Retrospective observational cohort study of out‐of‐hospital cardiac arrest outcomes in Tasmania 2010–2014

Abstract

ObjectiveThis study aims to present overall survival rates to hospital discharge for out‐of‐hospital cardiac arrest (OHCA) in Tasmania and to identify predictors of survival.MethodsA retrospective observational cohort study was undertaken from 1 January 2010 to 31 December 2014. A probabilistically linked data set was created from paramedic electronic medical records and hospital patient records. Logistic regression was used to assess factors associated with survival of OHCA.ResultsDuring the study, 2949 incidents of OHCA were reviewed and 1146 had emergency management provided, with an overall survival rate to hospital discharge of 135 (12%). A number of independent factors are associated with improved outcomes including if the initial presenting cardiac rhythm was either ventricular fibrillation or ventricular tachycardia (adjusted odds ratio [OR] 8.75, 95% confidence interval [CI] 5.15–14.89) (P < 0.0001) relative to those who were found in a non‐shockable rhythm. Another factor was age group (overall P < 0.001). Those aged 85+ years had a reduced overall survival rate (2.9%), which was lower than those <16 years of age (OR 0.37, 95% CI 0.07–1.94; adjusted OR 0.38, CI 0.03–1.00) (P < 0.001). The odds of surviving OHCA decreased by 9% for every minute defibrillation of a shockable rhythm was delayed were witnessed by a bystander (OR 0.90, 95% CI 0.85–0.95).ConclusionTime to defibrillation for witnessed arrests, other than paramedic witnessed arrest was associated with better overall survival rates than unwitnessed OHCA. Further factors such as the event being of cardiac aetiology, bystander cardio‐pulmonary resuscitation performed, initial presenting cardiac rhythm of ventricular fibrillation or ventricular tachycardia and decreasing age were all associated with increased probability of survival.

Establishment of a prediction model for prehospital return of spontaneous circulation in out-of-hospital patients with cardiac arrest

“…Ji et al [ 4 ], Morgan et al [ 5 ], and Navab et al [ 13 ] and others have established models in the United Kingdom, Australia, and Iran, respectively, to describe the influencing factors of clinical features and prehospital emergency measures on the ROSC rate as well as the survival rate of patients with OHCA. However, these researchers did not collect data on prehospital drug administration, including the use and dosage of epinephrine or other drugs.…”

“…Moreover, patients with prehospital ROSC (P-ROSC) have better neurological outcomes compared with those who do not. Some areas regions have reported high ROSC rates during hospital handovers, such as 25% in England[ 4 ] and 29.1% in Tasmania, Australia[ 5 ]. In China, however, the P-ROSC rate was only 6.26% in a recent survey in Beijing[ 6 ], demonstrating that a large gap still exists between countries.…”