DC Clinical Procedures & Protocols 3 — Questions and Answers
Question 1: After successful resuscitation from VF cardiac arrest, targeted temperature management (TTM) is most beneficial for which patient population?
- Patients with ROSC who are alert and oriented
- Comatose survivors of out-of-hospital cardiac arrest (Correct answer)
- Patients with persistent VF refractory to 4 shocks
- Patients in cardiogenic shock awaiting IABP
Correct answer: Comatose survivors of out-of-hospital cardiac arrest
TTM at 32–36°C is indicated for comatose post-cardiac arrest patients to reduce neurological injury from reperfusion damage.
Question 2: A rhythm strip shows a regular rate of 150 bpm with a sawtooth baseline and 2:1 conduction. This most likely represents:
- Atrial tachycardia with block
- Atrial flutter with 2:1 conduction (Correct answer)
- Junctional tachycardia
- AVNRT
Correct answer: Atrial flutter with 2:1 conduction
Atrial flutter characteristically produces a sawtooth F-wave pattern at ~300 bpm with the ventricular rate at a fraction determined by AV conduction ratio.
Question 3: The correct pad placement for anterior-posterior defibrillation uses one pad:
- Right subclavicular and left lateral chest wall
- Center of chest and between the scapulae on the back (Correct answer)
- Left subclavicular and right lateral chest wall
- Apex and right lateral rib
Correct answer: Center of chest and between the scapulae on the back
Anterior-posterior placement positions one pad over the precordium and the other on the posterior left thorax to maximize current through the heart.
Question 4: Which drug is first-line for treating symptomatic sinus bradycardia in a hemodynamically stable patient?
- Epinephrine 1 mg IV
- Atropine 0.5 mg IV (Correct answer)
- Dopamine infusion at 10 mcg/kg/min
- Isoproterenol 2 mcg/min
Correct answer: Atropine 0.5 mg IV
Atropine 0.5 mg IV is the first-line agent for symptomatic bradycardia, reversing vagal-mediated slowing of the SA and AV nodes.
Question 5: During CPR, the recommended compression-to-ventilation ratio for a single rescuer treating an adult victim is:
- 15:2
- 30:2 (Correct answer)
- 15:1
- 5:1
Correct answer: 30:2
Current AHA guidelines specify a 30:2 compression-to-ventilation ratio for single-rescuer adult CPR to minimize interruptions to chest compressions.
Question 6: A patient converts from VF to a sinus rhythm after the third shock. Post-ROSC, which antiarrhythmic infusion is typically initiated to prevent recurrence?
- Lidocaine 1.5 mg/kg bolus only
- Amiodarone 1 mg/min infusion for 6 hours then 0.5 mg/min (Correct answer)
- Procainamide 17 mg/kg loading dose IV
- Magnesium sulfate 4 g IV bolus
Correct answer: Amiodarone 1 mg/min infusion for 6 hours then 0.5 mg/min
Post-ROSC amiodarone maintenance infusion (1 mg/min × 6 h, then 0.5 mg/min × 18 h) is the standard protocol to suppress VF recurrence.
Question 7: In a patient with torsades de pointes, the preferred pharmacological treatment is:
- Amiodarone 150 mg IV
- Magnesium sulfate 1–2 g IV (Correct answer)
- Procainamide 500 mg IV
- Diltiazem 0.25 mg/kg IV
Correct answer: Magnesium sulfate 1–2 g IV
IV magnesium sulfate shortens the QT interval and suppresses early afterdepolarizations that trigger torsades de pointes.
DC Clinical Procedures & Protocols 3
After successful resuscitation from VF cardiac arrest, targeted temperature management (TTM) is most beneficial for which patient population?