Quiz 49, November 8th, 2019

Welcome to the 49th FOAMed Quiz. 

Enjoy!

Kirsten, Eefje, Hüsna, Joep and Rick

Question 1

Winter is coming! This means people start warming their houses. Unfortunately this is not always been done in a safe way.

Which of the following statements is true about carbon monoxide (CO) poisoning?

A: Carbon monoxide poisoning is always caused by inhaling gas

B: There is a validated relationship between carboxyhemoglobin levels and specific symptoms

C: Half-life of carbon monoxide at 100% FiO2 is ~1 hour

D: Arterial Blood Gas (ABG) is preferred to Venous Blood Gas (VBG) for diagnosis of CO poisoning

The correct answer is C

The internet book of critical care covered carbon monoxide poisoning this week.

Exposure to methylene chloride (paint remover) can cause CO poisoning (after being metabolized). This can occur several hours after exposure. There is no validated relationship between carboxyhemoglobin levels and specific symptoms. VBG is accurate for diagnosing CO poisoning. And the half-life of carbon monoxide at 100% FiO2 is ~1 hour (at 21% FiO2 ~5 hours, at 250% (hyperbaric oxygen)~20 minutes)

IBCC chapter & cast – Carbon monoxide poisoning

Question 2

Justin Morgenstern covered the coronary CT angiography (CCTA) on First10EM this week. Which of the following is true about the use of CCTA in patients with suspected Acute Coronary Syndrome (ACS) seen in the Emergency Department?

A: CCTA improves 30-day mortality

B: CCTA leads to a decrease in length of stay, but only if you have incredibly long lengths of stay to begin with

C: CCTA causes a huge increase in radiation

The correct answer is B

All relevant papers about this topic were briefly reviewed. It seems CCTA does not provide any clinical benefits over standard care. However, ‘’the patients enrolled in these studies were so low risk that they could not have possibly benefited from further testing.’’ So a role for CCTA is not fully excluded.

Question 3

You intubate a critically ill patient and you struggle with correct placement confirmation since capnography malfunctions. You decide to use ultrasound. Which of the following statements is true?

A: A bullet sign suggests oesophageal intubation

Bullet Sign. Source: https://www.nuemblog.com/

B: A double tract sign suggests endotracheal intubation

Double tract sign. Source: http://www.emdocs.net/

C: Ultrasound assessment has about 98% sensitivity for tracheal intubation

D: In ultrasound assessment of tracheal intubation the probe should be placed superior to the suprasternal notch in a longitudinal orientation

The correct answer is C

NUEM covered Ultrasound Confirmation of Endotracheal Tube Placement this week.

A bullet sign suggests endotracheal intubation. A double tract sign suggests oesophageal intubation. In ultrasound assessment of tracheal intubation the probe should be placed superior to the suprasternal notch in a transverse orientation. Ultrasound assessment has about 98% sensitivity for tracheal intubation.

Click image for link

Question 4

Which statement is true about dizziness and vertigo?

A: Associated neurological complaints, such as imbalance, dysarthria, or numbness raise the likelihood of TIA or stroke

B: When performing the Hallpike test, the head should be turned to the side 90 degrees prior to laying the patient back into the head-hanging position

C: The presence of auditory symptoms suggest a central cause of the vertigo

D: Vertigo after neck injury and is usually benign

The correct answer is A

CanadiEM covered dizzyness and vertigo in Crackcast episode 207

When performing the Hallpike test, the head should be turned to the side 45 degrees prior to laying the patient back into the head-hanging position. The presence of auditory symptoms suggest a peripheral cause of the vertigo. Neck injury can cause vertigo from vertebral artery dissection, resulting in posterior circulation ischemia.

CRACKCast E207 – Dizziness and Vertigo

Question 5

Which statement about urolithiasis is true?

A: Prevalence of kidney stones is higher in a cold and wet climate

B: A restrictive calcium diet decreases the risk of stone formation

C: Microscopic hematuria is present in only 50% of the patients

D: Intravenous (IV) hydration has no impact on stone passage

The correct answer is D

Daniel Tauber covered urolithiasis last week on emDOCs.

He clarifies why a calcium restrictive diet will not help to prevent urolithiasis, but paradoxically increases the risk of stone formation. He also emphasizes that the lack of microscopic hematuria can not be used to rule out kidney stones, since the sensitivity is only 85%. Prevalence is higher in hot, dry, arid climates such as mountain, desert, or tropical regions. IV hydration has no impact on stone passage.

EM@3AM: Urolithiasis

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This quiz was written by Eefje Verschuuren, Kirsten van der Zwet, Hüsna Sahin and Joep Hermans

Reviewed and edited by Rick Thissen

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