Shifts in Approach to VTE Prophylaxis for Trauma Patients
Shifts in Approach to VTE Prophylaxis for Trauma Patients
The past year has seen a significant shift in the approach to chemical venous thromboembolism (VTE) prophylaxis for hospitalized patients. Before 2011, increasing awareness drew the attention of the Surgeon General,and VTE prophylaxis rates began to be used to measure quality of care. Major physician organizations endorsed hospital-wide policies designed to reduce rates.
The American College of Physicians (ACP) published guidelines in late 2011 that questioned the efficacy of chemical prophylaxis for nonsurgical patients. In a summary meta-analysis, there was no overall mortality benefit from chemical prophylaxis, and bleeding rates were higher than previously reported. The guidelines stressed an individualized assessment for each patient and recommended against policies meant to increase chemical prophylaxis rates without regard to VTE risk.
What happened? Did we miss a landmark study that was included in this meta-analysis, but not in others? Nope. There was 1 additional study included in the meta-analysis that was published in 2008 and was not included in an earlier meta-analysis that drew different conclusions from the ACP, but it was not a "game-changer" study. There was simply a shift in focus by the folks who write the guidelines, assessing outcomes at different time points and questioning the importance of asymptomatic events. There was also an entire section devoted to patient values and perceptions, which in part drove the new conclusions drawn from the existing data.
What does this have to do with VTE prophylaxis for the trauma patient admitted to the intensive care unit? Recommendations regarding VTE prophylaxis in trauma patients have always been questionable. In the past, both the American College of Chest Physicians (ACCP) and the EAST guidelines advocated low-molecular-weight heparin (LMWH) as the agent of choice for prophylaxis. The ACCP rated this recommendation 1A, largely on the basis of a single randomized controlled trial (RCT) that showed superiority over unfractionated heparin (UFH) and on several other clinical trials that showed low bleeding rates but questionable efficacy.
The 9th consensus guidelines on VTE treatment and prevention, recently published by the ACCP, seem to have followed the trend set by the ACP. Although plenty of information on VTE prevention in the trauma patient has been published since 2008, nothing approached the quality of the RCT that drove the recommendations from the earlier statements. Still, the recommendations for chemical prophylaxis for trauma patients changed. The 1A recommendation for LMWH is gone, replaced by a 2C recommendation to use either UFH or LMWH.
Again, the change was due to an alternative look at VTE outcomes. In the most recent ACCP guidelines, the authors clearly state that the existing evidence for benefit in a general trauma population is of poor quality. In fact, they base recommendations on extrapolation from other populations as opposed to relying heavily on what little there is in the trauma literature. That being the case, don't go looking for that new study showing UFH is equivalent to LMWH in a trauma population; you won't find it.
There is much to learn from the evolution of VTE prophylaxis guidelines. The cynics will say that the newer recommendations will add to the confusion and cause physicians and patients to question the value of existing consensus statements. They will point to the limits inherent to any group-based approach, given that we've come full circle on individual risk stratification for each hospitalized patient. The limits to such an approach are particularly true for the trauma population, a heterogeneous group that defies easy classification. I believe the cynics will be correct on all accounts.
On the bright side, though, one could argue that the focus on patient values is critical to optimizing care. In an increasingly cost-conscious environment, the ability to deliver what matters, as opposed to what the experts and academics feel is best, becomes more important. Perhaps the updates to the 2012 ACCP guidelines bring us closer to this goal.
How does all this talk of values, outcomes, and preferences translate to the bedside of the critically ill trauma patient? I'm not sure much has changed. For hospitals with high acquisition costs for LMWH, UFH may now be an acceptable (and cheaper) alternative. Otherwise, I'd still favor LMWH on the basis of the study by Geerts and colleagues, and I'll continue to maintain a healthy respect for bleeding risk.
The past year has seen a significant shift in the approach to chemical venous thromboembolism (VTE) prophylaxis for hospitalized patients. Before 2011, increasing awareness drew the attention of the Surgeon General,and VTE prophylaxis rates began to be used to measure quality of care. Major physician organizations endorsed hospital-wide policies designed to reduce rates.
The American College of Physicians (ACP) published guidelines in late 2011 that questioned the efficacy of chemical prophylaxis for nonsurgical patients. In a summary meta-analysis, there was no overall mortality benefit from chemical prophylaxis, and bleeding rates were higher than previously reported. The guidelines stressed an individualized assessment for each patient and recommended against policies meant to increase chemical prophylaxis rates without regard to VTE risk.
What happened? Did we miss a landmark study that was included in this meta-analysis, but not in others? Nope. There was 1 additional study included in the meta-analysis that was published in 2008 and was not included in an earlier meta-analysis that drew different conclusions from the ACP, but it was not a "game-changer" study. There was simply a shift in focus by the folks who write the guidelines, assessing outcomes at different time points and questioning the importance of asymptomatic events. There was also an entire section devoted to patient values and perceptions, which in part drove the new conclusions drawn from the existing data.
What does this have to do with VTE prophylaxis for the trauma patient admitted to the intensive care unit? Recommendations regarding VTE prophylaxis in trauma patients have always been questionable. In the past, both the American College of Chest Physicians (ACCP) and the EAST guidelines advocated low-molecular-weight heparin (LMWH) as the agent of choice for prophylaxis. The ACCP rated this recommendation 1A, largely on the basis of a single randomized controlled trial (RCT) that showed superiority over unfractionated heparin (UFH) and on several other clinical trials that showed low bleeding rates but questionable efficacy.
The 9th consensus guidelines on VTE treatment and prevention, recently published by the ACCP, seem to have followed the trend set by the ACP. Although plenty of information on VTE prevention in the trauma patient has been published since 2008, nothing approached the quality of the RCT that drove the recommendations from the earlier statements. Still, the recommendations for chemical prophylaxis for trauma patients changed. The 1A recommendation for LMWH is gone, replaced by a 2C recommendation to use either UFH or LMWH.
Again, the change was due to an alternative look at VTE outcomes. In the most recent ACCP guidelines, the authors clearly state that the existing evidence for benefit in a general trauma population is of poor quality. In fact, they base recommendations on extrapolation from other populations as opposed to relying heavily on what little there is in the trauma literature. That being the case, don't go looking for that new study showing UFH is equivalent to LMWH in a trauma population; you won't find it.
There is much to learn from the evolution of VTE prophylaxis guidelines. The cynics will say that the newer recommendations will add to the confusion and cause physicians and patients to question the value of existing consensus statements. They will point to the limits inherent to any group-based approach, given that we've come full circle on individual risk stratification for each hospitalized patient. The limits to such an approach are particularly true for the trauma population, a heterogeneous group that defies easy classification. I believe the cynics will be correct on all accounts.
On the bright side, though, one could argue that the focus on patient values is critical to optimizing care. In an increasingly cost-conscious environment, the ability to deliver what matters, as opposed to what the experts and academics feel is best, becomes more important. Perhaps the updates to the 2012 ACCP guidelines bring us closer to this goal.
How does all this talk of values, outcomes, and preferences translate to the bedside of the critically ill trauma patient? I'm not sure much has changed. For hospitals with high acquisition costs for LMWH, UFH may now be an acceptable (and cheaper) alternative. Otherwise, I'd still favor LMWH on the basis of the study by Geerts and colleagues, and I'll continue to maintain a healthy respect for bleeding risk.
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