Cardiopulmonary resuscitation with synchronized ventilation versus 3:1 compression to ventilation ratio in a neonatal porcine model.

INTRODUCTION

Current neonatal resuscitation guidelines recommend a 3:1 Compression:Ventilation ratio (3:1 C:V) during cardiopulmonary resuscitation. One of the concerns with 3:1 C:V is lung derecruitment, which contributes to a delay in achieving return to spontaneous circulation (ROSC). An alternative approach might be chest compression synchronized ventilation (CCSV), which delivers a ventilation with each chest compression thereby achieving lung recruitment. We hypothesized that in asphyxiated newborn piglets with cardiac arrest CCSV vs 3:1 C:V would decrease the time to ROSC.

METHODS

Newborn piglets were anesthetized, intubated, instrumented, and exposed to 45-minute normocapnic hypoxia, followed by asphyxia. Piglets were randomized to either CCSV or 3:1 C:V. Piglets assigned to CCSV received 120 compressions/min with a ventilator-synchronized inflation delivered during every compression (CCSV-Mode, Weinmann Germany). In the 3:1 C:V group, piglets received 90 compressions/min and 30 ventilations/min. Compressions and ventilations were continued until ROSC. Continuous respiratory parameters, mean systemic artery pressures, and blood flows were measured.

RESULTS

Sixteen neonatal mixed breed pigs (1-3 days of age, weighing 1.8-2.5 kg) and were randomly assigned to CCSV or 3:1 C:V. The median (IQR) asphyxia time was not significantly different between CCSV (321 (264-384) s) and 3:1 C:V (416 (266-475) s) (p = 0.442). Time to ROSC was significantly lower using CCSV with 61 (51-118) s vs 170 (105-312) s with 3:1 C:V (p = 0.030). Rate of ROSC was 7/8 with CCSV and 5/8 with 3:1 C:V (p = 1.000).

CONCLUSIONS

In a neonatal piglet model of asystolic cardiac arrest, CCSV resulted in a significantly faster time to ROSC compared to 3:1 C:V. Using CCSV might be an alternative to 3:1 C:V for neonatal resuscitation, but further studies are warranted.