Outcomes from out-of-hospital cardiac arrest in Metropolitan Taipei: does an advanced life support service make a difference?
BACKGROUND
Out-of-hospital cardiac arrest (OHCA) is of major medical and public health significance. It also serves as a good indicator in assessing the performance of local emergency medical services system (EMS). There have been arguments for and against the benefits of advanced life support (ALS) over basic life support with defibrillator (BLS-D) for treating OHCA.


OBJECTIVE
The study was conducted to characterise the outcomes of cardiac arrest victims in an Asian metropolitan city; to evaluate the impacts of ALS versus BLS-D services; and to explore the possible patient and arrest factors that may be associated with the observed differences in the outcomes between the two pre-hospital care models.


METHODS
Taipei is an Asian metropolitan city with an area of 272 km(2) and a population of 2.65 million. The fire-based BLS-D EMS system was in the process of phasing in ALS capability. While there were 40 BLS-D teams in the 12 city districts, two ALS teams were set up in the central part of the city. In this prospective study, all adult non-traumatic OHCA from September 2003 to August 2004 were included. Patient, arrest, care, and outcome variables for OHCA victims were collected from prehospital run sheets, automatic defibrillators, and emergency department and hospital records.


RESULTS
Among 1423 OHCA included in the analysis, 1037 (73%) received BLS-D service, and 386 (27%) received ALS services. The initial shockable rhythms and early bystander CPR were strongly associated with better survival for victims of cardiac arrests. Compared to BLS-D, ALS patients had similar age, sex, witness status, the rate of bystander CPR, and response timeliness but more patients in asystole (84% versus 72%, p=0.005). Patients treated by ALS were more likely to result in significantly higher rates of return of spontaneous circulation (29% versus 21%; OR=1.51 (95% CI 1.15-2.00); p=0.002) and survival to emergency department/intensive care unit admission (23% versus 15%; OR=1.66 (95% CI 1.22-2.24); p=0.001), but there was no difference in the rate of survival to hospital discharge (7% versus 5%; OR=1.39 (95% CI 0.84-2.23); p=0.17). The outcome difference from ALS services was more pronounced among patients in asystole and without bystander CPR.


CONCLUSIONS
In this metropolitan EMS in Asia, the implementation of ALS services improved the intermediate, but not the final outcomes. Communities with larger populations and lower incidence of initial shockable rhythms than the OPALS study should also prioritise their resources in setting up and optimising systems of basic life support and early defibrillations. Further studies are warranted to configure the optimal care model for combating cardiac arrest.
Ma
Matthew Huei-Ming
MH
Department of Emergency Medicine, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 100, Taiwan. matthew@ntu.edu.tw
Chiang
Wen-Chu
WC
Ko
Patrick Chow-In
PC
Huang
Jimmy Ching-Chih
JC
Lin
Chi-Hao
CH
Wang
Hui-Chi
HC
Chang
Wei-Tien
WT
Hwang
Chien-Hwa
CH
Wang
Yao-Cheng
YC
Hsiung
Guan-Hwa
GH
Lee
Bin-Chou
BC
Chen
Shyr-Chyr
SC
Chen
Wen-Jone
WJ
Lin
Fang-Yue
FY
D022561:Advanced Cardiac Life Support / Q000379:methods*; D000368:Aged; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D010045:Outpatients; D012044:Regression Analysis; D012189:Retrospective Studies; D015996:Survival Rate; D013624:Taiwan / Q000453:epidemiology; D016896:Treatment Outcome; D014505:Urban Population