Ethanol monitoring of irrigating fluid absorption in transurethral prostatic surgery

The ethanol concentration in expired breath (EB-ethanol(A] was repeatedly measured in 50 patients undergoing transurethral prostatic surgery in which the irrigating fluid was 1.5% glycine + 2% ethanol in water. EB-ethanol(A) was compared at 10-min intervals to the serum sodium concentration, the serum glycine concentration, and the absorbed volume of irrigant. The EB-ethanol(A) was found to be related directly to the serum glycine concentration (R2 = 0.75) and, inversely, to changes in the serum sodium concentration (R2 = 0.81). The cumulative absorbed volume of irrigant could be predicted from a single EB-ethanol(A) reading at the end of each 10-min interval (R2 = 0.82); the reliability was improved by taking into account the absorption time (R2 = 0.89). Extravasation of irrigating fluid was indicated by a stable or increasing EB-ethanol(A) after the ethanol-tagged irrigant had been discontinued. Ethanol monitoring is a simple and inexpensive method of testing for the presence, and measuring the degree, of irrigant absorption in transurethral prostatic surgery.