Tag Archives: solid organ

VTE Prophylaxis After Solid Organ Injury

Venous thromboembolism (VTE)  is a common potential complication after traumatic injury. But typically, injury is associated with bleeding, so the trauma professional has to strike a balance between preventing bleeding and preventing clots.

Solid organ injury (liver and spleen, typically) is a common diagnosis after blunt trauma. Most trauma centers have protocols for VTE prophylaxis which apply to patients with those injuries. Older literature that I wrote about eight years divided the time frames for prophylaxis into early (within 3 days), late (greater than 3 days), and none. The authors of that article found that there was no association with untoward bleeding in the early group. And interestingly, there seemed to be less in that group. Unfortunately, the selection of the groups was biased, and the early VTE prophylaxis group had less severe injuries.

The surgery group at the Massachusetts General Hospital tried to clarify current practice by performing a deep dive into the Trauma Quality Improvement Program database. They searched the database to identify patients with “isolated” liver, spleen, kidney, and pancreas injury. They did this by excluding TBI, femur and pelvic fractures, spinal cord injury, and penetrating trauma. They also excluded patients with other other severe injuries with an abbreviated injury scale score of 3 or more.

The authors stratified patients into three groups: early VTE prophylaxis receiving the drug within 48 hours of arrival, intermediate within 48-72 hours, and late after 72 hours.

Here are the factoids:

  • A total of 3,223 patients met inclusion criteria
  • Prophylaxis was classified as early in 57%, intermediate in 22%, and late in 21%
  • About 3/4 received low molecular weight heparin and the remainder received unfractionated heparin
  • Late prophylaxis was associated with a 3x increase in both VTE and pulmonary embolism (PE)
  • Intermediate prophylaxis patient had a 2x increase in VTE but no increase in PE
  • Early prophylaxis showed a 2x increase in bleeding complications, especially in those with diabetes (?), spleen, and high-grade liver injury
  • A total of 60 of the 1,832 patients in the early group had bleeding events: 39 failed nonop mangement and were taken to OR, 8 underwent angioembolization, and 21 received blood transfusions

The authors concluded that early prophylaxis should be considered in patients who do not fall out as higher risk (spleen, high-grade liver, diabetics).

Bottom line: This retrospective study is probably as good as it’s going to get from a data quality standpoint. It’s larger than any single-institution series will ever be, although it suffers from the usual things most large database studies do. 

But it does show us strong associations with DVT and PE as the consequences of waiting to start VTE prophylaxis beyond 48 hours. The caveat is to be careful in certain patients, most notably diabetics and those with liver and spleen injuries, as they are at higher risk to develop complications leading to the OR or interventional radiology suite. 

I urge all of you to re-examine your VTE prophylaxis guideline and modify it to start your drug of choice as early as possible given the cautions for patients with spleen and high-grade liver injuries. The diabetes thing, well, that’s a mystery to me and I will wait for further confirmation to break those patients out separately.

If you are interested, you can see the Regions Hospital trauma program VTE guideline by clicking here.

References:

  • Thromboembolic prophylaxis with low-molecular-weight heparin in patients with blunt solid abdominal organ injuries undergoing nonoperative management: current practice and outcomes. J Trauma 70(1): 141-147, 2011.
  • Timing of thromboprophylaxis in patients with blunt abdominal solid organ injuries undergoing nonoperative management. J Trauma pulish ahead of print, October 12, 2020, doi: 10.1097/TA.0000000000002972

Solid Organ Injury Practice Guideline Updated

Regions Hospital developed a clinical practice guideline for solid organ management in 2002-2003. It has been revised a few times over the years, as any good guideline should with the availability of new data.

I’ve just put the finishing touches on the latest revision as a result of the updated organ scaling rules published by the American Association for the Surgery of Trauma. I reviewed the new scales for both liver and spleen earlier this year (links below). In the previous iteration of the scaling system, the importance of contrast pooling (pseudoaneurysm) or extravasation beyond the organ was not well defined. 

The new guideline explicitly includes these injuries in the high grade group, which for us is grade IV or V. Technically, pseudoaneurysm of the liver is only grade III, but in my opinion demands angiographic investigation and embolism. Thus the inclusion in the high grade / angiography arm of our guideline.

For those of you who have not seen this guideline before, there are several important directives that are listed on the left side of the page:

  • Patients are NOT made NPO
  • They do NOT have activity restrictions (such as bed rest)
  • Serial hemoglins are NOT drawn
  • An abdominal CT scan is NOT repeated

These changes were made in 2015 based on our clinical experience that properly selected patients almost never failAnd they still don’t, so why starve, restrain, poke, and re-irradiate them?

Additionally, we included explicit impact activity restrictions for post-discharge so that patients would get the same message from all members of our team.

Click the image below to download the guideline and have a look. I’m interested in your comments!

Related posts:

Update: Kidney Injury Scaling

Over the past two days, I’ve reviewed the new AAST organ injury scaling updates for spleen and liver injuries. Today, I’ll cover the new kidney grading scale.

Liver and spleen grading is generally simple, focusing on laceration depth and subcapsular hematoma coverage to determine the exact value. However, the kidney is totally different. Although technically a solid organ, it’s got a bunch of hollow, urine-containing stuff inside. This is the main determinant of the original scaling system: collection system involvement.

Like liver and spleen, the kidney scale was updated to take advantage of CT information. But once again, bleeding identified via the CT angiogram is incorporated into the higher grades. Active bleeding contained within Gerota’s fascia is assigned a grade of III. Extravasation escaping this fascia is assigned a IV.  The other grades remain unchanged.

Here are the updated guidelines. Click the image or link below it to open a bigger image in a new window.

Click to download larger image

Links:

Update: Liver Injury Scaling

In my last post, I reviewed the updated AAST organ injury scaling (OIS) for the spleen. Today, I’ll share details of the new version of liver grading.

First, the overall focus of the updated liver scale is similar to the spleen one: it incorporates a listing of criteria identified by CT scan that parallels the old anatomic criteria. The CT column contains all the old anatomic stuff, but now includes scaling for active bleeding.

The confusing part? Whereas contained active bleeding within the spleen was Grade IV and active bleeding escaping the spleen was Grade V in the updated scale, these drop down a grade in the liver. So bleeding contained with the liver parenchyma is Grade III and active extravasation escaping into the peritoneal cavity is only Grade IV. I presume this has to do with the abbreviated injury score (AIS) used to calculate ISS, and that the mortality hit from this degree of bleeding is less than that of the spleen.

The final difference between the updated scale and the original is the removal of Grade VI. This was previously described as hepatic avulsion, which is a nonsurvivable injury. The AIS for Grade VI liver used to be 6, which causes an immediate ISS calculation short circuit to 75. Which also means that survival is approximately 0%. This is not part of the OIS update, which may be due to the fact that it never occurs in anyone who makes it to a trauma center alive.

Here are the updated guidelines. Click the image or link below it to open a bigger image in a new window.

Click to download larger image

In the next post, I’ll review the new features of the kidney injury scale.

Update: Spleen Injury Scaling

Over the years, the American Association for the Surgery of Trauma (AAST) has developed and maintained a library of organ injury scales. Organ injury scaling allows us to compare apples to apples in research studies, and in many cases enables us to tailor interventions and predict outcomes. Many of the scales have been in place for decades and have not been updated. The spleen, liver, and kidney scales were introduced 25 year ago, and received their first update last December. During the next three posts, I’ll review what’s new and different with them.

The biggest change to all three scales has been the incorporation of specific vascular injuries seen on modern-day CT scans. It is recommended that scanning for solid organ injury be conducted using dual phase (arterial and portal venous) scanning techniques. This increases study sensitivity and provides the best images for accurate diagnosis and scaling. Also note that specific criteria are now provided for CT, intraoperative, and pathologic diagnosis.

Let’s start with the spleen today. Here are the updated guidelines. Click the image or link to get a bigger image in a new window.

Click to download larger image

The main change to this scale is the addition of active bleeding contained within the spleen (pseudo-aneurysm or contained extravasation) to Grade IV, and uncontained extravasation to Grade V.

In my next post, I’ll discuss the new features of the liver injury scale.