CCRN Critical Care Pharmacology 2 — Questions and Answers
Question 1: A patient on a continuous heparin infusion develops a platelet count drop from 240,000 to 90,000 on day 7. The 4T score is 6. What is the most appropriate next step?
- Increase the heparin dose
- Discontinue heparin and start an alternative anticoagulant (Correct answer)
- Transfuse platelets
- Switch to low-molecular-weight heparin
Correct answer: Discontinue heparin and start an alternative anticoagulant
A 4T score ≥4 indicates intermediate-to-high probability of HIT; heparin must be discontinued immediately and a non-heparin anticoagulant (argatroban or fondaparinux) initiated.
Question 2: Which electrolyte abnormality is the most dangerous complication of aggressive insulin therapy in DKA management?
- Hypernatremia
- Hypokalemia (Correct answer)
- Hyperphosphatemia
- Hypercalcemia
Correct answer: Hypokalemia
Insulin shifts potassium intracellularly, and patients with DKA are already total-body potassium depleted; hypokalemia can cause fatal cardiac arrhythmias.
Question 3: Which drug interaction poses a risk of serotonin syndrome in ICU patients receiving fentanyl alongside?
- Metoprolol
- Linezolid (an MAO inhibitor) (Correct answer)
- Vancomycin
- Furosemide
Correct answer: Linezolid (an MAO inhibitor)
Linezolid has MAO-inhibiting properties; combining it with serotonergic opioids like fentanyl can precipitate serotonin syndrome.
Question 4: A patient receiving IV amiodarone through a peripheral IV develops pain and erythema at the infusion site. What is the most likely complication?
- Amiodarone-induced pulmonary toxicity
- Phlebitis due to amiodarone's low pH and high osmolarity (Correct answer)
- Anaphylactic reaction to the polysorbate diluent
- Peripheral neuropathy
Correct answer: Phlebitis due to amiodarone's low pH and high osmolarity
Amiodarone IV formulation contains polysorbate 80 and has a low pH and high osmolarity, frequently causing phlebitis; central venous access is preferred for prolonged infusions.
Question 5: Which medication is used to reverse the anticoagulant effect of dabigatran (a direct thrombin inhibitor) in life-threatening bleeding?
- Protamine sulfate
- Vitamin K
- Idarucizumab (Praxbind) (Correct answer)
- Fresh frozen plasma
Correct answer: Idarucizumab (Praxbind)
Idarucizumab (Praxbind) is a monoclonal antibody fragment that specifically and rapidly reverses dabigatran's anticoagulant effect.
Question 6: Which vasopressor has positive inotropic effects primarily via beta-1 receptors and is added to norepinephrine in septic shock with myocardial depression?
- Phenylephrine
- Vasopressin
- Dobutamine (Correct answer)
- Dopamine
Correct answer: Dobutamine
Dobutamine is a beta-1 agonist that increases cardiac contractility and is used as an adjunct in septic shock complicated by myocardial depression or low cardiac output.
CCRN Critical Care Pharmacology 2
A patient on a continuous heparin infusion develops a platelet count drop from 240,000 to 90,000 on day 7.
The 4T score is 6.
What is the most appropriate next step?