Timing for Assessment of Bleeding Diathesis in Pediatric Blunt Traumatic Brain Injury

Intracranial hemorrhage may complicate blunt traumatic brain injury (TBI) or result from underlying bleeding disorders, and coagulation studies/factor level assays may be abnormal for both. Current studies do not identify when testing can reliably differentiate between traumatic injuries and bleeding disorders. We sought to evaluate the prevalence of coagulation abnormalities in the initial 36 hours after presentation for blunt TBI and determine a time period for subsequent normalization.

Patients under 18 years old with blunt TBI were identified from our institutional trauma registry from 2020 to 2022. Data collected included coagulation studies [prothrombin time (PT), partial thromboplastin time (PTT)], complete blood count, factor levels, final suspected/proven diagnosis, mechanism of injury, patient demographics, radiographic findings, and clinical interventions. Comparisons were made between laboratory values obtained and normal references, and differences were described.

Two hundred sixty-eight patients were identified. The majority were male, and the median age was 8.5 months (interquartile range 4-45.3 mo). The coagulation studies and factor level assays were more often completed for patients who suffered child physical abuse, whereas testing was obtained in <10% of patients following unintentional trauma. The mechanism of injury was unintentional blunt injury in 70.1%, abusive TBI in 27.2%, and a medical cause in 3%. Intracranial hemorrhage was identified in 49.2% of patients. Within 36 hours after presentation, the most common laboratory abnormality was significantly elevated PT [median 13.65 s (interquartile range 13.1-14.8 s)] as compared with the normal range ( P <0.001). This did not differ significantly based on the mechanism of trauma. Significant elevations were also seen for von Willebrand factor antigen and d-dimer. There were no patients with significant factor level deficiencies. Although 64% of patients had follow-up, only 11.8% had repeat laboratory testing, with persistent abnormalities observed in up to 7%.

Coagulation studies and factor level assays were not routinely obtained following blunt head trauma in pediatric patients. Coagulation abnormalities were, however, observed in >50% of patients who underwent testing. These patients may have coagulation abnormalities that persist for 2 weeks after injury without an underlying bleeding disorder. Further delineating the time frame of these abnormalities may inform practice guidelines for the diagnostic evaluation of underlying bleeding disorders and follow-up.