[Comparison of 3 combinations of 0.5% levobupivacaine and 1% mepivacaine in popliteal sciatic block in hallux valgus outpatient surgery].

BACKGROUND

To compare 3 combinations of 0.5% levobupivacaine (L) and 1% mepivacaine (M) for popliteal block for hallux valgus surgery.

METHODS

Prospective, double blind study of 120 patients undergoing unilateral hallux valgus outpatient surgery with posterior popliteal block with ultrasound-guided single injection. Patients were randomly allocated into three groups: G1: 20mL L+10mL M; G2: 10mL L+20mL M; and G3: 15mL L+15mL M. Recorded variables were: time of block, onset and reversal times for tibial and peroneal nerves block; postoperative pain until the 7(th) day by means of visual analogue scale (VAS), simple descriptive scale and the quality of nocturnal rest, complications, and patient satisfaction. ANOVA and chi2 were applied in the statistical analysis, with a P<0.05 considered significant.

RESULTS

Groups were homogeneous for demographic and surgical characteristics. None of the patients required intraoperative complementary analgesia or anaesthesia. Block onset was significantly longer in G1 than in G2 and G3 (39.4±14.7 versus 32.2±16.5 and 33.2±12minutes). Recovery time from sensory and motor block was significantly longer in G1 than in G2 and G3 (29.5±9.3 versus 22.2±8.2 and 24.8±7.9hours). Postoperative pain level was below VAS 30 (1-100) in the three groups; none of the patients experienced severe pain. Maximum pain level appeared at 24h postoperatively. Patient satisfaction was high and there were no complications.

CONCLUSIONS

Block onset time and anaesthetic efficacy was adequate in the three groups. The combination of 20mL levobupivacaine 0.5% with 10mL mepivacaine 1% provide a good alternative for a lasting postoperative analgesia.