2019. QUIZ 22. WEEK 07

Question 1

A Salicylate poisoning eventually leads to metabolic acidosis. However, what is a finding with regard to the acid base status in the first stage of toxicity?

A: Respiratory alkalosis

B: Respiratory acidosis

C: Metabolic acidosis

The correct answer is A

Josh Farkas published a podcast on salicylate in The Internet Book of Critical Care.

It seems salicylates affect the medulla directly, increasing respiratory drive and leading to respiratory alkalosis. Eventually (after developing a metabolic acidosis) a respiratory acidosis can be found as well.

IBCC chapter: Salicylate intoxication

Question 2

Your patient is brought to your Emergency Department having continuous convulsions for 15 minutes. Prehospital services gave this patient 2 times 5 mg midazolam intravenously with no effect. A quick chart review tells you the patient is using INH. What should be your next treatment option?

A: Phenytoin

B: Lorazepam

C: Valproate

D: Pyridoxine

The correct answer is D

Howard Greller (Tox and Hound) wrote a really good post about toxins disturbing the glutamate – GABA balance on EMcrit.

This patient most likely has a hydrazine intoxication. Remember the H in INH stands for hydrazide. Hydrazine intoxication leads to decreased production of GABA due to inhibition of glutamic acid decarboxylase (GAD) and activated pyridoxine. Seizures in these patients are due to depletion of GABA and therefore benzodiazepines are often not effective (they need GABA to work in the first place). The first line treatment should be to restore the GABA levels by giving pyridoxine (and reactivating the conversion of glutamate to GABA). The dose is 5 grams!! Afterwards you can follow your standard status epilepticus protocol.

Tox and Hound – No GABA GABA!

Question 3

A 4-year old boy comes in after a motor vehicle collision. His cervical spine is immobilised. His primary survey is unremarkable. He is cooperative, denies any cervical tenderness or dysesthesia. You want to clear the cervical spine without imaging, using the Nexus criteria. Which statement is true regarding the use of Nexus criteria in children?

A: Nexus criteria are notoriously unreliable in children under 12 years old

B: The evidence on diagnostic value of the Nexus criteria in children is just as strong as the evidence in adults

C: In children < 8 years old the evidence on the Nexus criteria is not too strong

The correct answer is C

Sean M. Fox wrote really useful review on pediatric cervical spine injury on Pediatric EM Morsels.

Well, Nexus is the best clinical decision tool we have on the clearance of the cervical spine in children. However, keep in mind that in in the original Nexus paper, of the 34000 patients only 905 where under 8 years old. Of these 905 patients, only 4 had injuries. So the evidence in this age group isn’t too strong. Personally I use a little Nexus and a lot of common sense in the young ones with suspected cervical spine injury.

Pediatric Cervical Spine Injury

Question 4

Your otherwise healthy 52 year old patient presents after syncope. He vomited a couple of times and has diarrhea as well. The Canadian Syncope Risk Score result is low (meaning a low risk on serious arrhythmic outcome < 30 days), the ECG is normal. You suspect a vagal syncope and you think he probably can go home. This recently published paper might give you the evidence to support this approach. According to this paper, how long should you observe this patient in the Emergency Department?

A: 1 hour

B: 2 hours

C: 10 hours

D: 24 hours

The correct answer is B

Clay Smith discussed this paper recently on Journal Feed.

After syncope, most clinically significant findings and adverse events happen within the first 6 hours of observation in medium and high risk patients and in the first 2 hours in low risk patients. The article combined the Canadian Syncope Risk Score (CSRS) and time of observation and found that with a low CSRS and an observation of 2 hours in the ED the risk of ‘’serious arrhythmic outcome’’ within 30 days was only 0,2%.

Article a day, Journal Feed

Question 5

Source image: www.LITFL.com

You evaluate a 32 year old patient with syncope. The physical exam is unremarkable and the ECG shows a pattern consistent with Wolf-Parkinson-White syndrome (WPW). Which of the following statements is true about ECG findings associated with WPW?

A: Positive delta wave in the precordial leads is associated with a left sided accessory pathway

B: Negative delta wave in leads V1 and V2 is associated with a left sided accessory pathway

C: Positive delta wave in leads V1 and V2 is associated with right sided accessory pathway

D: The QRS complex in WPW is often < 90 ms

The correct answer is A

Juliette Conte wrote a post about WPW on emDOCs

A positive delta wave in the precordial leads is associated with a left sided accessory pathway and a negative delta wave in leads V1 and V2 is associated with a right sided accessory pathway. The QRS complex is typically > 100 ms.

ECG Pointers: Syncope and Wolff-Parkinson-White

Thank you for joining us. Hope to see you next week!

Eefje and Rick, the FOAMed Quiz crew

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