Tag Archives: EAST2024

Abstracts

Best Of EAST 2024 #4: Chest Tube Irrigation Prevents Retained Hemothorax

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One of the potential complications of chest trauma causing hemothorax is the retained hemothorax. In most patients, retained blood slowly lyses and is reabsorbed. But a few do not, and scarring can occur that entraps the lung and interferes with pulmonary function. This can ultimately require a VATS or thoracotomy to resolve.

Several protocols have been developed to try to prevent a retained hemothorax. They include the use of lytics or an early VATS procedure. The group at the Medical College of Wisconsin performed a trial of thoracic cavity irrigation and compared the outcomes with patients who did not undergo irrigation. This was a single-center retrospective study performed over five years.

This appears to have been a common practice at this institution. Patients undergoing chest tube placement for hemothorax received irrigation of the chest cavity immediately after placement. The study excluded patients with chest tubes placed in other hospitals, tubes placed late (after 24 hours), or patients who had a chest procedure within 6 hours.

Here are the factoids:

  • A total of 370 patients were enrolled, and 225 (61%) received irrigation
  • Demographics of the groups were the same, with the exception that the irrigation group contained more patients with penetrating injury and fewer patients with flail chest
  • Use of irrigation was associated with significantly less incidence of retained hemothorax (10% vs 21%) or need for VATS (6% vs. 19%)
  • Chest tube duration (4 vs 6 days) and hospital length of stay 8 vs 10 days) were also significantly shorter

The authors concluded that irrigation prevents retained hemothorax and decreases the need for surgical intervention.

Bottom line: Well, this was a new one for me. The only prior study I could find was published in 2022 by a group at the University of Nevada at Las Vegas. They irrigated 82 of 198 patients undergoing chest tube placement. They noted a decrease in hospital, ICU, and ventilator days.

This study looks at something far more practical: interruption of the development of a complication. Although still a relatively small and single-institution study, it was well done and could easily detect statistical significance. 

The presenter should be prepared to discuss what impact the mechanism of injury (penetrating, flail chest) may have had on their results and the exact technique they used. How much fluid, what type, and how it was drained are all important questions to discuss.

This is a fascinating abstract indeed. If the presentation answers the questions, centers should consider updating their chest tube management algorithms.

References:

  1. Thoracic cavity irrigation prevents retained hemothorax and decreases surgical intervention in trauma patients. EAST 2024, Podium paper #17.
  2. The Volume of Thoracic Irrigation Is Associated With Length of Stay in Patients With Traumatic Hemothorax. J Surg Res. 2022 Nov;279:62-71.
Abstracts

Best of EAST 2024 #3: VTE Prophylaxis For Pediatric Trauma

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Venous thromboembolism (VTE) after trauma in adults has generated a considerable body of literature for guidance. However, there is much less information available regarding pediatric trauma. High-risk criteria for pediatric VTE after trauma have recently been released.

These criteria have not yet been evaluated prospectively or coupled with the administration of chemoprophylaxis. The Medical College of Wisconsin trauma group organized a prospective, multi-institutional study involving eight pediatric trauma centers. They studied VTE events within 30 days and bleeding complications. The children were stratified into three groups: no prophylaxis, early prophylaxis (within 24 hours), and late prophylaxis.

Here are the factoids:

  • A total of 460 patients were enrolled during a three-year period
  • The number of VTE events was very low at 25 (5.4%)
  • Patients who developed VTE had a median of 4 of the high-risk criteria, most commonly ICU stay>48 hours and TBI.
  • Half of patients received prophylaxis
  • VTE occurred in 1.6% receiving an early dose and 6.7% with late dosing
  • There were no bleeding complications

The authors concluded that prophylaxis in children at high risk for VTE was safe, but they could not demonstrate any risk reduction for those who had received chemoprophylaxis compared to those who had not.

Bottom line: This is another study that was cursed by low numbers. See the breakdown chart below:

There is a trend toward higher VTE in children receiving prophylaxis late or never. However, the number of subjects is far too low to detect significance. The good news is that there were no bleeding events in this modest sample of 257 patients. 

So what next? The authors state that “further subgroup analysis is ongoing to refine the high-risk criteria.” Good luck with that because subgrouping will deplete the numbers even further.

There are several things the authors could do to improve this work:

  • Get more subjects! Increase the number of centers participating, and consider sending it through the EAST Multicenter Trial process.
  • Streamline the list of high-risk criteria. There are quite a few of them. Try to focus on the most obvious ones and make sure each one has clear definitions. And set a threshold of how many must be present to trigger chemoprophylaxis.
  • Define the pediatric patient precisely. As children approach puberty, they behave more like adults as it pertains to VTE. State an explicit age cutoff.

This presentation should be a springboard to soliciting help from other pediatric trauma centers so this group can return to this meeting with compelling information.

Reference: The No Clot VTE study in high-risk pediatric trauma patients. EAST 2024 Podium paper #6.

Abstracts

Best of EAST 2024 #2: Prehospital End Tidal CO2 And Fibrinolysis

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Coagulopathy is the bane of every trauma professional. Trauma patients are bleeding to death until proven otherwise, and once they start bleeding, it only gets worse. A key component of this issue is the presence of fibrinolysis, which commonly occurs after severe trauma. Although the prime objective in managing these patients is definitive control of bleeding, antifibrinolytic therapy such as tranexamic acid (TXA) may be beneficial during the time before that can happen.

The trauma group at Denver Health has been studying fibrinolysis and finding things to do with TEG machines for many years. They postulated that, since hemorrhagic shock can cause hyperfibrinolysis (HF) and early administration of agents like TXA seem to work better when given early, wouldn’t it be nice to have a more objective way of identifying it as early as possible?

They designed a prehospital study that used end-tidal CO2 monitoring in the ambulance and correlated results with a TEG reading upon arrival at the hospital.  The study was prospective and observational and involved two Level I trauma centers. End-tidal CO2 was measured from the ventilator circuit or via nasal cannula capnography. The authors compared this reading to other possible shock indicators, such as systolic blood pressure and the shock index.

Here are the factoids:

  • A total of 138 patients were studied, and 13 had hyperfibrinolysis identified on hospital arrival
  • Of the 13, 9 required massive transfusion, and eight died
  • An ETCO2 value <17 mm Hg was determined to have a positive predictive value of 27% and a negative predictive value of 95%
  • The area under the receiver operating characteristic curve was 0.71, which was better than the blood pressure (0.58) and shock index (0.54)

The authors concluded that the ETCO2 was an accurate, objective, inexpensive, and noninvasive method of measuring the risk of hyperfibrinolysis that could guide the use of agents such as TXA.

Bottom line: A lot is going on in this abstract. The central concept is that it is trying to identify a surrogate for TEG-identified fibrinolysis available in the field. It compares ETCO2 with two other semi-objective indicators, blood pressure and shock index (pulse divided by blood pressure).

The biggest issue is that the number of patients with fibrinolysis was very small, only 13. Statistical comparisons of variables between the two groups are difficult because the number of HF patients in several subgroups was only 4 or 5. 

The sensitivity, specificity, and positive/negative predictive values are so-so. If the ETCO2 is above the 17mm Hg threshold, the likelihood of patients not having HF is good at 95%. But if it is below, the likelihood that they actually have HF is only 27% (true positive rate).

The area under the curve calculations is also not very impressive. Yes, an AUC of 0.71 is better than 0.54-0.58, but it is still not great.

One always has to be careful finding surrogates (ETCO2) for things you really want to measure (TEG LY30 > 3%). Many potential confounders can limit their usefulness. And this case is no different, which should be apparent from the numbers. Perhaps the data would be better if a much larger group of patients were studied. Unfortunately, this will probably take close to 1,000 subjects and require a multicenter trial. 

This is interesting preliminary work. It’s definitely not enough to change practice now. But with more work, and more patients, who knows?

Reference: Prehospital ETCO2 predicts hyperfibrinolysis in injured patients: implications for early use of antifibrinolytics in trauma. EAST 2024 Podium paper 3.

Abstracts

Best of EAST 2024 #1: MAP And Spinal Cord Injury

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The use of elevated mean arterial pressure (MAP) to help manage spinal cord injury has been a mainstay of treatment for years. The concept is similar to that used for management of severe traumatic brain injury. The theory is that there may be areas of the brain that are damaged, but not irretrievably so. Increasing MAP should improve perfusion and may protect areas in jeopardy from secondary injury.

As with so much in neurotrauma, few large and/or prospective studies exist. Although most centers have specific algorithms and MAP goals, optimal treatment still needs to be determined.

EAST sponsored a prospective, multicenter study to identify factors influencing neurologic outcomes after spinal cord injury. MAP augmentation was monitored, specifically its impact on the American Spinal Injury Association (ASIA) score between admission and discharge.

The ASIA Score is calculated by performing a very detailed exam consisting of myotomal motor function, a dermatomal sensory exam, and an anorectal exam. The exam takes quite some time to complete. The copy of the worksheet below should give you an idea of the level of detail:

The study was performed over 20 months, and 19 centers participated. They entered 222 patients, but only 164 had pre- and post-ASIA scores for comparison.

Here are the factoids:

  • Of the 164 patients studied, only 36 improved vs. 128 that showed no improvement by ASIA score
  • Demographics, hospital and ICU length of stay, and mortality were not significantly different between the groups
  • ISS was nearly identical (23 vs 25)
  • Three-quarters of injuries were to the cervical spine, about 10% to the lumbar spine, and the remainder to the thoracic spine. There was no correlation between injury location and recovery.
  • Presentation in the trauma bay (blood pressure, pulse, MAP, lactate, and Hgb) were the same in both groups
  • The MAP goal of >85 mm Hg was met about 75% of the time in both groups
  • Duration of MAP therapy was the same for the two groups, from 99-113 hours
  • There was a trend toward increased cardiac issues (atrial fibrillation, v-tach, elevated troponin) in the group with improved spinal cord recovery. This may be due to the medications used to increase MAP.

Bottom line: This is very interesting work and will make us question the utility of MAP therapy for spinal cord injury. However, this is not a cut-and-dried conclusion. Here are several things that come to mind:

  • What was the definition of “improvement?” ASIA is a complicated scoring system with many steps in the evaluation. Usually, the results are condensed into an overall “ASIA Impairment Scale,” or AIS.
    The AIS is not very granular, meaning that each step in the scale represents a large difference in function. Could patients have had improvements that did not change the AIS score but were functionally significant for the patient? For example, an improvement from a C5 to a C6 level makes a big difference in daily activities.
  • Was the study large enough? It is difficult to accumulate a large series of spinal cord injury patients. Combining this point with the previous one, was the statistical power present even to detect a meaningful difference in the AIS?
  • Was MAP>85 torr maintained reliably and for long enough? Patients had MAP therapy for just over four days, and it was only maintained above the threshold about 75% of the time. We have good evidence in the brain injury literature that a single bout of hypotension in patients with severe TBI significantly increases mortality. Could it be that maintaining increased spinal cord perfusion is equally important? Could a single low MAP cause damage? It would be interesting to see if patients who had very consistent MAP therapy, say greater than 90% or 95% of the time, had any difference in outcomes. Unfortunately, I suspect that the numbers would be far too low to prove anything.

This abstract brings up some interesting questions. However, I would not consider throwing out the use of MAP goals based on it. We need more patients to study and be better at applying this treatment if we hope to uncover whether it really works.

Reference: Does mean arterial pressure augmentation improve neurological recovery of blunt spinal cord injuries: an EAST multicenter trial. EAST 2024 Podium paper #1.

Abstracts

Coming Soon! The Best Of EAST 2024

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The 37th Annual Assembly of the Eastern Association for the Surgery of Trauma is just around the corner! And, as in previous years, I will be publishing regular posts on some of the abstracts I find the most interesting. Here are some of the topics I’ve selected:

  • MAP and spinal cord injury
  • VTE in pediatric patients
  • Chest irrigation and retained hemothorax
  • Accuracy of eFAST
  • More on the 35mm rule for pneumothorax
  • Pan-scanning and missed injuries
  • King Airway vs i-Gel Airway
  • Whole blood transfusion in pediatric patients
  • Whole blood and VTE risk
  • VTE prophylaxis in patients undergoing acute neurosurgical intervention

For each abstract covered, I will present the findings and give a short critique. Finally, I will provide some questions for the authors to consider, as they very same ones could come from the audience at their presentation!

If you have any particular abstracts you would like me to cover, please list in the comments section below and I will get it on the list!