The Richmond Acute Subdural Hematoma Score: A Validated Grading Scale to Predict Postoperative Mortality

BACKGROUND: Traumatic acute subdural hematomas (aSDHs) are common, life-threatening injuries often requiring emergency surgery. OBJECTIVE: To develop and validate the Richmond acute subdural hematoma (RASH) score to stratify patients by risk of mortality after aSDH evacuation. METHODS: The 2016 National Trauma Data Bank (NTDB) was queried to identify adult patients with traumatic aSDHs who underwent craniectomy or craniotomy within 4 h of arrival to an emergency department. Multivariate logistic regression modeling identified risk factors independently associated with mortality. The RASH score was developed based on a factor's strength and level of association with mortality. The model was validated using the 2017 NTDB and the area under the receiver operating characteristic curve (AUC). RESULTS: A total of 2516 cases met study criteria. The patients were 69.3% male with a mean age of 55.7 yr and overall mortality rate of 36.4%. Factors associated with mortality included age between 61 and 79 yr (odds ratio [OR] = 2.3, P <.001), age ≥80 yr (OR = 6.3, P <.001), loss of consciousness (OR = 2.3, P <.001), Glasgow Coma Scale score of ≤8 (OR = 2.6, P <.001), unilateral (OR = 2.8, P <.001) or bilateral (OR = 3.9, P <.001) unresponsive pupils, and midline shift >5 mm (OR = 1.7, P <.001). Using these risk factors, the RASH score predicted progressively increasing mortality ranging from 0% to 94% for scores of 0 to 8, respectively (AUC = 0.72). Application of the RASH score to 3091 cases from 2017 resulted in similar accuracy (AUC = 0.74). CONCLUSION: The RASH score is a simple and validated grading scale that uses easily accessible preoperative factors to predict estimated mortality rates in patients with traumatic aSDHs who undergo surgical evacuation.