Evaluating Analgesic Efficacy of Single Femoral Nerve Block versus Combined Femoral-Sciatic Nerve Block Post Total Knee Arthroplasty.

BACKGROUND

With increasing knee replacement surgeries, there has been a constant search for effective pain control modality.

AIMS

We compared the analgesic effect of femoral nerve block (FNB) alone with combined femoral and sciatic nerve block (SNB) for postoperative pain management after total knee arthroplasty (TKA).

SETTING AND DESIGN

This was a prospective observational study.

METHODS

A total of 150 adult patients of American Society of Anesthesiologists physical status class I and II scheduled for elective TKA under spinal anesthesia with 3.4-mL bupivacaine 0.5% and 20-μg fentanyl were randomly allocated to two groups. Group F patients received a single shot FNB with 20 ml 0.375% ropivacaine and Group FS patients received combined FNB with 20 mL of 0.375% ropivacaine and SNB with 40 ml of 0.375% ropivacaine at the end of surgery. The primary outcome was the change in Numeric Rating Scale (NRS) scores between Groups F and FS at 6, 12, 18, 24, and 48 h later. The secondary outcome was total doses of opioid required in both groups.

RESULTS

The demographic data were comparable in both groups. The NRS scores were higher and statistically significant in Group F than that in Group FS at all five measured time points ( < 0.00001), and the total pain score with a mean of 15.43 in Group F and a mean of 9.61 in Group FS was statistically significant. Significantly more opioid consumption was seen postoperatively in Group F as compared to Group FS at 12, 18, 24, and 48 h as depicted by < 0.00001.

CONCLUSIONS

We conclude that the FNB, when combined with SNB, shows superior results than femoral block alone. SNB reduced pain scores and opiate consumption postoperatively up to 48 h.