CPR - Certified Paramedic Response Electrical Therapy Principles Questions and Answers 1 — Questions and Answers
Question 1: A 68-year-old male is found to be in unstable atrial flutter. His vital signs are BP 80/50 mmHg, HR 160, and he has an altered mental status. Which of the following is the most appropriate initial energy setting for synchronized cardioversion using a biphasic defibrillator?
- 50-100 joules (Correct answer)
- 120-200 joules
- 200 joules
- 360 joules
Correct answer: 50-100 joules
For narrow-complex supraventricular tachycardias like atrial flutter, the recommended initial energy setting for synchronized cardioversion is typically lower. According to AHA guidelines, an initial shock of 50-100 joules is appropriate for symptomatic atrial flutter.
Question 2: You are performing transcutaneous pacing (TCP) on a patient with symptomatic bradycardia. After achieving electrical capture on the monitor, what is the most critical next step to ensure the therapy is effective?
- Increase the pacing rate to 80 beats per minute.
- Administer sedation for patient comfort.
- Confirm mechanical capture by palpating a pulse. (Correct answer)
- Document the millamperage (mA) setting.
Correct answer: Confirm mechanical capture by palpating a pulse.
While electrical capture (a pacer spike followed by a QRS complex) is necessary, it does not guarantee the heart is actually contracting and producing a pulse. The paramedic must confirm mechanical capture by palpating a central pulse (like the femoral) or observing an improved blood pressure. This ensures the electrical stimulation is resulting in effective cardiac output.
Question 3: Which of the following scenarios correctly describes the primary difference between synchronized cardioversion and defibrillation?
- Cardioversion is used for bradycardic rhythms, while defibrillation is for tachycardic rhythms.
- Defibrillation delivers a shock timed with the R-wave, while cardioversion is unsynchronized.
- Cardioversion is indicated for pulseless patients, while defibrillation is for patients with a pulse.
- Defibrillation is an unsynchronized shock for pulseless, chaotic rhythms, while cardioversion is a synchronized shock for unstable tachycardias with a pulse. (Correct answer)
Correct answer: Defibrillation is an unsynchronized shock for pulseless, chaotic rhythms, while cardioversion is a synchronized shock for unstable tachycardias with a pulse.
The key distinction lies in the timing of the shock and the patient's cardiac status. Defibrillation is used for life-threatening, pulseless arrhythmias like Ventricular Fibrillation (VF) and pulseless Ventricular Tachycardia (VT), delivering an unsynchronized, high-energy shock. Synchronized cardioversion is used for patients who have a pulse but are unstable due to a tachyarrhythmia (e.g., atrial fibrillation, atrial flutter, stable VT); the shock is timed to the R-wave to avoid the vulnerable T-wave period.
Question 4: A paramedic is treating a 4-year-old child weighing 18 kg who is in ventricular fibrillation. According to current AHA guidelines, what is the recommended initial energy dose for defibrillation?
- 18 joules (1 J/kg)
- 36 joules (2 J/kg) (Correct answer)
- 72 joules (4 J/kg)
- 100 joules (adult dose)
Correct answer: 36 joules (2 J/kg)
Current pediatric advanced life support guidelines recommend an initial defibrillation dose of 2 J/kg for a shockable rhythm like ventricular fibrillation. For an 18 kg child, this calculates to 36 joules (18 kg * 2 J/kg).
Question 5: When preparing for electrical therapy, which of the following safety precautions is essential to prevent arcing and ensure effective energy delivery?
- Placing pads directly over an implanted pacemaker to capture it.
- Applying the pads over a transdermal medication patch.
- Ensuring the patient's chest is clean and dry. (Correct answer)
- Using a smaller pad size for better skin contact.
Correct answer: Ensuring the patient's chest is clean and dry.
Moisture (like sweat or water) on the chest can cause the electrical current to travel across the skin surface (arc) instead of through the heart, resulting in an ineffective shock and potential skin burns. Therefore, wiping the chest dry is a critical safety and efficacy step. Pads should not be placed over medication patches or implanted devices.
Question 6: A patient with a regular, wide-complex tachycardia and a blood pressure of 88/50 mmHg is being treated. The decision is made to perform synchronized cardioversion. What is the recommended initial energy level for this rhythm?
- 25 joules
- 50 joules
- 100 joules (Correct answer)
- 200 joules
Correct answer: 100 joules
For a stable, regular, monomorphic wide-complex tachycardia (presumed Ventricular Tachycardia), the AHA recommends an initial synchronized shock of 100 joules. If the initial shock is unsuccessful, energy levels can be increased in subsequent attempts.
CPR - Certified Paramedic Response Electrical Therapy Principles Questions and Answers 1
A 68-year-old male is found to be in unstable atrial flutter.
His vital signs are BP 80/50 mmHg, HR 160, and he has an altered mental status.
Which of the following is the most appropriate initial energy setting for synchronized cardioversion using a biphasic defibrillator?