Outcome and Prognostic Factors of Patients in Out-Of-Hospital Cardiac Arrests Presenting with Non-Shockable Rhythm in Hong Kong

Abstract

Objective To obtain the recent local epidemiological data and evaluate factors associated with outcomes of adult patients in non-traumatic non-shockable out-of-hospital-cardiac-arrest (OHCA) in Hong Kong. Methods It was a cross-sectional study lasting for nine months (from July 2009 to March 2010) in two emergency departments (ED) which served a population of 1.1 million. All non-traumatic OHCA patients aged equal or greater than 18 years presented with non-shockable cardiac rhythms to ED without postmortem changes were included. The pre-hospital factors, managements and outcomes were recorded in a standardised data entry form at the time of patient consultation. Logistic regression was used to evaluate the relationship between survival to admission (STA) and various prognostic factors. Results A total of 348 patients fulfilled the inclusion criteria. The mean age was 75.9 years old. Overall, there were 61 patients (17.5%) with restoration of spontaneous circulation and 58 patients (16.7%) had STA. The survival to hospital discharge (STD) rate was 0.86% (3 patients). Factors independently associated with better prognosis in terms of STA were initial pulseless electrical activity arrest (PEA) rhythm in ED (OR=4.72, 95% CI 2.30-9.69), witnessed arrest (OR=8.00, 95% CI 3.38-18.96) and non-cardiac cause of arrest (OR=2.17, 95% CI 1.00-4.67). Conclusion STA for adults presenting with non-traumatic non-shockable OHCA in our centre is 16.7%. Witnessed non-shockable OHCA patients presenting with initial PEA arrest rhythm and with a presumed non-cardiac in etiology are significantly associated with higher STA rate.