Clinical paperQuality of cardiopulmonary resuscitation before and during transport in out-of-hospital cardiac arrest☆
Introduction
A number of studies have consistently reported <1% survival to hospital discharge for out-of-hospital cardiac arrest patients transported to hospital with ongoing cardiopulmonary resuscitation (CPR).1, 2, 3 It has been speculated that this might partly be explained by much poorer quality of CPR during transport than on site as reported in manikin studies4, 5, 6, 7 with one exception,8 as quality of CPR appears to affect patient survival.9, 10, 11
Performing CPR in a moving vehicle can also be hazardous to the personnel, and it was suggested in CPR guidelines both in 200012 and 200513 that transport with ongoing CPR of patients resistant to advanced life support on site might be unethical.
Quality of CPR during transport has not previously been reported for patients. Tools based on transthoracic impedance changes from the ECG recordings are now available for evaluating quality of clinical CPR.14, 15 We have therefore studied quality of CPR performed by ambulance crews both before and during transport in consecutive cases over a three and a half year period. The study was retrospective, which avoids a possible positive Hawthorne effect on CPR quality from the knowledge of being studied.16 We were also interested in seeing if the prognosis of these patients was as uniformly dismal as reported 10–15 years ago.1, 2, 3 There is some evidence that new guidelines17 with increased focus on chest compressions and reducing hands-off intervals will improve quality of CPR at least on-scene and consequently improve survival rates.18
Section snippets
Study design and recruitment
The city of Oslo is a one-tiered centralised community run EMS system for a population of 540,000. On weekdays between 7:30 a.m. and 10 p.m. a physician-manned ambulance staffed by two paramedics and an anaesthesiologist functions on the same level as the regular paramedic staffed ambulances. In Oslo paramedics have full authority to discontinue CPR out-of-hospital without physician consult or transport to hospital. The decision to start transport to hospital with ongoing CPR is based on
Results
Seventy-five (9.5%) of 787 cardiac arrest cases receiving CPR on site from May 2003 throughout 2006 also received CPR during transport to hospital, 66 of these patients received manual chest compressions while nine patients were treated with a mechanical chest compression device (LUCAS, Jolife AB, Lund, Sweden). For analysis of CPR quality, 17 cases were excluded due to failure to transfer ECG with impedance signals, and 15 as they did not contain usable data both before and during transport.
Discussion
This is the first clinical study reporting CPR quality during transport. For manual CPR time without chest compressions increased with a concomitant decrease in number of compressions per minute during transport. This deterioration in quality is in agreement with most previously published manikin data,4, 5, 6 and although Havel et al.8 found no difference in chest compression quality on a manikin for 10 health care professionals during 8 min of CPR on site versus in a moving car, there was
Conclusions
The fraction of time without chest compressions increased during transport of out-of-hospital cardiac arrest patients. While 5% survived to hospital discharge, more information is needed to determine which patients benefit from transport to hospital with ongoing CPR.
Conflict of interest
Olasveengen has no conflicts of interest to declare. Wik is on a Medical Advisory Board for Physio-Control, has in the past consulted for Laerdal and Jolife, and is the principle investigator for a multi-centre mechanical chest compression device study sponsored by Zoll. Steen is a member of the board of directors for Laerdal Medical and The Norwegian Air Ambulance.
Acknowledgements
We thank all physicians and paramedics working in the Oslo EMS Service. The study was supported by grants from Eastern Norway Regional Health Authority, Ulleval University Hospital, Norwegian Air Ambulance Foundation, Laerdal Foundation for Acute Medicine, Anders Jahres Fund. Heartstart 4000SP with the necessary analysis software was provided by Philips Medical Systems (Andover, MA, USA), and the necessary software for analysing data from the LIFEPAK 12 defibrillators was provided by
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A Spanish translated version of the summary of this article appears as Appendix in the final online version at 10.1016/j.resuscitation.2007.07.001.