Postoperative Recovery Time After Knee Arthroscopic Surgery Using Low Dose Mepivacaine Spinal Anesthesia Versus General Anesthesia: A Retrospective Propensity Score Matched Cohort Study.

General anesthesia (GA) is the preferred technique in ambulatory surgery because GA is associated with a predictable recovery time. However, it carries higher risk of postoperative nausea and vomiting and drowsiness when compared with spinal anesthesia (SA). This study aimed to determine whether the recovery time in mepivacaine of 30 mg SA is noninferior when compared with GA. Our single-center retrospective study used a multivariable logistic regression to model anesthetic modality as a function of age, sex, body mass index, and American Society of Anesthesiologists physical status to generate a propensity score for each patient for matching. After screening 455 patients, 111 patients in each group were matched. SA was associated with 23.0 minutes (95% CI, -∞ to 31.0; P < .0001) longer recovery time, shorter operating room time (-8.0 minutes, 95% CI -13.0 to -3.0), more likely to bypass phase 1 recovery (OR, 2.77; 95% CI, 1.20 to 6.88) and less opioid use (-0.5 mg; 95% CI, -3.7 to -0.0001) but no difference in length of stay (LOS). Spinal anesthesia was correlated with inferior recovery time. The associated phase 1 bypass and similar LOS suggest SA as a viable alternative to GA.