Bilateral ankle blocks: a prospective audit.

Background: There are significant advantages to the practice of bilateral ankle block. However, clinicians are reluctant to employ this technique due to concerns over reliability, local anaesthetic longevity and toxicity, surgical efficiency, and patient comfort.

Methods: Sixty-six patients undergoing bilateral ankle blocks during mid- and forefoot surgery were audited to determine success rate, local anaesthetic safety and efficacy, and patient acceptance. Intravenous sedation was administered both during insertion of ankle blocks and intraoperatively, as requested by the patient and as deemed necessary by the anaesthetist. The choice of local anaesthesia was either a 50/50 mixture of lignocaine 1.5% plain and ropivacaine 7.5 mg/mL, ropivacaine 7.5 mg/mL alone or ropivacaine 7.5 mg/mL and clonidine 1 microg/kg.

Results: A total of 89% of patients had a successful bilateral ankle block. Ropivacaine and clonidine combination, ropivacaine, and ropivacaine and lignocaine combination provided a mean length of action of 17 h, 14 h and 8 h, respectively. No adverse local anaesthetic events were reported. Sixty-one per cent of patients remembered intraoperative events; only one patient would choose not to have the procedure performed again under ankle blocks.

Conclusions: The present audit demonstrates that bilateral ankle blocks are a safe and efficient technique. With appropriate doses of sedative drugs both during insertion of the ankle block and surgery, patients remain comfortable.