Pulmonary embolism without deep venous thrombosis: De novo or missed deep venous thrombosis?

BACKGROUND: Pulmonary embolus (PE) is thought to arise from a deep venous thrombosis (DVT). Recent data suggest that PE can present without DVT, inferring that PE can originate de novo (DNPE). We examined the relationship between DVT and PE in trauma patients screened for DVT with duplex sonography (DS). We sought to validate the incidence of PE without evidence of DVT and to examine the clinical significance of this entity. METHODS: We reviewed the medical records of all trauma patients from July 2006 to December 2011 with PE who also had serial surveillance DS (groin to ankle). Demographics, severity of injury, interventions, signs and symptoms of PE, as well as chest computerized tomography findings were collected. Patients with no DS evidence of DVT either before or within 48 hours of PE diagnosis (DNPE) were compared with those with DVT (PE + DVT). RESULTS: Of 11,330 patients evaluated by the trauma service, 2,881 patients received at least one DS. PE occurred in 31 of these patients (1.08%): 19 (61%) were DNPE, and 12 (39%) were PE + DVT. Compared with patients with PE + DVT, patients with DNPE were significantly younger and had more rib fractures, pulmonary contusions, infections, pulmonary symptoms, and peripherally located PEs on computerized tomography. CONCLUSION: This is the first report of the clinical course of DNPE without embolic origin in a population with comprehensive duplex surveillance. In our series, DNPE seems to be more prevalent after trauma, to be clinically distinct from PE following DVT, and to likely represent a local response to injury or inflammation; however, further research is warranted to fully understand the pathophysiology of DNPE. LEVEL OF EVIDENCE: Care management study, level III.

The impact of preinjury anticoagulants and prescription antiplatelet agents on outcomes in older patients with traumatic brain injury.

BACKGROUND: Anticoagulants and prescription antiplatelet (ACAP) agents widely used by older adults have the potential to adversely affect traumatic brain injury (TBI) outcomes. We hypothesized that TBI patients on preinjury ACAP agents would have worse outcomes than non-ACAP patients. METHODS: This was a 5.5-year retrospective review of patients 55 years and older admitted to a Level I trauma center with blunt force TBI. Patients were categorized as ACAP (warfarin, clopidogrel, dipyridamole/aspirin, enoxaparin, subcutaneous heparin, or multiple agents) or non-ACAP. ACAP patients were further stratified by class of agent (anticoagulant or antiplatelet). Initial and subsequent head computerized tomographic results were examined for type and progression of TBI. Patient preadmission living status and discharge destination were identified. Primary outcome was in-hospital mortality. Secondary outcomes were progression of initial TBI, development of new intracranial hemorrhage (remote from initial), and the need for an increased level of care at discharge. RESULTS: A total of 353 patients met inclusion criteria: 273 non-ACAP (77%) and 80 ACAP (23%). Upon exclusion of three patients taking a combination of agents, 350 were available for advanced analyses. ACAP status was significantly related to in-hospital mortality. After adjustment for patient and injury characteristics, anticoagulant users were more likely than non-ACAP patients to show progression of initial hemorrhage and develop a new hemorrhagic focus. However, compared with non-ACAP users, antiplatelet users were more likely to die in the hospital. Among survivors to discharge, anticoagulant users were more likely to be discharged to a care facility, but this finding was not robust to adjustment. CONCLUSION: Older TBI patients on preinjury ACAP agents experience a comparatively higher rate of inpatient mortality and other adverse outcomes caused by the effects of antiplatelet agents. Our findings should inform decision making regarding prognosis and caution against grouping anticoagulant and antiplatelet users together in considering outcomes. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Back to the future: reducing reliance on torso computed tomography in the initial evaluation of blunt trauma.

BACKGROUND: Reliance on chest-abdomen-pelvis computed tomography (CAP) in the initial evaluation of blunt trauma is a major source of patient radiation exposure. Our trauma surgeon group (TSG) modified its practice to limit the use of CAP. We evaluated the effect of this practice change on patient radiation exposure and diagnostic accuracy. METHODS: We compared data on blunt injury trauma activations evaluated by the five-member TSG for two 6-month intervals, before (T1) and after (T2) instituting the practice change. Patient demographic and injury data, complications, torso imaging and radiation dosage were collected. Following analysis of T1, the surgeon with the lowest CAP use was identified and found to have no errors or delays in diagnosis. The TSG agreed to adopt that surgeon's focus on findings of the physical examination and Focused Assessment Sonography for Trauma to reduce CAP use in the initial evaluation. T2 was analyzed to assess the effect of implementation of this guideline. RESULTS: There were 897 patients in T1 and 948 in T2. In the two intervals, patients did not differ by age, sex, mortality, or probability of survival. CAP use decreased by 38.5% with a significant drop in mean patient radiation exposure (p < 0.001). There were no missed injuries or delays in diagnosis in either interval. CONCLUSION: The use of CAP and its associated radiation burden in the initial evaluation of blunt trauma can be reduced without diagnostic errors by comparing use and identifying best practice. This process has implications for optimal trauma care. LEVEL OF EVIDENCE: Diagnostic study, level IV; case management study, level IV.

Delayed intracranial hemorrhage after blunt trauma: are patients on preinjury anticoagulants and prescription antiplatelet agents at risk?

BACKGROUND: Trauma centers are more frequently evaluating patients who are receiving anticoagulant or prescription antiplatelet (ACAP) therapy at the time of injury. Because there are reports of delayed intracranial hemorrhage (ICH) after blunt trauma in this patient group, we evaluated patients receiving ACAP with a head computed tomography (CT) on admission (CT1) followed by a routine repeat head CT (CT2) in 6 hours. We hypothesized that among patients with no traumatic findings on CT1 and a normal or unchanged interval neurologic examination, the incidence of clinically significant delayed ICH would be zero. METHODS: We retrospectively reviewed adult blunt trauma patients admitted to our Level I trauma center from January 2006 to August 2009 who were receiving preinjury ACAP therapy. We reviewed medications, mechanism of injury, head CT results, and outcomes. Demographic data, injury severity scores, international normalized ratio, and neurologic examinations were recorded. We determined the incidence of delayed ICH on CT2 for patients with a negative CT1. RESULTS: Five hundred patients qualified for the protocol. Of these, 424 patients (85%) had a negative CT1. Among these patients, mean age was 75 years; 210 (50%) were male. Fall from standing was the most common mechanism of injury found in 357 patients (84%). Warfarin alone was taken in 68%, clopidogrel alone in 24%, and other agents in 2%. Six percent of patients were taking two agents. Mean international normalized ratio for patients on warfarin was 2.5. Among patients with a negative CT1, CT2 was obtained in 362 patients (85%) and was negative in 358 patients (99%). Four patients (1%) with a negative CT1 had a positive (n = 3) or equivocal (n = 1) CT2. All the changes on CT2 were minor and had either resolved or stabilized on third head CT. Of the four patients with positive or equivocal CT2, none had a change in neurologic examination; however, two had symptoms that could be attributed to head injury. Three were discharged home and one died of cardiac disease unrelated to head trauma. CONCLUSIONS: The incidence of delayed ICH in our study was 1%. However, none of the delayed findings were clinically significant. Among patients on ACAP therapy with a negative CT1 and a normal or unchanged neurologic examination, a routine CT2 is unnecessary. We recommend a period of observation to recognize those patients with symptoms that could be due to delayed ICH.