Predictive Factors for Intraoperative Blood Loss during Percutaneous Nephrolithotomy

To evaluate the factors that may increase bleeding during Percutaneous nephrolithotomy (PCNL) and correlate them with outcome.

Analytical study.

The Kidney Centre postgraduate Training Institute, Karachi, Pakistan, from July to December 2016.

Consecutive patients who underwent PCNL from July to December 2016 were prospectively enrolled. Drop in hemoglobin was divided into three groups: mild <1 gm/dl, moderate 1-2 gm/dl and major >2 gm/dl. Factors such as age, gender, comorbidities, body mass index (BMI), operative time, creatinine levels, renal cortical thickness, stone size, its characteristics and location, puncture type and site, and need for blood transfusion were assessed by Chi-square/ Fisher exact test and Kruskal Wallis test. Predictive factors were assessed by multinomial logistic-regression analyses.

Total 305 patients were enrolled in the study. Median age was 37 (27.5-49.1) years with predominantly males (n=217, 71.8%). Median BMI was 27.3 (24.6-31.4) Kg/m2 and mean stone size was 2.7 (2.1-3.4) cm. Two hundred and ninety-seven (97.7%) stones were radio-opaque. Operative time was 95 (60-127) minutes. There were 50.8% patients who had moderate drop in hemoglobin (1-2 gm/dl). Stone size, BMI and operative time were strongly associated with significant drop in hemoglobin. Complete stone clearance was achieved in 256 (84%) patients. Thirty (9.8%) patients needed blood transfusion. None of the patients required angioembolisation.

BMI, stone size, and operative time were strongly associated with intraoperative blood loss during PCNL.