Interpleural bupivacaine for analgesia during chest drainage treatment for pneumothorax. A randomized double-blind study.

The ability of interpleural analgesia to reduce the pain caused by an indwelling chest drain was evaluated in 22 patients treated for spontaneous pneumothorax. Intermittent 8-hourly bolus injections of 20 ml bupivacaine 0.5% with epinephrine were compared with placebo in a randomized double-blind fashion. Visual analogue pain scale (VAS) scores were registered after the 1st, 2nd, 4th, 7th and 10th injections. The scores were significantly lower in the bupivacaine group at 5, 15, 30 and 60 min after the first injection. No significant differences in pain scores were found after 4 or 8 h. Pain scores in the bupivacaine group were also reduced after the 2nd, 4th, 7th and 10th injections, but compared with placebo the differences were significant only after the 2nd and 7th injections. Parenteral morphine consumption was not significantly lower in the bupivacaine group. Arterial blood gases were unaffected by the treatment in both groups. It is concluded that interpleural analgesia using bupivacaine given as bolus injections at 8-h intervals significantly reduces the pain caused by a chest drain within 5 min of injection, but the duration of pain relief is less than 4 h.