Combined preoperative femoral and sciatic nerve blockade improves analgesia after anterior cruciate ligament reconstruction: a randomized controlled clinical trial.

STUDY OBJECTIVE

To compare preoperative femoral (FNB) with combined femoral and sciatic nerve block (CFSNB) in patients undergoing arthroscopic anterior cruciate ligament (ACL) reconstruction.

DESIGN

Prospective, randomized clinical trial.

SETTING

Ambulatory surgery center affiliated with an academic medical center.

PATIENTS

Sixty-eight American Society of Anesthesiology physical status I and II patients undergoing arthroscopic ACL reconstruction.

INTERVENTIONS

Subjects randomized to the CFSNB group received combined femoral and sciatic nerve blocks preoperatively, whereas patients randomized to the FNB group only received femoral nerve block preoperatively. Both groups then received a standardized general anesthetic with a propofol induction followed by sevoflurane or desflurane maintenance. Intraoperative pain was treated with fentanyl. Pain in the postanesthesia care unit (PACU) was treated with ketorolac and opiates. Patients with significant pain despite ketorolac and opiates could receive a rescue nerve block.

MEASUREMENTS

Our primary outcome variable was highest Numeric Rating Scale (NRS) pain score in PACU. NRS pain scores, opioid consumption, opioid adverse effects, and patient satisfaction were assessed perioperatively until postoperative day 3.

MAIN RESULTS

The highest PACU NRS pain score was significantly higher in the FNB group compared with the CFSNB group (7 [3-10] vs 5 [0-10], P=.002). The FNB group required significantly larger doses of opioids perioperatively (31.8 vs 19.8mg intravenous morphine equivalents, P<.001). PACU length of stay was significantly longer in the FNB group (128.2 vs 103.1minutes, P=.006). There was no significant difference in opioid consumption, pain scores, or patient satisfaction on postoperative days 1-3 between groups.

CONCLUSIONS

Preoperative CFSNB for arthroscopic ACL reconstruction improves analgesia, decreases opioid consumption perioperatively, and decreases PACU length of stay when compared with FNB alone.