[Experiences with routine monitoring of ethanol concentration in expired air in transurethral prostate resection]

During transurethral resection of the prostate (TURP), systemic influx of hypotonic irrigating fluid is a life-threatening event. Its occurrence can lead to TUR syndrome. Addition of ethyl alcohol to the irrigating fluid and analysis of alcohol concentration in the expiratory breath constitute a simple but sensitive monitoring technique for early detection of an influx event and its extent. Clinical experience with this method in 50 patients who underwent TURP is reported. The following parameters were determined: heart beats per minute (heart rate), mean arterial pressure, sodium concentration in the serum, duration of resection, and weight of resected tissue. At 10-min intervals, the alcoholic concentration of the expiratory breath of each patient was measured with the AlcoMed 3011 analyzer (Biotest, Dreieich, Germany). Active measurement was possible in 40 patients, and a passive analytic procedure was used in 5 other patients in whom general anaesthesia was induced. In the remaining 5 patients, the monitoring could not be performed because of a medical history of significant alcohol abuse. A suprapubic trokar was used to decrease intravesical pressure in 16 patients. In 8 of 45 patients, alcohol concentration was > 0.2@1000. Three of them developed TUR syndrome. With regard to the frequency of an influx event, there was no significant difference between resections using a trokar and those performed without a trokar. In addition, there was no correlation between this frequency and the duration of resection or the weight of resected tissue. In single cases, influx of considerable fluid volume was found, whereas in 28 patients, duration of resection was far longer than 60 minutes with no signs of an influx event. Mean arterial pressure and heart rate were not altered in 47 patients during the course of the surgical procedure; however, a decrease in these parameters was observed in the 3 patients who developed TUR syndrome. In each of the 8 patients with increased alcohol concentrations, a significant decrease in the serum sodium concentration was observed. There was no change in sodium concentration during the postoperative course in the remaining 42 patients. The data indicate that monitoring of the alcohol load in the expiratory breath is a simple, non-invasive, reliable and cost-efficient way of detecting an influx of fluids during TURP and allows the anaesthetist to take early steps to prevent the development of TUR syndrome.