Quiz 111, April 16th, 2021

Welcome to the 111th FOAMed Quiz.

 

Source image: www.pixabay.com

Question 1

Your 64-year old male patient was brought in by EMS with a decreased level of consciousness. He is hypotensive and EMS reports that they found an empty bottle of doxepin, a tricyclic antidepressant (TCA).

Which of the following ECG abnormalities is atypical for a TCA overdose?

A: Prominent R wave in aVR

B: Widened QRS segment

C: Diffuse T-top inversion

D: QTc prolongation

The correct answer is C

TCA overdose was covered on Canadiem this week.

Sinus tachycardia is likely to appear first due to the anticholinergic effects. Widening of the QRS segment is typical and often seen in TCA overdose. It is an important predictor of the clinical course, as opposed to drug levels. A QRS width of >100 ms carried a 33% risk of seizures in this previous study while a QRS width >160 ms carried a 50% risk of dysrhythmias. QTc prolongation >430 ms and a prominent R wave in aVR (R/S ratio >0.7) are also frequently seen.

Inverted T-waves are atypical for TCA overdose and can be seen in various conditions.

Vicious Cycles: Management of the Tricyclic Antidepressant Overdose

Case courtesy of Dr David Cuete, Radiopaedia.org, rID: 22770

Question 2

Your patient comes in with acute onset headache and vomiting since 2 hours. Which of the following comorbidities may decrease the accuracy of the CT-scan for sub arachnoid hemorrhage (SAH)?

A: Anemia

B: Hypertriglyceridemia

C: Diabetes mellitus

D: Hemochromatosis

The correct answer is A

EMOttawa covered SAH this week.

Anemia will make acute blood less hyperdense on CT of the brain and intracerebral hemorrhage more difficult to appreciate. In patients polycythemia, for example, CT imaging may demonstrate hyperdense cerebral vasculature.

EMOttawa Podcast Episode 3: Thunderclap Headache

Source image: www.dontforgetthebubbles.com

Question 3

A 13 year old boy visits the ED after twisting his right foot during football. The X-ray is shown above. You wonder whether you are looking at a zone 1 fracture of the fifth metatarsal (pseudo Jones) or a normal apophysis.

Which of the following statements is correct and may help you distinguish between the two?

A: The apophysis of the base of the fifth metatarsal will not appear before 14 years of age in boys, so this has to be a fracture

B: There is no apophysis at the base of the fifth metatarsal, so this has to be a fracture

C: A fracture line through the base of the fifth metatarsal will run transversely, while the apophysis will run longitudinally, so this is not a fracture

D: A fracture line through the base of the fifth metatarsal will run longitudinally, while the apophysis will run transversely, so this has to be a fracture

The correct answer is C

Don’t forget the bubbles covered foot and toe injuries last week.

The apophysis of the base of the fifth metatarsal is often mistaken for a zone 1 fracture. The apophysis appears at about 12 years in boys. A fracture line through the base of the fifth metatarsal will run transversely, while the apophysis will run longitudinally.

An irregular apophysis at the base of the fifth metatarsal is seen in apophysitis. This self limiting condition is called Iselin disease.

Source image: www.emdocs.net

Question 4

Your 52 year old patient comes in after accidentally ingesting a bone while eating a chicken wing. There is a mild stridor, but no respiratory distress and a saturation of 98%. You administer nebulized lidocaine and plan to retrieve the foreign body with Magill or sponge forceps during laryngoscopy. A GlideScope® and standard Macintosh laryngoscope (size 3 blade) are available. Which one is most effective in retrieving the foreign body according to available evidence?

A: GlideScope®

B: Macintosh

C: Both are equally effective

The correct answer is B

EMDocs covered upper airway foreign bodies last week.

A 2012 paper by Je et al. covered this topic. 28 first year emergency residents with little prior airway management experience extracted hypopharyngeal foreign bodies using a Macintosh laryngoscope and GlideScope®. The success rate in relation to time to extraction was significantly higher with the Macintosh laryngoscope than with the GlideScope® (p < 0.001).

I guess the difficulty in foreign body extraction using a GlideScope® may be the hyperangulated blade. I wonder how standard geometry blade video laryngoscopy holds up against direct laryngoscopy.

Source image: www.pixabay.com

Question 5

Back to basics: resuscitation fluids.

The most commonly used fluid is still 0.9% Sodium Chloride. But do you know what is being administered to the patient?

What is the pH of 0.9% Sodium Chloride?

A: 5.5

B: 6.4

C: 7.4

D: 8.2

The correct answer is A.

Resuscitation fluids were discussed by ALiEM this week.

The differences between them, mainly based on the different electrolyte amounts, were shown for the most commonly used; 0.9% Sodium Chloride, Lactated Ringer’s solution,
Plasma Lyte A and blood.

Is Lactated Ringer’s Solution Safe for Hyperkalemia Patients?

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This quiz was written by Sophie Nieuwendijk, Denise van Vossen, Gijs de Zeeuw, Nicole van Groningen and Joep Hermans

Reviewed and edited by Rick Thissen