All posts by The Trauma Pro

VTE Prophylaxis After Solid Organ Injury

November 16, 2020 The Trauma Pro Leave a comment

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

Procedures

Cricothyrotomy In The COVID Age

November 9, 2020 The Trauma Pro Leave a comment

COVID-19 has changed everything. Our patients and even our co-workers could be harboring the virus. Workplace precautions have changed. Many of the minutiae of living have changed. All trauma professionals are concerned with protecting themselves from contagion in order to continue providing vital care to more patients.

We have a fairly good understanding of how the virus spreads. Aerosols and aerosolizing procedures are a major risk factor for involved personnel. In general, hospitals already have processes and policies in place for the most common aerosolizing procedure, endotracheal intubation. Even in emergency circumstances, this is a relatively controlled procedure.

But what about cricothyrotomy? This is far less commonly performed, and as such is prone to more variability. Surgeons at Northwestern University in Chicago tested several techniques for more safely performing this procedure. They placed three different types of draping materials commonly found in or around a trauma bay over their hands in an attempt to decrease aerosolization produced during the procedure.

They tested these drapes using a cricothyrotomy simulator based on a porcine trachea. To identify aerosolization, they atomized fluoroscein into the trachea and monitored the procedure with an ultraviolet light.

The first drape tested was a clear plastic x-ray cassette holder. The advantage of using this as a drape is its transparency. The surgeon does not need to peek under the plastic while performing the crich. Unfortunately, the stiffness and slipperiness of the plastic makes it prone to sliding off the procedure site.

A dry blue surgical towel was used next. This performed a bit better, but still slipped off the operative field. Black light inspection showed a significant amount of aerosol contamination of the edge of the towel and the surgeon’s gown.

Finally, a wet blue surgical towel was tested. The towel easily stayed in place and retained nearly all of the aerosolized fluoroscein. There was a negligible amount on the surgeon’s gown.

Bottom line: The authors recommended that wet surgical towels be placed over their hands and used as a barrier when performing a cricothyrotomy in a COVID positive or unknown patient. The reality is that this will apply to this procedure in just about any acute trauma patient you see. Obviously, this trick does not eliminate aerosolization. Rather, it dramatically reduces the amount and hence, the risk to the surgeon and other personnel in the room. It’s not perfect, but definitely worth it!

To view a video demonstrating the technique and results for each of the drapes, click here.

Reference: Emergency cricothyrotomy during the COVID-19 pandemic: how to suppress aerosolization. Trauma Surgery Acute Care Open 5(1):e000482, 2020.

Head

Everything You Wanted To Know About: Cranial Bone Flaps

October 30, 2020 The Trauma Pro Leave a comment

Patients with severe TBI frequently undergo surgical procedures to remove clot or decompress the brain. Most of the time, they undergo a craniotomy, in which a bone flap is raised temporarily and then replaced at the end of the procedure.

But in decompressive surgery, the bone flap cannot be replaced because doing so may increase intracranial pressure. What to do with it?

There are four options:

The piece of bone can buried in the subcutaneous tissue of the abdominal wall. The advantage is that it can’t get lost. Cosmetically, it looks odd, but so does having a bone flap missing from the side of your head. And this technique can’t be used as easily if the patient has had prior abdominal surgery.

2. Some centers have buried the flap in the subgaleal tissues of the scalp on the opposite side of the skull. The few papers on this technique demonstrated a low infection rate. The advantage is that only one surgical field is necessary at the time the flap is replaced. However, the cosmetic disadvantage before the flap is replaced is much more pronounced.

3. Most commonly, the flap is frozen and “banked” for later replacement. There are reports of some mineral loss from the flap after replacement, and occasional infection. And occasionally the entire piece is misplaced. Another disadvantage is that if the patient moves away or presents to another hospital for flap replacement, the logistics of transferring a frozen piece of bone are very challenging.

4. Some centers just throw the bone flap away. This necessitates replacing it with some other material like metal or plastic. This tends to be more complicated and expensive, since the replacement needs to be sculpted to fit the existing gap.

So which flap management technique is best? Unfortunately, we don’t know yet, and probably never will. Your neurosurgeons will have their favorite technique, and that will ultimately be the option of choice.

Reference: Bone flap management in neurosurgery. Rev Neuroscience 17(2):133-137, 2009.

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