Arterial to endtidal carbon dioxide gradient during pediatric laparoscopic fundoplication

Background: Discrepancies between arterial carbon dioxide (P_aCO₂) and endtidal carbon dioxide (ETCO₂) measures have been demonstrated in ventilated children with cyanotic congenital heart disease, infants with respiratory failure and during visceral and urological laparoscopic surgery.

Objectives: Our objective was to assess the extent of the P_aCO₂ to ETCO₂ gradient in children during laparoscopic fundoplication.

Methods: We prospectively collected data on patient characteristics, surgical conditions, pH, ETCO₂and P_aCO₂ during laparoscopic fundoplication using carbon dioxide insufflation in children age <29 months.

Results: Data were collected on nine cases, four cases aged <1 year. A P_a-ETCO₂ gradient was present during insufflation. The gradient was larger in children age less than 1 year but statistically significantly different from a value of zero, only at t = 30 min (mean = 8 mmHg, sem = 0.81, P = 0.004) and t = 60 min (mean = 5 mmHg, sem = 1, P = 0.014). Minute ventilation was increased from 20% to 100% to control ETCO₂.

Conclusions: ETCO₂ may not accurately represent arterial values during laparoscopic fundoplication, especially in the infant when carbon dioxide insufflation is used. Consideration should be given to placing an arterial line for blood gas measurement in some patients.