Chest compression by two-thumb encircling method generates higher carotid artery blood flow in swine infant model of cardiac arrest

Objective Two-Thumb(TT) technique provides superior quality chest compressions compared with Two-Finger(TF) in an instrumented infant manikin. Whether this translates to differences in blood flow, such as carotid arterial blood flow(CABF), has not been evaluated. We hypothesized that TT-CPR generates higher CABF and Coronary Perfusion Pressure(CPP) compared with TF-CPR in a neonatal swine cardiac arrest model. Methods Twelve anesthetized & ventilated piglets were randomized after 3 min of untreated VF to receive either TT-CPR or TF-CPR by PALS certified rescuers delivering a compression rate of 100/min. The primary outcome, CABF, was measured using an ultrasound transonic flow probe placed on the left carotid artery. CPP was calculated and end-tidal CO2(ETCO2) was measured during CPR. Data(mean ± SD) were analyzed and p-value ≤0.05 was considered statistically significant. Results Carotid artery blood flow (% of baseline) was higher in TT-CPR (66.2 ± 35.4%) than in the TF-CPR (27.5 ± 10.6%) group, p = 0.013. Mean CPP (mm Hg) during three minutes of chest compression for TT-CPR was 12.5 ± 15.8 vs. 6.5 ± 6.7 in TF-CPR, p = 0.41 and ETCO2 (mm Hg) was 29.0 ± 7.4 in TT-CPR vs. 20.7 ± 5.8 in TF-CPR group, p = 0.055. Conclusion TT-CPR achieved more than twice the CABF compared with TF-CPR in a piglet cardiac arrest model. Although CPP and ETCO2 were higher during TT-CPR, these parameters did not reach statistical significance. This study provides direct evidence of increased blood flow in infant swine using TT-CPR and further supports that TT chest compression is the preferred method for CPR in infants.