Fatty Liver Is an Independent Risk Factor for Delayed Recovery from Anesthesia

Fatty liver (FL) is associated with altered activity of hepatic drug-metabolizing enzymes, but the clinical significance is unknown. Many anesthetic agents are metabolized in the liver. We aimed to determine whether FL impacts recovery from anesthesia as a surrogate for altered drug metabolism. This was a single-center, retrospective, case-control study of all adults who underwent anesthesia and concurrent abdominal imaging (n = 2,021) in a hospital setting. FL (n = 234) was identified through radiology reports. Anesthesia recovery, the primary endpoint, was defined by Aldrete's recovery score (RS, 0-10), assessed following postanesthesia care unit (PACU) arrival, with RS ≥8 considered discharge eligible. FL and controls were compared using univariate and multivariate analyses, adjusting for confounders. A secondary matched-pairs analysis matched FL and controls 1:1 for confounders. Time from airway removal to discharge eligibility was compared using multivariate Cox regression. On PACU arrival, 54.1% of FL were discharge eligible compared to 61.7% of controls (P = 0.03), with lower activity scores on univariate (P = 0.03) and multivariate analysis (P = 0.03). On matched-pairs analysis, discharge eligibility, activity, consciousness, and total RSs were lower in FL (P ≤ 0.04 for all). Median time from airway removal to discharge eligibility was 43% longer in FL (univariate, P = 0.01; multivariate hazard ratio, 1.32; P = 0.046). To further exclude confounding by obesity, we performed a sensitivity analysis limited to a body mass index <30, where FL was still associated with lower activity (P = 0.03) and total RS (P = 0.03). Conclusion: Patients with FL have delayed recovery from anesthesia, suggesting altered drug metabolism independent of metabolic risk factors.