Quiz 81, August 21th, 2020

Welcome to the 81th FOAMed Quiz. 

Enjoy!

Eefje, Nicole, Joep and Rick

Question 1

Source image: http://brownemblog.com/

A 28 year old female comes in with suspected first trimester bleed. Her last menstrual period was about 5 weeks ago. Her B-hCG comes back 4000 mIU/mL.

Should an intrauterine pregnancy be visible on ultrasound?

A: Intrauterine pregnancy should be visible on both transvaginal and transabdominal ultrasound in this case

B: Intrauterine pregnancy should not yet visible on both transvaginal and transabdominal ultrasound in this case

C: Intrauterine pregnancy should be visible on transvaginal ultrasound but is unlikely to be visible on transabdominal ultrasound

The correct answer is C

BrownEM covered first trimester ultrasound and hydatidiform mole this week.
Intrauterine pregnancy can usually be seen at B-hCG levels > 1500 via trans-vaginal ultrasound and > 6500 via trans-abdominal ultrasound.

Question 2

Source image: emcrit.org

Catecholamine-resistant vasodilatory shock (CRVS), in which hypotension persists despite the use of high-dose vasopressors, carries a 50% to 80% mortality.

The 2019 ATHOS-3 trial showed that in patients with severe vasodilatory shock, administration of angiotensin II (ATII) is associated with a 45% absolute increase in MAP response compared to placebo.

This suggests in most people with CRVS, there is significant disturbance in the RAAS likely resulting from impairment of ACE function. However, identification of patients with RAAS disturbance is challenging because ATII levels cannot be measured in most labs.

This recently published paper assesses renin levels as an easy to assess surrogate for ATII levels and so to predict which patients with CRVS would benefit from ATII therapy.

What does this paper show?

A: Patients with RAAS disturbance cannot be identified through simple laboratory assessment of serum renin levels

B: Renin assessment could be used to identify patients without RAAS disturbance, in whom treatment with angiotensin II would likely be beneficial

C: Renin has the potential to be used to identify CRVS patients at high risk for poor outcome and who may benefit from treatment with synthetic angiotensin II

D: Patients with serum renin levels above the study population median had a significantly reduced risk of mortality.

The correct answer is C

Scott Weingard discussed this paper with the author on the EMCrit podcast. 

Patients with RAAS disturbance can be readily identified through simple laboratory assessment of serum renin levels. 

Renin assessment could be used to identify patients without RAAS disturbance, in whom treatment with angiotensin II would likely be futile.

Patients with serum renin levels above the study population median had a significantly increased risk of mortality. 

And indeed: Renin has the potential to be used to identify CRVS patients at high risk for poor outcome and who may benefit from treatment with synthetic angiotensin II.

Question 3

Source image: Pixabay.org

A 58 year old male with a medical history of gastroesophageal reflux disease and hypertension presents to your emergency department with abdominal pain. This morning he had one episode of coffee ground emesis. He reports frequent cocaine use with his last use three days ago.

Conventional X-ray reveals a pneumoperitoneum. You suspect bowel perforation caused by cocaine use.

Which of the following statements is true about cocaine use and bowel perforations?

A: Cocaine causes bowel perforation in previously affected bowels only

B: Cocaine stimulates norepinephrine reuptake in the presynaptic nerve endings leading to arterial vasoconstriction

C: The onset of symptoms typically occurs within one hour to sixty hours after cocaine use

The correct answer is C.

This week Eric Beyer covered the cocaine gut on ALiEM.

Bowel ischemia due to cocaine use is caused by blocking norepinephrine reuptake in presynaptic nerve endings. This leads to arterial vasospasm or constriction which can lead to complete bowel wall ischemia and perforation. Cocaine use can also exacerbate underlying peptic ulcer disease. Symptoms of a cocaine-induced bowel perforation typically occur between one and sixty hours after cocaine use.

SAEM Clinical Image Series: The Cocaine Gut

Question 4

Source image: emdocs.net

A 25-year old man presents to your Emergency Department with a painful and swollen thumb after he fell on it during a soccer game with his friends. The X-ray shows a fracture of the first metacarpal base.

Which of the following statements is true about 1st metacarpal base fractures?

A: Bennett fractures are multi-fragmented

B: Bennett fractures are considered stable fractures

C: Rolando fractures require operative management due to the intrinsic instability of the fracture

D: Fracture lines in Bennett fractures typically form a Y or a T shape

The correct answer is C.

This week Rachel Bridwell covered metacarpal base fractures on EmDocs.

Bennett fractures occur on the ulnar side. The base of the 1st MCP can subluxate due to an intact Abductor Pollicis Longus and Brevis and Extensor Pollicis Longus and Brevis.

Both Bennett and Rolando fractures are considered unstable.

Rolando fractures are complex fractures. Operative fixation is necessary.

Fracture lines in Rolando fractures typically form a Y or a T shape

Question 5

Your 4 year old patient presents with a hemolytic anemia, abdominal pain, thrombocytopenia and acute renal failure. You suspect Haemolytic-Uremic Syndrome (HUS).

About 90% of HUS cases follow an infection. Which is the most commonly encountered causative pathogen?

A: Entero-Haemorrhagic E. Coli (EHEC)

B: Streptococcus pneumoniae

C: Staphylococcus aureus

D: Klebsiella pneumoniae

The correct answer is A

Don’t forget the Bubbles covered HUS last week.

´´About 90% of cases follow an infection, most commonly with entero-haemorrhagic E. Coli (EHEC). Other infective causes to be considered include Shigella and Streptococcus pneumoniae.´´

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This quiz was written by Eefje Verschuuren, Nicole van Groningen and Joep Hermans

Reviewed and edited by Rick Thissen

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