And we'll now call forward our final speaker before the break, Dr. Shin. And hopefully, Dr. Shin will finally answer for us what we should do about DVT prophylaxis. So, please. All right. Hello, everyone. My name is David Shin. I'm a PGY3 at the University of Florida, and I'm here to talk to you about my research, which is titled, Early VT Prophylaxis in TBI, Chemoprophylaxis in TBI Patients is Safe and Effective. I have no conflicts of interest. I am a member of the United States Army, and the views in this presentation are not necessarily representative of that organization. So just some, you know, quick background. Everyone knows that TBI remains a major public health issue. There are an estimated 2.5 million visits for this problem in the ED in 2010. And overall, as you can see on this chart here, the trend appears to be increasing. Patients who have suffered a TBI are at increased risk of developing VTE due to an increased immobility, primary brain injury, and focal motor deficits. There remains considerable controversy regarding the timing of initiating of DVT chemoprophylaxis. The current guideline from the Brain Trauma Foundation regarding this topic, which is a level three recommendation, states that low molecular weight heparin or low dose unfractionated heparin may be used in combination with mechanical prophylaxis. However, there is an increased risk for expansion of intracranial hemorrhage. There's no level one or level two evidence to support the use of DVT chemoprophylaxis, unfortunately. Those current guidelines are based on seven class three studies. The majority of the patients in these studies received their chemoprophylaxis at 48 to 72 hours after admission. And there continues to be wide variability across the country regarding the timing of initiation after hospital admission for TBI. Our institution at the University of Florida is especially aggressive with regard to initiating heparin or Lovenox with essentially all patients receiving their first dose within 24 hours. So the aims of the study was to show two things. One is that DVT chemoprophylaxis does not result in worsening intracranial hemorrhage. And two, that this chemoprophylaxis also decreases the incidence of DVT and or PE. So we performed an IRB-approved retrospective chart review of the UF trauma database of any patient that had an admirable head CT over a 10-year period from 2005 to 2015. Unfortunately, we had to exclude everyone before the implementation of our EMR of EPIC because of a lack of documented heparin or Lovenox administration time. Hospital hospital transfers were excluded. Patients that did not have any prophylactic anticoagulation were excluded, although this number was somewhere between 10 and 15 patients. And patients without any neurosurgery involvement were also excluded. You can see a list of information that we collected, some general things such as age, sex, type of injury, their GCS, their injury severity score, presence of DVT, PE, and so on and so forth. So we used the time of the admission CT as a surrogate marker for admission because the way that patients come into our institution as trauma patients are there, they're brought into our trauma bay and they have their initial survey, at which point they're brought almost immediately within 15 minutes to the scanner for their full-body CT. The time of administration was calculated by subtracting the time of first dose in the MAR from the time of the CT. And patients were divided into early versus late administration, less than 12 hours and greater than 12 hours. And primary outcomes were then rates of DVT or PE as well as radiographic worsening. The variables that were compared categorically were compared using the likelihood ratio test for potential confounding, and continuous variables were evaluated with the Wilcoxon-Rankson test. So in total we had 521 patients in our study. 167 of them had repeat imaging within 72 hours. The most common injuries in these patients were traumatic subarachnoid hemorrhage, contusion, and subdural hematoma. In total there were 22 DVTs and 8 PEs, so a total of 25 unique DVT-PE events. The vast majority of these patients either had no neurosurgery intervention or received their interventions such as intracranial monitoring or craniotomy and then remained neurologically stable afterwards. So here's a data table showing the comparison of our two groups. We had a lot more patients in the early group, 390, versus the late group. And you can see here there at the bottom our DVT and DVT-PE comparison shows that there was a statistically significant difference in the rates between the early and late group. This table also does show that there was a difference in the GCS and ISS between the two groups, indicating that these two variables were potential confounders for this finding of the decreased rate of DVT and PE. So then in order to account for that confounding, we applied an inverse propensity score weighting system to account for the confounding effects of GCS and ISS. And then we calculated an odds ratio using the score as well using the logarithmic regression for DVT-PE and radiographic worsening between these two groups. So overall we found that if you were in the late group, you had almost 2.5 times more likelihood of developing a DVT, and this effect was larger in the DVT-PE group with a ratio of 2.789. So there's no difference in the radiographic worsening between the two groups. So overall rate of DVT and PE in this group was about 4.8%. Historically, the rate of DVT in the TBI population is as high as 25% with mechanical prophylaxis alone. The rates of DVT-PE within the study populations that the trauma guidelines were created from range from 4% to 17%, indicating that our patients were definitely on the lower end of that spectrum. Additionally, the rates of hemorrhage expansion in both of our groups was approximately 10%, and studies have shown that the average rate for intracranial hemorrhage expansion in those guidelines were from 6% to 24%, showing that our patients were also in line with those patients in those studies. There's some pretty significant limitations of the study. One is that it was retrospective. Obviously we missed over 2,500 patients because of the timing of the dose. It was not available readily prior to the implementation of EPIC. And ideally it would have been better to have balanced groups, specifically with regard to GCS and injury severity score, because that would have eliminated our need for the inverse propensity score weighting system. So in conclusion, we showed that late administration of chemoprophylaxis does result in a statistically significant increase in odds ratio for developing a DVT or DVT or PE. Early versus late use between these two groups did not result in a difference in the radiographic progression of hemorrhage. And we found that in patients early versus late, it was safe to give these patients chemoprophylaxis, and it was effective in reducing thromboembolic events. Thank you for your time, and I'll take questions. Yes, sir. The majority of our patients were given Heparin, like over 95%, but we did not compare the two groups. We did, but the total number of patients that would have progressed and then progressed clinically enough to require more like neurosurgery afterwards was only like, was like less than 1%. So the N wasn't high enough to look at whether or not that progression was significant enough in that patient population. So we don't know. We don't know, basically. Thank you, Dr. Shin.

Dr. David Shin

early venous thromboembolism prophylaxis

traumatic brain injury patients

chemoprophylaxis

thromboembolic events