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 (ornato@aol.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.
1.Zheng ZJ, Croft JB, Giles WH, Mensah GA. Sudden cardiac death in the United States, 1989 to 1998.
Circulation. 2001;104:2158-216311684624
Google ScholarCrossref 2.Becker LB, Smith DW, Rhodes KV. Incidence of cardiac arrest: a neglected factor in evaluating survival rates.
Ann Emerg Med. 1993;22:86-918424622
Google ScholarCrossref 3.Eisenberg MS, Horwood BT, Cummins RO, Reynolds-Haertle R, Hearne TR. Cardiac arrest and resuscitation: a tale of 29 cities.
Ann Emerg Med. 1990;19:179-1862301797
Google ScholarCrossref 4.Ornato JP, McBurnie MA, Nichol G.
et al. The Public Access Defibrillation (PAD) trial: study design and rationale.
Resuscitation. 2003;56:135-14712589986
Google ScholarCrossref 5.Lombardi G, Gallagher J, Gennis P. Outcome of out-of-hospital cardiac arrest in New York City: the Pre-Hospital Arrest Survival Evaluation (PHASE) study.
JAMA. 1994;271:678-6838309030
Google ScholarCrossref 6.Becker LB, Ostrander MP, Barrett J, Kondos GT. Outcome of CPR in a large metropolitan area: where are the survivors?
Ann Emerg Med. 1991;20:355-3612003661
Google ScholarCrossref 7.Weisfeldt ML, Becker LB. Resuscitation after cardiac arrest: a 3-phase time-sensitive model.
JAMA. 2002;288:3035-303812479769
Google ScholarCrossref 8.White RD, Hankins DG, Bugliosi TF. Seven years' experience with early defibrillation by police and paramedics in an emergency medical services system.
Resuscitation. 1998;39:145-15110078803
Google ScholarCrossref 9.Valenzuela TD, Roe DJ, Nichol G, Clark LL, Spaite DW, Hardman RG. Outcomes of rapid defibrillation by security officers after cardiac arrest in casinos.
N Engl J Med. 2000;343:1206-120911071670
Google ScholarCrossref 10.Caffrey SL, Willoughby PJ, Pepe PE, Becker LB. Public use of automated external defibrillators.
N Engl J Med. 2002;347:1242-124712393821
Google ScholarCrossref 11.Hallstrom AP, Ornato JP, Weisfeldt M.
et al. Public-access defibrillation and survival after out-of-hospital cardiac arrest.
N Engl J Med. 2004;351:637-64615306665
Google ScholarCrossref 12.Cobb LA, Fahrenbruch CE, Walsh TR.
et al. Influence of cardiopulmonary resuscitation prior to defibrillation in patients with out-of-hospital ventricular fibrillation.
JAMA. 1999;281:1182-118810199427
Google ScholarCrossref 13.Eftestol T, Wik L, Sunde K, Steen PA. Effects of cardiopulmonary resuscitation on predictors of ventricular fibrillation defibrillation success during out-of-hospital cardiac arrest.
Circulation. 2004;110:10-1515210599
Google ScholarCrossref 14.Wik L, Hansen TB, Fylling F.
et al. Delaying defibrillation to give basic cardiopulmonary resuscitation to patients with out-of-hospital ventricular fibrillation: a randomized trial.
JAMA. 2003;289:1389-139512636461
Google ScholarCrossref 15.Halperin HR, Guerci AD, Chandra N.
et al. Vest inflation without simultaneous ventilation during cardiac arrest in dogs: improved survival from prolonged cardiopulmonary resuscitation.
Circulation. 1986;74:1407-14153779922
Google ScholarCrossref 16.Ralston SH, Voorhees WD, Babbs CF. Intrapulmonary epinephrine during prolonged cardiopulmonary resuscitation: improved regional blood flow and resuscitation in dogs.
Ann Emerg Med. 1984;13:79-866691623
Google ScholarCrossref 17.Michael JR, Guerci AD, Koehler RC.
et al. Mechanisms by which epinephrine augments cerebral and myocardial perfusion during cardiopulmonary resuscitation in dogs.
Circulation. 1984;69:822-8356697465
Google ScholarCrossref 18.Kern KB, Ewy GA, Voorhees WD, Babbs CF, Tacker WA. Myocardial perfusion pressure: a predictor of 24-hour survival during prolonged cardiac arrest in dogs.
Resuscitation. 1988;16:241-2502849790
Google ScholarCrossref 19.Sanders AB, Ewy GA, Taft TV. Prognostic and therapeutic importance of the aortic diastolic pressure in resuscitation from cardiac arrest.
Crit Care Med. 1984;12:871-8736488827
Google ScholarCrossref 20.Sanders AB, Ogle M, Ewy GA. Coronary perfusion pressure during cardiopulmonary resuscitation.
Am J Emerg Med. 1985;3:11-143970745
Google ScholarCrossref 21.Wolfe JA, Maier GW, Newton JR Jr.
et al. Physiologic determinants of coronary blood flow during external cardiac massage.
J Thorac Cardiovasc Surg. 1988;95:523-5323343860
Google Scholar 22.Paradis NA, Martin GB, Rivers EP.
et al. Coronary perfusion pressure and the return of spontaneous circulation in human cardiopulmonary resuscitation.
JAMA. 1990;263:1106-11132386557
Google ScholarCrossref 23.McDonald JL. Coronary perfusion pressure during CPR in human beings [abstract].
Ann Emerg Med. 1983;12:144
Google ScholarCrossref 24.Kern KB. Coronary perfusion pressure during cardio-pulmonary resuscitation.
Baillieres Clin Anaesthesiol. 2000;14:591-609
Google Scholar 25.Halperin H, Paradis N, Ornato J. Improved hemodynamics with a novel chest compression device during a porcine model of cardiac arrest [abstract].
Circulation. 2002;106:(19 suppl 2)
538
Google Scholar 26.Casner M, Andersen D, Isaacs SM. The impact of a new CPR assist device on rate of return of spontaneous circulation in out-of-hospital cardiac arrest.
Prehosp Emerg Care. 2005;9:61-6716036830
Google ScholarCrossref 27.Jacobs I, Nadkarni V, Bahr J.
et al. Cardiac arrest and cardiopulmonary resuscitation outcome reports: update and simplification of the Utstein templates for resuscitation registries.
Resuscitation. 2004;63:233-24915582757
Google ScholarCrossref 28.Jacobs I, Nadkarni V, Bahr J.
et al. Cardiac arrest and cardiopulmonary resuscitation outcome reports: update and simplification of the Utstein templates for resuscitation registries.
Circulation. 2004;110:3385-339715557386
Google ScholarCrossref 29.Cummins RO, Chamberlain DA, Abramson NS.
et al. Recommended guidelines for uniform reporting of data from out-of-hospital cardiac arrest: the Utstein Style.
Circulation. 1991;84:960-9751860248
Google ScholarCrossref 30.Cummins RO, Chamberlain DA, Abramson NS.
et al. Recommended guidelines for uniform reporting of data from out-of-hospital cardiac arrest: the Utstein Style.
Ann Emerg Med. 1991;20:861-8741854070
Google ScholarCrossref 31.The Brain Resuscitation Clinical Trial II Study Group. A randomized clinical trial of calcium entry blocker administration to comatose survivors of cardiac arrest: design, methods, and patient characteristics.
Control Clin Trials. 1991;12:525-5451657528
Google ScholarCrossref 32.Halperin HR, Tsitlik JE, Gelfand M.
et al. A preliminary study of cardiopulmonary resuscitation by circumferential compression of the chest with use of a pneumatic vest.
N Engl J Med. 1993;329:762-7688350885
Google ScholarCrossref 33.Timerman S, Cardoso LF, Ramires JA, Halperin H. Improved hemodynamic performance with a novel chest compression device during treatment of in-hospital cardiac arrest.
Resuscitation. 2004;61:273-28015172705
Google ScholarCrossref 34.Wik L, Kramer-Johansen J, Myklebust H.
et al. Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest.
JAMA. 2005;293:299-30415657322
Google ScholarCrossref 35.Abella BS, Alvarado JP, Myklebust H.
et al. Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest.
JAMA. 2005;293:305-31015657323
Google ScholarCrossref 36.Abella BS, Sandbo N, Vassilatos P.
et al. Chest compression rates during cardiopulmonary resuscitation are suboptimal: a prospective study during in-hospital cardiac arrest.
Circulation. 2005;111:428-43415687130
Google ScholarCrossref