Analgesic efficacy of systemic lidocaine using lean body mass based dosing regime versus placebo in bariatric surgery: a prospective, randomised, double-blind, placebo-controlled, single-centre study.

BACKGROUND: Intravenous lidocaine is used as an adjuvant analgesic agent in perioperative settings. It has been investigated in various patient populations and surgical interventions, but there are limited data on its efficacy, particularly for patients undergoing bariatric surgery. Obese patients are at high risk of postoperative respiratory complications and can be expected to benefit from anaesthetic techniques that minimise opioid administration. METHODS: We studied administration of lidocaine hydrochloride 1% i.v. to general anaesthesia at a dose of 1.5 mg kg-1 (lean body mass×1.28) or placebo in patients undergoing bariatric surgery. Subjects randomly assigned to each group were surveyed for 48 h after surgery for experienced pain (primary outcome), and administered opioids, postoperative nausea and vomiting (PONV), resumption of bowel function, and length of hospital stay (secondary outcomes). RESULTS: We recruited and randomised 140 subjects to either the lidocaine or placebo group; 137 completed the study. Subjects with pain numeric rating scale (NRS) >3 within the first 4 h postoperatively were similar in both groups (proportion of any NRS >3 within first 4 h lidocaine group: 47/68 (69%) vs placebo group: 44/69 (63%), P=0.507; within first h P=0.177, within second h P=0.513, within third h P=0.145, within fourth h P=0.510). There was no difference in maximal pain score, opioid consumption, recovery of bowel function, incidence of PONV, or length of hospital stay. CONCLUSIONS: Lidocaine does not improve postoperative pain scores, analgesia, or any secondary outcomes in patients undergoing bariatric surgery. CLINICAL TRIAL REGISTRATION: NCT03667001.

Targeting Higher Intraoperative Blood Pressures Does Not Reduce Adverse Cardiovascular Events Following Noncardiac Surgery.

BACKGROUND: Intraoperative arterial hypotension is strongly associated with postoperative major adverse cardiovascular events (MACE); however, whether targeting higher intraoperative mean arterial blood pressures (MAPs) may prevent adverse events remains unclear. OBJECTIVES: This study sought to determine whether targeting higher intraoperative MAP lowers the incidence of postoperative MACE. METHODS: This single-center randomized controlled trial assigned adult patients at cardiovascular risk undergoing major noncardiac surgery to an intraoperative MAP target of ≥60 mm Hg (control) or ≥75 mm Hg (MAP ≥75). The primary outcome was acute myocardial injury on postoperative days 0-3 and/or 30-day MACE/acute kidney injury (AKI) (acute coronary syndrome, congestive heart failure, coronary revascularization, stroke, AKI, and all-cause mortality). The secondary outcome was 1-year MACE. RESULTS: In total, 458 patients were randomized (intention-to-treat population: 451). The cumulative intraoperative duration with MAP <65 mm Hg was significantly shorter in the MAP ≥75 group (median 9 minutes [interquartile range: 3 to 24 minutes] vs 23 minutes [interquartile range: 8-49 minutes]; P < 0.001). The primary outcome incidence was 48% for MAP ≥75 and 52% for control (risk difference -4.2%; 95% CI: -13% to +5%), the primary contributor being AKI (incidence 44%). Acute myocardial injury occurred in 15% (MAP ≥75) and 19% (control) of patients. The secondary outcome incidence was 17% for MAP ≥75 and 15% for control (risk difference +2.7; 95% CI: -4% to +9.5%). CONCLUSIONS: These findings do not support universally targeting higher intraoperative blood pressures to reduce postoperative complications. Despite a 60% reduction in hypotensive time with MAP <65 mm Hg, no significant reductions in acute myocardial injury or 30-day MACE/AKI could be found. (Biomarkers, Blood Pressure, BIS: Risk Stratification/Management of Patients at Cardiac Risk in Major Noncardiac Surgery [BBB]; NCT02533128).