Today’s abstract continues the theme of VTE prophylaxis. The authors introduce another timing parameter in this one: the “door-to-prophylaxis” time. Just as it sounds, this is the time interval between admission to the ED and initiating chemo-prophylaxis. Just like some centers struggle with how long to wait to start it after a solid organ injury (see previous post here), many find it challenging to get it ordered in the first place.

The authors retrospectively reviewed their registry data over four years. They compared adult patients who arrived as a highest-level of activation and received blood during their resuscitation. They were divided into two groups: those with DVT or pulmonary embolism (VTE group) and those without (no VTE group). The door-to-prophylaxis time was defined as the time from hospital arrival to the first dose of medication.

Here are the factoids:

• Just over 2,000 patients met inclusion criteria, with 106 experiencing VTE and 1,941 without it
• VTE patients had higher ISS (29 vs. 24), higher lactate levels (4.6 vs. 3.9), and more post-ED blood transfusions (8 vs. 2)
• There was no difference in the need for dose adjustment or missed doses between the groups
• Door-to-prophylaxis time was significantly longer in the VTE group (35 vs. 25 hours)
• When controlling for age, sex, ISS, lactate, and post-ED transfusions, each hour of delay increased the likelihood of VTE by 1.5%

The authors concluded that the door-to-prophylaxis time was significantly associated with increased incidence of VTE. They suggest that the door-to-prophylaxis time should be utilized as a performance improvement metric for this condition.

Bottom line: Unfortunately, we need a lot more information here. There was not enough room for details about the statistical analysis in the abstract, but they will be essential to know. And the authors remind us that this study shows association, not causation. 

Severe injury and blood transfusion are already known to be associated with a higher likelihood of VTE. The fact that the longer door-to-prophylaxis group had more frequent VTE may very well be due to their higher ISS and greater number of transfusions. Those events themselves may have led to the hesitation in starting a heparin.

Early prophylaxis is certainly a desirable goal in any trauma patient. But we need more than a new metric. We need more concrete information on the specific reasons for the delay and to prove that it is safe to give the drug early in patients who have those potential delaying factors.

Reference: “Door-to-prophylaxis” time as a novel quality improvement metric in preventing venous thromboembolism following traumatic injury. AAST 2023, Plenary paper #38.