Risk Factors for Recurrent Hematoma After Surgery for Acute Traumatic Subdural Hematoma.

OBJECTIVE:The development of postcraniotomy hematoma (PCH) after surgery for acute traumatic subdural hematoma (aSDH) has been associated with an increased risk of a poor outcome. The risk factors contributing to PCH remain poorly understood. Our aim was to study the potential risk factors for PCH in a consecutive series of surgically evacuated patients with aSDH. METHODS:A total of 132 patients with aSDH treated at Turku University Hospital (Turku, Finland) from 2008 to 2012 were enrolled in the present retrospective cohort study. The demographic, clinical, laboratory, and imaging data were collected from the medical records. A comprehensive analysis of the data using 6 different univariate methods, including machine learning and multivariate analyses, was conducted to identify the factors related to PCH. RESULTS:The incidence of PCH after primary surgery for traumatic aSDH was 10.6%. The patients experiencing PCH were younger (P = 0.04). No difference was found in the use of anticoagulant or antiplatelet medication for the patients with and without PCH. Multivariate analyses identified alcohol inebriation at the time of injury (odds ratio [OR], 12.67; P = 0.041) and hypocapnia (OR, 26.09; P = 0.003) as independent risk factors for PCH. The patients with PCH had had hyponatremia (OR, 0.08; P = 0.018) less often, and their maximal systolic blood pressure was lower (OR, 0.94; P = 0.009). The area under the curve for the multivariate model was 0.96 (P = 0.049), with a Youden index of 0.88. CONCLUSIONS:The results suggest that alcohol inebriation at the time of injury and hypocapnia during hospitalization are risk factors for the development of PCH.