ABSTRACT
Aim: The aim of this study was to review the changes in CO2 excretion and anesthetic management during thoracoscopy in children.
Methods: We analyzed end-tidal carbon dioxide concentration (EtCO2; kPa) during CO2 pneumothorax. EtCO2 was measured on a continuous basis by using a positive sampling system and recorded every 10 minutes. Baseline and highest EtCO2 were used to derive the maximum change in the intraoperative period. EtCO2 was also analyzed in three time periods: (1) preinsufflation, (2) during insufflation of CO2 into the chest, and (3) after desufflation. Core temperature was also recorded as an index of thermoregulation. Data are presented as the mean ± standard error of the mean. Differences within time periods were compared by using paired t tests or repeated measures analysis of variance. Correlation between changes in EtCO2 and patient demographics was performed by using linear regression. The pattern of change was compared to children undergoing laparoscopy.
Results: Median age was 1.9 years (range, 1 day to 15 years). EtCO2 increased significantly from preinsufflation 5.1 ± 0.2 to 6.4 ± 0.3 during insufflation (P < 0.01); values were still significantly elevated after desufflation 6.4 ± 0.4 (P < 0.01). Single-lung ventilation was associated with higher EtCO2 levels during insufflation than with two-lung ventilation (P = 0.02). Maximum change in the EtCO2 in the group undergoing one-lung ventilation negatively correlated to patient weight (r2 = 0.25, P = 0.02); this correlation was not present with two-lung ventilation (r2 = 0.02, P = 0.84). Laparoscopy increased EtCO2 from 4.7 ± 0.2 preinsufflation to 5.3 ± 0.2 (P < 0.001) during and decreased to 4.8 ± 0.2 postdesufflation (P = 0.60). There was a significant increase in core temperature from 35.9 ± 0.3 to 36.9 ± 0.2 postoperatively (P = 0.007).
Conclusions: There is a significant increase in EtCO2 in children undergoing thoracoscopy, which is higher than during laparoscopy. Changes in EtCO2 are larger in smaller children undergoing single-lung ventilation. Thoracoscopy may preserve intraoperative thermoregulation.
