Evaluation of An End-Tidal CO2 Detector During Pediatric Cardiopulmonary Resuscitation

Abstract

Objective. To determine the utility of a disposable colorimetric end-tidal CO2 detector during pediatric cardiopulmonary resuscitation (CPR) for (1) confirming endotracheal tube (ETT) position, and (2) assessing the relationship between end-tidal CO2 recorded by this method and outcome of pediatric CPR. Design/setting. Prospective observations during CPR in a university children's hospital. Participants. Forty children (28 male, 12 female) aged 1 week to 10 years (25 children aged ≤1 year, mean age 27.2 months, median 7 months), weighing 2.5 to 40 kg (31 children weighing ≤15 kg, mean 10.94 kg, median 7 kg) who underwent a total of 48 endotracheal intubations during CPR. Methods. After intubation, ETT position was verified by usual clinical methods including direct visualization. The device was attached between the ETT and ventilation bag, the patient was manually ventilated, and a first reading was obtained. Any color change from purple (Area A, end-tidal CO2 < 0.5%) to tan or yellow (Area B or C, end-tidal CO2 ≥ 0.5%) was considered to be positive for airway intubation. CPR was conducted as pen Pediatric Advanced Life Support guidelines. A second reading was obtained when the decision to discontinue CPR was made. Results. All nine esophageal tube positions were correctly identified by the detector. Thirty-three of 39 tracheal tube positions were correctly identified (P < .001). For verifying ETT position, the device had a sensitivity of 84.6%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 60%. Readings were obtained at the end of CPR in 25 patients. All 13 patients who regained spontaneous circulation and survived to ICU admission had a second reading in the C range, while none of the 12 patients with a second reading in the A or B range survived. Both the first and second end-tidal CO2 readings in the C range correlated significantly with short-term survival (P = .01 and P < .001, respectively). Two patients were eventually discharged from the hospital. Conclusions. During CPR a positive test confirms placement of the ETT within the airway, whereas a negative test indicates either esophageal intubation or airway intubation with poor or absent pulmonary blood flow and requires an alternate means of confirmation of tube position. The detector may be of prognostic value for return of spontaneous circulation and short-term survival.