Podcast 996: D-Dimer
Emergency Medical Minute
Contributor: Travis Barlock, MD Educational Pearls: D-dimer: fibrin degradation product used to evaluate for clot formation and breakdown Threshold: <500ng/mL rules out venous thromboembolism in low risk patients Elevated D-dimer indicates recent or ongoing intravascular coagulation and fibrinolysis YEARS score: algorithm to assess PE risk using three clinical criteria Criteria: signs of DVT, hemoptysis, and PE as the most likely diagnosis YEARS score of 0 with D-dimer <1000 ng/mL: PE can be ruled out YEARS score of ≥1 with D-dimer <500 ng/mL: PE can be ruled out A study found...
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Podcast 995: Melatonin
Emergency Medical Minute
Contributor: Taylor Lynch MD Educational Pearls: Melatonin is an endogenous hormone released primarily by the pineal gland Also released by extrapineal regions in the retina, the GI tract, and some immune cells Peak secretion occurs at night and is suppressed during the day Secretion and production decrease with age Older patients experience the greatest improvement in sleep latency and sleep quality Mechanism of action in the suprachiasmatic nucleus of the hypothalamus MT1 receptor Reduces normal firing MT2 receptor Shifts the circadian rhythm FDA approved for insomnia ...
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Episode 995: UTI Diagnosis
Emergency Medical Minute
Contributor: Travis Barlock, MD Educational Pearls: Foul-smelling urine and cloudy urine are commonly misinterpreted as indicators of a UTI. However, these findings alone are not diagnostic. Criteria for UTI: Presence of localized urinary symptoms: Suprapubic pain Dysuria Hesitancy Urgency Urinalysis with WBC > 10 Urine culture with > 100,000 CFU/mL Colonization differs from infection - many patients harbor asymptomatic bacteria but do not have a true infection. Consequences of overtreatment One review showed 45% of patients treated with antibiotics for a presumed UTI...
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Podcast 994: Biphasic Anaphylaxis
Emergency Medical Minute
Contributor: Aaron Lessen, MD Educational Pearls: What is anaphylaxis and what are its treatments? Anaphylaxis is a broad term for potentially life threatening allergic reactions that can progress to cardiovascular collapse (anaphylactic shock). It is triggered by IgE and antigen cross-linking on mast cells to induce degranulation and the release of histamines, which can cause diffuse vasodilation and respiratory involvement with end-organ hypoperfusion. First line treatment is the immediate administration of epinephrine at 0.01 mg/kg (max dose for pediatrics is 0.3 mg and for...
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Podcast 993: Personalized Gene Editing Therapy
Emergency Medical Minute
Contributor: Alec Coston, MD Educational Pearls: Disclaimer: this has nothing to do with the ER but is too cool to not talk about. Condition: Carbamoyl phosphate synthetase 1 (CPS1) deficiency Rare inborn error of metabolism Inability to properly break down ammonia Leads to severe hyperammonemia and hepatic encephalopathy Natural history: Without treatment, typically fatal within the first few weeks of life Even with current standard treatments, life expectancy is often limited to ~5–6 years Breakthrough treatment: A team of researchers at the Children’s Hospital of...
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Tox Talks 2025 Recap 2, Methemoglobinemia and Errors
Emergency Medical Minute
Contributors: Travis Barlock MD, Ian Gillman PA, Jacob Altholz MD, Jeffrey Olson MS4 In this episode, EM attending Travis Barlock and medical student Jeffrey Olson listen in to the two remaining cases presented from EMM’s recent event, Tox Talk 2025. Talk 1- Methemoglobinemia- Ian Gillman Cyanosis + chocolate-colored blood + normal PaO₂ + pulse ox stuck at ~85% = Methemoglobinemia → Treat with methylene blue The medications that can cause it can be remembered with… Watch out with methylene blue as it can cause serotonin syndrome While treating with methylene blue the...
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Podcast 992: Fentanyl for Asthma
Emergency Medical Minute
Contributor: Alec Coston, MD Educational Pearls: BiPAP is often effective in severe asthma, but many patients struggle with mask tolerance due to intense air hunger–driven anxiety, often compounded by hypoxia. Benzodiazepines are commonly used for anxiety, but they can depress respiratory drive, making clinical improvement difficult to interpret (a lower RR may reflect sedation rather than true physiologic improvement). Low-dose fentanyl is a useful alternative when patients cannot tolerate BiPAP despite coaching. Opioids blunt the perception of dyspnea and are well established for...
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Episode 991: BRASH
Emergency Medical Minute
Contributor: Aaron Lessen, MD Educational Pearls BRASH Syndrome: Bradycardia Renal Failure AV Nodal Blockade Shock Hyperkalemia Clinical Features: Profound bradycardia and shock in patients on AV nodal blockers: Commonly, Beta Blockers or Calcium Channel Blockers Etiology: Caused by an inciting kidney injury: Common triggers include precipitating illness, dehydration, or medications Results in hyperkalemia The enhanced effect of the combination of AV nodal blockade and hyperkalemia leads to a more profound presentation of shock. ...
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Episode 990: Tramadol, or rather, Trama-don’t
Emergency Medical Minute
Contributor: Taylor Lynch, MD Educational Pearls: What is tramadol and how does it work? Tramadol is a Schedule IV opioid analgesic used for moderate pain and is often perceived as safer than other opioids due to lower abuse potential. It is a prodrug with weak direct μ-opioid receptor activity. The parent compound also inhibits serotonin and norepinephrine reuptake, giving it SSRI/SNRI-like properties. Tramadol is metabolized by CYP2D6 into O-desmethyltramadol (ODT), which has significantly stronger μ-opioid receptor agonism than the parent drug. What are the concerns with...
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Episode 989: Young Strokes
Emergency Medical Minute
Contributor: Aaron Lessen, MD Educational Pearls: The Case 24F brought in for anxiety. Patient is tearful, not talking, and potentially hyperventilating. History from boyfriend is that she suddenly stopped talking and started crying and it was hard to understand what she was saying. On exam, patient appears anxious and has a gaze preference for the right side and is still having difficulty speaking. Decision is made to stroke alert patient. CT shows early MCA stroke and M2 occlusion. Patient is treated by IR with mechanical thrombectomy. What are the risk factors for strokes in young...
info_outlineContributor: Jorge Chalit-Hernandez, OMS4
Educational Pearls:
- What is the toxic dose of acetaminophen?
- 7.5 grams, in an adult. The safe daily limit is 4 grams in an adult with a normally functioning liver.
- This is equivalent to fifteen 500mg pills.
- What are the symptoms of acetaminophen toxicity?
- First 24 hours, symptoms are non-specific e.g. nausea, vomiting, lack of appetite. Can also be asymptomatic.
- 24-72 hours, hepatotoxicity occurs (causing yellow skin, pruritus, abdominal pain, bleeding, and confusion)
- Fulminant liver failure at 72-96 hours
- Liver function tests (LFTs) peak at 72-96 hours.
- When would you give activated charcoal?
- Within 4 hours of ingestion.
- The risk of activated charcoal is that it can be very dangerous if aspirated so use with caution with a poorly mentating patient
- When would you give N-acetylcysteine (NAC)?
- The peak absorption of acetaminophen occurs at about 4 hours with acute ingestions
- Use the Rumack–Matthew nomogram to plot the serum level of acetaminophen versus the time since ingestion to see if you are above the treatment line.
- If the ingestion time is unknown then just give it.
- How do you dose NAC?
- 3 bag system: First, a 150 mg/kg bolus is administered IV over 15-60 minutes (Bag 1), then a 50 mg/kg drip is administered over 4 hours (Bag 2), then a 100 mg/kg drip is administered over the following 16 hours (Bag 3).
- This is the Prescott Protocol that requires three bag of IV fluids
- 2 bag system: There is a simplified protocol that only requires 2 bags, 200mg/kg IV over 4 hours (Bag 1) followed by 100mg/kg over 16 hours (Bag 2)
- Less risk of anaphylactoid reactions with a 2-bag system due to the high rate of IV NAC given in the 3 bag system.
- 3 bag system: First, a 150 mg/kg bolus is administered IV over 15-60 minutes (Bag 1), then a 50 mg/kg drip is administered over 4 hours (Bag 2), then a 100 mg/kg drip is administered over the following 16 hours (Bag 3).
- What are the endpoints for stopping NAC?
- If the INR is <1.5
- If the acetaminophen level is < 10 mcg/mL or undetectable
References
- Hodgman MJ, Garrard AR. A review of acetaminophen poisoning. Crit Care Clin. 2012 Oct;28(4):499-516. doi: 10.1016/j.ccc.2012.07.006. PMID: 22998987.
- Rumack BH, Matthew H. Acetaminophen poisoning and toxicity. Pediatrics. 1975 Jun;55(6):871-6. PMID: 1134886.
- Sudanagunta S, Camarena-Michel A, Pennington S, Leonard J, Hoyte C, Wang GS. Comparison of Two-Bag Versus Three-Bag N-Acetylcysteine Regimens for Pediatric Acetaminophen Toxicity. Ann Pharmacother. 2023 Jan;57(1):36-43. doi: 10.1177/10600280221097700. Epub 2022 May 19. PMID: 35587124.
Summarized by Jeffrey Olson, MS4 | Edited by Jeffrey Olson and Jorge Chalit, OMS4