Podcast Episodes : Emergency Medicine News

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EM Logic with Brady Pregerson, MD

The EM Logic Podcast was born of 20 years of observation that errors in medicine often occur not because of limited knowledge or being unaware of the latest literature but because the provider was on autopilot or failed to use basic logic in decision-making.

EM Logic is meant to complement but never replace what health care providers learn in medical school, residency, and the evidence-based literature. It is meant to get you thinking rather than just following management algorithms you have learned during your career.

Dr. Pregerson will focus on the pitfalls of confusing cause with coincidence, being falsely reassured by normal tests, and getting burned by illogical assumptions. He hopes it will improve the care you provide and your patients’ outcomes, and keep you from being an honored guest at your department’s next peer review meeting.

Dr. Pregerson has been practicing emergency medicine since 2000, lecturing and writing about medical topics since 2004, and has reviewed more than 180 malpractice cases since 2008. He is the author of three EM pocket references, the creator of EMresource.org and EM1minuteconsult.com, and the author of the EMN column BradyCardia (http://bit.ly/BradyCardiaEMN.

If you would like to be considered as a guest on a future episode, contact Dr. Pregerson at [email protected]

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Original music by David Kirshman. All rights reserved.

Creator: Brady Pregerson, MD
Duration: 13:15
Emergency Medicine News 
Lab values aren’t just lab values, and there’s a logic to understanding how to interpret them. Listen in to hear all about this fascinating topic and read more in the Show Notes.
Creator: Brady Pregerson, MD
Duration: 10:06
Emergency Medicine News 
It’s true that EPs should be looking for horses when they hear hoofbeats, but sometimes they have to go on a zebra hunt, says Dr. Pregerson. Tune in to hear why gastroenteritis, anxiety, and dehydration should set off your Spidey senses. Listen in to hear the answers and read more in the Show Notes.
Creator: Brady Pregerson, MD
Duration: 8:02
Emergency Medicine News 
Why are most bleeding gastric ulcers painless? Why do people have a vasovagal reflex in the first place? Dr. Pregerson says there are logical answers that he can’t prove are right but most likely are. Listen in to hear the answers and read more in the Show Notes.
Creator: Brady Pregerson, MD
Duration: 13:19
Emergency Medicine News 

Show Notes:

First ask, “Are you having pain now?” If your patient answers no, consider this unstable angina until proven otherwise even if the pain went away with an antacid. Antacids relieve pain in about 15 percent of ACS. Why? Coincidence. The real lesson here is that the percentage of acute coronary syndrome that presents as unstable angina is probably 15 percent at a minimum. It’s actually probably at least twice that because not everyone tries an antacid. If you are looking for unstable angina, you are less likely to be fooled by false-negative troponins. This is still true of high-sensitivity troponin, although supposedly some literature says it can rule out unstable angina if the level is below the level of detection at least three hours out from peak pain and presentation. It has to be better than normal; it has to be undetectable.

Second Troponin v. Second History: I would like to be spread the following lesson to everyone in EM: “Before you do a second troponin, do a second history!” You need to really nail down the timing and duration of symptoms the best you can or you may be misled. Some patients speak their own language: “Constant” can mean “frequent.” Most of us already know that “no medical problems” can mean “no untreated medical problems” to a lot of people. It is safest to start with the assumption that all chest pain is unstable angina until proven otherwise, that the pain is episodic lasting five to 10 minutes, and that the troponin and ECG may both be useless.

HEART Score Logic: The HEART score is super useful and can help protect you if you send the wrong patient home, but you should still try to avoid doing that. The HEART score’s major blind spot is unstable angina because the troponin and ECG may be normal if pain lasts less than 20 to 30 minutes. Another caveat of the HEART score is grouping together all the patients with scores from 0-3. If the risk of this group is about one to two percent on average, logic dictates that patients with a score of 0-1 are actually at lower risk, but those with a score of 2-3 are likely at higher risk, perhaps three to four percent or even more. What is the actual risk associated with a HEART score of 3? We won’t know until someone does the study, but risk jumps to 10 to 20 percent once you hit the 4-6 score group. If you extrapolate the data, the risk of a MACE at 30 days is probably two to three times the HEART score, so for 3 it would be nine percent, if you use logic.

Back to the question, “Are you having pain now?” If your patient answers yes, your next question should be, “When did the current episode start?” Or better yet, “When was the last time you had no discomfort?” If it was less than two hours earlier, you should be doing serial ECGs every 30 minutes if you can, so you don’t miss a STEMI with an initially nondiagnostic or even near-normal ECG. It can take two hours or even more for ST elevation to manifest in some cases. You want that to be picked up early, not eight hours later when your patient is on the floor and it is too late for cath to help much.
Creator: Brady Pregerson, MD
Duration: 12:00
Emergency Medicine News 

Show Notes:

Head-Jolt sign: This is about 99% sensitive and 50% specific for meningitis. Have patients rapidly turn their head side to side. If it doesn’t hurt or they have to do it twice, make sure they don’t have meningitis. I will often grab their head and do it for them, but first definitely explain what I am doing to family members.

Eyes-Red eyes: Consensual photophobia or limbal flush suggests iritis or keratitis rather than conjunctivitis.

Pulmonary exam: Demonstrating how you want them to breathe and having them breathe more rapidly in and out is quicker and more sensitive for abnormal lung sounds. If you think you hear consolation when performing lung exam, ask a yes or no question. This can help continue your history, speed up your exam, and identify a pneumonia (a sort of modified egophony). After that and the end of an exhale, tell them to stop breathing and stick out their tongue (if no mask) while you listen to the heart with your stethoscope closer to the heart and without interference from lung sounds or, worse yet, speech. Bonus: Look at their tongue for hydration status.

Vascular-Pulses in the feet: Comparing pedal pulses is critical when there is a possibility of a knee dislocation, an aortic dissection, or acute limb ischemia, all of which can be sneaky and time-sensitive. Popliteal arterial injuries often are diagnosed late due to severe leg pain or spontaneous knee reduction. Aortic dissection rarely extends into an arm but almost always extends into a leg. Acute limb ischemia can mimic DVT, sciatica, or even a stroke.

Ortho-Pain location: Have them touch the exact spot that hurts the most. Without this and a confirmatory exam, you may end up imaging the wrong part of the spine or extremity. If you are lucky, it will only cause a delay; if you are not, it can cause a disaster. I have seen many misses or near misses due to this.

Ortho-Arm/hand neuro exam: Have the patient make an OK sign with the wrist in dorsiflexion and third fourth and fifth fingers spread apart. This allows you to evaluate the median (C5-8), ulnar (C8-T1), and radial nerves (C6-C8) in a five-second motor exam.
Creator: Brady Pregerson, MD
Emergency Medicine News 

Show Notes:
CTs don’t rule out strokes: CT scans only rule out bleeds. This is what I teach my patients, my residents, and myself. This obviously goes double for TIAs. We know this as physicians, but I am surprised by the number of misses that seem to occur when stroke/TIA was a consideration, but then the CT is negative. These misses with false negative head CTs are almost exclusively in cases where the physician probably had low pretest probability for a stroke because either the symptoms were atypical or the patient was quite young. But a substantial minority of strokes are in young patients or are atypical, and these are exactly the types of strokes that CT scans are more likely to miss so it shouldn’t really alter your post-test probability that much.
Do you have a better explanation for the presentation? I think in such cases the question to ask is, “Do I have a better explanation for the clinical presentation than stroke?” If you do and the fit is good, then it is probably logical to make that diagnosis. But if you don’t or the clinical fit is not really that good, then you should think long and hard about admitting for a stroke workup even if it’s a bit of a battle. This is especially true if this is the first time for this patient. Have they been worked up for something similar before with an admission? Beware of wastebasket diagnoses.
Know atypical presentations of stroke/TIA: A medical student can diagnose a classic stroke or classic TIA. It takes wisdom and logic to diagnose stroke/TIA with atypical presentations such as the ones below.

    • Posterior circulation strokes mimicking a migraine but with something that doesn’t fit.
    • Vertigo that doesn’t fit labyrinthitis or BPPV.
    • Other posterior circulation strokes: a variety of acute presentations; 2.5 times more likely to be missed than anterior circulation strokes. Blurry vision=nystagmus.
    • Anterior circulation strokes that mimic intoxication with altered mental status often from expressive or receptive aphasia.
Young patients with no known risk factors: ~10% of strokes.
Creator: Brady Pregerson, MD
Duration: 7:26
Emergency Medicine News 

Show Notes:

PID is often missed because the exam can be unimpressive. Remember more than 50 percent of men and more than 80 percent of women have no symptoms with chlamydia, so if you use your logical brain, it follows many cases are mild. In terms of risk, remember that PID is not always an STI; it is caused by vaginal flora in about 15 percent of cases.

Fitz-Hugh-Curtis (FHC) is also often missed, and you are probably missing it if you are not diagnosing about one case a year. The classic case is pleuritic RUQ pain in a sexually active woman, normal LFTs, elevated D-dimer, and normal CT angiograph of the chest. If it is from chlamydia, patients almost never have pelvic symptoms. Incubation is usually about three weeks. Do a sexual history. If there is a new partner, consider FHC even if the pain is nonpleuritic. Gallstones can be a red herring.

HSV meningitis is often missed. Most of the cases I have diagnosed had been seen by at least one other clinician in the prior week. It often follows a mild primary infection that has just irritation but no rash or blistering. About 50 percent of HSV1-positive and about the same percentage of HSV2-positive patients have never had an outbreak, so it follows that mild cases likely occur and are missed. Meningitis can start mild, and elevated CSF RBCs only occur about half of the time.

Creator: Brady Pregerson, MD
Duration: 9:38
Emergency Medicine News 

Show Notes:

Return Precautions: These are your safety net, and there’s a huge variance in what physicians write. The nucleus should always be to return if not improving or worse or if anything new happens. Logic: Most people don’t want to return for the same thing that you just sent them home for, so you must emphasize this, focusing on things like syncope, abdominal pain, fever, and vomiting.

Incidental Findings: Diagnose lung and adrenal nodules, ovarian cysts, etc., and give them copies, tell them to follow up, and write it in the aftercare. This can be a big medicolegal risk. It’s important that it is not so incidental when someone who doesn’t ovulate has free fluid in the abdomen.

Abnormal Labs and BP: From most common to least common include hypertension, glucose >LFTs, K+, Na+ >others.

Sedating Medications: Not just driving. Even taking a bus or walking home. Don’t rely on the pharmacist.  Malpractice usually doesn’t cover third parties. Read more: https://bit.ly/3K8tPs6.

Creator: Brady Pregerson, MD
Duration: 11:46
Emergency Medicine News 

Show Notes

Classic PE: Pleuritic chest pain, shortness of breath, tachycardia, and S1Q3T3 after starting an oral contraceptive on a long flight to get chemo.

Large PE Misses: About 20 percent of PEs are painless and probably about 50 percent of the large ones are painless, but this is rarely taught. The logic is that there is collateral circulation. Large PEs almost always cause SOB, however. These PEs often mimic ACS or sepsis due to tachycardia (rare in ACS) or low blood pressure, ischemic ECG changes, and elevated troponin/BNP/WBC. A bedside echo can really help if the patient is unstable, as can an ECG. Look for a dilated RV on the echo. Look for a new right axis or T-wave inversion in both inferior and anterior leads on the ECG because both of these are rare in ACS.

Small PE Misses: : Pleuritic chest pain only. The logic is that there is no collateral circulation so there is a lung infarct, which causes pain. No SOB, normal vitals, normal ECG, no known risk factors. Use PERC or D-dimer if you don’t have a more likely diagnosis. You may know the PERC, but do you also know the exclusion criteria? (https://bit.ly/3L7NRUz.)

Too Many Chest CTs: COVID is a more likely diagnosis most of the time for PERC so don’t dimer them unselectively! The logic is how many PEs have you and your colleagues diagnosed with a mildly elevated D-dimer or when you had a better explanation for symptoms but you were just CYA? Better than logic is logic and literature: Use age-adjusted D-dimer and YEARS criteria to minimize unnecessary CT. Both are validated and can be used in pregnant patients as well. (https://bit.ly/3L7NRUz.) Also know the causes of false-negative D-dimer (on thinners, symptoms less than a week).

Creator: Brady Pregerson, MD
Duration: 10:35
Emergency Medicine News 

Show Notes

Therapeutic Trials: Maalox relieves pain in 15 percent of cases of ACS. Why? The logical answer is coincidence, so before you order Maalox, ask if the pain is already improving. Do the same for NTG, and you will be less likely to get fooled by coincidences.

Second Troponin:Before doing a second troponin, do a second history to nail down the timing and duration as best as possible. Otherwise, you may end up wasting time, or worse, giving yourself false reassurance.

Pain Duration:Assume all cardiac chest pain is unstable angina until proven otherwise and that every chest pain patient has episodic pain lasting five-10 minutes, making the troponin and ECG useless.

HEART score:Not as useful if pain has resolved because the troponin and ECG may be useless. Score grouping may also overestimate risk in a patient with a score of 0-1 and underestimate risk in a patient with a score of 3. Use the info in scores, but don’t blindly follow them. Apply logic!