Hemodynamic Changes After Retroperitoneal CO2 lnsuff lation for Posterior Retroperitoneoscopic Adrenalectomy Reiner M. Giebler, MD*, Martin K. Walz, Mm, Klaus Peitgen, Mm, and Ralf U. Scherer, MD* *Institute of Anesthesiology, tDepartment of General Surgery, University Hospital Essen, Essen, Germany Intraoperative complications and hemodynamic alter- ations during posterior capnoretroperitoneoscopic adrenalectomy in the prone position were investigated in 16 consecutive patients using invasive hemodynamic monitoring. Under general anesthesia with propofol and fentanyl, hemodynamic changes were made before (M,) and during retroperitoneal CO, insufflation (15 mm Hg) [M,]; 20 mm Hg [M,]. Retroperitoneal insuf- flation resulted in a significant increase of cardiac output (+72%), stroke volume (+42%), mean arterial pressure (+39%), and mean pulmonary arterial pres- sure (+36%). Although retroperitoneal inflation was accompanied by a significant increase of central venous pressure (+37%), an increase of preload may have led to higher filling pressures. Heart rate, systemic vascular resistance, and pulmonary vascular resistance did not show significant changes. One pneumothorax and two cutaneous emphysemas occurred. We have demon- strated, in a small number of patients, that retroperito- neal CO, insufflation for posterior capnoretroperito- neoscopic adrenalectomy in the prone position results in hemodynamic changes without apparent adverse effects. (Anesth Analg 1996;82:827-31) R etroperitoneoscopic adrenalectomy is a new sur- gical technique that could be performed in the prone or the lateral position (l-3). The prone position is advantageous during conventional adrena- lectomy for tumors ~10 cm as far as blood loss, post- operative morbidity, and length of hospital stay are concerned (4). We recently described retroperitoneo- scopic adrenalectomy in the prone position using distension trocars developed for preperitoneal endoscopic herniorrhaphies (3). During conventional laparoscopic adrenalectomy, intraperitoneal CO2 insuf- flation (5,6) is followed by a marked decrease in cardiac output (CO) and an increase in systemic vascular resis- tance (SVR) (7). It is not known whether this impairment of circulatory function can be avoided during retroperi- toneal subphrenic CO, insufflation. Since the retroperi- toneal cavity, which is artificially created by the surgeon, is much smaller than the abdominal cavity, we hypoth- esized that hemodynamic changes should be less marked during retroperitoneoscopic adrenalectomy. There are no studies on the hemodynamic changes after retroperitoneal, subphrenic inflation of CO2 in humans Accepted for publication November 28, 1995. Address correspondence and reprint requests to Reiner M. Giebler, MD, Institute of Anesthesiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen, Germany. 01996 by the International Anesthesia Research Society 0003.2999/96/$5.00 in the prone position. We, therefore, studied these changes in 16 consecutive patients undergoing posterior retroperitoneoscopic adrenalectomy. Methods After obtaining local ethics committee approval and written, informed consent, 16 consecutive patients scheduled for elective unilateral (8 left-sided and 7 right-sided) or bilateral (n = 1) retroperitoneoscopic adrenalectomy were studied for 1 yr (July 1994-July 1995). There were no exclusion criteria. The size of adrenal tumors ranged from 1.5 to 5.5 cm. One day preoperatively, the patients were classified according to the American Society of Anesthesiologists (ASA) classification. Patients suffering from pheochromocy- toma (n = 3) were treated with phenoxybenzamine (150-240 mg/d orally) for 21 days prior to surgery. All patients were given flunitrazepam 1 mg orally 1 h preoperatively. General anesthesia was induced with propofol 1.5 “g/kg, fentany15 pg/kg, and atra- curium 0.5 mg/kg intravenously. After endotracheal intubation, patients were ventilated with an oxygen- nitrous oxide mixture (Fio, 0.33) and a positive end- expiratory pressure of +3 cm H,O using a volume- cycled ventilator. End-tidal CO, was adjusted to 32-36 mm Hg by changing tidal volume. Anesthesia was An&h Analg 1996;82:827-31 827