Objective To compare the effects of different perfusate on internal environment in patients undergoing transurethralelectroprostatectomy(TURP).Methods Forty-two elder patients with benign prostatic hyperplasia undergoing TURP were randomly divided into two groups.The patients in group A(22 patients)received 5%GS as perfusate and those in group B(20 patients)5% mannitol.Blood electrolytes,blood sugar,hemoglobin(Hb),hematocrit(Hct)and central venous pressure(CVP)were measured before surgery,perfusion 45,90mi...