR. Among the pigs with increased CPP after epinephrine injection (n=10), mean Slope was significantly higher at the time of peak drug concentration than prior to drug administration, 8.8 (2.6) vs. 7.1 (1.5), mean difference 1.7 (0.5, 3.0) (P=0.011). Pearson correlation coefficient for the relationship between CPP and Slope was 0.77 (P=0.002) when one outlier was omitted.
Conclusion: Epinephrine improved hemodynamics during laboratory quality CPR in pigs, but not with quality simulating clinically reported CPR performance. Slope VF waveform analysis reflected changes in CPP.