Monitoring irrigating fluid absorption during transurethral resection of the prostate (TURP); a comparison between 1 and 2% ethanol as a tracer.

In a series of 35 transurethral resections of the prostate 1% ethanol was compared to 2% ethanol as a marker of the irrigating fluid. The ethanol concentration in the expired breath of the patient (EB-ethanol) correlated significantly to the irrigant absorption, as measured volumetrically, and to the change in the serum sodium concentration at 10-min intervals during the operation. The pattern of changes in EB-ethanol indicated whether the main part of the absorption entered through the intravenous or the extravascular route. With 1% ethanol added to the irrigating solution the absorption of 100-150 ml in 10 min could readily be detected. The sensitivity was twice as great with 2% ethanol; however, 1% ethanol is sufficient for routine procedures as it permits absorption to be detected long before it is large enough to produce a TUR syndrome. Monitoring ethanol in the expired breath provides the surgeon with an instrument to check that preventive steps against further absorption are effective.