So real quick, here’s 3 slides I found helpful from Dr. Camilo Castillo’s talk yesterday on spine injury. I’m sure there were others, but here’s 3. Obviously these are his, so if you steal these, please reference him.

Interesting case from recently I thought I’d share… a 71 year old female brought by EMS with an unusual report (never happens, right?). Initial call went out for hip pain for the past couple days and well as shortness of breath and not acting right today. Was initially awake, alert, and speaking normally on EMS arrival but developed acute respiratory distress en route and required intubation. On arrival was tachycardic to 130s-140s and had SBP of 100s. Skin was cool and mottled appearing. No obvious external signs of trauma. Pupils equal and reactive. No reported fall but family was unsure. Pretty broad differential at this point, anywhere from PE to intracranial injury to sepsis to MI to …, especially difficult due to lack of context and inconsistent reports.

Chest xray in room 9 showed what appeared to be a widened mediastinum. To fully evaluate for PE vs dissection, we proceeded from room 9 with CTA of chest and abdomen, to also cover for intra-abdominal injury. CT head and cspine were also done and negative. Lactic was elevated at 5, WBC was 32, and troponin was 0.5. Blood pressure began to trend downward, so we continued fluids. CTAs were quickly viewed and demonstrated ascending aortic pseudoaneurysm with rupture due to penetrating ulcer, resulting in mediastinal hematoma and hemopericardium. Blood pressure continued to trend downward into the 70s systolic. We continued fluids, and started blood. Bedside US demonstrated the aforementioned hemopericardium but no signs of tamponade, so we could hold off on pericardiocentesis.. Also placed central line and started pressors. Transferred to Jewish for OR and had definitive repair.

So that went pretty quickly but had some interesting findings. Penetrating aortic ulcer is something I hadn’t seen before but usually occurs secondary to atherosclerosis. Basically the intima of the aorta becomes denuded due to atherosclerotic plaque formation and can progress through the aortic wall, leading to intramural hematoma and eventually dissection and/or perforation. Interestingly, this is not a common cause of dissection, being the initiating lesion in less than 5% of dissection.

Dissection is something we’ve all learned about and something we always have to be concerned for, as they can go pretty badly pretty quickly. Classically, these patients have “tearing chest pain radiating to the back” and are hypertensive, but as this case demonstrates that is not always the case. They can nonspecific complaints or nonspecific exams. CT is the gold standard for diagnosis, chest xray can show the widened mediastinum or obscuration of aortic knob but these are unreliable. If you have a suspicion, best to order CT and act quickly. D-dimer is also emerging as a possible screening modality, as it has demonstrated 97% sensitivity, but has poor specificity (56%). We all know the classic teaching on how to treat these as well, with rate control first (esmolol or labetalol) and BP control if needed (nitroprusside or nicardipine). However, this presumes that they are hypertensive, so what about the hypotensive patient, like we saw? Definitely something to act on quickly and correct. A 2005 study showed that hypotension is not a common characteristic of dissection (29% of patients studied), but had significantly higher mortality than patients without hypotension.

So what can cause hypotension in the dissecting patient? First off, it’s much more common in type A dissections than type B. The most common reasons for these patients to become hypotensive are acute cardiogenic failure and tamponade. The cardiogenic failure can result from involvement of the coronary arteries causing a STEMI, or from aortic valve involvement causing aortic regurgitation. If blood collects in the pericardium, it can cause tamponade, and pretty quickly at that. Tamponade is relatively rare, but has a very high early mortality. Other possible reasons for hypotension can include hypovolemia from blood loss into the chest, or spinal ischemia that can lead to a neurogenic shock.

Awesome, right? So many reasons for hypotension in an already really sick patient. Having these in mind though is very important as it guides management and can be crucial for rapid intervention. Bedside US is quick and can identify a tamponade, and quick pericardiocentesis can stabilize for surgical intervention. Early pressor use can be beneficial in acute cardiogenic or neurologic shock. Of course all of these are stabilizing measures until you can get the patient to a surgeon, but it’s always important to preserve perfusion to those vital organs. Fluids and blood can help with the possibility of volume loss, although that’s a much less common reason. Also be judicious in the patient that is in acute cardiogenic failure.

Thanks for sticking with me on that one. I’ve also included links to video for pericardiocentesis, as it is a procedure we don’t get a ton of practice with. Enjoy!

• Resources:
• Tintinalli’s Emergency Medicine 8th Edition, Chapter 59, pages 412-415
• Uptodate: Overview of acute aortic dissection and other acute aortic syndromes
• Tsai, T, et al. Clinical Characteristics of Hypotension in Patients with Acute Aortic Dissection. The American Journal of Cardiology Vol 95. January 2005
• Isselbacher, E., Cigarroa, J., Eagle, K. Cardiac Tamponade Complicating Proximal Aortic Dissection. Circulation. American Heart Association Journals. Volume 90, No 5. Novemnber 1994

In case any of you need a refresher on donning/doffing PPE, see videos below. The first is on normal PPE. Would recommend skipping to the 5 minute mark or so on the first one.

https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DbG6zISnenPg%26feature%3Dshare_email&data=02%7C01%7Cadam.ross%40louisville.edu%7Cb26b5cd106bc410bc36608d7ce7a6b82%7Cdd246e4a54344e158ae391ad9797b209%7C0%7C0%7C637204897498164783&sdata=src2WeSc06Os21NKeWiSnUC2U5u60ZSoJ37dIzHYNvo%3D&reserved=0

This video below is on the donning/doffing of PAPRs/hoods. We haven’t moved towards using these just yet, and I’ll provide some additional review/education/training in the near future, especially if we begin to push towards using them. Can skip to about the 4 minute mark on this one if you like.

First off, it’s not currently recommended to perform CT Chest on all suspected Covid patients.

If you’re doing a CT Chest for rule-out Covid-19 you must put this in the order comments/indication. If you’re scanning a patient who is under isolation precautions due to possible Covid, and order a CT PE Protocol, put Possible Covid, Rule-Out PE. The reason behind this is they’ll take the patient to the basement so that they don’t have to shut down the ED scanner. Thanks.

We had our January journal club at Vines, discussing 3 articles on different topics.

1- The first was an editorial on legal cases related to use of medical stents. The authors highlight the inter-rater difference in assessment of coronary blockages between even advanced interventional cardiologists. This has legal implications as cardiologists are prosecuted for unnecessary procedures. This article is important to EM no as much for the medical content (we don’t place stents), but for the precedent of the legal system prosecuting physicians for doing what they were trained to do.

2- The second article in Annals EM looked at 24,459 ED patients with chest pain who were deemed to require outpatient stress testing. The conclusion: “Less than one third of patients completed outpatient stress testing within the guideline-recommended 3 days after initial evaluation. More important, the low adverse event rates suggest that selective outpatient stress testing is safe. In this cohort of patients selected for outpatient cardiac stress testing in a well-integrated health system, there does not appear to be any associated benefit of stress testing within 3 days, nor within 30 days, compared with those who never received testing at all. The lack of benefit of obtaining timely testing, in combination with low rates of objective adverse events, may warrant reassessment of the current guidelines.” Notice that this does not change guidelines, but ads to the conversation on proper use of resources and how aggressively we should work up chest pain in low risk patients.

3- The final article, the 2018 flu guidelines, sound similar to prior years, with focus of testing and treatment on patients at risk for complications. They do throw in the recommendation to test “if the results might influence antiviral treatment decisions or reduce use of unnecessary antibiotics, further diagnostic testing, and time in the emergency department, or if the results might influence antiviral treatment or chemoprophylaxis decisions for high-risk household contacts.” Physicians should start treatment right away for

• Persons of any age who are hospitalized with influenza, regardless of illness duration prior to hospitalization (A-II).
• Outpatients of any age with severe or progressive illness, regardless of illness duration (A-III).
• Outpatients who are at high risk of complications from influenza, including those with chronic medical conditions and immunocompromised patients (A-II).
• Children younger than 2 years and adults ≥65 years (A-III).
• Pregnant women and those within 2 weeks postpartum (A-III).

And we can consider treatment for

• Outpatients with illness onset ≤2 days before presentation (C-I).
• Symptomatic outpatients who are household contacts of persons who are at high risk of developing complications from influenza, particularly those who are severely immunocompromised (C-III).
• Symptomatic healthcare providers who care for patients who are at high risk of developing complications from influenza, particularly those who are severely immunocompromised (C-III).

Hope everyone enjoyed Journal Club, looking forward to the February articles

Wanted to post a couple links for Transvenous Pacemaker insertion. I think it’s mentioned in at least 1 or both, but the preferred site as Tej mentioned is either the right IJ or the Left IJ, followed by the right subclavian, and lastly the left subclavian (save the left subclavian so they can put a permanent pacemaker in here).

This one is unfortunately completely silent, but is annotated well and also has the exact type of pacemaker box we have in the ED (Bay 1, bottom shelf).

This is the one Tej showed by Jess Mason @ EM:RAP.

I find myself regularly fascinated by the accuracies (and frequent inaccuracies) of our subjective findings regarding Trauma. Consider how often we hear about details, mechanism, intrusion, extrication time to name a few, and how heavily they guide both pre-hospital and ED workups.  Some interesting studies I have come across are regarding blood loss estimation.  Next time you hear report about blood loss at the scene, contemplate (and feel free to cackle and wisely reference) the following studies: 

The first, published in Prehospital Emergency Care, tested a cohort of EMTs and paramedics on estimating blood volumes spilled on to carpet and vinyl surfaces.  Blood product was poured onto these surfaces and participants estimated total volume demonstrated at six different spill sites.  Mean percent errors of 74% and 56% were calculated for initial estimations!   A similar study published in The Journal of Trauma: Injury, Infection, and Critical Care produced similar results, where only 8% of the 99 providers tested were within 20% of the actual volume, and only 24% were within 50% of actual volume.

Perhaps the more interesting feature of the first study is the post-estimation training that occurred afterwards.  One arm of the cohort returned to the initial scene where actual blood loss was revealed followed by some education on making volume estimates.  The second arm had similar education however this was performed in a classroom using slides instead of returning to the original scene.   Both groups were retested with new scenarios and both demonstrated improvement in mean percent errors to 59% (return to scene) and 45% (slides and classroom), suggesting this may be learn-able skill! 

It turns out we are not much better than our pre-hospital colleagues at blood estimation.  A study from the Western Journal of Emergency Medicine examined a cohort of 56 emergency physicians (mixed residents and attendings).  Participants were tested with 4 different scenarios where specific amounts of blood were poured onto a bedsheet, on gauze, a t-shirt and into a commode.   The mean standard error for all estimates was 116% with a range of 0% to 1233%. Only 8% tested were within 20% of the true value (sound familiar?)!

The next question I arrived at, which you may be thinking yourself, was the fact that these studies do not include scenario or vital signs.  One would expect that would result in more accurate estimates.  Unfortunately, the rabbit hole of my literature search revealed that, even equipped with additional information, both pre-hospital providers and emergency room physicians continued to be poor estimators of blood loss.  A study from The Journal of Trauma tested estimations in set amount of blood amounts (300 mL, 800 mL, and 1500 mL) in a “stable” patient and in an “unstable” patient.  Researchers found that in the stable patient (i.e. normal blood pressure and heart rate) blood loss was underestimated in larger amounts and overestimated in the 300 mL patient.  Remarkably, in the unstable patient, blood loss in both 800 and 1500 mL scenarios were underestimated.  Of the 870 estimates made, 51% were underestimated, 39% were overestimated and only 10% were exact. 

As so nicely asked in the discussion with Frank et al “one has to direct the question if visually estimated blood loss is of any pre-clinical value and worth being mentioned during handover in the emergency unit.“   Perhaps not, but there may be hope with additional training!

 References: 

1. Patton K., Funk DL., McErlean M., Bartfield JM. (2001) Accuracy of estimation of external blood loss by EMS personnel. The Journal of Trauma: Injury, Infection, and Critical Care. 50(5):914-916. 
2. Moscati, R., Billittier, AJ, Marshall, B., Fincher, M., Jehle, D., Braen, GR. (1999) Blood loss estimation by out-of-hospital emergency care providers. Prehospital Emergency Care, Jul-Sep;3(3): 239-42. 
3. Ashburn, J. C., Harrison, T., Ham, J. J., & Strote, J. (2012). Emergency physician estimation of blood loss. The western journal of emergency medicine, 13(4), 376-9. 
4. Frank M., Schmucker U, Stengel D, Fischer L, Lange J, Grossjohann R, Ekkernkamp A, Matthes G. (2010) Proper estimation of blood loss on scene of trauma: tool or tale? The Journal of Trauma. Nov;69(5):1191-5.