Changes in oncotic pressure, osmolality and electrolytes following transurethral resection of the prostate using...

Thirteen patients undergoing resection of benign prostatic hyperplasia were given furosemide 40 mg at the end of the procedure. The changes in body weight, colloid oncotic pressure (COP), osmolality, electrolyte concentrations and several haematological variables were compared with the values of 13 patients treated similarly, but without furosemide. During the operation there was an estimated mean absorption of 300 ml of irrigating fluid (glycine 1.5%). There was a significant peroperative decrease in serum sodium concentration, osmolality, COP, and haemoglobin concentration in both groups. The furosemide group had a more rapid return of COP towards preoperative values, and this group did also approach the preoperative weight more rapidly than the control group. In 10 selected patients variations in the total aminoacid pattern were measured. There was a significant increase in glycine concentration, with the maximum increase ten times the preoperative value. In the absence of uncontrolled bleeding, the resorption of fluid during TUR leads to hypervolemia and reduction in serum sodium and COP. This may lead to the TUR syndrome, as illustrated by one of our patients. Treatment in the symptomatic patient consists of reduction of circulating blood volume and when this is achieved, hypertonic saline may be beneficial if there are neurological symptoms.