The ahead study: managing anticoagulated patients who suffer head injury.

OBJECTIVES & BACKGROUND: Existing practice in emergency departments (ED) in the UK for managing anticoagulated patients after blunt head trauma is variable and based on limited evidence. We aimed to determine the head injury complication rate within this group of patients and identify risk factors associated with a poor outcome.

METHODS: A prospective observational multi-centre study enrolled patients taking warfarin who attended 33 emergency departments in England and Scotland after blunt head trauma. ED attendance data and patient reported outcomes were collected over an 18-month period from October 2011. Head injury complication was defined by head injury-related death, neurosurgery resulting from injury, clinically-significant CT head scan or re-attendance with significant head injury complications. Factors including neurological status (Glasgow Coma Score, GCS), level of anticoagulation (INR) and neurological symptoms were entered into multivariate logistic regression analyses as predictors of a poor outcome.

RESULTS: A total of 3566 patients were enrolled; anonymised clinical data was submitted for 99.1% of patients. The age range was 18 to 101 years (median 81 yrs, IQR 12), 48.7% were men. Mean initial INR was 2.67 (SD 1.34, IQR 1.1), 80.5% patients had a GCS of 15 and 68.1% did not report any associated neurological symptoms. 59.3% of patients had a CT head scan with a significant head injury-related finding identified in 5.6%. Reversal therapy was given to 5.3% of patients, only 19 (0.5%) patients underwent neurosurgery and 42 (1.2%) patients died of a head injury-related death. The overall rate of head injury complication was found to be 6.1%. Multivariate logistic regression modelling found GCS <13 (OR 12.7; 95% CI 2.41 to 67.2), vomiting (OR 3.09; 95% CI 1.71 to 5.61) and loss of consciousness (OR 2.53; 95% CI 1.54 to 4.15) to be significantly associated with a poor outcome. In univariate analyses an INR >4 was associated with an increased risk of an adverse outcome, however it made no significant contribution to the multivariable models.

CONCLUSION: This is the largest cohort of anticoagulated head injury patients ever reported. The head injury complication rate was 6.1% which correlates well with previous findings. INR was not found to be associated with a poor outcome however GCS <13, vomiting and loss of consciousness were identified as significant risk factors for an adverse outcome in anticoagulated patients with a head injury.