Randomised trial showing that lidocaine should be "squirted" through a peritoneal drain before it is removed

A block randomised, non-blinded trial was performed to see if injecting lidocaine down a surgical drain could reduce the pain associated with its removal. A total of 36 women who had a closed suction intraperitoneal drain after elective gynaecological surgery were randomly allocated to conventional drain removal or drain removal 5-10 min after squirting 10 ml 2% lidocaine down the drain tube. We found that the pain associated with removal of the drain is variable but can be reduced significantly with lidocaine. The median pain score (95% range) during drain removal was 3.0 (2.5 - 5.0) in the group allocated lidocaine compared with 5.5 (4.6 - 6.5) if lidocaine was not used (median difference = 2.0; 95% confidence interval for the difference between medians is 1 - 3.5). In summary, the median pain score was halved by injecting lidocaine down the drain tubing before removal.