Prediction of clinical manifestations of transurethral resection syndrome by preoperative ultrasonographic estimation of prostate weight

BACKGROUND This study aimed to investigate the relationship between preoperative estimated prostate weight on ultrasonography and clinical manifestations of transurethral resection (TUR) syndrome. METHODS The records of patients who underwent TUR of the prostate under regional anesthesia over a 6-year period were retrospectively reviewed. TUR syndrome is usually defined as a serum sodium level of < 125 mmol/l combined with clinical cardiovascular or neurological manifestations. This study focused on the clinical manifestations only, and recorded specific central nervous system and cardiovascular abnormalities according to the checklist proposed by Hahn. Patients with and without clinical manifestations of TUR syndrome were compared to determine the factors associated with TUR syndrome. Receiver operating characteristic curve analysis was used to determine the optimal cutoff value of estimated prostate weight for the prediction of clinical manifestations of TUR syndrome. RESULTS This study included 167 patients, of which 42 developed clinical manifestations of TUR syndrome. There were significant differences in preoperative estimated prostate weight, operation time, resected prostate weight, intravenous fluid infusion volume, blood transfusion volume, and drainage of the suprapubic irrigation fluid between patients with and without clinical manifestations of TUR syndrome. The preoperative estimated prostate weight was correlated with the resected prostate weight (Spearman's correlation coefficient, 0.749). Receiver operator characteristic curve analysis showed that the optimal cutoff value of estimated prostate weight for the prediction of clinical manifestations of TUR syndrome was 75 g (sensitivity, 0.70; specificity, 0.69; area under the curve, 0.73). CONCLUSIONS Preoperative estimation of prostate weight by ultrasonography can predict the development of clinical manifestations of TUR syndrome. Particular care should be taken when the estimated prostate weight is > 75 g.