Continuous infusion versus single bolus popliteal block following major ankle and hindfoot surgery: a prospective, randomized trial.

Background: Popliteal sciatic nerve blockade is a commonly used technique employed in the management of postoperative pain following foot and ankle surgery. Recent studies have shown that for outpatient surgery, for moderately painful procedures, a continuous infusion of local anesthesia via an in-dwelling catheter for 48 to 72 hours leads to reduced opiate analgesic requirements and improved pain and patient satisfaction scores.

Materials And Methods: A prospective, randomized, double blind, placebo-controlled trial of a continuous infusion of bupivacaine verses normal saline via a popliteal catheter after a single bolus popliteal block for 72 hours after major ankle and hind foot surgery was performed in 54 patients.

Results: The average pain scores overall were low (range, 1.1 to 3.6 on a Visual Analogue Scale of 0 to 10) throughout the study period. Statistically significantly lower pain scores with significantly less requirement for supplementary opiate analgesic agents were seen in the treatment group.

Conclusion: Despite the statistically significant findings, with such low pain scores in both groups, we believe it remains debatable whether the extra time and cost involved warrants the use of a continuous popliteal blockade over a single bolus injection.