Category Archives: Resuscitation

Best of EAST 2023 #2: REBOA In Cardiac Arrest

January 3, 2023 The Trauma Pro Leave a comment

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) remains one of the shiny new trauma toys. Yet, with nearly a decade of human study, we are still struggling to define the right patients to benefit from it.

A group of REBOA superfans sought to perform a secondary analysis of a research database from the US Department of Defense of patients at six Level I centers in the US. It contained outcomes of patients in hemorrhagic shock due to non-compressible bleeding below the diaphragm. The authors analyzed the subset of patients who presented in cardiac arrest and underwent either REBOA or resuscitative thoracotomy (RT).

Here are the factoids:

There were 454 patients in the database, and 72 underwent either REBOA or RT
REBOA patients were significantly older (46 vs. 35 years) and were more commonly victims of blunt injury (81% vs. 46%)
AIS for abdomen was lower in the REBOA group, but AIS head and chest were the same
Times from arrival to aortic occlusion and to procedure completion were significantly longer in the REBOA group
REBOA patients received more red cells and plasma in the ED, but 24-hour transfusions were the same
Mortality was the same between REBOA and RT, and did not change even after some statistical magic

The authors concluded that REBOA was not associated with a survival or transfusion advantage in patients already in arrest.

Bottom line: I was amazed to see a negative result from a group who tend to be avid REBOA cheerleaders. And although the abstract conforms to my own bias about REBOA, there are several things to consider here.

First, the sample size is very small. A total of 72 patients from the database fit the cardiac arrest on arrival criterion. There is also no information on prehospital arrest duration for the patients. The dead tend to stay dead despite just about any intervention.

Here are my questions for the presenter and authors:

Have you performed a power analysis to determine how many patients were needed to show real differences between the groups? Were you getting close with the 72, or a lot more needed?
Also, you did not break down how many of the 72 patients were in the REBOA vs RT groups. Please provide those numbers.
Were you able to determine how long the patients had been in arrest before arrival? This could definitely influence survival rates.
Did you analyze the subset of survivors in each group? You noted that times to procedure start and completion were longer with REBOA. Did the survivors get to aortic occlusion sooner? Could you identify any subjective factors that seemed associated with their survival?

I wouldn’t get too depressed yet about the efficacy of REBOA in these patients. This study just tells us that REBOA is not a miracle cure for cardiac arrest, but we can still continue to learn more about this device and which patients it is best suited for.

Reference: REBOA AND RESUSCITATIVE THORACOTOMY ARE ASSOCIATED WITH SIMILAR OUTCOMES AFTER TRAUMATIC CARDIAC ARREST. EAST 2023 podium abstract #11.

Resuscitation

How To Remember Those “Classes of Hemorrhage”

October 14, 2022 The Trauma Pro Leave a comment

The Advanced Trauma Life Support course lists “classes of hemorrhage”, and various other sources list a similar classification for shock. I’ve not been able to pinpoint where these concepts came from, exactly. But I am sure of one thing: you will be tested on it at some point in your lifetime.

Here’s the table used by the ATLS course:

classes_of_shock

The question you will always be asked is:

What class of hemorrhage (or what % of blood volume loss) is the first to demonstrate systolic hypotension?

This is important because prehospital providers and those in the ED typically rely on systolic blood pressure to figure out if their patient is in trouble.

The answer is Class III, or 30-40%. But how do you remember the damn percentages?

multiscore-maxi1

It’s easy! The numbers are all tennis scores. Here’s how to remember them:

Class I	up to 15%	Love – 15
Class II	15-30%	15 – 30
Class III	30-40	30 – 40
Class IV	>40%	Game (almost) over!

Bottom line: Never miss that question again!

Complications, Resuscitation

Are Transfusing Too Much Blood During The MTP?

August 12, 2022 The Trauma Pro Leave a comment

The activation of the massive transfusion protocol (MTP) for hypotension is commonplace. The MTP provides rapid access to large volumes of blood products with a simple order. Trauma centers each design their own protocol, which usually includes four to six units of PRBC per MTP “pack.”

This rapid delivery system, coupled with rapid infusion systems, allows the delivery of large volumes of blood and other blood products very quickly. But could it be that this system is too slick, and we are a bit too zealous, and could even possibly transfuse too much blood?

The trauma group at Cedars-Sinai in Los Angeles retrospectively reviewed their own experience via registry data with their MTP over a 2.5 year period for evidence of overtransfusion. All patients who received blood via the MTP were included. Patients who had a continuous MTP > 24 hours long, those who died within 24 hours, and those who had a missing post-resuscitation hemoglobin (Hgb) were excluded.

The authors arbitrarily defined overtransfusion as a Hgb > 11 at 24 hours. They also compared the Hgb at the end of the MTP and upon discharge with this threshold. They chose this Hgb value because it allows for some clinical uncertainty in interpreting the various endpoints to resuscitation.

Here are the factoids:

240 patients underwent MTP during the study period, but 100 were excluded using the criteria above, leaving 140 study patients
Average injury severity was high (24) and 38% suffered penetrating injury
Median admission Hgb was 12.6
At the conclusion of the MTP, 71% were overtransfused using the study definition, 44% met criteria 24 hours after admission, and 30% did at time of discharge
Overtransfused patients were more likely to have a penetrating mechanism, lower initial base excess, and lower ISS (median 19)

The authors concluded that overtransfusion is more common than we think. This may lead to overutilization of blood products, which has become much more problematic during the COVID epidemic. They recommend that trauma centers track this metric and consider it as a quality of care measurement.

Bottom line: This is a nicely crafted and well-written study. It asks a simple question and answers it with a clear design and analysis. The authors critique their own work, offering a comprehensive list of limitations and a solid rationale for their assumptions and conclusions. They also offer a good explanation for their choice of Hgb threshold in defining overtransfusion.

I agree that overtranfusion truly does occur, and I have seen it many times first-hand. The most common reason is the lack of well-defined and reliable resuscitation endpoints. How do we know when to stop? What should we use? Blood pressure? Base excess? TEG or ROTEM values? There are many other possibilities, but none seem reliable enough to use in every patient.

Patients with penetrating injury proceeding quickly to OR more commonly experience overtransfusion. This may be due to the reflexive administration of everything in each cooler and the sheer speed with which our rapid infuser technology can deliver products. The more product in the cooler, the more that is given, which may lead to the overtranfused condition.

The authors suggest reviewing the makeup of the individual MTP packs, and this makes sense. Are there too many in it? This could be a contributing factor to overtransfusion. It might be an interesting exercise to do a quick registry review at your own center to obtain a count of the number of MTP patients with a final Hgb > 11. If you find that your numbers are high, consider reducing the number of red cell packs in the cooler to just four. But if you already only include four, don’t reduce it any further. And in any case, critically review the clinical indicators your surgeons use to decide to end the MTP to see if, as a group, they can settle on one to use consistently.

Reference: Overtransfusion of packed red blood cells during massive transfusion activation: a potential quality metric for trauma resuscitation. Trauma Surg Acute Care Open 7:e000896., July 26 2022.

Resuscitation

When To Stop The Massive Transfusion Protocol

May 10, 2022 The Trauma Pro Leave a comment

Initiating the massive transfusion protocol (MTP) is generally easy. Some centers use the Assessment of Blood Consumption score (ABC). This consists of four easy parameters:

Heart rate > 120
Systolic blood pressure < 90
FAST positive
Penetrating mechanism

The presence of two or more indicators reliably predicts a 50% chance of needing lots of blood.

The shock index (SI) is also used. It’s more quantitative, just divide the heart rate by the systolic blood pressure. The normal value is < 0.7. As it approaches 0.9, the risk for massive transfusion doubles. This technique requires a little calculation, but is easily doable.

Or you can just let your trauma surgeons decide when to order it. Unfortunately, this sometimes gets forgotten in the mayhem.

However it got started, your MTP is now humming right along. How do you know when to stop? This is much trickier, and unfortunately can’t be as easily quantified. Here are the general principles:

All surgical bleeding must be controlled. Hopefully your patient didn’t get too cold or acidotic during the case, resulting in lots of difficult to control nonsurgical bleeding (oozing).
Hemodynamics are stabilizing. This doesn’t necessarily mean they are quite normal yet, just trying to approach it.
Vasopressors are off, or at least being weaned.
Volume status is normalizing. You may need an echo to help with this assessment.

If you have TEG, it probably wasn’t very useful. Until now. This is the ideal time to run a sample so you can top off any specific products your patient might need.

If you don’t have TEG, get a full coag panel including CBC, INR, PTT, lytes with ionized calcium.

Once the patient is in your ICU, continue monitoring and tweaking their overall hemodynamic and coagulation status until they are approaching normal. Then watch out for additional insults or any new and/or unsuspected bleeding. If this does occur, the threshold for return to the OR should be low. Unfortunately it is common for arteries in spasm to resume bleeding after warming and vasodilation.

When you are finally satisfied that there is no more need for the MTP, let your blood bank know so they can start restocking products and getting ready for the next go around!

Resuscitation

Blunt Traumatic Arrest In Kids: Are They Little Adults?

April 8, 2022 The Trauma Pro Leave a comment

Over and over, we hear that children are not just little adults. They are a different size, a different shape. Their “normal” vital signs are weird. Drug doses are different; some drugs don’t work, some work all too well.

But in many ways, they recover more quickly and more completely after injury. What about after what is probably the biggest insult of all, cardiac arrest after blunt trauma? The NAEMSP and the ACS Committee on Trauma previously released a statement regarding blunt traumatic arrest (BTA):

“Resuscitation efforts may be withheld in any blunt trauma patient who, based on out-of-hospital personnel’s thorough primary patient assessment, is found apneic, pulseless, and without organized ECG activity upon arrival of EMS at the scene.“

The groups specifically point out that the guidelines do not apply to the pediatric population due to the scarcity of data for this age group.

The Children’s Hospital of Los Angeles and USC conducted a study of the National Trauma Data Bank, trying to see if children had a better outcome after this catastrophic event. Patients were considered as children if they were up to and including age 18.

Here are the factoids:

Of 116,000 pediatric patients with blunt trauma, 7,766 had no signs of life (SOL) in the field (0.25%)
The typical male:female distribution for trauma was found (70:30)
75% of those without SOL in the field never regained them. Only 1.5% of these survived to discharge from the hospital.
25% regained SOL with resuscitation, and 14% of them were discharged alive.
499 patients underwent ED thoracotomy, and only 1% survived to discharge. There was no correlation of thoracotomy with survival.
It appeared that there was a tendency toward survival for the very young (age 0-4) without SOL, but statistical analysis did not bear this out

Bottom line: Children are just like little adults when it comes to blunt cardiac arrest after trauma. Although it is a retrospective, registry-based study, this is about as big as we are likely to see. And don’t get suckered into saying “but 1.5% with no vital signs ever were discharged!” This study was not able to look at the quality of life of survivors, but there is usually significant and severe disability present in the few adult survivors after this event.

Feel free to try to re-establish signs of life in kids with BTA. This usually means lots of fluid and/or blood. If they don’t respond, then it’s game over. And, like adults, don’t even think about an emergency thoracotomy; it’s dangerous to you and doesn’t work!

Reference: Survival of pediatric blunt trauma patients presenting with no signs of life in the field. J Trauma 77(3):422-426, 2014.

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