The use of ethanol as a marker to detect and quantify the absorption of irrigation fluid during transurethral resection of the prostate.

During transurethral resection of the prostate (TURP), the irrigation fluid is often absorbed by the circulatory system and/or the region around prostate occasionally resulting in severe signs and symptoms. Instant detection and qualification of absorption of irrigation fluid have not been possible earlier. A method involving tagging of the irrigation fluid with ethanol for detection and quantification of absorbed irrigation fluid by measurement of ethanol in expired breath (EB) has been developed. The validity of measuring EB ethanol to detect and quantify absorption of irrigation fluid was studied in 13 patients undergoing TURP. The EB ethanol was compared with three other methods: I. Isotope tagging of the irrigation fluid and detection of absorbed fluid using a scintillation detector placed over large blood vessels. 2. Measuring changes in serum-sodium every 10 min. 3. Regular interval monitoring (RIM) of the difference between volume used for irrigation and volume recovered from patients every 10 min. The method of measuring EB ethanol was found to be highly valid. The possibility of detecting absorption and the incidence of absorption using EB ethanol in the clinical routine was studied in 192 patients undergoing TURP. Half of them absorbed irrigation fluid, 25% absorbed more than 400 ml. The proportion of patients absorbing irrigation fluid was the same for both experienced and inexperienced resectionists. Clinical assessment of absorption of irrigation fluid was performed by the resectionists and the supervising nurses in 118 patients undergoing TURP. Prerequisites for massive absorption were found by the resectionist in 8/9 patients. The resectionist falsely indicated absorption in 22 patients. The nurses correctly indicated 3/9 patients and falsely indicated 4 patients. To investigate the method measuring EB ethanol to detect absorption of irrigation fluid during general anaesthesia, 20 patients underwent TURP and EB ethanol was compared with the RIM method. There was a good correlation between the methods. Elevated pressure in the bladder and the prostatic fossa is a prerequisite for absorption of irrigation fluid. Detection and quantification of absorbed irrigation fluid by EB ethanol was used for comparing 102 patients operated on with and without a pressure warning device alarming at 1.5 kPa in the bladder. using the device reduced both the volume of absorbed irrigation fluid, and the number of patients absorbing irrigation fluid. Both ethanol per se and haemodilution by absorbed irrigation fluid may have impacts on the coagulation system. To investigate the influence of absorption of ethanol tagged mannitol on bleeding time, measurements were performed before and after TURP in 57 patients. No difference in bleeding time was found among patients who absorbed irrigation fluid as compared with those who did not. In conclusion, measurement of ethanol in EB for detection and quantification of absorbed irrigation fluid is a highly valid method when compared with three other methods. Absorption of irrigation fluid was found in 50% of the patients undergoing TURP. Clinical assessments of absorption of irrigation fluid are unreliable. EB ethanol can be used in patients during general anaesthesia. Using a pressure warning device decreases the volume of absorbed irrigation fluid, as well as the number of patients absorbing it. Absorption of ethanol tagged mannitol as irrigation fluid has no influence on bleeding time.