Aims
We sought to investigate whether mean arterial pressure (MAP) control and anaesthetic depth, measured via bispectral index (BIS), were associated with mortality and functional recovery.
Methods
Retrospective analysis was conducted on 1023 patients undergoing hip fracture surgery between 1/6/12-30/6/16. MAP control was categorised as tight (≤12% below), intermediate (13-24% below), loose (≥25% below), and BIS as deep (≤40) or light (≥45). Outcomes included 30- and 120-day mortality, return to baseline cognition, return to pre-admission mobility, and residence status (home/residential aged care facility), adjusting for Charlson Comorbidity Index (CCI), American Society of Anaesthesiologists (ASA) status, Nottingham Hip Fracture Score (NHFS).
Results
No association was observed between MAP control or anaesthetic depth and 30-day mortality. At 120 days, higher mortality was seen with tight versus intermediate MAP control (14.2% vs 6.7%, p=0.004), but this disappeared after adjustment. Cognitive recovery exceeded 90%, with no differences by MAP or BIS status. By 30 days, fewer than 40% regained baseline mobility, and 37% did not return to pre-fracture residence. On multivariable analysis, ASA status (odds ratio (OR) 2.00, p=0.02 30-day; OR 1.95, p=0.01 120-day) and NHFS (OR 1.35, p=0.04 120-day) were associated with mortality. CCI, NHFS, and surgical timing were independently associated with recovery outcomes.
Conclusion
MAP control and anaesthetic depth were not independently associated with mortality or recovery. Comorbidity association with outcomes underscores the importance of perioperative risk stratification and tailored evidence-based multidisciplinary interventions.