Intensive care medicine demands the near constant management of risk, which in any given clinical scenario is frequently limited by a paucity of evidence. In such circumstances, clinicians commonly rely on anecdote, legacy, plausibility, expert consensus, and key stakeholder opinion, which promote conformity and potentially limit recrimination. However, this may also suppress critical thinking and impede practice change. Although countless different scenarios exist, the timing of venous thromboembolism (VTE) chemoprophylaxis following traumatic brain injury (TBI) is a commonly encountered and intensely debated example.
Current international recommendations provide little guidance, with the latest Brain Trauma Foundation guidelines stating: “There is insufficient evidence to support recommendations regarding the preferred agent, dose, or timing of pharmacologic prophylaxis for deep vein thrombosis”. 1
Carney N, Totten AM, O’Reilly C, et al. Guidelines for the management of severe traumatic brain injury, fourth edition. Neurosurgery 2017; 80: 6-15.
Spano PJ, Shaikh S, Boneva D, et al. Anticoagulant chemoprophylaxis in patients with traumatic brain injuries: a systematic review. J Trauma Acute Care Surg 2020; 88: 454-60.
In Australia and New Zealand, this certainly appears to be the case. In the multicentre, multinational Erythropoietin in Traumatic Brain Injury (EPO-TBI) trial, all participants received protocolised screening for deep vein thrombosis via twice weekly bilateral lower limb compression ultrasonography. 3
Nichol A, French C, Little L, et al. Erythropoietin in Traumatic Brain Injury (EPO-TBI): a double-blind randomised controlled trial. Lancet 2015; 386: 2499-506.
Nichol A, Gantner D, Presneill J, et al. Protocol for a multicentre randomised controlled trial of early and sustained prophylactic hypothermia in the management of traumatic brain injury. Crit Care Resusc 2015; 17: 92-100.
Skrifvars MB, Bailey M, Presneill J, et al. Venous thromboembolic events in critically ill traumatic brain injury patients. Intensive Care Med 2017; 43: 419-28.
Skrifvars MB, Bailey M, Presneill J, et al. Venous thromboembolic events in critically ill traumatic brain injury patients. Intensive Care Med 2017; 43: 419-28.
Skrifvars MB, Bailey M, Presneill J, et al. Venous thromboembolic events in critically ill traumatic brain injury patients. Intensive Care Med 2017; 43: 419-28.
Data from Park and colleagues, 6
Park S, Kalfas K, Fazio TN, et al. Venous thromboembolism prophylaxis and related outcomes in patients with traumatic brain injury and prolonged intensive care unit stay. Crit Care Resusc 2021; 4: 364-73.
Park S, Kalfas K, Fazio TN, et al. Venous thromboembolism prophylaxis and related outcomes in patients with traumatic brain injury and prolonged intensive care unit stay. Crit Care Resusc 2021; 4: 364-73.
Park S, Kalfas K, Fazio TN, et al. Venous thromboembolism prophylaxis and related outcomes in patients with traumatic brain injury and prolonged intensive care unit stay. Crit Care Resusc 2021; 4: 364-73.
In contrast, secondary intracranial haematoma occurred in 43% of patients, with a median onset on day 1. 6
Park S, Kalfas K, Fazio TN, et al. Venous thromboembolism prophylaxis and related outcomes in patients with traumatic brain injury and prolonged intensive care unit stay. Crit Care Resusc 2021; 4: 364-73.
Park S, Kalfas K, Fazio TN, et al. Venous thromboembolism prophylaxis and related outcomes in patients with traumatic brain injury and prolonged intensive care unit stay. Crit Care Resusc 2021; 4: 364-73.
While the external validity of these data must be viewed very cautiously, they should prompt closer examination of local practice. The observation that the majority of secondary intracranial haematoma events were mild, occurred early, and in the absence of notable coagulopathy is consistent with clinical observation. Indeed, expansion of an existing intracranial haematoma or development of additional areas of intraparenchymal haemorrhage most often represents the expected evolution of a severe underlying brain injury. Moreover, recent data suggest that 40 mg enoxaparin subcutaneous daily as VTE chemoprophylaxis is unlikely to significantly alter plasma anti-Xa activity in many trauma patients. 7
Rakhra S, Martin EL, Fitzgerald M, Udy A. The ATLANTIC study: anti-Xa level assessment in trauma intensive care. Injury 2020; 51: 10-4.
The article by Park et al 6
Park S, Kalfas K, Fazio TN, et al. Venous thromboembolism prophylaxis and related outcomes in patients with traumatic brain injury and prolonged intensive care unit stay. Crit Care Resusc 2021; 4: 364-73.
Despite these limitations, Park and colleagues 6
Park S, Kalfas K, Fazio TN, et al. Venous thromboembolism prophylaxis and related outcomes in patients with traumatic brain injury and prolonged intensive care unit stay. Crit Care Resusc 2021; 4: 364-73.
Rappold JF, Sheppard FR, Carmichael Ii SP, et al. Venous thromboembolism prophylaxis in the trauma intensive care unit: an American Association for the Surgery of Trauma Critical Care Committee Clinical Consensus Document. Trauma Surg Acute Care Open 2021; 6: e000643.