Quiz 122, July 23th, 2021

Welcome to the 122th FOAMed Quiz.

 

Question 1

Source image: rebelem.com

Both conventional X-ray and point of care ultrasound (POCUS) can be used to diagnose pneumothorax.

This recently published meta-analysis is about X-ray versus POCUS for diagnosis of pneumothorax in trauma patients.

9 studies were included with a total of 1271 patients.

Which imaging modality had the highest sensitivity for pneumothorax in trauma patients?

A: POCUS

B: X-ray

C: POCUS and X-ray were equally sensitive

The correct answer is A.

The paper was covered on JournalFeed last week.

The overall sensitivity of chest ultrasonography was 0.91 (95% confidence interval [CI] 0.85 to 0.94) and the specificity was 0.99 (95% CI 0.97 to 1.00). The sensitivity of chest radiography was only 0.47 (95% CI 0.31 to 0.63) and the specificity was 1.00 (95% CI 0.97 to 1.00).

In 8 of 9 studies, POCUS was performed by Emergency Physicians.

Question 2

Source image: sinaiem.org/

The recently published TTM2 trial is about hypothermia versus normothermia in post cardiac arrest. 1861 patients that were unconscious after out of hospital cardiac arrest (OHCA) were included. They were randomised to cooling to target 33 degrees celsius (targeted hypothermia) or cooling if the temperature reached 37,8 degrees celsius (targeted normothermia).

The primary outcome was death from any cause at 6 months.The main secondary outcome was a poor functional outcome at 6 months, defined as a score of 4 to 6 on the modified Rankin scale.

What did the authors find?

A: Targeted hypothermia did not lead to a lower incidence of death by 6 months than targeted normothermia, but it did lead to a lower incidence of poor functional outcome by 6 months compared to targeted normothermia

B: Targeted hypothermia did lead to a lower incidence of death by 6 months and it did lead to a lower incidence of poor functional outcome by 6 months compared to targeted normothermia

C: Targeted hypothermia did not lead to a lower incidence of death by 6 months and it did not lead to a lower incidence of poor functional outcome by 6 months than targeted normothermia

The correct answer is C

RCEM and RebelEM (among others) covered the recently published TTM2 trial.

465 of 925 patients (50%) in the hypothermia group had died by 6 months, compared with 446 of 925 (48%) in the normothermia group (P = 0.37). 55% in the hypothermia group had moderately severe disability or worse, compared with 479 of 866 (55%) in the normothermia group.

Hypothermia seems to be not beneficial for unconscious patients after OHCA compared to normothermia according to this well done paper.

TTM2: Hypothermia vs Normothermia for Out-of-Hospital Cardiac Arrest

Question 3

Source image: https://www.rcemlearning.co.uk/

Aortic dissection can present with a wide variety of symptoms.

In type A aortic dissection (TAAD), which symptom is most commonly present?

A: Cerebral Malperfusion Syndrome

B: Myocardial Malperfusion Syndrome (RCA or LCA)

C: Cardiac tamponade

D: Aortic regurgitation

The correct answer is D.

County EM covered aortic dissection this week.

The incidence of aortic regurgitation in TAAD is 50-66%.
The incidence of cardiac tamponade in TAAD is 20-36%.
The incidence of myocardial malperfusion in TAAD is 10-15%.
The incidence of cerebral malperfusion in TAAD is 6-14%.

Malperfusion Syndromes of Aortic Dissection

Question 4

Source image: unicef.org

Although evidence does not support the use of antibiotics in uncomplicated upper respiratory tract infections (URTI), they are still quite widely prescribed.

This recently published paper is about the concept of delayed antibiotic prescription (DAP) in children with uncomplicated URTI. This means the parents received a prescription for antibiotics, which they could start if their child was not improving after some days or if the child got sicker. The most commonly prescribed antibiotic was amoxicillin.

436 children were randomised to receive either immediate antibiotic prescription (IAP), DAP or no antibiotic prescription (NAP). Primary outcomes were symptom duration and severity.

What did the authors find?

A: Patients receiving NAP showed shorter symptom duration and decreased severity in children with uncomplicated respiratory infections compared to patients receiving IAP or DAP

B: Patients receiving IAP showed shorter symptom duration and decreased severity in children with uncomplicated respiratory infections compared to patients receiving NAP or DAP

C: Patients receiving DAP showed shorter symptom duration and decreased severity in children with uncomplicated respiratory infections compared to patients receiving NAP or IAP

D: There was no statistically significant difference in symptom duration or severity in children with uncomplicated respiratory infections who received DAP compared to NAP or IAP

The correct answer is D

First10EM, EMOttawa and others covered the paper last week.

Delayed antibiotic prescription reduced the (inappropriate) use of antibiotics in children with uncomplicated URTI compared to immediate antibiotic use. Less antibiotics was not associated with a worse clinical course. This makes sense, for antibiotics simply do not work in this patient category. This is another piece of evidence to support the practice of not prescribing antibiotics for uncomplicated URTI.

Interestingly, the authors found that 80 percent of parents in the immediate antibiotic group believed that antibiotics were very or extremely effective, compared to 40 percent in the delayed antibiotic group and 30 percent in the no antibiotic group.

Delayed Antibiotic Prescription for Children With Respiratory Infections: A Randomized Trial

Question 5

Source image: emdocs.net/

Myocarditis can cause a wide variety of ECG changes. One of these changes is a fragmented QRS (fQRS or sometimes called Ferrero’s sign).

What is the clinical significance of a fragmented QRS?

A: None, a fragmented QRS is a random finding

B: A fragmented QRS cannot be caused by myocarditis. Underlying ischemia is very likely

C: A fragmented QRS in myocarditis represents structural tissue changes. Beware of arrhythmias

The correct answer is C.

EMdocs covered the significance of a fragmented QRS in myocarditis last week.

A fragmented QRS represents structural tissue changes (fibrosis). These structural changes in the myocardium lead to an increased chance of arrhythmias. It is certainly not a benign finding and it is not only caused by ischemia.

ECG Pointers: Myocarditis and QRS fragmentation

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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