Mouth to mouth ventilation does not improve CPR
When performed by a bystander, cardiopulmonary resuscitation (CPR) with chest compression alone provides similar survival to standard CPR with chest compression plus mouth to mouth ventilation in sudden cardiac arrest, according to a new study.
Researchers at the University of Washington, in Seattle, compared the outcome of 520 cases of cardiac arrest outside hospital. In each case, a bystander was randomised to receive telephone instructions by a fire department dispatcher, who provided either standard CPR instructions with mouth to mouth ventilation or instructions for chest compression alone. Instructions for compression took only 1.4 minutes less than instructions for compression plus mouth to mouth breathing, the report indicates.
Resuscitation methods being demonstrated at a specialist unit (JAMES HERMIT, GLASGOW)
Overall, 64 patients, 29 (10.4%) in the mouth to mouth breathing group and 35 (14.6%) in the chest compression only group, survived to hospital discharge, the authors report. This difference was not significant, and adjustment of the results for the patient's age, race, location, fire department response time, and other factors in a logistic regression model yielded similar results (New England Journal of Medicine 2000;342:1546-53).
"This challenges preconceived notions, but provides some proof that the challenge is realistic. I think people need to think rationally and carefully about the process of teaching and performing the various components of CPR," said lead author Dr Alfred Hallstrom, director of the Clinical Trials Coordinating Center in Seattle, which is affiliated with the University of Washington.
Enrolment into the study, which ran from January 1992 to August 1998, totalled 1296 cases of cardiac arrest. However, 776 cases were excluded for various reasons, the most common being misdiagnosis of cardiac arrest and arrest due to drug overdose or alcohol intoxication.
In an editorial accompanying the study, Dr Gordon A Ewy of the University of Arizona Sarver Heart Center called the paper a "landmark study" that "will encourage efforts to re-evaluate the way we teach and perform basic CPR." He said that simplification of CPR instructions would be beneficial: "Authorities in CPR have come to realise that our standard method of performing basic CPR is difficult for the average layperson to learn, retain, and perform" (New England Journal of Medicine 2000;342:1599-600).
However, mouth to mouth resuscitation should not be abandoned, according to a statement from the American Heart Association. "A trained rescuer is very likely going to increase the chances of survival by doing mouth to mouth along with chest compression," said Dr Jerry Potts, director of science for the association's emergency cardiovascular care programme. "People should be taught both components of CPR and be able to respond quickly if someone near them has cardiac arrest."
Scott Gottlieb, New York
studentBMJ 2000;08:217-258 July ISSN 0966-6494
