Microcatheter continuous spinal anaesthesia in the post-operative period: a prospective study of its effectiveness and complications.

One hundred patients (aged 22-86 years, mean 62.5), undergoing lower limb orthopaedic surgery, received continuous spinal anaesthesia using a 28 s.w.g. catheter inserted through a 22 s.w.g. Quincke needle. Post-operative pain relief was provided by bolus injections of 1-2.5 mL 4 h-1 of plain 0.25% bupivacaine. The mean dose of bupivacaine required for sufficient pain relief in 93% of patients was 1.6 +/- 0.2 (1.3-1.9) mL 4 h-1. The highest dose was needed between 4 and 8 h post-operatively. No dependence of dose on age or type of operation was found. Technical problems with the microcatheter occurred in 12%. The most frequent complaint was post-operative backache (12%). Only one patient suffered from post-dural puncture headache on the day after surgery. There was no microbiological contamination of the catheter tips after removal. In the post-operative interview, 89% of the patients were completely satisfied with CSA; 91% would prefer this technique to general anaesthesia.