Defibrillation 101: Understanding How and When to Use a Defibrillator for Nursing Students

What is Defibrillation?

• ⚡ Defibrillation is the process of delivering an electrical current to the heart to restore a normal cardiac rhythm.
• 💡 It can be delivered externally via pads or internally through an implanted device.
• 📌 The first external defibrillator, created in 1957, weighed 240 lbs, a stark contrast to modern, lighter devices.

Why Defibrillation is Crucial

• ❤️ Heart disease is the leading cause of death in the U.S., with ventricular fibrillation (V-fib) being a common cause of sudden cardiac arrest.
• 📈 Early defibrillation is critical, as survival rates decrease by approximately 10% for every minute that passes without it.

Shockable Heart Rhythms

• ⚠️ The two primary deadly heart rhythms that respond to defibrillation are ventricular fibrillation (V-fib) and pulseless ventricular tachycardia (pulseless VTAC).
• 〰️ V-fib presents as a chaotic, wavy line on the cardiac monitor, indicating disrupted electrical impulses and ineffective ventricular contraction.
• ⚡ Pulseless VTAC involves fast but ineffective contractions, leading to a significant drop in cardiac output and a lack of pulse, with a rate over 100 bpm and wide QRS complexes.

How Defibrillation Works and Device Types

• 🔌 Defibrillation works by causing a simultaneous depolarization of the myocardium, creating a momentary pause in cardiac activity, allowing a normal rhythm to potentially resume.
• 🏥 Common defibrillator types include the Automated External Defibrillator (AED), the Advanced Life Support (ALS) defibrillator used by medical professionals, Implanted Cardioverter Defibrillators (ICDs), and Wearable Cardioverter Defibrillators (WCDs).
• ⚙️ ALS defibrillators can often be used manually or in an AED-like analyze mode.

Defibrillator Settings and Safe Practices

• ⚡ Defibrillators use joules as a unit of energy; biphasic defibrillators are current and use lower energy levels than older monophasic devices.
• 📈 For biphasic defibrillators, the recommended starting dose for adults is 120-200 joules, increasing stepwise up to 360 joules if needed.
• ✅ Safety precautions include removing excessive chest hair, jewelry, drying the skin, ensuring good pad contact, avoiding placement over breast tissue or pacemakers, ensuring oxygen is off before shocking, and confirming all rescuers are clear.
• 🔄 Immediately resume chest compressions after delivering a shock, and do not pause to check for a pulse for at least two minutes.