Impact of preoperative nutritional status on morbidity and mortality in elderly patients undergoing subdural hematoma evacuation: the role of the Geriatric Nutritional Risk Index

OBJECTIVE Nutritional status has been shown to impact patient outcomes across several neurosurgical procedures. However, few prior studies have assessed associations between preoperative nutritional status and outcomes in elderly patients undergoing subdural hematoma evacuations. The aim of this study was to identify associations between preoperative nutritional status and short-term outcomes in patients aged 65 years and older undergoing subdural hematoma evacuation. METHODS A retrospective cohort study was performed using the American College of Surgeons National Surgical Quality Improvement Program database. Geriatric patients (≥ 65 years of age) were categorized into three groups based on the Geriatric Nutritional Risk Index (GNRI): normal, malnourished, and severely malnourished. Patient demographic characteristics, comorbidities, and adverse events (AEs) were assessed. Multivariate logistic regression analyses were used to identify independent predictors of 30-day postoperative AEs, extended length of hospital stay (LOS), 30-day mortality, and nonroutine discharge. RESULTS Of 2026 study patients, 908 (44.8%) had normal GNRI status, 564 (27.8%) had malnourished GNRI status, and 554 (27.3%) had severely malnourished GNRI status. The proportions of patients who experienced minor AEs (normal 12.7% vs malnourished 13.3% vs severely malnourished 19.0%, p = 0.003) and severe AEs (normal 25.3% vs malnourished 20.7% vs severely malnourished 35.7%, p ≤ 0.001) were greatest in the severely malnourished cohort. Mean LOS significantly increased along with increasing malnourishment (normal 9.1 ± 6.9 days vs malnourished 9.7 ± 7.0 days vs severely malnourished 11.3 ± 7.6 days, p ≤ 0.001), whereas the proportions of patients with 30-day mortality (normal 15.5% vs malnourished 15.6% vs severely malnourished 24.0%, p ≤ 0.001) and nonroutine discharge (normal 59.4% vs malnourished 66.1% vs severely malnourished 69.9%, p ≤ 0.001) similarly increased with increasing malnourishment. On multivariate analyses, severe malnourished status was significantly associated with increased odds of developing any AE (adjusted OR [aOR] 1.72, CI 1.33–2.23, p ≤ 0.001) and extended LOS (aOR 1.47, CI 1.11–1.95, p = 0.007), whereas malnourished status but not severely malnourished status was associated with increased odds of nonroutine discharge (aOR 1.46, CI 1.12–1.92, p = 0.006). Neither malnourished (p = 0.474) nor severely malnourished status (p = 0.367) was associated with increased odds of 30-day mortality. CONCLUSIONS The authors’ findings suggest that preoperative nutritional status may have implications for short-term outcomes after subdural hematoma evacuation in patients aged 65 years and older. Further studies are necessary to better optimize nutritional status perioperatively in this patient population.