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

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.