Passive Oxygen Insufflation Is Superior to Bag-Valve-Mask Ventilation for Witnessed Ventricular Fibrillation Out-of-Hospital Cardiac Arrest
Received 22 January 2009; received in revised form 27 March 2009 and 23 April 2009; accepted 15 June 2009. published online 07 August 2009.
Study objective
Assisted ventilation may adversely affect out-of-hospital cardiac arrest outcomes. Passive ventilation offers an alternate method of oxygen delivery for these patients. We compare the adjusted neurologically intact survival of out-of-hospital cardiac arrest patients receiving initial passive ventilation with those receiving initial bag-valve-mask ventilation.
Methods
The authors performed a retrospective analysis of statewide out-of-hospital cardiac arrests between January 1, 2005, and September 28, 2008. The analysis included consecutive adult out-of-hospital cardiac arrest patients receiving resuscitation with minimally interrupted cardiopulmonary resuscitation (CPR) consisting of uninterrupted preshock and postshock chest compressions, initial noninvasive airway maneuvers, and early epinephrine. Paramedics selected the method of initial noninvasive ventilation, consisting of either passive ventilation (oropharyngeal airway insertion and high-flow oxygen by nonrebreather facemask, without assisted ventilation) or bag-valve-mask ventilation (by paramedics at 8 breaths/min). The authors determined adjusted neurologically intact survival from hospital and public records and by telephone interview and mail questionnaire. The authors compared adjusted neurologically intact survival between ventilation techniques by using generalized estimating equations.
Results
Among the 1,019 adult out-of-hospital cardiac arrest patients in the analysis, 459 received passive ventilation and 560 received bag-valve-mask ventilation. Adjusted neurologically intact survival after witnessed ventricular fibrillation/ventricular tachycardia out-of-hospital cardiac arrest was higher for passive ventilation (39/102; 38.2%) than bag-valve-mask ventilation (31/120; 25.8%) (adjusted odds ratio [OR] 2.5; 95% confidence interval [CI] 1.3 to 4.6). Survival between passive ventilation and bag-valve-mask ventilation was similar after unwitnessed ventricular fibrillation/ventricular tachycardia (7.3% versus 13.8%; adjusted OR 0.5; 95% CI 0.2 to 1.6) and nonshockable rhythms (1.3% versus 3.7%; adjusted OR 0.3; 95% CI 0.1 to 1.0).
Conclusion
Among adult, witnessed, ventricular fibrillation/ventricular tachycardia, out-of-hospital cardiac arrest resuscitated with minimally interrupted cardiac resuscitation, adjusted neurologically intact survival to hospital discharge was higher for individuals receiving initial passive ventilation than those receiving initial bag-valve-mask ventilation.
aArizona Department of Health Services Bureau of Emergency Medical Services and Trauma System, Phoenix, AZ
bDepartment of Emergency Medicine, Maricopa Medical Center, Phoenix, AZ
cUniversity of Arizona Sarver Heart Center, Tucson, AZ
dDepartment of Medicine, University of Arizona College of Medicine, Tucson, AZ
eDepartment of Emergency Medicine, University of Arizona College of Medicine, Tucson, AZ
fCritical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA
gDepartment of Emergency Medicine, Mayo Clinic, Jacksonville, FL
Address for correspondence: Bentley J. Bobrow, MD, Department of Emergency Medicine, Maricopa Medical Center, 2601 E Roosevelt St, Phoenix, AZ 85008; 602-364-0580
Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article that might create any potential conflict of interest. The authors have stated that no such relationships exist. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement.
Supervising editor: Henry E. Wang, MD, MS
Author contributions: BJB, GAE, LC, RAB, ABS, TFV, RWH, and KBK conceived the study. All authors designed the study. BJB, GAE, and LC supervised the conduct of the analysis. BJB and LC supervised the data collection. BJB and LC recruited the participating EMS agencies. LC and VC managed the data including quality control. VC provided statistical advice on study design and performed the final analysis of the data. BJB, GAE, RAB, ABS, and TFV drafted the article and all authors contributed substantially to its revision. BJB takes responsibility for the paper as a whole.
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