The initial energy selection for defibrillation in pulseless ventricular tachycardia for a:

Appeared in: GMCH - 2016

Explanation

Pulseless Ventricular Tachycardia (VT) is a life-threatening, shockable rhythm requiring immediate defibrillation.
According to Advanced Cardiovascular Life Support (ACLS) guidelines, the initial energy dose for a biphasic defibrillator is between 120-200 Joules.
The specific dose may be manufacturer-dependent, but 150 J is a widely accepted and commonly used initial energy setting for biphasic defibrillation in adults.
This approach provides effective termination of the arrhythmia while minimizing potential myocardial injury compared to higher energy levels.

Option A: This energy level (32 J) is therapeutically insignificant for adult defibrillation with any type of device. The standard dose for a monophasic defibrillator is 360 J.
Option B: This energy level (16 J) is far too low for defibrillating an adult in pulseless VT. It would be ineffective.
Option C: This energy level (100 J) is insufficient for a monophasic defibrillator, which requires a standard dose of 360 J to effectively defibrillate an adult.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Defibrillation energy settings for pulseless ventricular tachycardia as background academic context rather than a clinical decision trigger.
Prompt recognition of a shockable rhythm (pulseless VT/VF) and immediate defibrillation are critical links in the chain of survival, significantly improving patient outcomes.
Nurses must be familiar with the specific type of defibrillator (monophasic or biphasic) available in their unit to select the correct energy dose quickly and safely during a cardiac arrest.
During a code, the nurse's role includes ensuring team safety by loudly calling 'Clear!' and visually verifying that no one is in contact with the patient or the bed before the shock is delivered.

How to Approach the Question

First, identify the key elements of the question: 'initial energy', 'defibrillation', and 'pulseless ventricular tachycardia'.
Recognize that pulseless VT is a life-threatening emergency treated according to ACLS (Advanced Cardiovascular Life Support) protocols.
Recall the two main types of defibrillators and their standard energy settings for adults: monophasic (360 J) and biphasic (120-200 J).
Evaluate each option against these standards.
Eliminate options A, B, and C as they list incorrect energy levels for the specified defibrillator type.
Confirm that option D, 'Biphasic defibrillator is 150 J', falls within the correct recommended range for an initial shock with a biphasic device.

Concept Tested & Keywords

Concept Tested: Defibrillation energy settings for pulseless ventricular tachycardia
Stem keywords: initial energy selection, defibrillation, pulseless ventricular tachycardia
Lead-in keywords: for a
Negative lead-in flag: false

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E6 Medicine Davidson Principles Practice 24e pp. 502-504, 477-479

Practise the full GMCH - 2016

Attempt every question from this paper in a timed mock, then review the full solution for each one.