Blood loss during transurethral resection of the prostate as measured by the chromium-51 method.

Purpose: To evaluate blood loss during transurethral resection of the prostate (TURP), and its predictive factors, using the chromium 51 (51Cr) labeling method. Patients and Methods: From January to June 2008, 41 patients who underwent TURP for symptomatic benign prostatic hyperplasia (BPH) at four French urology centers were included in the analysis. Red cells volume was measured by the 51Cr method 1 day before TURP, and on postoperative day 3. Overall blood loss was estimated by multiplication of red cells volume loss and preoperative venous hematocrit value. Results: Mean preoperative red cells volume was 1997 mL. Mean loss of red cells volume was 209 ml, which corresponds to an estimated blood loss of 507 mL. Mean delta of hematocrit and hemoglobin were 1.4% and 0.71 g/dL, respectively. In univariate analysis, prostate volume, weight of resected tissue, preoperative red cells volume, and resection time were significantly and directly associated with loss of red cells volume (P = 0.038, P = 0.004, P = 0.002, and P = 0.039, respectively). Bipolar and monopolar TURP did not lead to significant difference of red cells loss. In multivariate analysis, both preoperative red cells volume and weight of resected tissue were independent predictors of red cells loss (P = 0.017 and P = 0.048 respectively). Conclusion: We present the first study to measure blood loss secondary to TURP using the 51Cr method. This technique allowed evaluating blood loss not only during the surgical procedure but also during the postoperative period. We learned from this study that, on average, blood loss from the procedure until postoperative day 3 was more than 500 mL, which is larger than previously reported amounts as measured by other methods. Because significant blood loss might occur during the postoperative period, the 51Cr method should be used to measure blood loss when evaluating new emerging techniques to manage BPH.