The treatment of (VF and pulseless VT) Ventricular Fibrillation and Pulseless Ventricular Tachycardia is included in the Cardiac Arrest Algorithm. VF and pulseless VT are shockable rhythms and treated in similar fashion. Asystole and PEA are also included in the cardiac arrest algorithm but are non-shockable rhythms.
Ventricular fibrillation and pulseless ventricular tachycardia are treated using the left branch of the cardiac arrest arrest algorithm.
Click below to view the cardiac arrest algorithm diagram. When done click again to close the diagram. Cardiac Arrest Algorithm Diagram
Many of the patients that experience sudden cardiac arrest demonstrate VF at some point in their arrest, therefore, training emphasis is placed on the cardiac arrest algorithm.
Rapid treatment of VF using the cardiac arrest algorithm has been established as the best scientific approach to restoring spontaneous circulation.
There are several important points that should be considered when initiating the cardiac arrest algorithm:
- High-quality CPR should be performed until the defibrillator is attached the patient.
- Interruptions in chest compressions should be kept to a minimum.
- Rapid use of the defibrillator should be emphasized.
- If possible, use a manual defibrillator over an AED since the use of the AED can result in prolonged interruptions in chest compressions for rhythm analysis and shock administration.
CPR is always immediately resumed for 2 minutes (5 cycles) between each shock.
Defibrillation and the Shock
Most defibrillators used today are biphasic. Biphasic means that the electrical current travels from one paddle to the other paddle and then back in the other direction. The biphasic shock also requires less energy to restore normal heart rhythm and helps to reduce skin burns and cellular damage to the heart.
When using a biphasic defibrillator with VF or pulseless VT, start with the dose recommended by the manufacturer which is typically 120-200 J. If the manufacturer recommended shock dose is unknown start with the maximum available dose. Every shock after the initial shock should be of equal or greater dose strength. Increase the dosing in a stepwise fashion as needed. (Example: 120 J » 200 J » 300 J » 360 J.)
To ensure safety during the shock, providers should always announce the following statement, “I am going to shock on three. One, I’m clear…Two, you’re clear…Three, everybody is clear.”
Do you know the difference between defibrillation, synchronized cardioversion, and unsynchronized cardioversion? Find out here.
VF and Pulseless VT Medications
A vasopressor is a medication that produces vasoconstriction and a rise in blood pressure. The vasopressor that is used for the treatment of VF/Pulseless VT is epinephrine.
Epinephrine is primarily used for its vasoconstrictive effects. Vasoconstriction is important during CPR because it will help increase blood flow to the brain and heart.
Rhythm checks should be performed after 5 cycles of CPR. Limit rhythm checks to less than 10 seconds to minimize interruptions in CPR. Pulse checks should be performed when a rhythm check reveals a change in the rhythm to a rhythm that is organized and could be generating a pulse.
Amiodarone, lidocaine, and magnesium are antiarrhythmic medications that are used in the left branch of the Cardiac Arrest Algorithm. These medications were be reviewed in more detail in the previous lesson.