Effect of intravascular volume expansion on renal function during prolonged CO2 pneumoperitoneum

Objective To evaluate whether intravascular volume expansion would improve renal bloo d flow and function during prolonged CO2 pneumoperitoneum. Summary Background Data Although laparoscopic living donor nephrectomies have a considerably reduce d risk of complications for the donors, significant concerns exist regardin g procurement of a kidney in the altered physiologic environment of CO2 pne umoperitoneum. Recent studies have documented adverse effects of CO2 pneumo peritoneum on renal hemodynamics. Methods Renal and systemic hemodynamics and renal histology were studied in a porci ne CO2 pneumoperitoneum model, After placement of a pulmonary artery cathet er, carotid arterial line, Foley catheter, and renal artery ultrasonic flow probe, CO2 pneumoperitoneum (15 mmHg) was maintained for 4 hours. Pigs wer e randomized into three intravascular fluid protocol groups: euvolemic (3 m L/kg/hour isotonic crystalloid), hypervolemic (15 mL/kg/hour isotonic cryst alloid), or hypertonic (3 mL/kg/hour isotonic crystalloid plus 1.2 mL/kg/ho ur 7.5% NaCl). Results In the euvolemic group, prolonged CO2 pneumoperitoneum caused decreased ren al blood flow, oliguria, and impaired creatinine clearance. Both isotonic a nd hypertonic volume expansions reversed the changes in renal blood flow an d urine output, but impaired creatinine clearance persisted. Conclusions Intravascular volume expansion alleviates the effects of CO2 pneumoperitone um on renal hemodynamics in a porcine model, Hypertonic saline (7.5% NaCl) solution may maximize renal blood flow in prolonged pneumoperitoneum, but i t does not completely prevent renal dysfunction in this setting, This study suggests that routine intraoperative volume expansion is important during laparoscopic live donor nephrectomy.