A retrospective review of femoral nerve block for postoperative analgesia after knee surgery in the pediatric population.

BACKGROUND

To investigate the outcomes of pediatric patients receiving a femoral nerve block (FNB) in addition to general anesthesia for arthroscopic knee surgery compared with those receiving general anesthesia alone.

METHODS

This retrospective review included all patients undergoing arthroscopic knee surgery from January 2009 to January 2011 under general anesthesia both with and without a FNB. After the induction of general anesthesia, those patients selected for regional anesthesia received a FNB using real-time ultrasound or nerve stimulator guidance. For the FNB, 0.2 to 0.4 mL/kg of local anesthetic solution was injected around the femoral nerve at the level of the inguinal crease. Intra-articular injection of bupivacaine (0.25%, 10 mL) was administered by the surgeon for all patients not receiving a FNB. Additional analgesic medications, PACU length of stay, duration of hospitalization, hospital course, and any acute or nonacute complications were recorded and evaluated.

RESULTS

There were no adverse effects related to the FNB. Using a 0 to 10 visual analogue scale (0=no pain), there was a statistically significant difference in both the high (4.0 ± 4.0 vs. 5.3 ± 3.1, P=0.0004) and low (1.5 ± 1.8 vs. 2.1 ± 2.0, P=0.002) pain scores in patients who received a FNB versus those who did not with the scores being lower in those who had received a FNB. There was a decreased need for the use of opioids postoperatively (61% vs. 71%, P=0.04) and a decreased duration of postoperative stay in patients who were admitted to the hospital (11.7 ± 8.1 vs. 15.8 ± 10 h, P=0.044) in individuals who had a FNB. There was a significantly lower admission rate in patients undergoing anterior cruciate ligament repair in the FNB group (72% vs. 95%, P=0.001). There was no difference in the incidence of postoperative nausea and vomiting between the groups.

CONCLUSION

After arthroscopic knee surgery in pediatric patients, a FNB shortens hospital stay, reduces opioid requirements, and decreases postoperative pain scores. For anterior cruciate ligament repairs, FNB lowers postoperative admission rates.

CLINICAL EVIDENCE

Level III.