Incidence and outcomes of out-of-hospital cardiac arrest with shock-resistant ventricular fibrillation: Data from a large population-based cohort☆

Received 25 January 2010; received in revised form 27 March 2010; accepted 14 April 2010. published online 31 May 2010.

Abstract

Background

The increasing survival rates after out-of-hospital cardiac arrests (OHCA) are due mainly to improvements in the first 3 steps of the chain of survival. The aim of this study was to describe the temporal trends of OHCA incidence and outcomes with shock-resistant ventricular fibrillation (VF) requiring advanced life support procedures.

Methods

All our subjects were persons aged 18 years or more who had suffered OHCA of presumed cardiac etiology, were witnessed by bystanders, treated by emergency medical service (EMS), and had VF as initial rhythm. Our study was conducted in Osaka Prefecture, Japan from May 1, 1998 through December 31, 2006. Data were collected by EMS personnel using an Utstein-style database. We evaluated the temporal trends of incidence and outcomes of shock-resistant VF.

Results

During the study period, there were 8782 witnessed OHCA cases of presumed cardiac etiology. Among them, 1733 had VF as an initial rhythm, 392 of whom were shock-resistant. While the age-adjusted annual incidence of witnessed VF increased from 2.0 to 3.3 per 100,000 inhabitants, that of shock-resistant VF underwent little change during the study period. The proportion of shock-resistant VF among witnessed VF decreased from 37.0% to 19.0%. Neurologically intact 1-month survival rates after shock-resistant VF remained low at 5.6% even in 2006.

Conclusion

The actual incidence of shock-resistant VF has remained unchanged, and their outcomes continue to be dismal. Further efforts are required to reduce the mortality rates of such shock-resistant VF to achieve improved survival after OHCA.

Keywords: Basic life support (BLS), Adult, Cardiac arrest, Defibrillation, Emergency medical service, Return of spontaneous circulation, Utstein template, Ventricular fibrillation

a Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15 Yamada-Oka, Suita City, Osaka 565-0871, Japan

b Kyoto University Health Service, Yoshida-Honmachi, Sakyo-ku, Kyoto City, Kyoto 606-8501, Japan

c Senri Critical Care Medical Center, Saiseikai Senri Hospital, 1-1-6 Tsukumodai, Suita City, Osaka 565-0862, Japan

d Emergency and Critical Care Medical Center, Osaka City General Hospital, 2-13-22 Miyakojima Hondori, Miyakojima-ku, Osaka 534-0021, Japan

e Osaka Mishima Emergency Critical Care Center, 11-1 Minami-Akutagawa-cho, Takatsuki City, Osaka 569-1124, Japan

f Critical Care and Trauma Center, Osaka General Medical Center, 3-1-56 Mandai-Higashi, Sumiyoshi-ku, Osaka City, Osaka 558-8558, Japan

g Osaka Prefectural Nakakawachi Medical Center of Acute Medicine, 3-4-13 Nishi-Iwata, Higashi-Osaka City, Osaka 578-0947, Japan

h Osaka Prefectural Senshu Critical Care Medical Center, 2-24 Rinku-Ourai Kita, Izumi-Sano City, Osaka 598-0048, Japan

i Emergency and Critical Care Medical Center, Osaka Police Hospital, 10-31 Kitayama-cho, Tennoji-ku, Osaka City, Osaka 543-0035, Japan

j Traumatology and Critical Care Medical Center, National Hospital Organization Osaka National Hospital, 2-1-14 Hohenzaka, Chuo-ku Osaka City, Osaka 540-0006, Japan

k Department of Emergency and Critical Care Medicine, Kinki University School of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama City, Osaka 589-8511, Japan

l Department of Emergency Medicine, Osaka Medical College Hospital, 2-7 Daigaku-machi, Takatsuki City, Osaka 569-8686, Japan

m Osaka Prefectural Council of Emergency Care Facilities, 4-11 Rokumantai-cho, Tennoji-ku, Osaka City, Osaka 543-0074, Japan

n National Defense Medical College Hospital, 3-2 Namiki, Tokorozawa City, Saitama 359-8513, Japan

o Center for Medical Education, Kyoto University Graduate School of Medicine, Yoshida Konoe-cho, Sakyo-ku, Kyoto City, Kyoto 606-8501, Japan

p Hoshigaoka Koseinenkin Hospital, 4-8-1 Hoshigaoka, Hirakata City, Osaka 573-8511, Japan

Corresponding author. Tel.: +81 75 753 2401; fax: +81 75 753 2424.

☆ A Spanish translated version of the abstract of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2010.04.015.

PII: S0300-9572(10)00243-1

doi:10.1016/j.resuscitation.2010.04.015

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