Monitored Anesthesia Care and Soft Tissue Infiltration with Local Anesthesia for Older Adults with Hip Fracture: A Multi-Center Feasibility Randomized Clinical Trial - Project Summary/Abstract Delirium, characterized by fluctuating disturbances of cognition, is common in older adults undergoing hip fracture surgery. Anesthesia may exacerbate delirium severity, especially in patients with dementia who are at heightened risk for delirium onset. Monitored anesthesia care with soft-tissue infiltration with local anesthesia (MAC-STILA) is a novel approach that involves anesthesiologist titration of intravenous sedation to a level that preserves spontaneous breathing followed by surgeon administration of a local anesthetic injected directly into the surgical site. MAC-STILA may provide significant benefit to hip fracture patients by avoiding adverse effects of traditional anesthesia approaches but has not been widely tested. We propose a multi-center clinical trial to demonstrate feasibility of randomizing older hip fracture patients to MAC-STILA versus the current standard of care involving general anesthesia and to determine efficacy of MAC-STILA for reducing incidence and severity of post-operative delirium. The trial will be conducted at 6 hospitals and coordinated by the Major Extremity Trauma Research Consortium. Using the Delphi approach, we will first achieve consensus on standards for MAC-STILA among a panel of orthopedic surgeons and anesthesiologists at 6 participating hospitals to facilitate reproducibility and evaluation. We will then enroll and randomize 140 patients, stratified by baseline cognitive impairment. We will examine aspects of trial feasibility including recruitment rate, rate of crossover to a different anesthesia approach, factors associated with treatment crossover, and data completeness. We will examine the effect of MAC-STILA compared with general anesthesia on delirium incidence and severity using validated cognitive assessments through post-operative day 5 or time of discharge. We will also explore the treatment effect on delirium among patients with baseline cognitive impairment and by sex. Secondary outcomes include intraoperative physiologic parameters (e.g. blood pressure, heart rate), post operative complications, postoperative pain and narcotic use, cognitive function at 30- and 90-days post discharge, and 30 and 90-day mobility, disability, and mortality. The goal of this study is to demonstrate feasibility and establish the preliminary data needed to support a larger, rigorously designed multi-site effectiveness trial.
