Quantitative end-tidal CO2 can predict increase in heart rate during infant cardiopulmonary resuscitation

Aim: To determine the end-tidal CO2 (ETCO2) value that predicts a HR > 60 beats per minute (bpm) with the best sensitivity and specificity during neonatal/infant cardiopulmonary resuscitation (CPR) defined as chest compressions ± epinephrine in neonates/infants admitted to a CVICU/PICU. Methods: This was a retrospective cohort study from 1/1/08 to 12/31/12 of all infants ≤6 month of age who received CPR and had ETCO2 documented during serial resuscitations in the pediatric (PICU) or pediatric cardiovascular intensive care units (CVICU) of Children's Medical Center of Dallas. A receiver operator characteristic (ROC) curve was generated to determine the ETCO2 cut-off with the best sensitivity and specificity for predicting HR > 60 bpm. Each ETCO2 value was correlated to the infant's HR at that specific time. Results: CPR was provided for 165 infants of which 49 infants had quantitative ETCO2 documented so only these infants were included. The majority were in the CVICU (81%) and intubated (84%). Mean gestational age was 36 ± 3 weeks and median age (interquartile range) at time of CPR was 30 (16–96) days. An ETCO2 between 17 and 18 mmHg correlated with the highest sensitivity and specificity for return of a HR > 60 bpm. Area under the curve for the ROC is 0.835. Conclusions: This study provides critical clinical information regarding correlation between ETCO2 values and an adequate rise in heart rate in neonates and young infants during CPR. Quantitative ETCO2 monitoring allows CPR to progress uninterrupted without need to pause to check heart rate every 60 seconds until the critical ETCO2 threshold is reached. Quantitative ETCO2 monitoring as an adjunct to cardiac monitoring during infant CPR might enhance perfusion and improve outcomes.