The effect of the choice of irrigation fluid on cardiac stress during transurethral resection of the prostate: a comparison between 1.5% glycine and 5% glucose.

PURPOSE: Variable amounts of irrigation fluid are absorbed during transurethral prostate resection. Previous studies suggest that cardiac stress occurs as a result of transurethral prostate resection, possibly due to glycine absorption. We performed a prospective, blinded, randomized trial comparing 1.5% glycine with 5% glucose irrigating solution. We assessed whether glycine or glucose irrigation for transurethral prostate resection is associated with cardiotoxicity, as measured by troponin I and echocardiogram changes. MATERIALS AND METHODS: Between December 2001 and March 2003, 250 patients were recruited. Changes in immediate postoperative vs preoperative echocardiogram and serum cardiac troponin I indicated perioperative myocardial stress. Intraoperative irrigating fluid absorption was measured with 1% ethanol as a marker. Operative details recorded were anesthesia type, resection time, resected tissue weight and temperature change. Blood loss was measured with transfusions considered. Postoperatively blood assessments included serum glycine assay. RESULTS: Five patients (4%) in the glycine group and 3 (2%) in the glucose group had significantly increased troponin I after surgery. Of these men 1 per group had myocardial infarction and the remainder had transient ischemia. Logistic regression was used to identify factors associated with an unfavorable outcome, which was recorded as a significant increase in troponin I or ischemic changes on echocardiography. Increasing patient age and blood loss were associated with an unfavorable outcome (OR 1.84 and 1.24, respectively). We noted no significant differences in the 1.5% glycine and 5% glucose groups with regard to troponin I/echocardiogram. However, when the glycine assay was compared with adverse outcomes, an increased glycine assay was found to be associated with echocardiogram changes (p = 0.001) and with increased troponin I levels (relative risk 10.71). CONCLUSIONS: Transurethral prostate resection has an effect on the myocardium perioperatively. Glycine absorption causes echocardiogram changes and it is associated with increased troponin I. Increasing patient age and blood loss are associated with myocardial insult. The risk of increased blood loss was accumulative with each unit lost. Unrecognized blood loss or glycine absorption may explain the increase in morbidity and mortality previously reported in patients who undergo transurethral prostate resection.

Is using ethanol-glycine irrigating fluid monitoring and 'good surgical practice' enough to prevent harmful absorption during transurethral resection of the prostate?

OBJECTIVE: To evaluate the utility of using a tracer of 1% ethanol in 1.5% glycine for the early detection of irrigation fluid absorption during transurethral resection of the prostate (TURP). PATIENTS AND METHODS: In all, 126 men undergoing TURP were irrigated with a solution of 1% ethanol and 1.5% glycine; their expired air was tested for ethanol every 20 min, and again at the end of the procedure. Maximum absorption by the breath-ethanol reading was compared with the serum concentration of absorbed glycine (analysed by anion-exchange chromatography). RESULTS: Complete data on 120 men were assessed; 75% of the men absorbed irrigation fluid, with glycine levels above the normal range. The sodium levels tended to decrease with increasing glycine levels (Spearman's rank correlation coefficient, - 0.57; 120 men) and five men (4%) developed clinical features of the TUR syndrome. There was a weak correlation between breath-ethanol levels and serum glycine levels (Spearman's rank correlation coefficient, 0.54). The experience of the surgeon, the weight of the resected chips, and the operative duration were not significantly predictive of irrigation fluid absorption. CONCLUSIONS: A rising breath-ethanol level indicates irrigation fluid absorption. However, irrigating fluid absorption is unpredictable, supporting the case for alternative, potentially safer irrigants.

A comparison of the effect of 1.5% glycine and 5% glucose irrigants on plasma serum physiology and the incidence of transurethral resection syndrome during prostate resection.

OBJECTIVE: To examine changes in the pathophysiology and frequency of the transurethral resection (TUR) syndrome with two irrigation fluids, as variable amounts of irrigation fluid are absorbed during TUR of the prostate (TURP), and although polar solutes are required to prevent an effect on diathermy, the solutes may have effects when absorbed. PATIENTS AND METHODS: Between December 2001 and March 2003, 250 patients were included in a prospective randomized trial comparing glycine 1.5% with 5% glucose irrigation fluids. We measured blood loss, fluid absorption, temperature change, biochemistry including a glycine assay, and peri-operative symptoms. Blood samples were taken immediately before and immediately, 5 and 24 h after TURP. Irrigating fluid absorption during TURP was measured with 1% ethanol as a marker and breath ethanol measurements. Operative details were recorded, including the type of anaesthesia (with or with no sedation), resection time and weight of resected tissue. Peri-operative symptoms were documented prospectively. TUR syndrome was defined as a serum sodium level of < or = 125 mmol/L with two or more associated symptoms or signs of TUR syndrome. RESULTS: Five (2%) patients had TUR syndrome; all five were irrigated with glycine, although this difference was not statistically significant (P = 0.06). Of the five men, three had hypotension, four were tired, one was nauseous, two had parasthesia, two had 'uneasiness', one had blurred vision and two were confused; none had chest pain. There was a large variation between the groups in the level of glycine assayed immediately after TURP; a high glycine level was associated with the TUR syndrome (P = 0.01). There was no difference between the groups in levels of sodium, potassium, urea, creatinine, osmolality, calcium, haematocrit, albumin serum levels or peri-operative blood loss (defined as a change from before to after TURP in haemoglobin level, accounting for transfusions). CONCLUSIONS: An increase in serum glycine was associated with TUR syndrome; there were large variations in the amounts of glycine absorbed, reaching levels many times the upper limit of normal. In other studies, glycine was reportedly toxic, and that the levels recorded were many times the upper limit of normal may have both immediate and long-term effects.