Resuscitation (2006) 70, 193—200
CLINICAL PAPER
Prehospital transcutaneous cardiac pacing for symptomatic bradycardia or bradyasystolic cardiac arrest: A systematic review夽 Jonathan Sherbino a, P. Richard Verbeek a,b, Russell D. MacDonald a,c, Bruce V. Sawadsky c,d, Andrew C. McDonald a, Laurie J. Morrison a,e,∗ a
Division of Emergency Medicine, Department of Medicine, University of Toronto, Toronto, Ont., Canada b Sunnybrook Osler Centre for Prehospital Care, Sunnybrook and Women’s College Health Sciences Centre, Toronto, Ont., Canada c Ontario Air Ambulance Services Corporation, Toronto, Ont., Canada d Department of Family and Community Medicine, University of Toronto, Toronto, Ont., Canada e Prehospital and Transport Medicine Research Program, Sunnybrook and Women’s College Health Sciences Centre, Toronto, Ont., Canada Received 10 October 2005 ; received in revised form 30 November 2005; accepted 30 November 2005
KEYWORDS Cardiac arrest; Bradyarrythmias; Emergency medical services; Pacing
Summary Background: Advanced cardiac life support (ACLS) guidelines suggest transcutaneous cardiac pacing (TCP) for the treatment of symptomatic bradycardia (SB) and bradyasystolic cardiac arrest (BACA). Many EMS systems are extrapolating these guidelines and employing TCP in the prehospital setting. Our objective was to conduct a systematic review to determine the efficacy of prehospital TCP in the management of these two conditions. Methods: MEDLINE (1966—2004), EMBase and Science Citation Index (1980—2004) were searched using: prehospital/emergency medical services; external/transcutaneous; pacing. Two reviewer teams blinded to the source and author conducted a hierarchical selection (title, abstract, article) and quality assessment using a validated scale. Kappa agreement at each level of review was measured. Data abstraction was done by consensus. Results: Thirty-four articles were identified and seven selected (Kappa agreement; title: 0.85, abstract: 0.78, full article: 0.82). Article quality was poor in all trials.
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A Spanish translated version of the summary of this article appears as Appendix in the online version at doi:10.1016/ j.resuscitation.2005.11.019 ∗ Corresponding author at: Suite B 104, Prehospital and Transport Medicine Research Program, Sunnybrook and Women’s College Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ont., Canada M4N 3M5. Tel.: +1 416 480 5959; fax: +1 416 480 5888. E-mail address:
[email protected] (L.J. Morrison). 0300-9572/$ — see front matter © 2006 Published by Elsevier Ireland Ltd. doi:10.1016/j.resuscitation.2005.11.019
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J. Sherbino et al. There were three case series (BACA, n = 215), three unblinded randomised controlled trials (one BACA, two BACA + SB), and one subgroup (SB) analysis. In the case series of paced BACA patients, 0/215 survived to hospital discharge. In the BACA trials 16/509 (paced) versus14/497 (control) survived to discharge. In a subgroup of one SB trial 5/6 (paced) versus 1/7 (control) survived to discharge (p = 0.01). When a SB trial subgroup was combined with a case series 4/27 (paced) versus 0/24 (control) survived to discharge (p = 0.07). Conclusions: In the prehospital setting, there is no evidence to support the use of TCP in bradyasystolic cardiac arrest. There is inadequate evidence to determine the efficacy of prehospital TCP in the treatment of symptomatic bradycardia. © 2006 Published by Elsevier Ireland Ltd.
Introduction Since the advent of the first external pacemaker by Zoll in 1952,1 transcutaneous cardiac pacemakers (TCP) have gained widespread clinical use. First advocated for cardiac emergencies in 1980,2 the International Liaison Committee on Resuscitation (ILCOR) Guidelines 2000 recommend the use of TCP for the treatment of both haemodynamically symptomatic bradycardia and asystolic cardiac arrest.3 These recommendations received Class I support for symptomatic bradycardia; however the use of TCP in asystole was not recommended routinely. The advanced cardiac life support (ACLS) guidelines for the use of TCP focus on in-hospital medical care. Yet, the ACLS guidelines have been interpreted and adopted by numerous emergency medical services (EMS) systems to include the use of prehospital TCP. This extrapolation of the data and the guidelines may be premature. Justification for prehospital TCP requires consideration of clinical benefit, operational feasibility and economic costs. Clinical benefit, including both efficacy and safety, is of prime importance to provide a rationale to determine operational feasibility and inform economic arguments of equipment, training and maintenance of certification expenses. Since the individual trials cited by the ILCOR Guidelines 2000 have not provided sufficient clinical evidence of prehospital efficacy, this line of inquiry may benefit from a systematic review. Using Hunt and McKibbon’s strategy,4 a search of MEDLINE from 1966 to 2005 using the content terms ‘pacemaker, artificial’ and ‘emergency medical services’ did not identify a single systematic review evaluating the prehospital use of TCP in either haemodynamically symptomatic bradycardia or bradyasystolic cardiac arrest.
Objective The objective of this study is to review the literature systematically and synthesise the evidence
evaluating the efficacy of prehospital transcutaneous cardiac pacing in a non-traumatic, adult population with haemodynamically symptomatic bradycardia or bradyasystolic cardiac arrest.
Methods Data sources Using the content terms prehospital OR emergency medical services; external OR transcutaneous; pacing OR pace; and the Cochrane search strategy5 a comprehensive search was performed. MEDLINE was searched from 1966 to 2004. EMBase and Science Citation Index were searched from 1980 to 2004. The Canadian Institute for Health Research was contacted for unpublished trials and ongoing grants.6 The National Institute of Health website was also reviewed for unpublished trials and ongoing grants.7 A hand search of the bibliographies of selected articles was performed.
Study selection Two independent reviewers performed a hierarchical selection of studies (P.R.V. and R.D.M.), blinded to author and journal: title; title plus abstract; complete article. The inclusion criteria were euthermic, non-traumatised adults, who experienced prehospital haemodynamically symptomatic bradycardia or bradyasystolic cardiac arrest. Symptomatic bradycardia was defined a priori as a heart rate less than 60 beats per minute and at least one of the following: systolic blood pressure less than 80 mmHg; a change in mental status; angina pectoris; or acute pulmonary oedema.8 Bradyasystolic cardiac arrest was defined as the absence of a palpable pulse in the presence of an electrocardiographic bradycardic or asystolic rhythm.8 All study designs, including controlled trials, case control trials and case series, were eligible for inclusion. Inter-rater reliability using a weighted kappa was calculated at each level of hierarchical selection.
Prehospital transcutaneous cardiac pacing for symptomatic bradycardia
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Two additional independent reviewers (B.V.S and A.C.M), blinded to journal, author, and the results and discussion section of each article, scored the quality of the final selected articles using the Jadad score.9
pendent reviewer. The combined Jadad score for all of the articles was 1 out of 5, suggesting uniformly poor quality trial methodology.
Data abstraction
Population All of the articles involved adult, non-traumatised patients who were euthermic. All EMS systems were tiered responses, with initial basic life support administered by emergency medical technicians. All patients in each of the trials received standard ACLS care,3 which included (as appropriate): external chest compressions; electrical defibrillation; tracheal intubation; intravenous (IV) fluids; IV epinephrine (adrenaline) and atropine. The EMS system descriptions and inclusion criteria for studies of bradyasystolic cardiac arrest and/or symptomatic bradycardia are shown in Tables 1 and 2, respectively.
Data abstraction was performed independently by two reviewers (J.S. and L.J.M). Agreement was achieved by consensus. The a priori primary endpoints of all-cause mortality in-hospital; at 6 months; 1 year were abstracted. In addition, the secondary endpoints of survival to hospital admission, improvement in blood pressure, neurological function (e.g. cerebral performance category) and quality of life were also extracted.
Results Study selection and assessment Thirty-four articles were identified, including 16 duplicate articles. Twenty-seven articles were excluded for failure to meet the inclusion criteria, which required the study to address TCP and be conducted in the prehospital setting; leaving seven articles. Kappa agreement at the level of title selection was 0.85, for title plus abstract it was 0.78, and for selection using the complete article it was 0.82. None of the seven articles had a Jadad score9 of more than two out of five from either inde-
Table 1
Data synthesis
Intervention The Pace-Aid (Cardiac Resuscitator Corp.; Wilsonville, OR), Pacetronics Model NI-1 (Pacetronics; Carlsbad, CA), the Trans-Pace (Micromedical Devices Inc.; Englewood, CO), the Zoll NTP (Zoll Medical; Cambridge, MA), the Quick-Pace (Physio-Control; Redmond, WA), and the HeartAid 97 (Cardiac Resuscitator; Lake Oswego, WA) transcutaneous pacemakers were used. The TCP intervention was effectively the same in all of the trials. There were no differences in ACLS standard of care in any of the control groups.
Bradyasystolic cardiac arrest inclusion criteria
Author
Year
ACLS Setting response (rural vs. urban)
TCP model
Manufacturer
Asystole Pulseless Postbradycardia defibrillation asystole
Zoll Medical; Physio-Control; Cardiac Resuscitator Pacetronics
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y Y
Y Y
N N
Y
Y
Y
Cummins et al.10 1993 P
Mixed
Zoll NTP; Quick-Pace; Heart Aid 97
Barthell et al.11
1988 P
Urban
Hedges et al.16
1987 P
Mixed
Pacetronics NI-1 Trans-Pace
Eitel et al.12 Paris et al.13
1987 P + RN 1984 P ± MD
Mixed Urban
Zoll NTP Pace-Aid
Falk et al.14
1983 P
Urban
Pace-Aid
Micromedical Devices Inc. Zoll Medical Cardiac Resuscitator Corp. Cardiac Resuscitator Corp.
P: paramedic; RN: registered nurse; MD: physician; ACLS: advanced cardiac life support.
196 Table 2
J. Sherbino et al. Symptomatic bradycardia inclusion criteria
Author
Year
ACLS response
Setting (rural vs. urban)
TCP model
Manufacturer
Bradycardia
Blood pressure
GCS
Hedges et al.15
1991
P
Mixed
Trans Pace; Quick-Pace
‘Slow’ HR
Slow capillary refill
