Sciatic nerve block with lateral popliteal approach for hallux vagus correction. Comparison between 0.5% bupivacaine and 0.75% ropivacaine.

Objective: In this study the authors compared the clinical profile of 2 local anesthetic drugs in the sciatic nerve block used during hallux valgus correction, a surgical procedure known to be post-operatively extremely painful. Since hallux valgus correction is painful post-operatively, many attempts have been tried to ensure a long-lasting analgesia. Block of the sciatic nerve appears to be the right choice balancing ease to performance, satisfaction of the patient and duration of action.

Methods: The authors investigated the use of 20 ml of 0.5% bupivacaine or 0.75% ropivacaine regarding the speed of onset, quality and length of duration of sciatic nerve block performed with a lateral popliteal approach. Sixty ASA I-III patients (aged 19-73 years) were enrolled in this trial. Written informed consent was asked and obtained. A 20 G 50 mm Teflon coated Crawford needle, delivering 0.5 mA at 2 Hz, was used to locate and block the sciatic nerve in the popliteal fossa with a lateral approach.

Results: Patients in the ropivacaine group required about 13 minutes to achieve a complete block and about 16 minutes were needed in the bupivacaine group for the anesthesia to be complete. The length of analgesia was 16 h for the ropivacaine group and 13 h for the bupivacaine group. This kind of approach to block the sciatic nerve appeared to the authors to be very easy to perform, with the patient lying in a natural position. Surgical anesthesia required less than 30 min in both groups to be ready, while the ropivacaine group had a longer length of analgesia compared to the bupivacaine group.

Conclusions: Patient satisfaction was high in both groups.