Elsevier

Resuscitation

Volume 80, Issue 4, April 2009, Pages 407-411
Resuscitation

Clinical paper
Effect of implementation of new resuscitation guidelines on quality of cardiopulmonary resuscitation and survival☆

https://doi.org/10.1016/j.resuscitation.2008.12.005Get rights and content

Abstract

Background

During cardiopulmonary resuscitation (CPR), advanced life support (ALS) providers have been shown to deliver inadequate CPR with long intervals without chest compressions. Several changes made to the 2005 CPR Guidelines were intended to reduce unnecessary interruptions. We have evaluated if quality of CPR performed by the Oslo Emergency Medical System (EMS) improved after implementation of the modified 2005 CPR Guidelines, and if any such improvement would result in increased survival.

Materials and methods

Retrospective, observational study of all consecutive adult cardiac arrest patients treated during a 2-year period before (May 2003–April 2005), and after (January 2006–December 2007) implementation of the modified 2005 CPR Guidelines. CPR quality was assessed from continuous electronic recordings from LIFEPACK 12 defibrillators where ventilations and chest compressions were identified from transthoracic impedance changes. Ambulance run sheets, Utstein forms and hospital records were collected and outcome evaluated.

Results

Resuscitation was attempted in 435 patients before and 481 patients after implementation of the modified 2005 CPR Guidelines. ECGs usable for CPR quality evaluation were obtained in 64% and 76% of the cases, respectively. Pre-shock pauses decreased from median (interquartile range) 17 s (11, 22) to 5 s (2, 17) (p = 0.000), overall hands-off ratios from 0.23 ± 0.13 to 0.14 ± 0.09 (p = 0.000), compression rates from 120 ± 9 to 115 ± 10 (p = 0.000) and ventilation rates from 12 ± 4 to 10 ± 4 (p = 0.000). Overall survival to hospital discharge was 11% and 13% (p = 0.287), respectively.

Conclusion

Quality of CPR improved after implementation of the modified 2005 Guidelines with only a weak trend towards improved survival to hospital discharge.

Introduction

Quality of cardiopulmonary resuscitation (CPR) has been shown to affect survival after cardiac arrest both in animal experiments1, 2, 3 and in clinical studies of bystander CPR.4, 5, 6 Recent clinical studies of advanced life support (ALS) both in- and out-of-hospital have shown substandard CPR with long pauses between too shallow chest compressions,7, 8, 9 and frequent hyperventilation.8, 10, 11 When retrospectively evaluated, defibrillation success increased with increasing compression depth and decreasing pre-shock pauses.12 Further efforts to improve in-hospital CPR quality through automated feedback from the defibrillator and structured post-event debriefing resulted in better chest compressions with less pauses and increased short term survival.13

Emerging evidence of widespread substandard CPR resulted in major changes in the international 2005 CPR Guidelines,14, 15 with focus on good quality chest compressions and avoiding unnecessary interruptions. Removal of stacked shocks, immediate uninterrupted chest compressions following each shock and increasing the compression:ventilation ratio to 30:2 in non-intubated patients, were all changes made with intent to reduce pauses in chest compressions and improve vital organ perfusion. Fewer pauses and better chest compression quality was hoped to improve overall survival after cardiac arrest.

We have evaluated if quality of CPR performed by the Oslo Emergency Medical System (EMS) improved after implementation of modified 2005 CPR Guidelines, and if any such improvement resulted in improved survival.

Section snippets

Description of Oslo

The city of Oslo covers 454 km2 and has 548 617 inhabitants (January 1st 2007) with 51% female population and 4.4% of the population over 80 years. Oslo has had a continuous population growth the last 20 years, mainly due to migration leading to a larger proportion of young adults 20–39 and lower proportion of children and adults >40 years compared to the rest of the country. Foreign immigrants now make up 24% of Oslo's population.16

Description of EMS and in-hospital treatment

The city of Oslo has a one-tiered centralised community run EMS

Results

During a 2-year period between May 2003 and April 2005 when modified 2000 ERC Guidelines were in effect, resuscitation was attempted in 435 patients (PRE). After the modified 2005 Guidelines had been fully implemented January 1st 2006, 481 patients were attempted resuscitated in the following 2 years (POST). The incidence of cardiac arrest with cardiac aetiology decreased from 73% to 66% (p = 0.021), whereas the proportion of patients receiving bystander BLS increased from 52% to 58% (p = 0.053),

Discussion

Our present results show that implementation of the new guidelines for cardiopulmonary resuscitation (CPR) aimed at reducing unnecessary pauses in chest compressions successfully reduced both hands-off ratios and pre-shock pauses. Although there was a weak trend towards improved survival, no statistically significant difference could be documented.

Compared to previous reports showing improved survival after implementation of various modified 2005 Guidelines,23, 24, 25, 26 it is disappointing

Conclusions

Quality of CPR improved after implementation of the modified 2005 Guidelines with reduction in both pre-shock pauses and total time without chest compressions. There was only a weak trend towards improved survival to hospital discharge.

Conflict of interest

Olasveengen has received honoraria from Medtronic (Oslo, Norway) and research support from Laerdal Medical Corporation (Stavanger, Norway). Vik, Kuzovlev and Sunde have no conflicts of interest to declare.

Acknowledgements

We thank all physicians and paramedics working in the Oslo EMS Service. We would also especially like to thank Lars Wik for invaluable assistance in data collection and Petter Andreas Steen for discussions and critique in drafting the manuscript.

Financial support: The study was supported by grants from South-Eastern Norway Regional Health Authority, Ulleval University Hospital, Norwegian Air Ambulance Foundation, Laerdal Foundation for Acute Medicine, Anders Jahres Fund. The necessary software

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    ☆

    A Spanish translated version of the summary of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2008.12.005.

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