All posts by The Trauma Pro

Philosophy

Use Of Radio-opaque Markers In Penetrating Trauma

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As I was browsing through my journal list this week, I ran into an interesting title for an article that is currently in press.

“The use of radio-opaque markers is medical dogma”

Catchy, especially since I love writing about dogma vs what is really supported by the literature. The author questions the justification of this practice and posits that there are risks to extrapolating information based on radiographs with markers placed by the trauma team.

OLYMPUS DIGITAL CAMERA

The author first reviewed the literature on the use of markers for penetrating injury, which started only recently, in 2002. Markers were initially used to precisely locate the penetration site since skin wounds (obviously) don’t show up on X-rays. Typically, these were just plain old paper clips. Some trauma professionals placed them directly over the wound. Others un-bent them and fashioned them into shapes that pointed to the exact location of the wound.

With the growing usage of CT scans to evaluate stable patients, modifications to the marker were made. Small arrow markers designed for use on x-rays were frequently used. However, even the very small ones could cause enough scatter on a CT scan to interfere with diagnosis. At some centers, Vitamin E capsules were taped on top of the wound. But thankfully, there are now special markers that can pinpoint the wound without degrading the tomographic image.

The author goes on to describe how gunshot wounds specifically are difficult to assess with a marker. Although the exact surface location may be noted, the underlying injuries vary due to size, distance, velocity, and trajectory change from tissue density or bone strikes. He also notes that it may not be wise to place a marker into a bloody field in a potentially combative patients.

The article concludes that the use of this technique for identifying anything other than surface location of penetrations lacks clinical evidence and is based only on expert opinion. Which essentially makes it dogma.

Bottom line: Here are my thoughts. First, the use of markers on penetrating wounds has been going on for much longer than the 20 years found in the trauma literature reviewed here. It has been a common practice among trauma surgeons for many, many decades. Most “seasoned” (old) trauma surgeons have been doing and teaching this for their entire careers. 

I concur that we have techniques like CT scan available to us now that provide an excellent view of the penetration trajectory. The skin wound is usually apparent on the scan, but may be improved with the use of a CT-approved marker.

So why still do this for the patient arriving in your trauma bay? An experienced trauma surgeon can get a good sense of the trajectory based on the entry point, the exit wound, and the location of any retained bullet or fragments. Rapid placement of some kind of marker on all wounds followed by a quick image allows them to roughly predict what was hit, and assess the possibility that there might be bleeding that would drive the team straight to the operating room. It can help direct the surgical exploration if imaging was unnecessary or contraindicated. 

So yes, this is dogma. The reality is that no one will ever be able to design a study that definitively evaluates the very soft outcomes that result from using this technique. But every senior trauma surgeon can easily cite numerous examples in their career when this method has been extremely useful. The lack of a study only means that there will never be any evidence-based guideline for the use of this technique. However, it is still acceptable to have a protocol based on substantial clinical experience. But as with all dogma, once that definitive study finally does comes along, the protocol must be modified to adhere to the findings of the study.

For now, keep using those markers! And I’m very interested in comments from both old and young trauma professionals on this topic.

Reference: The Use of Radio-opaque Markers is Medical Dogma, doi:10.1111/acem.1485, Dec 2023.

Resuscitation

Liquid Plasma vs FFP: Impact On Your Massive Transfusion Protocol

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In my last post, I discussed the growing number of choices for plasma replacement. Today I’ll look at some work that was done that tried to determine if any one of them is better than the others when used for the massive transfusion protocol (MTP).

As noted last time, fresh frozen plasma (frozen within 8 hours, FFP) and frozen plasma (frozen within 24 hours, FP) have a shelf life of 5 days once thawed. Liquid plasma (never frozen, LQP) is good for the 21 days after the original unit was donated, plus the same 5 days, for a total of 26 days.

LQP is not used at most US trauma centers. It is more commonly used in Europe, and a study there suggested that the use of thawed plasma increased short term mortality when compared to liquid plasma. To look at this phenomenon more closely, a group from UTHSC Houston and LSU measured hemostatic profiles on both types of plasma at varying times during their useful life.

All products were analyzed with thromboelastography (TEG) and thrombogram, and platelet count and microparticles, clotting factors, and natural coagulation inhibitors were measured. They chose 10 units of thawed FFP and 10 units of LQP, and assayed them every 5 days during their useful shelf life.

Here are the factoids:

  • Platelet counts were much higher in day 0 LQP (75K) vs day 0 thawed plasma (7.5K). Even at end of shelf life, the LQP was 1.5x higher than thawed (15K vs 10K).
  • Thrombogram showed that LQP had higher endogenous thrombin production until end of shelf life
  • TEG demonstrated that LQP had a higher capacity to clot that gradually declined over time. It became similar to thawed plasma at the end of its shelf life.
                         (TEG MA for liquid (LQP) and thawed (TP) plasma
  • Most clotting factors remained stable in LQP, with the exception of Factors V and VIII, which slowly declined

Bottom line: Liquid plasma sounds like good stuff, right? Although there are a few flaws in the collection aspect of this study, it gives good evidence that never frozen plasma has better coagulation properties when compared to thawed plasma. Will this translate into better survival when used in the MTP for trauma? One would think so, but you never really know until you try it. Our hospital blood bank infrastructure isn’t prepared to handle this product yet, for the most part. What we really need is a study that shows the survival advantage when using liquid plasma compared to thawed. But don’t hold your breath. It will take a large number of patients and some fancy statistical analysis to demonstrate this. I think we’ll have to look to our military colleagues to pull this one off!

Reference: Better hemostatic profiles of never-frozen liquid plasma compared with thawed fresh frozen plasma. J Trauma 74(1):84-91, 2013.

Resuscitation

Liquid Plasma vs FFP: Definitions

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I’ll spend the next two posts discussing plasma. This is an important component of any trauma center’s massive transfusion protocol (MTP). Coagulopathy is the enemy of any seriously injured patient, and this product is used to attempt to fix that problem.

And now there are two flavors available: liquid plasma and fresh frozen plasma. But there is often confusion when discussing these products, especially when there are really three flavors! Let’s review what they are exactly, how they are similar, and how they differ.

Fresh frozen plasma (FFP)
This is plasma that is separated from donated whole blood. It is generally frozen within 8 hours, and is called FFP. However, in some cases it may not be frozen for a few more hours (not to exceed 24 hours total) and in that case, is called FP24 or FP. It is functionally identical to FFP. But note that the first “F” is missing. Since it has gone beyond the 8 hour mark, it is no longer considered “fresh.” To be useful in your MTP, it must be thawed, and this takes 20-40 minutes, depending on technique.

Thawed plasma
Take a frozen unit of FFP or FP, thaw, and keep it in the refrigerator. Readily available, right? However, the clock begins ticking until this unit expires after 5 days. Many hospital blood banks keep this product available for the massive transfusion protocol, especially if other hospital services are busy enough to use it if it is getting close to expiration. Waste is bad, and expensive!

Liquid plasma (never frozen)
This is prepared by taking the plasma that was separated from the donated blood and putting it in the refrigerator, not the freezer. It’s shelf life is that of the unit of whole blood it was taken from (21 days), plus another 5, for a total of 26 days. This product used to be a rarity, but is becoming more common because of its longer shelf life compared to thawed plasma.

Finally, a word on plasma compatibility. ABO compatibility is still a concern, but Rh is not. There are no red cells in the plasma to carry any of the antigens. However, plasma is loaded with A and/or B antibodies based on the donor’s blood type. So the compatibility chart is reversed compared to what you are accustomed to when giving red cells.

Remember, you are delivering antibodies with plasma and not antigens. So a Type A donor will have only Type B antibodies floating around in their plasma. This makes it incompatible with people with blood types B or AB.

Type O red cells are the universal donor type because the cells have no antigens on the surface. Since Type AB donors have both antigens on their red cells, they have no antibodies in their plasma. This makes AB plasma is the universal donor type. Weird, huh? Here’s a compatibility chart for plasma.

Next time, I’ll discuss the virtues of the various types of plasma when used for massive transfusion in trauma.

Performance Improvement

Transfers In: Direct Admit vs Send To The ED

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Level I and II trauma centers are frequently asked to accept patients who need a higher level of care. This necessitates an inter-hospital transfer that is subject to scrutiny by the trauma performance improvement program of both trauma centers. The practice at many centers is to bring all transfer patients in through the emergency department. But is this really necessary?

Bringing Patients To Your Emergency Department

  • Patients can be reassessed to see if they meet any of your trauma activation criteria.
  • The work-up from the referring hospital can be re-evaluated. If some testing or imaging has been omitted, it can be obtained after arrival.
  • Specialist assessment may be more timely or may involve interventions that are more difficult after leaving the ED. Here’s an example. In some hospitals, orthopedics may choose to place a traction pin to provide initial fracture management. They may choose to use sedation, which may not be as readily available on a surgery ward.
  • Access to certain critical services may be more rapid from the emergency department. A patient may be more rapidly taken to the operating room or interventional radiology if the patient is in the emergency department.
  • It is easier to determine the correct admitting service in the ED prior to the actual admission. Sometimes patients are suitable for admission to a surgical subspecialist service, or to a medical service if they have complex comorbidities. Initial admission to the correct service from the ED is easier than later transfer.

But there are a few downsides to ED arrival:

  • The emergency department may be swamped. Taking a patient who could just as easily have been admitted directly increases congestion in the ED and slows throughput even further.
  • There is a built-in time delay going through any emergency department. You can count on patients spending eight hours, if not much, much more if they come to the ED first.
  • It’s a big dissatisfier for patients. They’ve already gone through this time-intensive process once and are usually not happy to have to do it again.

Direct Admissions

Direct admissions essentially reverse the pros and cons listed for emergency department evaluation.

There is a mistaken belief that the ACS Verification Review Committee looks askance direct admissions. This is not the case, and there are no criterion deficiencies that refer to them. Direct admits may be reported on the site visit pre-review questionnaire, and the reviewers may have questions about your numbers and how you identify them. Otherwise, each center is free to choose how they handle them.

Here are some guidelines for directing incoming patients to the most appropriate place.

  • Are you familiar with the referring physician or APP? If you have worked with them before and are confident of their evaluation skills, then a direct admission could be appropriate.
  • Is the referring hospital a trauma center, and are you familiar with how they work up patients? What has your previous experience with them been? Again, if they are part of your hospital system and/or you have had successful direct admissions from them in the past, consider it again.
  • Will the patient need rapid access to specialized services after arrival? Do they need to go to the operating room quickly? Or might they need advanced imaging that can be arranged more expeditiously from the ED?
  • Will they need any procedures after arrival that are more easily done in your ED? Do they need a complicated laceration repair best done with equipment in the ED? Will they require conscious sedation for a procedure?
  • Are you unsure of the most appropriate admitting service? Does the patient have significant comorbidities? Do you have two or more potential admitting services but just need to lay eyes on the patient to help you decide?
  • How busy is your ED? The longer the wait time, the more desirable it is to just skip it altogether, especially if none of the items above apply.

But make sure that you are able to accurately identify and track each and every direct admission coming into the hospital. Although high numbers of direct admission patients is not a violation of ACS standards, allowing trauma patients to get into the hospital on non-trauma services without being identified by the PIPS program is. I recommend that you review each and every one of them shortly after they arrive. Then make sure the decision-making was correct and the patient is on the service that best meets their needs.

Thorax

What You Need To Know About Blunt Cardiac Injury

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Blunt cardiac injury can be an enigma. Significant injuries are uncommon, and the literature on it consists of case reports and small series. The group at Scripps La Jolla has an excellent review article on the topic that is currently in press. This post will relate some of the key points in this nicely prepared article.

  • Use the correct nomenclature. For years, many have called this condition “cardiac contusion” or “myocardial contusion.” Unfortunately, these descriptors are too specific. The proper term is “blunt cardiac injury (BCI),” which encompasses the entire gamut of injury from asymptomatic contusion to pericardial injury to cardiac rupture.
  • BCI occurs more commonly than you think. If one defines BCI as any arrhythmia or cardiac enzyme elevation, it is fairly common. However, if the definition is limited to clinically significant sequelae such as potentially malignant arrhythmia or cardiac failure, the incidence is easily less than 1% in blunt trauma patients.
  • Be aware of the usual mechanisms of injury. This is a condition caused by blunt trauma, with motor vehicle crashes causing half and pedestrians struck by them another one-third. Motorcycle crashes and falls caused the remaining 12%.
  • Diagnosis can be challenging.
    • Physical examination is usually of little help. New onset of a heart murmur may indicate a serious cardiac injury but is exceedingly rare.
    • EKG evidence of a new onset arrhythmia is important, particularly bundle branch blocks, PVCs, and ST segment / T wave changes, which require further investigation.
    • CPK-MB enzyme measurements are useless. Please don’t get them.
    • Troponin T and Troponin I are frequently used but do not reliably predict BCI. Testing in asymptomatic patients is not helpful and may result in additional asymptomatic testing.
    • Echocardiography is not indicated in asymptomatic patients with isolated enzyme elevations.
    • Cardiac CT may be used to differentiate acute MI from BCI. Frequently, patients at risk are having a chest CT with contrast performed anyway.

Here is the recommended treatment algorithm:

  1. If BCI is possible based on mechanism of injury, follow the ATLS protocols and perform a physical exam, E-FAST, and place on EKG monitoring.
  2. If the patient is hemodynamically unstable, quickly identify and treat tamponade or tension pneumothorax if present. If significant arrhythmias are present, treat with appropriate medications. If heart failure is present, treat medically and evaluate for surgical problems such as valve, septum, or coronary artery injury.
  3. If the patient is hemodynamically stable, obtain a 12 lead EKG. If significant arrythmias are present, treat with appropriate medications. If there is organ hypoperfusion, obtain an echocardiogram. If this study reveals an effusion, a pericardial window is indicated. If the echo shows hypokinesis or structural injury, appropriate medical or surgical management should be carried out.
  4. Patients who have only significant arrhythmias should be admitted to a monitored bed for 24 hours. Once arrhythmias have resolved, the patent can be discharged.
  5. Patients with nonspecific EKG changes should have troponin levels drawn after 8 hours of observation in the ED. If elevated, admit to a monitored bed for 24 hours. Once EKG and troponin have normalized, the patent can be discharged.
  6. If EKG and labs are normal, may discharge home from the ED if there are no other indications for admission.

Reference: Diagnosis and Management of Blunt Cardiac Injury: What You Need to Know. J Trauma, accepted for publication. DOI: 10.1097/TA.0000000000004216