Witnessed arrest

Witnessed arrest!

Case Author: Howard A. Schwid, M.D.

Affiliation: University of Washington

Date of Last Modification: March 9, 2006

Learning Objectives:

1. Describe the differences in treatment for a witnessed versus unwitnessed arrest.

2. Describe the suggested technique for CPR.

Differences in Treatment for Witnessed and Unwitnessed Arrest:

1. If the healthcare provider witnesses the arrest and a defibrillator is immediately available, a pulseless patient can be immediately defibrillated.

2. If there is a delay between the onset of the arrest and the availability of the defibrillator, CPR should be initiated.

3. There is some evidence that patients with a cardiac arrest outside the hospital have better outcome if the healthcare providers perform 5 cycles of CPR prior to the first defibrillation attempt. See the references below.

4. A witnessed arrest with the defibrillator immediately available is fairly unusual. In most cases, CPR will be the first resuscitative step.

CPR Technique:

1. Early electrical defibrillation is the definitive treatment for V Fib.

2. CPR should be performed until the defibrillator is available.

3. For adults that are not intubated, compress 30 times then deliver 2 positive pressure breaths. Repeat this cycle at 100 compressions per minute.

4. Compress the chest "fast and hard". Compress over the lower half of the sternum but not ver the xiphoid.

5. Allow the chest to fully recoil between compressions.

6. Resume CPR immediately after electrical defibrillation. Continue for 5 cycles of CPR, then assess and continue the treatment algorithm. Three stacked shocks are no longer recommended.

References:

1. Cobb, Fahrenbruch, Walsh, Copass: Influence of cardiopulmonary resuscitation prior to defibrillation in patients with out-of-hospital ventricular fibrillation. JAMA 1999; 281; 1182-1188.

2. Wik, Hansen: Delaying defibrillation to give basic cardiopulmonary resuscitation to patients with out-of-hospital ventricular fibrilation: a randomized trial. JAMA 2003; 289: 1389-1395.