Helium and Carbon Dioxide Pneumoperitoneum in Patients with Pheochromocytoma Undergoing Laparoscopic Adrenalectomy

Abstract

Insufflation with helium is used to prevent respiratory acidosis, hypercapnia, and cardiovascular instability associated with carbon dioxide (CO₂) pneumoperitoneum. The aim of this prospective study was to compare CO₂ with helium pneumoperitoneum with special reference to respiratory and hemodynamic changes at different times during the operation. Altogether 22 pheochromocytoma patients undergoing laparoscopic adrenalectomy (LpA) were included using CO₂ in 11 patients (CO₂LpA) and helium in 11 patients (HeLpA). The insufflation pressure was 12 mmHg. The two groups were comparable with regard to demographic data and preoperative management. CO₂ and helium insufflation were associated with similar catecholamine increase. The most striking significant increase compared with the baseline was observed during tumor isolation: The mean plasma epinephrine (EPI) and norepinephrine (NE) levels increased 32.86-fold and 25.92-fold, respectively, in the CO₂LpA patients and 27.43-fold and 18.46-fold, respectively, in the HeLpA patients. HeLpA did not result in significant hypercarbia or acidosis at any measured intraoperative point; this was without any alteration in minute ventilation to maintain these normal PaCO₂, excess base (EB), and pH values. Significant increases of mean arterial pressure, pulmonary arterial pressure, pulmonary vascular resistance index, PaCO₂, EB, and acidosis were seen in the CO₂LpA patients at the time of tumor isolation and tumor removal compared with those in HeLpA patients. No patient required conversion to open surgery. There were no significant differences between CO₂LpA and HeLpA regarding mean operative time (117.50 ± 93.68 vs. 106.87 ± 16.60 minutes), mean blood loss (168.54 ± 78.63 vs. 142.02 ± 109.26 ml), hospital stay (4 days), the need for analgesics, or mean time required to return to normal activity (12 days). There was one wound infection in the HeLpA group and one wound hematoma and one case of atelectasis in the CO₂LpA group. Helium may be the agent of choice for abdominal insufflation in patients undergoing LpA for pheochromocytoma, eliminating the adverse hemodynamic and respiratory changes associated with CO₂ insufflation.