Chest compression during sustained inflation versus 3:1 compression-to-ventilation ratio during neonatal cardiopulmonary resuscitation of asphyxiated piglets.

Background: Current neonatal resuscitation guidelines recommend using the 3:1 chest compression-to-ventilation (C:V) ratio technique. However, an alternative technique using continuous compressions superimposed with a high distending pressure or sustained inflation (CC + SI) may improve return of spontaneous circulation (ROSC), survival, and post-resuscitation outcomes. Objective: In a piglet model of asphyxia-induced cardiac arrest, compare time to ROSC with CC + SI or 3:1C:V technique for providing neonatal cardiopulmonary resuscitation (CPR). Methods: Secondary analysis of 132 term newborn mixed breed piglets (1-3 days of age, weighing 1.7-2.4 kg) from six different studies, which were exposed to 30-50 min of normocapnic hypoxia followed by asphyxia until cardiac arrest. This was followed by CPR with either the CC + SI or 3:1C:V technique. Results: Although the proportion of piglets achieving ROSC was similar between CC + SI and 3:1C:V [59/83 (71 %) vs. 40/49 (82 %)], the time to ROSC was significantly shorter with CC + SI [median (IQR), 87.5 (66.8-147.5) vs. 120 (76.5-267) s; p = 0.0097], corresponding to a mean difference of -73.9 s (95 % CI -122.5 to -25.3). Survival up to 4 h did not differ between groups (risk ratios 1.04, 95 % Confidence intervals 0.82-1.32), with mean (SD) survival time among ROSC survivors of 237 (18) min for CC + SI vs 220 (55) min for 3:1C:V (p = 0.0623). In adjusted analyses, CC + SI yielded faster time to ROSC (Geometric Mean Ratio 0.67, 95 % CI 0.50-0.88), with no effect modification by FiO2, but a rate-dependent effect on time to ROSC; 4-h survival did not differ between methods. Conclusions: Use of the CC + SI technique during neonatal piglet resuscitation leads to a faster ROSC, with no difference in survival.