Friday, March 16, 2007

CPR guidelines represent a weakness of evidence based medicine

Note: I had the following post in preparation when Medpundit, Dr. Wes and Kevin M.D. commented on this issue.

At the Cleveland Clinic Heart-Brain Summitt Gordon Ewy, M.D., Chief of Cardiology at the University of Arizona College of Medicine and expert on resuscitation spoke on CPR and the 2005 AHA and ILCOR guidelines and made this statement: “An important reason for these continued poor outcomes is that both sets of guidelines, despite being updated in 2005, recommend an approach to out-of hospital cardiac arrest that is far from optimal.”

Ewy and his colleagues in Tucson have been telling us for years that our approach to CPR is fundamentally wrong. I first cited the evidence here and made follow up posts here and here. Simply put, the Arizona investigators recommend elimination of rescue breathing for adult out of hospital cardiac arrest (unless circumstances such as drowning or choking indicate a respiratory cause) and, for unwitnessed arrest, emphasize compressions rather than AED protocols as the initial modality of treatment. These new procedures have been implemented in public education programs and EMT protocols in Tucson. Ewy’s presentation summarizes and updates the evidence and is an excellent review of the topic.

Sometimes the wheels of EBM turn too slowly. The 2005 guideline authors, dutifully and painstakingly trying to be “evidence based”, largely ignored this evidence because it didn’t meet the EBM standard of randomized clinical trials. Nevertheless, the evidence is compelling, and subsequent studies continue to show marked survival improvement when the new protocols are used. I discussed this topic as an example of a failing of evidence based medicine in the last Medscape Roundtable Discussion on EBM.

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