Summary of findings and recommendations.

1Attestation: Referenced in textbooks and/or multiple (>5) peer-reviewed research publications; Harm: Not Food and Drug Administration (FDA)-approved and balance of evidence suggests harm with perineural use; FDA: FDA-approved for regional anesthesia; IND: Investigational New Drug status (or international equivalent) granted or waived for in at least one reviewed study.2a: Studies with Jadad score III+ or higher/total number of studies; b: % of studies with positive results; c: clinical significance of positive results (extent of prolongation of analgesia or sensory block).3Agency for HealthCare Research and Quality Levels of Evidence and Grades of Recommendations: Grade A: based directly on Level 1 evidence; Level 1a: evidence from meta-analysis of clinical trials; Level 1b: evidence from at least 1 randomized controlled trial.Abbreviations: PNB = peripheral nerve block; PONV = postoperative nausea and vomiting; ISB = interscalene block; FNB = femoral nerve block; GI = gastrointestinal.Summary of findings and recommendations.