Should We Abandon Ventilations During CPR?
By Bryan E. Bledsoe, DO, FACEP
May 2005, MERGINET—Gordon A Ewy, MD, professor and chief of cardiology at the University of Arizona in Tucson caught the attention of the national media recently when he published a paper in the journal Circulation that advocates abandoning ventilations in CPR. The article starts with the compelling quote, “Why is it that every time I press on his chest he opens his eyes, and every time I stop to breathe for him he goes back to sleep?”
Ewy reviews the three phases of cardiac arrest due to ventricular fibrillation. The first phase is the electrical phase which lasts ~5 minutes. The second phase is the hemodynamic phase and lasts a variable amount of time (5 to 15 minutes). The final phase is the metabolic phase . He points out that maintaining coronary perfusion pressure during the second phase is paramount for patient survival. And, he points out, that perfusion pressure is lost each time we stop compressions to ventilate the patient. He noted that, even following cardiac arrest, gasping lasts for 2 to 4 minutes. Furthermore, most patients have adequate oxygen stores to go some time without ventilation.
Why has survival from cardiac arrest been so bleak despite the advances in medicine? First, only 1 in 5 patients (at best) receive bystander CPR. Without bystander CPR, 80 percent of patients are already at a disadvantage. Second, it takes even the best rescuers at least 10 seconds to perform quality ventilations (during which time coronary perfusion pressure is lost).
Thus, Ewy recommends the following:
• Use dispatch-assisted CPR with chest compressions only (no ventilations).
• Provide early defibrillation by all levels of providers.
• Optimize guidelines for paramedics.
• Do chest compressions before defibrillation during the hemodynamic phase of cardiac arrest.
• Limit interruptions of chest compressions by rescue personnel.
• Avoid the immediate use of AEDs during the hemodynamic phase (AEDs used in this phase without perfusion may actually decrease the effectiveness of defibrillation).
• After a shock, do 200 compressions before rhythm analysis.
• When ventilation started, do not interrupt chest compressions.
• Consider hypothermia for patients in the metabolic phase of cardiac arrest.
This well-researched and
well-written article gives us considerable food for thought and should be
required reading for all
Ewy GA. “Cardiocerebral Resuscitation: The New Cardiopulmonary Resuscitation.” Circulation. 2005;111:2134-2142.