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.