Missed Injury / Delayed Diagnosis

Missed injuries (or delayed diagnosis in polite conversation) are the bane of any trauma program. Trauma professionals want to know that they’ve identified all significant injuries in their patients so no future harm will occur due to them.

But what exactly is a missed injury? The definitions tend to vary a bit, which is why their incidence varies so widely in the literature (1 – 39%). The simplest way to describe one is any injury that is identified after a set amount of time. But what is a reasonable time frame? Some define it as the time spent in the emergency department (highest incidence). Others count any injury found after a predetermined period of time (typically 24-48 hours). Some use even longer time intervals, so they obviously look the best and have the lowest incidence.

And what are the factors that contribute to us “missing” these injuries? As you can imagine, there are quite a few, but they boil down to two major categories:

  • Inadequate diagnostic technique (physical exam and/or technology) – I can’t see it
  • Inadequate recognition – I didn’t think of it

A good physical exam with the focused use of appropriate imaging is paramount. Sure, you could use a shotgun approach and just scan everything. The problem is that CT scans have limitations, but we tend to forget that. So we believe that if we don’t see anything on scan, it must not exist. Wrong! The physical exam may pick up suspicious findings that tell the clinician that a specialized study is necessary to rule a potential injury out.

The failure to recognize that an injury is present can occur with everyone that “touches” the patient. The EMT or physician may not appreciate a subtle injury. The radiologist may miss a problem on the images they read. The surgeon might even fail to notice another injury separate from the one she is operating for. Obviously, experience plays a large part in this factor. Students will fail to appreciate a potential injury that a senior clinician will detect rapidly.

What to do about it? In my next post, I’ll review a paper that tries to correlate missed injuries with time of admission. And finally, I’ll discuss some strategies to try to help keep it from happening to you.

Trauma Patient Mortality In ALS vs BLS Prehospital Transport

There is a presumption that more education and attainment of more advanced skills lead to greater expertise in just about any field. The same argument holds true for prehospital provider training. Training to be an ALS provider (advanced EMT or paramedic) should add extra value in patient care over and above BLS training (emergency medical responder or EMT).

One way to measure that added value is by comparing trauma patient mortality across those levels of training. Paradoxically, many studies have shown either no benefit or an actual increase in mortality. How does this make sense? Some have speculated that the advanced training leads providers to “stay and play” and use the skills that they have learned. Other possibilities include study design issues (low subject numbers) or failure to consider some unknown variables that impact mortality.

A paper published just this month from Hennepin County Medical Center in Minneapolis examined this phenomenon more closely to determine whether this effect is real or whether other factors are involved. They performed a retrospective study of a nationwide database of prehospital ground transports, selecting records that involved only injured patients. Only patients with documented ALS or BLS providers who were transported to Level I or II trauma centers were included. The ratio of ALS to BLS transports was about 15:1, so propensity matching was performed to create equal groups for comparison.

Here are the factoids:

  • A total of 1,154 matched pairs were available for study,
  • Overall, mortality was significantly lower in the patient group transported by ALS providers
  • Mortality was also significantly lower in older patients (age > 50) and those with mechanisms other than falls
  • There was no statistical difference in patients with falls or in those with prolonged transport times

The authors concluded that more advanced prehospital training is associated with survival. They recognized that there are many factors in the care process that are not captured in the usual databases that may have an impact on survival.

Bottom line: This study was nicely designed and well-executed. It has the largest subject pool of any of the papers published on this topic. It shows that survival is higher when ALS providers transport the patient. But keep in mind that it does not show causality. We don’t know exactly why this is true. It could certainly be the advanced education, but there is still the possibility of other variables that we either haven’t thought of or are not captured in the available databases. But until we know better, we should encourage all EMS providers to up their game, and skill level! 

Reference: Emergency medical services level of training is associated with mortality in trauma patients: A combined prehospital and in-hospital database analysis. Journal of Trauma and Acute Care Surgery ():10.1097/TA.0000000000004540, January 9, 2025.

Direct Oral Anticoagulant (DOAC) Reversal: Part 3

In my last two posts, I reviewed some older papers on the efficacy of Andexxa (andexanet alfa) for the reversal of Factor Xa inhibitor anticoagulants. Those results were not very impressive, especially considering the high cost of this drug.

In 2021, an article was published (reference 1) that performed a systematic review of the literature from 2017 to 2020. It concluded that “available evidence does not unequivocally support the clinical effectiveness of andexanet alfa or prothrombin complex concentrate to reverse factor Xa inhibitor-associated acute major bleeding.” This is a very roundabout way of saying that it didn’t really work. The authors also set out to perform a meta-analysis but could not do so, given the data’s low quality.

However, 2024 was a banner year for systematic reviews of this type of study! Four of them with meta-analyses were published comparing andexanet alfa (AA) with 4-factor prothrombin complex concentrate (PCC). And to keep it confusing, the conclusions were highly variable. Results were evaluated based on successful anticoagulation (hemostatic efficacy), mortality, and thrombotic complications. I also closely reviewed the conflict of interest information if any of the authors had any relationship to AstraZeneca, which owns both AA and the anticoagulant it reverses (Andexxa).

The results were very interesting. Here is a table that condenses the key points.

Reference # Hem. Effic. Mort. Thrombosis Conflict
2 AA better No diff. AA higher No
3 —– No diff. AA higher No
4 No diff. No diff. AA higher. Yes
5 AA better AA lower No diff. Yes

Many of the same original studies were analyzed in more than one of these reviews. And unfortunately, the results and confidence intervals were mysteriously a bit different in each review.

I specifically highlighted the efficacy and thrombosis results in red in Paper #4 because the authors stated that the efficacy of AA was qualitatively higher and the thrombotic complications the same. But their analysis in the body of the paper suggested otherwise. These were qualitative trends and are overhyped in the section most people read in PubMed, the abstract. My red text reflects how the abstract should have read. This is very misleading.

I also find it interesting that paper #5, with five of the nine authors either employed by or speaking for the company, was the only one that found the AA mortality lower and the thrombotic events no different than PCC. I believe this represents significant bias, and I find it hard to believe that the authors would be allowed to publish a negative or even neutral study about a drug that their company owns.

Bottom line: Who to believe?

Restoring clotting: Most of these studies indicated that andexanet alfa may restore hemostasis more effectively.

Preventing death: This drug doesn’t appear to reduce mortality, which is the outcome we are most interested in when treating these patients.

Thrombotic complications. These do seem to be more common when AA is given.

And even after ten years, cost is still a major consideration. The average cost of a course of treatment in 2023 was $26,787 (ref 6). Can we justify such an expense if it doesn’t seem to save lives? This is a decision that you and your hospital administration will have to work out. At least until much, much better data comes along.

References:

  1. Andexanet Alfa or Prothrombin Complex Concentrate for Factor Xa Inhibitor Reversal in Acute Major Bleeding: A Systematic Review and Meta-Analysis. Crit Care Med. 2021 Oct 1;49(10):e1025-e1036. doi: 10.1097/CCM.0000000000005059. PMID: 33967205.
  2. Efficacy and Safety of Andexanet Alfa Versus Four Factor Prothrombin Complex Concentrate for Emergent Reversal of Factor Xa Inhibitor Associated Intracranial Hemorrhage: A Systematic Review and Meta-Analysis. Neurocrit Care. 2024 Oct 8. doi: 10.1007/s12028-024-02130-y. Epub ahead of print. PMID: 39379749.
  3. Andexanet alpha versus four-factor prothrombin complex concentrate in DOACs anticoagulation reversal: an updated systematic review and meta-analysis. Crit Care. 2024 Jul 5;28(1):221. doi: 10.1186/s13054-024-05014-x. PMID: 38970010; PMCID: PMC11225147.
  4. Andexanet Alfa versus Four-Factor Prothrombin Complex Concentrate for the Reversal of Factor Xa (FXa) Inhibitor-Associated Intracranial Hemorrhage: A Systematic Review of Retrospective Studies. J Clin Med. 2024 May 24;13(11):3077. doi: 10.3390/jcm13113077. PMID: 38892788; PMCID: PMC11173120.
  5. Andexanet alfa versus PCC products for factor Xa inhibitor bleeding: A systematic review with meta-analysis. Pharmacotherapy. 2024 May;44(5):394-408. doi: 10.1002/phar.2925. Epub 2024 May 9. PMID: 38721837.
  6. Cost information link

Direct Oral Anticoagulant (DOAC) Reversal: Part 2

In the previous post, I reviewed some basic information on DOAC reversal. Five years ago, it was costly and questionably effective. So what has happened in the meantime?

In this post, I’ll review a big trial the pharma company was excited about and make a few comments.

ANNEXA-I Study

This study sought to evaluate the hemostatic effect of Andexanet administration in patients taking a Factor Xa inhibitor who suffered an intracranial hemorrhage.

Key points in this study:

  • It was a five-year, multicenter, randomized controlled trial
  • Subjects had to have taken their medication within 15 hours of the event, had an intracranial hemorrhage identified by CT within 12 hours of symptoms, and randomized in the study within two hours after the scan
  • There were 263 patients reversed with Andexanet and 267 with “usual care,” which was not clearly defined aside from administration of prothrombin complex concentrate (PCC)
  • Traumatic ICH was only present in about 13% of subjects, and the average volume was about 10 mL. Most were intracerebral hemorrhages (90%), with 5% or less being subdural hematomas.
  • Andexanet treatment was associated with increased “hemostatic efficacy,” a combination variable consisting of volume change, change in NIH Stroke Scale score, and no need for rescue therapy within 12 hours.   There was also decreased hematoma volume change by 3.8mm (12%), an increased number of thrombotic events (10% vs. 6%), and an increased number of ischemic strokes (6.5% vs. 1.5%) at 30 days. There was no difference in deaths at 30 days.
  • Hemostatic efficacy was highest in intracerebral hemorrhages and nearly ineffective for subdural hematomas
  • Hemostatic efficacy was significantly higher than that of patients who received PCC in the “usual care” arm, but it was no better than usual care without PCC (?)

Bottom line: Wow! That’s a lot of numbers. The company was excited because the trial was stopped early due to “superior [hemostatic] efficacy vs usual care.” Basically, what they are saying is that the combination of hematoma size, stroke scale, and lack of need for other rescue therapy was significantly lower in patients treated with andexanet alfa. 

But is this meaningful in trauma? There are several issues, IMHO:

  • The study was not powered to detect mortality or functional outcome differences, which is what we trauma people are really interested in
  • The primary outcome (hemostatic efficacy) was powered mainly by hematoma size change, which is not of any clear clinical significance
  • There were some shenanigans from company involvement in the study design, with several protocol amendments that occurred
  • It was not clear what “usual care” consisted of other than PCC administration in some patients
  • There was no information on costs

In my next post, I’ll cite several systemic reviews and meta-analyses to come to some final conclusions about this drug.

Reference: Andexanet for factor xa Inhibitor–Associated acute intracerebral hemorrhage. N Engl J Med. 2024;390(19):1745-1755.

Direct Oral Anticoagulant (DOAC) Reversal: Part 1

A new class of anticoagulants, the direct oral anticoagulants (DOACs), were introduced in 2010.  I started writing about them more than five years ago and was initially pessimistic about their safety profile in patients with head injuries. However, reversal agents and/or protocols were introduced, and the literature has borne out the fact that they appear to be safer than the old stand-by warfarin.

The most recent DOAC reversal agent, Andexxa (andexanet alfa), was approved in 2018. Today, I will republish a post on this agent five years ago and a year after the FDA approved it.  In my next post, I’ll refresh and update the trial data and cost, and review several systemic reviews with meta-analyses to come up with a consensus on its usefulness.


Here’s the repost:

Two classes of direct oral anticoagulant drugs (DOACs) are currently available: direct thrombin and Factor Xa inhibitors. Andexxa was designed to reverse the latter by providing a lookalike of Factor Xa to selectively bind to apixaban (Eliquis) and rivaroxaban (Xarelto).

The Austrian consensus paper I previously discussed recommended giving Andexxa to patients taking apixaban or rivaroxaban if it was not possible to show that the drugs were non-therapeutic. This means that reversal should be considered if your lab could not measure anti-Factor Xa levels promptly and the patient was known to be taking one of these agents.

Sounds cut and dried, right? Your patient is taking a Factor Xa inhibitor, and they are bleeding, so give the reversal agent. Unfortunately, it’s much more complicated than that.

  • The half-life of Andexxa is much shorter than that of the drugs it reverses. The reversal effect of Andexxa begins to wear off two hours after administration and is gone by four hours. On the other hand, the half-life of rivaroxaban is 10+ hours in the elderly. The half-life of apixaban is even longer, 12 hours. This means that it is likely that multiple doses of Andexxa would be necessary to maintain reversal.
  • There are no studies comparing the use of Andexxa with the current standard of care (prothrombin complex concentrate, PCC). The ANNEXA-4 study tried to do this. It was a single-arm observational study with 352 subjects. These patients were given Andexxa if major bleeding occurred within 18 hours of their DOAC dose. Two-thirds of the patients had intracranial bleeding. All were given a bolus followed by a two-hour drip. All showed dramatic drops in anti-Factor Xa levels, and 82% of patients had good or excellent hemorrhage control. However, 15% died, and 10% developed thrombotic complications.
  • The FDA clinical reviewers recommended against approval due to the lack of evidence for clinical efficacy. The director for the Office of Tissues and Advanced Therapies overruled the reviewers and allowed approval until a definitive study was completed. So far, there have been no justifiable claims that Andexxa is superior to PCC.
  • To be fair, PCC has not been compared to placebo either. So, we don’t really know how useful it is when treating bleeding after DOAC administration.
  • Andexxa is very expensive. Old literature showed a single dose price of $49,500, which has been revised downward. Effective October 2019, Medicare agreed to reimburse a hospital about $18,000 for Andexxa over and above the DRG for the patient’s care. Remember, two doses may be needed due to the long half-life of the Factor Xa inhibitors. This comes to about $36,000, which is much higher than the cost for PCC (about $4,000).

Bottom line: Any hospital considering adding Andexxa to their formulary should pay attention to all the factors listed above and do the math for themselves. Given the growing number of patients placed on DOACs, the financial and clinical impact will continue to grow. Is the cost and risk of this therapy justified by the meager clinical efficacy data available?

References:

  1. Full Study Report of Andexanet Alfa for Bleeding Associated with Factor Xa Inhibitors. NEJM 380(14):1326-1335, 2019.
  2. Key Points to Consider When Evaluating Andexxa for Formulary Addition. Neurocrit Care epub ahead of print, 22 Oct 2019.

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