Effect of corrective or palliative procedures on arterial to end-tidal carbon dioxide pressure difference in pediatric cardiac surgery

Background: The normal small difference (3–5 mmHg) between arterial (partial pressure of carbon dioxide [PaCO2]) and end-tidal carbon dioxide pressure (ETPCO2) increases in children with congenital heart disease. The present study was conducted to evaluate the effect of corrective or palliative cardiac surgery on this difference (known as DPCO2). Patients and Methods: In a prospective study, 200 children (aged <12 years old) candidate for corrective or palliative cardiac surgery were studied. Using arterial blood gas measurement and simultaneous capnography, DPCO2 was calculated at various intra- and postoperative periods. DPCO2 values were compared within and between corrective or palliative procedures. Results: Corrective and palliative procedures were carried out on 154 and 46 patients, respectively. Initial DPCO2 was higher than normal values in corrective or palliative procedures (15.50 ± 13.1 and 10.75 ± 9.1 mmHg, respectively). DPCO2 was higher in patients who underwent palliative procedure, except early after procedure. The procedure did not have any effect on the final DPCO2 in palliative group. Although DPCO2 decrease was significant in the corrective group, it did not return to normal values. Operation time was longer, and the need to inotropic support was higher in corrective procedures; however, longer periods of ventilatory support were needed in the palliative group. Complication rate and Intensive Care Unit stay time were the same in two operation types. Conclusions: DPCO2 did not change after palliative cardiac procedures. DPCO2 decreased after corrective procedures; however, it did not return to normal values at early postoperative period. Thus, DPCO2 may not have any clinical value in monitoring the quality of corrective or palliative procedures.