Risk factors for urinary retention following minor thoracic surgery.

OBJECTIVES Our goals were (i) to identify the incidence and risk factors of postoperative urinary retention in minor thoracic surgery patients and (ii) to develop a scoring system to predict postoperative urinary retention in these patients. METHODS Two hundred and ninety-two consecutive patients who underwent thoracic surgery without a pre- or intraoperative indwelling urinary catheter under general anaesthesia were used to identify the risk factors of postoperative urinary retention (post-void residual urine >200 ml) and to develop the scoring system predicting the incidence of this complication. We investigated past history, type of operation, operation time, amount of administered intravenous fluids, medications used perioperatively as well as demographic data. RESULTS The incidence rate of postoperative urinary retention was 11.6% (34/292). Independent risk factors and their scores were the following: age above 40 years (P < 0.001; two points); male (P = 0.002; one point); diabetes mellitus (P = 0.002; one point) and lung resection (P < 0.001; two points). The cut-off value for a model predicting postoperative urinary retention was five points (C-index = 0.88; 95% confidence interval: 0.83-0.94), with 73% sensitivity and 90% specificity. CONCLUSIONS In minor thoracic surgery patients, special attention should be paid to detect postoperative urinary retention in those with the following characteristics: age over 40 years, male gender, history of diabetes mellitus and candidates for lung resection. The use of the developed scoring system may help in identifying those high-risk patients who need more aggressive management to prevent bladder overdistension and associated urinary complications.