Ong MEH, Ornato JP, Edwards DP, Dhindsa HS, Best AM, Ines CS, Hickey S, Clark B, Williams DC, Powell RG, Overton JL, Peberdy MA. Use of an Automated, Load-Distributing Band Chest Compression Device for Out-of-Hospital Cardiac Arrest Resuscitation. JAMA. 2006;295(22):2629-2637. doi:10.1001/jama.295.22.2629
Author Affiliations: Departments of Epidemiology and Community Health (Dr Ong) and Biostatistics (Dr Best), Virginia Commonwealth University, and Department of Emergency Medicine (Drs Ong, Dhindsa, Ines, and Hickey), Department of Internal Medicine, Division of Cardiology (Dr Peberdy), and Department of Emergency Medicine and the Virginia Commonwealth University Reanimation, Engineering, and Shock Center (Drs Ornato and Peberdy), Virginia Commonwealth University Health System; The Richmond Ambulance Authority (Messrs Edwards and Overton); Department of Emergency Medicine, Chippenham & Johnston-Willis Hospital (Dr Clark); Department of Emergency Medicine, Richmond Community Hospital (Dr Williams); and Department of Emergency Medicine, St Mary's Hospital (Dr Powell), Richmond.
Context Only 1% to 8% of adults with out-of-hospital cardiac arrest survive to hospital discharge.
Objective To compare resuscitation outcomes before and after an urban emergency medical services (EMS) system switched from manual cardiopulmonary resuscitation (CPR) to load-distributing band (LDB) CPR.
Design, Setting, and Patients A phased, observational cohort evaluation with intention-to-treat analysis of 783 adults with out-of-hospital, nontraumatic cardiac arrest. A total of 499 patients were included in the manual CPR phase (January 1, 2001, to March 31, 2003) and 284 patients in the LDB-CPR phase (December 20, 2003, to March 31, 2005); of these patients, the LDB device was applied in 210 patients.
Intervention Urban EMS system change from manual CPR to LDB-CPR.
Main Outcome Measures Return of spontaneous circulation (ROSC), with secondary outcome measures of survival to hospital admission and hospital discharge, and neurological outcome at discharge.
Results Patients in the manual CPR and LDB-CPR phases were comparable except for a faster response time interval (mean difference, 26 seconds) and more EMS-witnessed arrests (18.7% vs 12.6%) with LDB. Rates for ROSC and survival were increased with LDB-CPR compared with manual CPR (for ROSC, 34.5%; 95% confidence interval [CI], 29.2%-40.3% vs 20.2%; 95% CI, 16.9%-24.0%; adjusted odds ratio [OR], 1.94; 95% CI, 1.38-2.72; for survival to hospital admission, 20.9%; 95% CI, 16.6%-26.1% vs 11.1%; 95% CI, 8.6%-14.2%; adjusted OR, 1.88; 95% CI, 1.23-2.86; and for survival to hospital discharge, 9.7%; 95% CI, 6.7%-13.8% vs 2.9%; 95% CI, 1.7%-4.8%; adjusted OR, 2.27; 95% CI, 1.11-4.77). In secondary analysis of the 210 patients in whom the LDB device was applied, 38 patients (18.1%) survived to hospital admission (95% CI, 13.4%-23.9%) and 12 patients (5.7%) survived to hospital discharge (95% CI, 3.0%-9.3%). Among patients in the manual CPR and LDB-CPR groups who survived to hospital discharge, there was no significant difference between groups in Cerebral Performance Category (P = .36) or Overall Performance Category (P = .40). The number needed to treat for the adjusted outcome survival to discharge was 15 (95% CI, 9-33).
Conclusion Compared with resuscitation using manual CPR, a resuscitation strategy using LDB-CPR on EMS ambulances is associated with improved survival to hospital discharge in adults with out-of-hospital nontraumatic cardiac arrest.
Approximately 400 to 460 000 individuals die every year from out-of-hospital cardiac arrest (OHCA),1 representing approximately one third of all cardiovascular deaths2 in the United States. Only 1% to 8% of individuals with OHCA survive to hospital discharge.3- 6 Patients who have ventricular fibrillation for less than 3 to 4 minutes (the electrical phase of cardiac arrest)7 fare relatively well if rescuers arrive quickly and provide prompt defibrillation.8- 11
However, once ventricular fibrillation has been present longer, the myocardium becomes depleted of adenosine triphosphate and defibrillation usually results in conversion to asystole or a pulseless electrical rhythm.7 Several studies suggest that a brief period of cardiopulmonary resuscitation (CPR) before defibrillation can increase intracellular adenosine triphosphate levels and improve survival.12- 14
Attaining a coronary perfusion pressure of more than 15 mm Hg is one of the best predictors of return of spontaneous circulation (ROSC) in animals15- 21 and humans.22,23 Manual chest compression provides only approximately one third of the normal blood supply to the brain and 10% to 20% of the normal blood flow to the heart.24 The use of a load-distributing band (LDB) device for chest compressions has been shown to achieve intrathoracic pressures higher than achievable safely during manual chest compression. The device improves coronary and systemic perfusion pressures and flows compared with those that can be achieved with manual CPR in animal models and in a small number of terminally ill patients.15,25 In addition, in 1 study,26 an LDB device was associated with improved ROSC compared with manual chest compression when used by paramedic fire captains in a large, urban emergency medical services (EMS) system.
The goal of our study was to compare survival outcomes in patients with OHCA treated before and after the LDB device was used on urban EMS ambulances.
Corresponding Author: Joseph P. Ornato, MD, Department of Emergency Medicine, Virginia Commonwealth University Medical Center, 1250 E Marshall St, 2nd Floor, Richmond, VA 23298-0401 (email@example.com).
Author Contributions: Dr Ong had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Ong, Ornato, Dhindsa, Peberdy.
Acquisition of data: Ong, Edwards, Ines, Hickey, Clark, Williams, Powell, Overton.
Analysis and interpretation of data: Ong, Best.
Drafting of the manuscript: Ong, Ornato, Best.
Critical revision of the manuscript for important intellectual content: Ong, Edwards, Dhindsa, Best, Ines, Hickey, Clark, Williams, Powell, Overton, Peberdy.
Statistical analysis: Ong, Best.
Administrative, technical, or material support: Ong, Edwards, Dhindsa, Ines, Hickey, Clark, Williams, Powell, Overton.
Study supervision: Ornato, Peberdy.
Financial Disclosures: Dr Ornato is a Science Advisor to ZOLL Circulation (Sunnyvale, Calif), the manufacturer of the Autopulse device used in the study. Dr Ornato reported receiving reimbursement for travel expenses to Science Advisory board meetings approximately twice yearly and a small honorarium amounting to less than $2000 per year. He reported no other financial benefits (stock, stock options) from this relationship. Because of this relationship, Dr Ornato did not have access to data acquisition, entry, or analysis during this study. No other authors reported financial disclosures.
Funding/Support: This study was not a sponsored project. The 3 LDB devices used during the evaluation phase were provided free by ZOLL Circulation. Eight additional devices were loaned to the EMS system by the manufacturer for 12 months when ambulance deployment occurred to provide feedback to the manufacturer on the device’s design/durability on ambulances. The EMS system subsequently purchased all of the devices along with 7 additional units.
Acknowledgment: We are grateful for the voluntary contributions of Thomas Franck, MD, MPH, Department of Epidemiology and Community Health, Virginia Commonwealth University; Andrew J. Anderson, Department of Emergency Medicine, Richmond Community Hospital; Patti Aldridge, RN, Department of Emergency Medicine, Retreat Hospital; and Lorie Liptak, Chris Schaeffer, Richard Pertgen, and Derek Andresen, all from the Richmond Ambulance Authority.