Abstract
Oliguria is a major problem during anesthesia, and renal-dose dopamine or furosemide is often used to maintain urine volume during general anesthesia. But both drugs have serious side effects and their renoprotective effect has been doubtful. Human atrial natriuretic peptide (hANP) is a 28-amino-acids peptide exhibiting various biological functions including renal protection and diuresis according to the water balance. Exogenous administration of hANP may increase urine volume and prevent acute renal failure after surgery. However, the recommended dose of hANP (0.1 micro-g/kg/min) may induce hypotension and anesthetic management may be difficult. Our investigation revealed the effects of low-dose hANP (0.01 micro-g/kg/min) on perioperative urine volume, blood pressure and renal function in patients undergoing orthopedic surgery. Continuous intravenous infusion of hANP at 0.01 micro-g/kg/min was started after induction of anesthesia, and was continued for 20 hours. No hypotension was observed during surgery. However, urine volume was twice that of the control group, except in patients with hypovolemia. Electrolytes did not change significantly during surgery. In addition, hemoglobin concentration was also maintained, while it significantly decreased in the control group. hANP might be an ideal diuretic for patients undergoing elective surgery.