Welcome to the 186th FOAMed Quiz.
Your 65 year old patient with Myasthenia Gravis presents with Myasthenic crisis and you decide to intubate the patient using RSI.
Which of the following statements is true regarding neuromuscular blockers?
A: A higher dose of non-depolarising agents and depolarising agents is generally required in patients with MG
B: A lower dose of non-depolarising agents and depolarising agents is generally required in patients with MG
C: A higher dose of non-depolarising agents and a lower dose of depolarising agents is generally required in patients with MG
D: A lower dose of non-depolarising agents and a higher dose of depolarising agents is generally required in patients with MG
The correct answer is D.
Neuromuscular blockers in Myasthenia Gravis were covered on UMEM last week.
Myasthenia Gravis patients have increased sensitivity to non-depolarizing agents and require lower doses than typically used. They have decreased expression of normal acetylcholine receptors which are required for depolarizing agents to work effectively and require higher doses than typically used.
Warfarin should not be used together with naproxen due to the chance of increased levels of warfarin.
What is the major mechanism for this drug interaction?
A: Naproxen increases absorption of warfarin
B: Naproxen can displace warfarin from the plasma protein binding sites, leading to more unbound warfarin available
C: Naproxen interacts with cytochrome P2C9 and decreases warfarin metabolism
D: Naproxen decreases active tubular secretion of warfarin
The correct answer is B
Geekymedics covered mechanisms of drug interaction last week.
Naproxen can displace warfarin from the plasma protein binding sites, leading to more unbound warfarin available, increasing its pharmacological effect (as well as toxic effects).
Which of the following is useful advice for ultrasound guided peripheral cannula placement?
A: Look for flash in the cannula hub, as soon as you see it, advance the cannula
B: Insert the needle at an angle of about 60 degrees. The steeper you go, the more visible the needle will be on the screen
C: Don’t use a tourniquet, for it will increase the chance of bleeding
D: Aim for a vein less than 1 cm deep
The correct answer is D.
DFTB covered ultrasound guided peripheral IV placement last week.
Never look for the flash of blood in the hub, look at your screen.
Insert the needle at 30-45 degrees. If you go steeper, the needle will be hard to visualize.
Always apply a tourniquet.
And indeed, aim for superficial veins. The deeper the vein, the more chance of dislocation.
5 top tips to gain confidence in ultrasound-guided peripheral IVs
The performance of D-dimer in exclusion of pulmonary embolism in COVID positive patients remains somewhat subject of debate.
In this recently published retrospective trial, 10837 patients who received a D-dimer and COVID test in the ED were analyzed. 4311 patients turned out to have COVID. Follow up to detect pulmonary embolism was 30 days.
What did the authors find?
A: A d-dimer cutoff of 500 ng/mL was found to perform a little bit better in COVID positive patients compared to COVID negative patients
B: A d-dimer cutoff of 500 ng/mL was found to perform a little bit better in COVID negative patients compared to COVID positive patients
C: A d-dimer cutoff of 500 ng/mL was found to perform equal in both groups
The correct answer is B.
The paper was covered on JournalFeed last week.
The prevalence of pulmonary embolism in the cohort was 3.7 percent.
A D-dimer cutoff value of 500 ng/mL had a sensitivity of 96.2 percent in COVID positive patients, compared to 98.5 percent in COVID negative patients. The NPV was 99.6 percent in COVID positive patients and 99.9 percent in COVID negative patients.
The sensitivity of age adjusted D-dimer cutoff (age times 10 with a lower limit of 500 ng/mL) had a sensitivity of 93.9 percent in COVID positive patients, compared to 97.1 percent in COVID negative patients.
The authors conclude that while the sensitivity of D-dimer with a cutoff of 500 ng/mL for pulmonary embolism was a little lower in COVID positive patients, it is still a useful marker.
Keep in mind the authors did not include any probability scores (like YEARS) in this paper, which would have been interesting. Furthermore, quite some d-dimer levels were not drawn because of suspected embolism, but purely for routine use in COVID patients.
Journal Feed Weekly Wrap-Up
The X-ray shown above belongs to your 46-year-old patient in the Emergency Department. It is a female with a history of diabetes mellitus and obesity. She fell onto her right knee and has difficulty with walking right now.
Which of the following diagnoses is most likely?
A: Quadriceps tendon rupture
B: Displaced tibial plateau fracture with posterior cruciate ligament injury
C: Patellar tendon rupture
D: Contusion of the knee
The correct answer is C.
This case was covered on SplintER Series this week.
Patellar tendon ruptures are most frequently seen in men under 40 years old. This is opposed to quadriceps tendon ruptures, which are typically seen in older patients. Risk factors of a patellar tendon rupture are; diabetes mellitus, chronic renal failure and gout.
The elevated patella is a sign of a patellar tendon rupture.
SplintER Series: Patellar Tendon Rupture
This quiz was written by Sophie Nieuwendijk, Denise van Vossen, Nicole van Groningen, Jeroen van Brakel, Noortje Geerts and Renée Deckers
Reviewed and edited by Rick Thissen