Results of an observational study support early initiation of venous thromboembolism (VTE) prophylaxis in patients with severe traumatic brain injury (sTBI).
The research suggests that starting anticoagulant therapy within 72 hours of hospital arrival significantly lowers the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE) in patients with sTBI, without increasing the risk of bleeding complications or death.
These results were published in the Journal of the American College of Surgeons.
“Physicians have traditionally been hesitant to initiate pharmacological blood clot prophylaxis early in patients with severe brain injuries because, while thinning the blood might prevent PE and DVT, it might also increase the risk of complications related to worsening intracranial hemorrhage,” said study author James P. Byrne, MD, of the University of Toronto in Ontario, Canada.
“We performed this study because there wasn’t clear evidence that starting prophylaxis early actually prevented blood clots, or whether this benefit would outweigh the risk of complications from intracranial hemorrhage. Current evidence-based guidelines don’t address the optimal timing for starting prophylaxis in patients with severe TBI.”
The researchers looked at data on 3634 adult patients with sTBI who were treated at 186 trauma centers participating in the American College of Surgeons Trauma Quality Improvement Program. The patients received VTE prophylaxis with either low-molecular-weight heparin or unfractionated heparin between 2012 and 2014.
The researchers divided patients into 2 groups: early prophylaxis (started within 72 hours of hospital arrival) or late prophylaxis (started after 72 hours). The primary outcomes were PE or DVT. The secondary outcomes were late neurosurgical interventions (performed after 72 hours) and in-hospital death.
The team used propensity-score matching to emulate the design of a randomized, controlled trial and minimize selection bias. This method took into account a large set of patient baseline and injury factors, and yielded a cohort of 2468 patients. Outcomes were then compared between early and late prophylaxis groups.
Results
The researchers found that early VTE prophylaxis was associated with significantly lower rates of PE (adjusted odds ratio [aOR]=0.48; 95% CI 0.25–0.91) and DVT (aOR=0.51; 95% CI 0.36–0.72) than late prophylaxis.
“No previous study has shown that patients who receive early prophylaxis have lower rates of pulmonary embolism, which is important because this complication is a potentially fatal one,” Dr Byrne noted.
“We also found that trauma centers that most frequently used early prophylaxis in their patients had significantly lower rates of deep vein thrombosis, compared with counterparts where fewer patients received early prophylaxis, with no difference in rates of late neurosurgical intervention or mortality.”
Specifically, there was no significant difference between early prophylaxis and late prophylaxis groups with respect to rates of in-hospital mortality (aOR=1.10; 95% CI 0.84–1.45) or late neurosurgical interventions, including craniotomy/craniectomy (aOR=0.86; 95% CI 0.53–1.40) and intracranial monitor (aOR=0.76; 95% CI 0.37–1.58).
The researchers said this is the largest study to date comparing the effectiveness and safety of early versus late VTE prophylaxis in patients with sTBI.
A limitation of this study was the fact that statistical methods could not account for confounding factors that were not measured in the study dataset. One such factor was changes in patterns of intracranial hemorrhage on head CT scan, which would influence physician decision-making.
“The takeaway message is that early prophylaxis really does matter in patients with severe traumatic brain injury, in terms of reducing a patient’s risk of pulmonary embolism or deep vein thrombosis,” Dr Byrne said.
“Our findings suggest that this is possible without increasing the risk of the most feared complications, such as the need to take a patient to the operating room to evacuate intracranial hemorrhage or death. In other words, it’s possible to prevent PE or DVT with early prophylaxis, without putting patients at risk of bad outcomes, and we should be striving to achieve this.”
