Does intraprostatic vasopressin prevent the transurethral resection syndrome?

To determine whether intraprostatic vasopressin (IPVP) prevents the transurethral resection (TUR) syndrome during prostatectomy.

The study comprised 36 consecutive patients (mean age 68 years) with prostates clinically assessed as >/= 20 g who underwent standard transurethral prostatectomy (TURP). Ten units of vasopressin in 0.5 mL were diluted with 9.5 mL isotonic saline and injected into the prostate transrectally before TURP. Blood samples were taken before and immediately after TURP to measure serum sodium concentration and free haemoglobin levels. The TURP irrigant used was cooled, boiled water maintained at 70-80 cmH2O pressure during resection. Twenty patients had alcohol added to the irrigant and their breath alcohol assessed at 10-min intervals during TURP. All patients had their pulse rate, blood pressure and sensorium monitored continuously. Extreme care was taken to avoid and/or identify capsular damage during resection.

The mean weight of tissue resected was 36 g and the mean resection time 24 min. There was no significant change in clinical variables during TURP. In 19 patients the breath alcohol changes were insignificant. Changes in free haemoglobin were not significant, but the levels decreased after TURP in four patients, caused by the dilution consequent on the infusion of 800-1000 mL isotonic saline during surgery. Serum sodium concentrations showed only insignificant decreases, except in one patient whose breath alcohol suggested the absorption of 500 mL of irrigant. This patient's serum sodium concentration decreased by 9 mmol/L; 1 L of 5% dextrose was infused during the procedure and capsular damage was recognized early during TURP.

Insignificant volumes of irrigant entered the circulation of the patients during TURP with water irrigation and IPVP. The greatest risk factor for fluid entry during TURP is capsular damage. IPVP decreases bleeding and therefore improves visibility, so allowing the early identification of capsular damage. IPVP seems therefore to be of help during TURP by decreasing bleeding and allowing insignificant volumes of irrigant to enter the vasoconstricted vessels; it appears to prevent the TUR syndrome.