Is end-tidal CO2 an accurate measure of arterial CO2 during laparoscopic procedures in children and neonates with cyanotic congenital heart disease?

BACKGROUND/
PURPOSE: Children with cyanotic congenital heart disease (CCHD) may require laparoscopic procedures. There are no data on the ability of capnography to predict arterial carbon dioxide concentrations (PaCO2) in patients with CCHD during pneumoperitoneum.
METHODS: Seven patients (age 1 to 35 months) with CCHD undergoing laparoscopic Nissen fundoplication are presented. Standard general endotracheal anesthesia was administered. The operations were performed either by or in consultation with the cardiac anesthesia team. During each case, concomitant PaCO2 and end-tidal carbon dioxide (ETCO2) measurements were made via an arterial line and capnograph before and after insufflation of the abdomen. The PaCO2-ETCO2 gradients before and during pneumoperitoneum were then compared using a paired Student's t test.
RESULTS: There was a statistically significant increase in the PaCO2-ETCO2 gradient (5.7 v 13.4) after insufflation compared with baseline (P <.015).
CONCLUSIONS: These preliminary results show that ETCO2 is not a reliable monitor of PaCO2 in patients with CCHD undergoing laparoscopic procedures. The authors feel that close monitoring, including arterial blood gas measurements, and an experienced anesthesia team are necessary to perform laparoscopic procedures in patients with CCHD. Copyright 2001 by W.B. Saunders Company.