(HealthDay News) – For patients on warfarin with minor head trauma who have an initial negative computed tomography (CT) scan, 24-hour observation followed by an additional CT scan identifies the majority of cases of delayed bleeding, according to a study published online Jan. 16 in the Annals of Emergency Medicine.

Vincenzo G. Menditto, MD, from the Ospedali Riuniti di Ancona in Italy, and colleagues conducted a prospective case series of 97 patients receiving warfarin, with no intracranial lesions on a first CT scan after minor head trauma. For 87 of these patients, 24 hours of observation, followed by a second CT scan, were performed before discharge. The frequency of death, admission, neurosurgery, and delayed intracranial hemorrhage was evaluated.

The researchers found that repeat CT scanning revealed new hemorrhagic lesions in five patients (6%); three of these patients were subsequently hospitalized and one received craniotomy. Two patients with negative second CT scans were readmitted two and eight days after discharge with symptomatic subdural hematomas, but did not require surgery. Two of the five patients with delayed bleeding identified at the second CT scan, and the two patients readmitted later, had an initial international normalized ratio (INR) greater than 3. For an initial INR greater than 3, the relative risk of delayed hemorrhage following minor head trauma was 14 (95% CI, 4–49).

“For patients receiving warfarin who experience minor head injury and have a negative initial head CT scan result, a protocol of 24-hour observation followed by a second CT scan will identify most occurrences of delayed bleeding. An initial international normalized ratio greater than 3 suggests higher risk,” the authors write.

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