CPR Special Resuscitation Circumstances 3 — Questions and Answers
Question 1: A patient in cardiac arrest is found with a suspected pulmonary embolism as the cause. What is the recommended thrombolytic agent and dose for arrest-level PE?
- Alteplase 50mg IV bolus (Correct answer)
- Heparin 80 units/kg IV bolus
- Streptokinase 250,000 units over 30 minutes
- Tenecteplase 0.5mg/kg IV bolus
Correct answer: Alteplase 50mg IV bolus
Alteplase 50mg IV bolus is the recommended thrombolytic dose for cardiac arrest suspected to be caused by massive pulmonary embolism.
Question 2: During resuscitation of a lightning strike victim, which phenomenon explains why the cardiac arrest may be easier to reverse than other etiologies?
- Lightning causes a massive DC countershock that may spontaneously terminate within seconds, leaving a viable myocardium (Correct answer)
- Lightning destroys the AV node, causing a predictable complete heart block that responds to pacing
- The electromagnetic pulse from lightning depletes intracellular calcium, which is quickly replenished
- Lightning induces only atrial fibrillation, which self-terminates in most patients
Correct answer: Lightning causes a massive DC countershock that may spontaneously terminate within seconds, leaving a viable myocardium
Lightning delivers a massive direct current shock that often causes transient cardiac arrest with a viable myocardium, making these arrests highly salvageable with prompt CPR.
Question 3: In a morbidly obese patient in cardiac arrest, how should hand placement and compression depth be modified?
- Standard hand placement but increase compression depth to at least 2.4 inches due to increased chest wall compliance (Correct answer)
- Move hands higher on the sternum to avoid liver injury and compress at standard depth
- Use standard placement and depth; body habitus does not alter CPR technique
- Place hands lower on the sternum and reduce rate to 80 per minute
Correct answer: Standard hand placement but increase compression depth to at least 2.4 inches due to increased chest wall compliance
Standard xiphoid-avoidance hand placement is maintained, but providers may need to increase force to achieve adequate compression depth through a thicker chest wall.
Question 4: A patient is in cardiac arrest after ingesting a massive dose of a tricyclic antidepressant (TCA). In addition to standard ACLS, which treatment is most critical?
- Sodium bicarbonate 1-2 mEq/kg IV to achieve serum pH of 7.45-7.55 (Correct answer)
- Flumazenil 0.2mg IV to reverse CNS depression
- Activated charcoal via nasogastric tube during CPR
- Magnesium sulfate 2g IV to stabilize the membrane
Correct answer: Sodium bicarbonate 1-2 mEq/kg IV to achieve serum pH of 7.45-7.55
Sodium bicarbonate reverses TCA-induced sodium channel blockade by increasing serum pH and providing a sodium load, narrowing the QRS and improving cardiac output.
Question 5: What is the primary cause of cardiac arrest in anaphylaxis, and how does it alter ACLS management?
- Distributive shock and airway obstruction; epinephrine 1mg IV every 3-5 min plus aggressive fluid resuscitation (Correct answer)
- Primary ventricular fibrillation; standard ACLS with defibrillation takes priority over epinephrine
- Vasospasm; nitroglycerin is added to the ACLS algorithm
- Myocardial infarction; aspirin and fibrinolytics should be administered immediately
Correct answer: Distributive shock and airway obstruction; epinephrine 1mg IV every 3-5 min plus aggressive fluid resuscitation
Anaphylactic arrest is driven by vasodilation and airway compromise, so IV epinephrine and high-volume fluid resuscitation are critical additions to standard ACLS.
Question 6: A patient arrested after beta-blocker overdose fails to respond to standard ACLS and epinephrine. What high-dose rescue therapy should be considered?
- High-dose insulin euglycemic therapy (HIET) with insulin 1 unit/kg IV bolus (Correct answer)
- Atropine 3mg IV followed by transcutaneous pacing
- Calcium gluconate 3g IV over 5 minutes
- Norepinephrine infusion at 0.5 mcg/kg/min
Correct answer: High-dose insulin euglycemic therapy (HIET) with insulin 1 unit/kg IV bolus
High-dose insulin euglycemic therapy (HIET) improves myocardial carbohydrate metabolism and is a primary antidote for refractory beta-blocker and calcium channel blocker toxicity.
Question 7: During resuscitation of a trauma patient in cardiac arrest, which intervention is the highest priority before standard ACLS?
- Identify and treat reversible causes (4 H's and 4 T's) including hemorrhage, tension pneumothorax, and tamponade (Correct answer)
- Establish IV access and administer epinephrine 1mg IV immediately
- Perform endotracheal intubation to secure the airway before compressions
- Obtain a 12-lead ECG to identify the underlying rhythm
Correct answer: Identify and treat reversible causes (4 H's and 4 T's) including hemorrhage, tension pneumothorax, and tamponade
Traumatic cardiac arrest is almost always caused by reversible factors; identifying and treating hemorrhage, tension pneumothorax, or tamponade is the primary intervention.
CPR Special Resuscitation Circumstances 3
A patient in cardiac arrest is found with a suspected pulmonary embolism as the cause.
What is the recommended thrombolytic agent and dose for arrest-level PE?