Background: Although the cardiovascular effect of CO2 insufflation has not been reported in pediatric thoracoscopy, several clinical trials have demonstrated significant hemodynamic deterioration in adults. We investigated the concept of therapeutic hypercapnia for counteracting the hemodynamic effect of induced capnothorax.
Methods: Twelve pediatric patients who underwent video-assisted thoracoscopic patent ductus arteriosus closure were enrolled in the study. Cardiorespiratory variables were determined during baseline T1 and after CO2 insufflation at pressures of 2 mm Hg T2, 4 mm Hg T3, 6 mm Hg T4, 8 mm Hg T5, and 10 mm Hg T6.
Results: CO2 insufflation was not associated with any adverse hemodynamic effects. Cardiac output and central venous oxygen saturation increased progressively throughout the study protocol. Relative to baseline peak velocity, systolic flow time corrected for heart rate, heart rate, and central venous pressure increased significantly during insufflation, but systolic and diastolic blood pressure remained unchanged. Arterial CO2 increased from 40.7 +/- 3 at T1 to 61 +/- 1.6 at T6 mm Hg. Arterial oxygen tension increased from 170.9 +/- 3.3 at T1 to 182 +/- 2 at T6; arterial PH decreased from 7.31 +/- 1.2 at T1 to 7.14 +/- 4.6 at T6.
Conclusion: Hypercapnia targeting CO2 50-70 mm Hg was associated with increased cardiac output, central venous O2, and arterial O2 tension in patients undergoing video-assisted thoracoscopic patent ductus arteriosus closure using one-lung ventilation without any deleterious cardiopulmonary effects.