Continuous capnography monitoring during resuscitation in a transitional large mammalian model of asphyxial cardiac arrest.

Overview

BACKGROUND: In neonates requiring chest compression (CC) during resuscitation, neonatal resuscitation program (NRP) recommends against relying on a single feedback device such as end-tidal carbon dioxide (ETCO₂) or saturations (SpO₂) to determine return of spontaneous circulation (ROSC) until more evidence becomes available. METHODS: We evaluated the role of monitoring ETCO₂ during resuscitation in a lamb model of cardiac arrest induced by umbilical cord occlusion (n = 21). Lambs were resuscitated as per NRP guidelines. Systolic blood pressure (SBP), carotid and pulmonary blood flows along with ETCO₂ and blood gases were continuously monitored. Resuscitation was continued for 20 min or until ROSC (whichever was earlier). Adequate CC was arbitrarily defined as generation of 30 mmHg SBP during resuscitation. ETCO₂ thresholds to predict adequacy of CC and detect ROSC were determined. RESULTS: Significant relationship between ETCO₂ and adequate CC was noted during resuscitation (AUC-0.735, P < 0.01). At ROSC (n = 12), ETCO₂ rapidly increased to 57 ± 20 mmHg with a threshold of ≥32 mmHg being 100% sensitive and 97% specific to predict ROSC. CONCLUSION: In a large mammalian model of perinatal asphyxia, continuous ETCO₂ monitoring predicted adequacy of CC and detected ROSC. These findings suggest ETCO₂ in conjunction with other devices may be beneficial during CC and predict ROSC.