Microsoft word - saem abstract june 2011 final.doc

The Prevalence Of Immediate And Delayed Intracranial Hemorrhage In Patients
With Pre-injury Anticoagulant Use And Head Trauma
Daniel K. Nishijima, MD, MAS1, Steven R. Offerman MD2, Dustin Ballard MD3, David
Vinson MD4, Uli Chettipally MD, MPH5, Adina S. Rauchwerger MPH6, Mary E. Reed
DrPH6, James F. Holmes, MD, MPH1 for the Clinical Research in Emergency Services
and Treatment (CREST) Network
1Department of Emergency Medicine, UC Davis School of Medicine
2Kaiser Permanente South Sacramento Medical Center 3Kaiser Permanente San Rafael Medical Center and Medical Offices 4Kaiser Permanente Sacramento Medical Center and Medical Offices 5Kaiser Permanente South San Francisco Medical Center and Medical Offices 6Kaiser Permanente Division of Research, Oakland Background: Patients on warfarin or clopidogrel are considered at increased risk for
traumatic intracranial hemorrhage (tICH) following blunt head trauma. The rate of immediate and delayed tICH in these patients, however, is unknown. We hypothesized that the prevalence for immediate tICH is similar between patients on clopidogrel and warfarin and the rate of delayed tICH in both groups is < 1%. Methods: This is a prospective, observational, six center study (two trauma centers and
four community hospitals) evaluating the prevalence of immediate and delayed tICH in adult patients on warfarin or clopidogrel. Delayed tICH was defined as tICH on cranial CT scan within two weeks after an initial normal CT scan in the absence of repeat head trauma. Patients were enrolled in the emergency department (ED) and followed up after two weeks by phone or medical record review if hospitalized. Measured outcomes included immediate and delayed tICH. Data were analyzed with descriptive statistics. Results: 870 patients with a median age of 78 years (IQR 70-85) were enrolled (capture
rate of 83%). Anticoagulant use included warfarin (622 patients, 71%) and clopidogrel 248 patients, 29%). Both warfarin and clopidogrel groups had similar patient characteristics (table). Of patients receiving a CT in the ED, the rate of immediate tICH on CT was higher in patients on clopidogrel (29/231, 13%; 95% CI 8.6-18%) than on warfarin (27/591, 4.6%; 95% CI 3.0-6.6%). Delayed tICH was identified in 4/563 (0.71%; 95% CI 0.19-1.8%) patients on warfarin and 0/201 (0%; 95% CI 0-1.8%) patients on Conclusion: Patients on clopidogrel had a significantly higher rate of tICH on CT scan
as compared to those on warfarin. Routine cranial CT scanning is indicated in patients on clopidogrel with blunt head trauma. The rate of delayed tICH was very low and only occurred in patients on warfarin. Discharging these patients from the ED after a normal CT scan is safe but appropriate instructions are required as delayed ICH may occur.
Table: Patient characteristics
Characteristic
Warfarin
Clopidogrel

Source: http://kpcrest.net/images/SAEM_abstract_June_2011_Final.pdf