Don’t Hospitalize Warfarin & Minor TBI

There have been a few retrospective, observational studies evaluating the outcomes of anticoagulated patients with minor head injury.  The incidence reported by such series ranges from 6% in observation with mandatory repeat CT, to 0.6% with discretionary CT.

This series from Singapore reports: 0.3%.
In this series, all patients taking warfarin and having minor head trauma underwent protocolized initial CT and hospitalization for observation.  Repeat CT was performed, however, only at the discretion of the treating physicians.  Of the 295 patients hospitalized, only 11 underwent repeat CT, and only 1 abnormality was identified.  That one patient underwent neurosurgical intervention.  Of the remainder, no patients returned within two weeks of the initial incident with a further episode of delayed bleeding.  Thus, 0.3%.
Is it the difference between mandatory and discretionary repeat CT resulting in the wide range of reported incidence of delayed hemorrhage?  But, if there aren’t any symptomatic changes, are the extra hemorrhages detected clinically important?
Interestingly enough, they also reported three deaths from nosocomial pneumonia.  So, yes, the risk of delayed hemorrhage is non-zero – but likely lower than the risks associated with hospitalization.
“Outcomes of warfarinized patients with minor head injury and normal initial computer tomographic scan”