Criteria for drain removal following liver resection.

BACKGROUND Abdominal drains have been placed prophylactically and removed in liver resection without robust evidence. The present study was designed to establish the optimal time for removal of such drains. METHODS Data on abdominal prophylactic drains were analysed in a consecutive series of patients who underwent liver resection for malignancy between 2006 and 2009. Bilirubin levels in drain fluid were measured and bacteriological cultures were taken on days 1, 3, 5 and 7 after surgery. Drains were removed on day 3 if the drain-fluid bilirubin level was less than 5 mg/dl and bacteriological cultures were negative. Drains remained in situ until these conditions were met. RESULTS A total of 514 abdominal drains were placed in 316 patients operated on in the study period. Fifty-eight patients (18·4 per cent) had positive drain-fluid cultures and 14 (4·4 per cent) had bile leakage (drain-fluid bilirubin level 5 mg/dl or more). Only one patient required ultrasound-guided abdominal drainage. On multivariable analysis, drain-fluid bilirubin level on day 3 after surgery was the strongest predictor of infection (odds ratio 15·11, 95 per cent confidence interval 3·04 to 92·11; P < 0·001). The area under the receiver operating characteristic curve on day 3 had the highest predictive value: 83·6 per cent accuracy and 3·9 per cent false-positive rate for a drain-fluid bilirubin level of 3·01 mg/dl (51·5 µmol/l). CONCLUSION The '3 × 3 rule' (drain-fluid bilirubin level below 3 mg/dl on day 3 after operation) is an accurate criterion for removal of prophylactically placed abdominal drains in liver resection.