UMEM Educational Pearls

Category: Toxicology

Title: Valproic acid toxicity

Keywords: Valproic acid (PubMed Search)

Posted: 10/16/2014 by Hong Kim, MD, MPH (Emailed: 11/28/2020)
Click here to contact Hong Kim, MD, MPH

Valproic acid (VPA) is often used to treat seizure disorder and mania as a mood stabilizer. The mechanism of action involves enhancing GABA effect by preventing its degradation and slows the recovery from inactivation of neuronal Na+ channels (blockade effect).

VPA normally undergoes beta-oxidation (same as fatty acid metabolism) in the liver mitochondria, where VPA is transported into the mitochondria by carnitine shuttle pathway.

In setting of an overdose, carnitine is depleted and VPA undergoes omega-oxidation in the cytosol, resulting in a toxic metabolite.

Elevation NH3 occurs as the toxic metabolite inhibits the carbomyl phosphate synthase I, preventing the incorporation of NH3 into the urea cycle.

Signs and symptoms of acute toxicity include:

  • GI: nausea/vomiting, hepatitis
  • CNS: sedation, respiratory depression, ataxia, seizure and coma/encephalopathy (with serum concentration VPA: > 500 mg/mL)

Laboratory abnormalities

  • Serum VPA level: signs of symptoms of toxicity does not correlate well with serum level.
  • NH3: elevated
  • Liver function test: elevated AST/ALT
  • Basic metabolic panel: hypernatremia, metabolic acidosis
  • Complete blood count: pancytopenia

Treatment: L-carnitine

  • Indication: hyperammonemia or hepatotoxicity
  • Symptomatic patients: 100 mg/kg (max 6 gm) IV (over 30 min) followed by 15 mg/kg IV Q 4 hours until normalization of NH3 or improving LFT
  • Asymptomatic patients: 100 mg/kg/day (max 3 mg) divided Q 6 hours.

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Category: Critical Care

Title:

Keywords: Botulism, IVDA (PubMed Search)

Posted: 7/2/2019 by Robert Brown, MD (Emailed: 11/28/2020)
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Takeaways

Don’t miss the injecting drug users with botulism!

Wound botulism presents as descending paralysis when Clostridium botulinum spores germinate in anaerobic necrotic tissue. There have been hundreds of cases in the last decade, but it is poorly reported outside of California.

Black tar heroin and subcutaneous injection (“skin popping”) carry the highest risk, but other injected drugs and other types of drug use suffice. C botulinum spores are viable unless cooked at or above 85°C for 5 minutes or longer and this is not achieved when cooking drugs. 

Early administration of botulism anti-toxin (BAT) not only saves lives but can prevent paralysis and mechanical ventilation. An outbreak of 9 cases between September 2017 and April 2018 cost roughly $2.3 million, in part because patients didn’t present on average until 48 hours after symptom onset and it took an additional 2-4 days before the true cause of their respiratory depression and lethargy were understood. One patient died.

PEARL: talk to your injecting drug users about the symptoms of botulism: muscle weakness, difficulty swallowing, blurred vision, drooping eyelids, slurred speech, loss of facial expression, descending paralysis, and difficulty breathing. Consider botulism early in your patients who inject drugs but who do not respond to naloxone or who exhibit prolonged symptoms. Testing at the health department is performed with mouse antibodies to Botulism Neurotoxin (BoNT) combined with the patient’s serum.

 

 

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Category: International EM

Title: Fever and Polyarthralgia

Keywords: International, Chikungunya, vector-borne, (PubMed Search)

Posted: 3/5/2014 by Andrea Tenner, MD (Emailed: 11/28/2020)
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Case Presentation:

53 yo male presents with fever, myalgia, maculopapular rash, and severe polyarthralgia. He just returned from a cruise to the Caribbean islands.

Clinical Question:

What is the diagnosis?

Answer:

Chikungunya Virus

  • Travelers who go to the Caribbean are at risk of getting chikungunya. Cases have been reported in Saint Martin, Martinique, and Guadeloupe. In addition, travelers to Africa, Asia, and islands in the Indian Ocean and Western Pacific are also at risk.
  • Mosquito vector, incubation 3-7 days
  • Joints involved are typically hands and feet, usually symmetric, severe arthralgia often debilitating
  • Dx: serology - ELISA, IgM
  • Treatment: IVF, NSAIDS, supportive

Bottom Line:

  • Include Chikungunya in your differential of non-specific fever, rash, headache and arthralgia in travelers the Caribbean and endemic areas.

University of Maryland Section of Global Emergency Health

Author: Veronica Pei, MD

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Category: Critical Care

Title: Utilization of the Mechanical Ventilator in Cardiac Arrest

Keywords: CPR, Cardiac Arrest (PubMed Search)

Posted: 11/15/2016 by Rory Spiegel, MD (Emailed: 11/28/2020)
Click here to contact Rory Spiegel, MD

It is well documented that when left to our own respiratory devices we will consistently over-ventilate patients presenting in cardiac arrest (1). A simple and effective method of preventing these overzealous tendencies is the utilization of a ventilator in place of a BVM. The ventilator is not typically used during cardiac arrest resuscitation because the high peak-pressures generated when chest compressions are being performed cause the ventilator to terminate the breath prior to the delivery of the intended tidal volume. This can easily be overcome by turning the peak-pressure alarm to its maximum setting. A number of studies have demonstrated the feasibility of this technique, most recently a cohort in published in Resuscitation by Chalkias et al (2). The 2010 European Resuscitation Council guidelines recommend a volume control mode at 6-7 mL/kg and 10 breaths/minute (3).

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Category: Critical Care

Title:

Keywords: amikacin, Torsades de pointes, QT prolongation (PubMed Search)

Posted: 8/20/2019 by Quincy Tran, MD (Emailed: 11/28/2020)
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Torsades de pointes and QT prolongation Associated with Antibiotics

 

Methods

The authors queried the United States FDA Adverse Event Reporting System (FAERS) from 01/01/2015 to 12/31/2017 for reports of Torsade de points/QT prolongation (TdP/QT).

Reporting Odd Ratio (ROR) was calculated as the ratio of the odds of reporting TdP/QTP versus all other ADRs for a given drug, compared with these reporting odds for all other drugs present in FAERS

Results

FAERS contained 2,042,801 reports from January 1, 2015 to December 31, 2017. There were 3,960 TdP/QTP reports from the study period (0.19%).

 

Macrolides               ROR 14 (95% CI 11.8-17.38)

Linezolid                  ROR 12 (95% CI 8.5-18)

Amikacin                 ROR 11.8 (5.57-24.97)

Imipenem-cilastatin ROR 6.6 (3.13-13.9)

Fluoroquinolones   ROR 5.68 (95% CI 4.78-6.76)

 

Limitations:

These adverse events are voluntary reports

There might be other confounded by concomitant drugs such as ondansetron, azole anti-fungals, antipsychotics.

 

Bottom Line:

This study confimed the previously-known antibiotics to be associated with Torsades de pointes and QT prolongation (Macrolides, Linezolid, Imipenem and Fluoroquinolones). However, this study  found new association between amikacin and Torsades de pointes/QT prolongation.

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Category: Visual Diagnosis

Title: What's the Diagnosis? Case by Dr. Ali Farzad

Posted: 4/7/2014 by Haney Mallemat, MD (Emailed: 11/28/2020) (Updated: 11/28/2020)
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Question

23 year-old female presents complaining of progressive right lower quadrant pain after doing "vigorous" pushups. CT abdomen/pelvis below. What’s the diagnosis? (Hint: it’s not appendicitis)

 

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Category: Critical Care

Title: Lung Protective Ventilation in the Emergency Deparment

Keywords: lung protective ventilation, ARDS (PubMed Search)

Posted: 3/21/2017 by Rory Spiegel, MD (Emailed: 11/28/2020)
Click here to contact Rory Spiegel, MD

While lung protective ventilatory strategies have long been accepted as vital to the management of patients undergoing mechanical ventilation, the translation of such practices to the Emergency Department is still limited and inconsistent.

Fuller et al employed a protocol ensuring lung-protective tidal volumes, appropriate setting of positive end-expiratory pressure, rapid weaning of FiO2, and elevating the head-of-bed. The authors found that the number of patients who had lung protective strategies employed in the Emergency Department increased from 46.0% to 76.7%. This increase in protective strategies was associated with a 7.1% decrease in the rate of pulmonary complications (ARDS and VACs), 14.5% vs 7.4%, and a 14.3% decrease in in-hospital mortality, 34.1% vs 19.6%.

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Category: Toxicology

Title: Hydrofluoric Acid Burns

Keywords: hydrofluoric acid, burn, chemical burn, HFA, calcium gluconate (PubMed Search)

Posted: 9/5/2010 by Dan Lemkin, MD, MS (Emailed: 11/28/2020) (Updated: 10/2/2010)
Click here to contact Dan Lemkin, MD, MS

Hydrofluoric acid is a weak acid used primarily in industrial applications for glass etching and metal cleaning/plating. It is contained in home rust removers. Although technically a weak acid, it is very dangerous and burns can be subtle in appearance while having severe consequences.

Hydrofluoric acid burn

Wilkes G. Hydrofluoric Acid Burns. Jan 28, 2010. 
http://emedicine.medscape.com/article/773304-overview

  • 2 mechanisms that cause tissue damage*
    • corrosive burn from the free hydrogen ions
    • chemical burn from tissue penetration of the fluoride ions
  • Clinical features*
    • Cutaneous burns - absent findings to white-blue appearance
    • Pulmonary edema
    • Hypocalcemia, hyperkalemia, hypomagnesemia
  • Treatment*
    • Decontaminate by irrigation with copious amounts of water.
    • With any evidence of hypocalcemia, immediately administer 10% calcium gluconate IV.
    • Cutaneous burns:
      • Apply 2.5% calcium gluconate gel to the affected area. If the proprietary gel is not available, constitute by dissolving 10% calcium gluconate solution in 3 times the volume of a water-soluble lubricant (eg, KY gel). For burns to the fingers, retain gel in a latex glove.
      • If pain persists for more than 30 minutes after application of calcium gluconate gel, further treatment is required. Subcutaneous infiltration of calcium gluconate is recommended at a dose of 0.5 mL of a 5% solution per square centimeter of surface burn extending 0.5 cm beyond the margin of involved tissue (10% calcium gluconate solution can be irritating to the tissue).
        • Do not use the chloride salt because it is an irritant and may cause tissue damage.

*Extracted from emedicine article.

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Question

50 year-old male with cough and dyspnea. What's the diagnosis?

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Category: Visual Diagnosis

Title: Visual Dx (Courtesy of Maite Huis in 't Veld)

Posted: 10/5/2018 by Michael Bond, MD (Emailed: 11/28/2020) (Updated: 11/28/2020)
Click here to contact Michael Bond, MD

Question

33 y/o M with PMH of ETOH induced pancreatitis presents with epigastic/RUQ pain & N/V after drinking last night, per patient his usual “pancreas pain”. The nurse shows you his blood tubes because they look “milky”. Lipase 1200, Ca 6.8.

 



What lab test would you add?

 

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While chest X ray (CXR) is routinely obtained in the setting of traumatic injury, ultrasound (US) is a fast and reliable way to evaluate for life-threatening traumatic injuries requiring emergent intervention, and is supported by the Eastern Association for the Surgery of Trauma (EAST) guidelines. A recent Cochrane Review compared the test characteristics of chest US vs CXR for detection of traumatic pneumothorax when using Chest CT or thoracostomy as the gold standard.

  • Primary end point: sensitivity and specificity for pneumothorax
  • US performed by nonradiologists.
  • 9 studies, 1271 patients, 410 of which had a pneumothorax
  • Summary sensitivity: US 0.91 (95% CI 0.85-0.94), ranging from  0.82-0.98 in the included studies, vs. CXR 0.47 (95% CI 0.31- 0.63) ranging from 0.09 to 0.75
  • Summary specificity: US 0.99 (95% CI 0.97-1.00, ranging from  0.96-1.00 vs. CXR 1.00 (95% CI 0.97- 1.00), ranging from 0.98 to 1.00

There possible weaknesses of this study, including blinding in the original studies, and several studies may or may not have been at risk for bias as their risk of bias was ‘unclear’.  However, the results were consistent across the studies analyzed and remained similar after sensitivity analysis.

Several anatomical as well as patient care issues may confound US findings for pneumothorax such as the presence of bleb, prior thoracic surgery or pathology, as well as main stem intubation.

Bottom line:  While the presence of pneumothorax is on either CXR or US is highly likely to represent the a true pneumothorax, ultrasound is a far superior screen for the detection of pneumothorax in the trauma patient.

 

 

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Category: Pediatrics

Title: Tinea Capitis

Posted: 3/9/2013 by Rose Chasm, MD (Emailed: 11/28/2020) (Updated: 11/28/2020)
Click here to contact Rose Chasm, MD

  • Tinea capitis (ringworm of the scalp) is caused by dermatophytic fungi
  • Trichophyton tonsurans is the most common species in the US, and does NOT flouresce under Wood's lamp
  • Griseofulvin (20-25mg/kg/ day orally) is the standard first-line therapy in children older than 2 years, and has a good safety profile
  • Both tablet and suspension formulations are available, and it should be taken with food that are high in fat to increase drug concentrations
  • NO laboratory assessment of hepatic enzymes is required during the 8-week therapy course in children who have no history or clinical examination findings concerning for liver disease.
  • Topical antifungal agents are ineffective because they do not penetrate sufficiently into the hair shaft.

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Category: Pediatrics

Title: Visual Diagnosis Pediatrics: Case thanks to Ari Kestler MD (@KestlerMD) and Haney Mallemat MD (@CriticalCareNow)

Keywords: non-accidental trauma, clavicle fracture, neonate, pediatrics, abuse (PubMed Search)

Posted: 10/4/2014 by Ashley Strobel, MD (Emailed: 11/28/2020)
Click here to contact Ashley Strobel, MD

Question

Q: What is wrong with this baby? And what Dx should you entertain?

Previously healthy 7d old presents after difficulty feeding, one episode of vomiting and now with intermittent apneic episodes.

 

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Attachments

Clavicle_Fracture.jpg (1,743 Kb)


Category: Orthopedics

Title: Fulcrum test

Posted: 10/1/2017 by Brian Corwell, MD (Emailed: 11/28/2020) (Updated: 11/28/2020)
Click here to contact Brian Corwell, MD

https://www.physio-pedia.com/Fulcrum_Test


Category: Infectious Disease

Title: Avian Influenza H7N9

Posted: 4/12/2013 by Andrea Tenner, MD (Emailed: 11/28/2020) (Updated: 11/28/2020)
Click here to contact Andrea Tenner, MD

General Information:

-As of April 5th, 14 confirmed cases of a new influenza A virus (H7N9) have occurred in China.  Six of those have died. 

-Presumed transmission via infected poultry in bird markets, and thus far no person-to-person transmission has occurred.

-Likely susceptible to oseltamavir or inhaled zanamivir

 

Area of the world affected:

-China

Relevance to the US physician:

- Suspect in patients with a respiratory illness and appropriate travel history.

- Refer to CDC within 24 hours if test positive for flu A but cannot be subtyped

- If H7N9 is suspected, patients should be under droplet and airborne precautions

 

Bottom Line:

No human-to-human transmission from H7N9 thus far, but the possibility exists.  Any unsubtypeable influenza A patient should be placed on droplet and airborne precautions and oseltamavir or zanamivir started immediately.

 

University of Maryland Section of Global Emergency Health
Author: Andi Tenner, MD, MPH

 

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Category: Orthopedics

Title: Morel-Lavall e lesion

Posted: 10/1/2017 by Brian Corwell, MD (Emailed: 11/28/2020) (Updated: 11/28/2020)
Click here to contact Brian Corwell, MD

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126145/


Category: Critical Care

Title: Adrenal Insufficiency

Posted: 4/12/2013 by Haney Mallemat, MD (Emailed: 11/28/2020) (Updated: 11/28/2020)
Click here to contact Haney Mallemat, MD

Adrenal insufficiency (AI) can be a life-threating condition and is classified as primary (failure of the adrenal gland) or secondary (failure of hypothalamic- pituitary axis).

Common causes of primary adrenal insufficiency include autoimmune destruction, infectious causes (TB and CMV), or interactions with drugs (e.g., anti-fungals, Etomidate, etc.). Secondary causes are usually due to abrupt withdrawal of steroids after chronic use, although sepsis and diseases of the hypothalamus or pituitary (e.g., CVA) may occur.

Signs and symptoms include fatigue, weakness, skin pigmentation, dizziness, abdominal pain, and orthostatic hypotension; it should be suspected with any of the following: hyponatremia, hyperkalemia, hypoglycemia, hypercalcemia, low free-cortisol level, and hemodynamic instability despite resuscitation.

Treatment:
• Correct underlying the disorder
• Resuscitation and hemodynamic support
• Correct hypoglycemia and electrolyte abnormalities
• Treat with hydrocortisone, cortisone, prednisone, or dexamethasone +/- fludrocortisone (Note: dexamethasone is attractive choice in the ED because it will not interfere with ACTH stimulation test)


 

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