Monitored Anesthesia Care-Soft Tissue Infiltration with Local Anesthesia (MAC-STILA) Decreases Incidence of Short-Term Postoperative Altered Mental Status in Hip Fracture Patients.

Abstract

Objective: To determine if the occurrence of short-term post-operative altered mental status (AMS) was lower in geriatric patients undergoing operative repair of hip fractures with Monitored Anesthesia Care and Soft-Tissue Infiltration with Local Anesthesia (MAC-STILA) when compared with general anesthesia (GA).

Design: Retrospective cohort study.

Setting: Two U.S. hospitals within a single academic medical center.

Patient selection criteria: Geriatric patients with hip fractures (AO/OTA 31A and 31B) undergoing operative repair were identified. Propensity matching was performed in a 1:2 ratio to minimize selection bias (age, sex, BMI, ASA class, fracture pattern, fixation construct, pre-injury ambulatory status, and assistive device use).

Outcome measures: Patients who underwent surgical fixation with MAC-STILA were compared with GA. Primary outcome was post-operative AMS, defined as missing ≥1 items on the alert and oriented assessment (person, place, and time) at any point from post-operative days 0-3.

Results: After matching, 228 patients (76 MAC-STILA: 152 GA) were included in the analysis. The average age of patients in both groups was 83 years. In the MAC-STILA group, 62% were female and 33% had baseline dementia while in the GA group 66% were female and 29% had baseline dementia. Treating patients with MAC-STILA was associated with 72% lower odds of having AMS compared with GA, controlling for baseline comorbidity and dementia (OR: 0.28. 95% CI: 0.09-0.075, p=0.016). Among patients with baseline dementia, the rate of AMS was lower in patients treated with MAC-STILA compared with GA (64.0% vs 95.3%, p = 0.001).

Conclusion: Monitored Anesthesia Care and Soft-Tissue Infiltration with Local Anesthesia (MAC-STILA) was associated with lower odds of short-term postoperative altered mental status (AMS) compared to general anesthesia (GA) in hip fracture patients undergoing operative repair. Given the high rate of post-operative AMS and complications associated with geriatric hip fracture patient, MAC-STILA should be considered for use in patients with increased risk of post-operative AMS, particularly in the setting of preoperative dementia.

Level of evidence: Therapeutic III.