Regional Anesthesia and Pain Outcomes After Anterior Cruciate Ligament Reconstruction Surgery in Pediatric Patients: Society of Pediatric Anesthesia Improvement Network

BACKGROUND: Optimal perioperative pain management is unknown for adolescent patients undergoing anterior cruciate ligament reconstruction (ACLR). The study aimed to determine the association of nerve blocks with short- and long-term pain outcomes and factors influencing self-reported neurological symptoms. METHODS: We performed a multisite, prospective observational study of adolescent patients undergoing ACLR. Perioperative data included demographics, block details, anesthetic, and surgical techniques. Self-reported surveys documented pain scores, medication use, and neurological symptoms at various time points after the surgery (postoperative day [POD] 1, POD 3, week 6, and month 6). Associations between different groups of peripheral nerve blocks (PNBs) and the absence of a block were analyzed for their effects on acute postoperative pain outcomes. In addition, factors influencing self-reported neurological outcomes were determined using both univariate and multivariate regression. RESULTS: Data from 519 subjects (aged 15 years, 55.7% female) showed that 23.9% of patients with anterior plus posterior nerve blocks (A+P PNB) reported severe postanesthesia care unit (PACU) pain scores, compared to 40% with no PNB and 38.3% with anterior PNB (A-PNB). Patients receiving A-PNB or A+P PNB had significantly lower intraoperative morphine equivalents (MEs) (0.49 mg/kg and 0.46 mg/kg, respectively) vs no block patients (0.61 mg/kg). Total PACU MEs were lower for any patient who received a PNB. Multivariable logistic regression analysis showed that patients who received A+P PNB or a hamstring autograft had lower POD 1 severe pain scores (odds ratio [OR] = 0.35; 95% confidence interval [CI], 0.15-0.84 and OR = 0.35; 95% CI, 0.15-0.83, respectively). Patients with PNBs with local anesthesia concentration (LAC) greater than 0.25% reported higher POD1 pain scores (OR = 2.14; 95% CI, 1.1-4.16) compared to those with lower LAC. Patients with PNB catheters had reduced POD 1 pain. Multivariable logistic regression analysis for numbness at week 6 revealed a greater odds of numbness for A-PNB with LAC >0.25% (OR = 5.13; 95% CI, 1.27-20.8). At month 6, patients receiving PNB with perineural steroid adjuvant were more likely to report numbness (dexamethasone OR = 5.93; 95% CI, 1.61-21.9, methylprednisolone OR = 11.3; 95% CI, 2.16-58.6). CONCLUSIONS: Patients who received A+P PNB had lower postoperative pain scores than those who received no block. Additional studies are necessary to discern how PNB type, graft harvest site, LAC, and adjuvants influence pain control, persistent numbness, and weakness.