Comparing clinical predictors of deep venous thrombosis versus pulmonary embolus after severe injury

Abstract

Background The traditional paradigm is that deep venous thrombosis (DVT) and pulmonary embolus (PE) are different temporal phases of a single disease process, most often labeled as the composite endpoint venous thromboembolism (VTE). However, we theorize that after severe blunt injury, DVT and PE may represent independent thrombotic entities rather than different stages of a single pathophysiologic process and therefore exhibit different clinical risk factor profiles. Methods We examined a large, multi-center prospective cohort of severely injured blunt trauma patients to compare clinical risk factors for DVT and PE, including indicators of injury severity, shock, resuscitation parameters, comorbidities and VTE prophylaxis. Independent risk factors for each outcome were determined by cross-validated logistic regression modeling using advanced exhaustive model search procedures. Results The study cohort consisted of 1,822 severely injured blunt trauma patients (median ISS = 33, median base deficit = −9.5). Incidence of DVT and PE were 5.1% and 3.9% respectively. Only 9 of 73 (5.7%) patients with a PE were also diagnosed with DVT. Independent risk factors associated with DVT include prophylaxis initiation within 48 hours (OR 0.57, 95% CI 0.36–0.90) and thoracic AIS ≥ 3 (OR 1.82, 95% CI 1.12–2.95), while independent risk factors for PE were serum lactate >5 (OR 2.33, 95% CI 1.43–3.79) and male gender (OR 2.12, 95% CI 1.17–3.84). Both DVT and PE exhibited differing risk factor profiles from the classic composite endpoint of VTE. Conclusion Deep venous thrombosis and pulmonary embolus exhibit differing risk factor profiles following severe injury. Clinical risk factors for diagnosis of DVT after severe blunt trauma include the inability to initiate prompt pharmacologic prophylaxis and severe thoracic injury, which may represent overall injury burden. In contrast, risk factors for PE are male gender and physiologic evidence of severe shock. We hypothesize that post-injury DVT and PE may represent a broad spectrum of pathologic thrombotic processes as opposed to the current conventional wisdom of peripheral thrombosis and subsequent embolus. Level of Evidence Prognostic study, Level III

Generalized Information Matrix Tests for Detecting Model Misspecification

“…Although Golden et al [23] did not provide explicit regularity conditions and a detailed analysis of their proposed general class of GIMTs, Golden et al [23] introduced key formal definitions, provided an informal discussion of relevant theoretical results, and reported the results of a comprehensive simulation study of a realistic epidemiological analysis problem using logistic regression for six new GIMTs that exhibited appealing level and power performance. This approach for the detection of model misspecification has now been used in observational and randomized controlled trial studies [7][8][9][10].…”

“…For example, in health economics, estimates of the impact of clinical treatments [3,4], care systems [5], and health policy interventions on health outcomes [6] are dependent on the underlying assumption that the model to be tested is correctly specified. Further, model misspecification testing is essential for statistical analysis of randomized control trials [7,8] and observational studies [9,10]. For these reasons, this paper introduces a unified framework for identifying, classifying, and developing a wide range of specification tests.…”

Microparticles impact coagulation after traumatic brain injury

“…One of the major pathophysiologic disturbances shown to be predictive of increased morbidity and mortality after TBI is acute traumatic coagulopathy, with reported incidences ranges from 10%–97.5% [2–5]. After this immediate hypocoagulable state, a subacute hypercoagulable state develops with the incidence of deep vein thrombosis ranging from 1.8%–44% in major trauma patients [6–8]. More specifically, the presence of head injury is predictive of an increased risk for thrombotic events [9].…”

What's new in emergencies, trauma and shock? Trauma-associated venous thromboembolism: A potentially preventable cause of morbidity and mortality

“…The authors have rightly pointed out their limitation of not mentioning the severity, site, and nature of trauma as all these have serious implications on the chances of VTE development. Brakenridge et al .,[ 5 ] in their study of 1822 posttraumatic patients, have shown that the site and severity of the injury does matter. Severe thoracic trauma has shown to be significantly associated with the risk of development of PE.…”