Patient factors associated with 30-day morbidity, mortality, and length of stay after surgery for subdural hematoma: a study of the American College of Surgeons National Surgical Quality Improvement Program

Objective: Surgery for subdural hematoma (SDH) is a commonly performed neurosurgical procedure. This study identifies patient characteristics associated with adverse outcomes and prolonged length of stay (LOS) in patients who underwent surgical treatment for SDH.

Methods: All patients in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) who were treated via craniotomy or craniectomy for SDH between 2005 and 2012 were identified. Patient demographics, comorbidities, and 30-day outcomes were described. Multivariate regression was used to identify predictors of adverse events.

Results: A total of 746 surgical procedures performed for SDH were identified and analyzed. Patients undergoing this procedure were 64% male with an average age (± SD) of 70.9 ± 14.1 years. The most common individual adverse events were death (17%) and intubation for more than 48 hours (19%). In total, 34% experienced a serious adverse event other than death, 8% of patients returned to the operating room (OR), and the average hospital LOS was 9.8 ± 9.9 days. In multivariate analysis, reduced mortality was associated with age less than 60 years (relative risk [RR] = 0.47, p = 0.017). Increased mortality was associated with gangrene (RR = 3.5, p = 0.044), ascites (RR = 3.00, p = 0.006), American Society of Anesthesiologists (ASA) Class 4 or higher (RR = 2.34, p = 0.002), coma (RR = 2.25, p < 0.001), and bleeding disorders (RR = 1.87, p = 0.003). Return to the OR was associated with pneumonia (RR = 3.86, p = 0.044), male sex (RR = 1.85, p = 0.015), and delirium (RR = 1.75, p = 0.016). Serious adverse events were associated with ventilator dependence preoperatively (RR = 1.86, p < 0.001), dialysis (RR = 1.44, p = 0.028), delirium (RR = 1.40, p = 0.005), ASA Class 4 or higher (RR = 1.36, p = 0.035), and male sex (RR = 1.29, p = 0.037). Similarly, LOS was increased in ventilator dependent patients by 1.56-fold (p = 0.002), in patients with ASA Class 4 or higher by 1.30-fold (p = 0.006), and in delirious patients by 1.29-fold (p = 0.008).

Conclusions: Adverse outcomes are common after surgery for SDH. In this study, 18% of the patients died within 30 days of surgery. Factors associated with adverse outcomes were identified. Patients and families should be counseled about the serious risks of morbidity and death associated with acute traumatic SDH requiring surgery.