Morbidity and mortality in elderly patients undergoing evacuation of acute traumatic subdural hematoma

OBJECTIVE Acute traumatic subdural hematoma (atSDH) can be a life-threatening neurosurgical emergency that necessitates immediate evacuation. The elderly population can be particularly vulnerable to tearing bridging veins. The aim of this study was to evaluate inpatient morbidity and mortality, as well as predictors of inpatient mortality, in a national trauma database. METHODS The authors queried the 2016-2017 National Trauma Data Bank registry for patients aged 65 years and older who had undergone evacuation of atSDH. Patients were categorized into three age groups: 65-74, 75-84, and 85+ years. A multivariable logistic regression model was fitted for inpatient mortality adjusting for age group, sex, race, presenting Glasgow Coma Scale (GCS) category (3-8, 9-12, and 13-15), Injury Severity Score, presence of coagulopathy, presence of additional hemorrhages (epidural hematoma [EN], intraparenchymal hematoma [IPH], and subarachnoid hemorrhage [SAH]), presence of midline shift > 5 mm, and pupillary reactivity (both, one, or none). RESULTS A total of 2508 patients (35% females) were analyzed. Age distribution was as follows: 990 patients at 65-74 years, 1096 at 75-84, and 422 at 85+. Midline shift > 5 mm was present in 72% of cases. With regard to additional hemorrhages, SAH was present in 21%, IPH in 10%, and EDH in 2%. Bilaterally reactive pupils were noted in 90% of patients. A major complication was observed in 14.4% of patients, and the overall mortality rate was 18.3%. In the multivariable analysis, the presenting GCS category was found to be the strongest predictor of postoperative inpatient mortality (3-8 vs 13-15: OR 3.63, 95% CI 2.68-4.92, p < 0.001; 9-12 vs 13-15: OR 2.64, 95% CI 1.79-3.90, p < 0.001; 30% of overall variation), followed by the presence of SAH (OR 2.86, 95% CI 2.21-3.70, p < 0.001; 25% of overall variation) and the presence of midline shift > 5 mm (OR 2.40, 95% CI 1.74-3.32, p < 0.001;11% of overall variation). Model discrimination was excellent (c-index 0.81). Broken down by age decile group, mortality increased from 8.0% to 15.4% for GCS 13-15 to around 36% for GCS 9-12 to almost as high as 60% for GCS 3-8, particularly in those aged 85 years and older. CONCLUSIONS The present results from a national trauma database will, the authors hope, assist surgeons in preoperative discussions with patients and their families with regard to expected postoperative outcomes following surgical evacuation of an atSDH.