Lumbar plexus blockade reduces pain after hip arthroscopy: a prospective randomized controlled trial.

BACKGROUND: Hip arthroscopy causes moderate to severe postoperative pain. We hypothesized that performance of a lumbar plexus block (LPB) would reduce postoperative pain in the postanesthesia care unit (PACU) for patients discharged home on the day of surgery.

METHODS: Patients received a combined spinal epidural with IV sedation, ondansetron, and ketorolac. Half of the patients (n = 42) also underwent a single-injection bupivacaine LPB. Postoperative analgesia (PACU and after discharge) was provided with oral hydrocodone/acetaminophen (5/500 mg) and an oral nonsteroidal antiinflammatory drug. IV hydromorphone was given as needed in the PACU.

RESULTS: The LPB reduced pain at rest in the PACU (GEE: β estimate of the mean on a 0 to 10 scale = -0.9; 95% confidence interval = -1.7 to -0.1; P = 0.037). Mean PACU pain scores at rest were reduced by the LPB from 4.2 to 3.3 (P = 0.048, 95% confidence interval for difference = 0.007-1.8; uncorrected for multiple values per patient, using independent samples t test for preliminary evaluation comparing pain between the groups). There were no statistically significant differences in PACU analgesic usage, PACU pain with movement, and patient satisfaction. No permanent adverse events occurred, but 2 LPB patients fell in the PACU bathroom, without injury. Three unplanned admissions occurred; one LPB patient was admitted for epidural spread and urinary retention. Two control patients were admitted, one for oxygen desaturation and one for pain and nausea.

CONCLUSION: LPB resulted in statistically significant reductions in PACU resting pain after hip arthroscopy, but the absence of improvement in most secondary outcomes suggests that assessment of risks and benefits of LPB should be individualized.