What is a defibrillator procedure called?

Defibrillation Procedure Terminology

The procedure of using a defibrillator to deliver an electrical shock to the heart is called defibrillation. 1

Types of Defibrillation Procedures

Defibrillation procedures can be categorized based on the type of device used and the clinical context:

External Defibrillation

• Manual External Defibrillation: Performed by healthcare professionals using manual defibrillators that require interpretation of cardiac rhythm and manual selection of energy levels 2
• Automated External Defibrillation: Performed using Automated External Defibrillators (AEDs) that automatically analyze heart rhythm and determine if a shock is needed 1, 2

Internal Defibrillation

• Implantable Cardioverter Defibrillator (ICD): A surgically implanted device that monitors heart rhythm and delivers shocks when necessary 1
• Wearable Defibrillator (Life Vest): An external wearable device that continuously monitors heart rhythm and delivers shocks when needed 3

Technical Aspects of Defibrillation

Waveform Types

• Monophasic Waveform Defibrillation: Older technology where current flows in one direction 1
• Biphasic Waveform Defibrillation: Modern technology where current flows in two directions, allowing for more effective defibrillation at lower energy levels with less myocardial damage 1, 2

Energy Delivery

• Fixed Energy Protocol: Uses the same energy level for all shocks 1
• Escalating Energy Protocol: Increases energy levels for subsequent shocks if initial attempts fail 1

Electrode Placement for Defibrillation

The standard positions for electrode placement include:

• Anterolateral: One electrode below the right clavicle and the other outside the normal cardiac apex 1, 2
• Anteroposterior: One electrode on the front of the chest and the other on the back 1
• Anterior-left infrascapular: One electrode on the front and one below the left shoulder blade 1
• Anterior-right infrascapular: One electrode on the front and one below the right shoulder blade 1

For optimal effectiveness:

• Electrodes should be 8-12 cm in diameter for adults 1
• In women, electrodes should be placed under breast tissue 1, 2
• For hirsute males, the chest should be shaved prior to electrode application 1

Clinical Protocol for Defibrillation

Modern defibrillation protocols have evolved from multi-shock sequences to single-shock protocols:

• Single-Shock Protocol: Current standard practice - deliver one shock followed immediately by CPR 1
• Three-Shock Sequence: Older protocol that has been replaced due to evidence showing better outcomes with the single-shock approach 1

Important Considerations

• The success of defibrillation decreases by approximately 7-10% for each minute of delay without CPR, and by 3-4% with bystander CPR 1, 2
• Biphasic defibrillators have shown equivalent or higher success rates at lower energy levels compared to monophasic defibrillators 1
• For patients with implanted devices (pacemakers or ICDs), electrodes should not be placed directly over the device 2
• Safety measures include ensuring no one is touching the patient during shock delivery and avoiding defibrillation in oxygen-enriched environments 2

Special Considerations: Cardioversion vs. Defibrillation

It's important to distinguish between:

• Defibrillation: Delivery of unsynchronized electrical shock for life-threatening arrhythmias like ventricular fibrillation 4, 5
• Cardioversion: Delivery of synchronized electrical shock timed with the QRS complex for treating certain arrhythmias like atrial fibrillation 4, 5

The key difference is that cardioversion synchronizes the shock with the cardiac cycle to avoid delivering energy during the vulnerable period of ventricular repolarization, which reduces the risk of inducing ventricular fibrillation.