End tidal carbon dioxide is as reliable as transcutaneous monitoring in ventilated postsurgical neonates.

OBJECTIVES: To compare the agreement, precision and repeatability of end tidal carbon dioxide (EtCO2 ) and transcutaneous carbon dioxide (TcCO2 ) with partial pressure of arterial CO(2) ( PaCO2) in postoperative neonates.

PATIENTS: Fifty mechanically ventilated neonates without lung disease, and with no contraindications for either TcCO2 or EtCO2 monitoring.

INTERVENTIONS: Paired TcCO2 and EtCO2 values were recorded with three consecutive measurements within the first 48 h of surgery.

MAIN OUTCOME MEASURES: EtCO2, TcCO2 and PaCO2 triplets were compared using Bland-Altman plots.

RESULTS: One hundred thirty-two triplet measures of CO(2) were recorded with mean PaCO2 43.5 (7.3) mm Hg, EtCO2 38.8 (6.4) mm Hg and 43.8 (8.8) mm Hg (p<0.0001 for EtCO2 against PaCO2; paired t test). The PaCO2 - EtCO2 bias±2SD was 4.1±9.0 mm Hg and -0.8±13.0 mm Hg for PaCO2 - TcCO2. 56.1% of EtCO2, and 60.6% of TcCO2 values were within ±5 mm Hg of paired PaCO2.

CONCLUSIONS: In postoperative neonates, EtCO2 and TcCO2 demonstrated a clinically acceptable agreement with PaCO2.