Traumatic out-of-hospital cardiac arrests in Melbourne, Australia.

INTRODUCTION Many consider attempted resuscitation for traumatic out-of-hospital cardiac arrest (OHCA) futile. This study aims to describe the characteristics and profile of adult traumatic OHCA. METHODS The Victorian Ambulance Cardiac Arrest Registry (VACAR) was used to identify all trauma related cases of OHCA in patients aged ≥16 years. RESULTS Between 2000 and 2009, EMS attended 33,178 OHCAs of which 2187 (6.6%) had a traumatic aetiology. The median age (IQR) of traumatic OHCA cases was 36 (25-55) years and 1612 were male (77.5%). Bystander CPR was performed in 201 cases (10.2%) with median (IQR) EMS response time 8 (6-11)min. The first recorded rhythm by EMS was asystole seen in 1650 (75.4%), PEA in 294 (13.4%) cases and VF in 35 cases (1.6%). Cardiac output was present in 208 (9.5%) cases who subsequently had an EMS witnessed OHCA. EMS attempted resuscitation in 545 (24.9%) patients of whom 84 (15.4%) achieved ROSC and were transported, and 27 (5.1%) survived to hospital discharge; 107 were transported with CPR of whom 8 (7.4%) survived to hospital discharge. Where EMS attempted resuscitation in traumatic OHCAs, survival for VF was 11.8% (n=4), PEA 5.1% (n=10) and asystole 2.4% (n=3). In EMS witnessed traumatic OHCA, resuscitation was attempted in 175 cases (84.1%), 35 (16.8%) patients achieved sustained ROSC before transport of whom 5 (14%) survived to leave hospital and 60 (28.8%) were transported with CPR of whom 6 (10%) survived to leave hospital. Compared to OHCA cases with 'presumed cardiac' aetiology traumatic OHCAs were younger [median years (IQR): 36 (25-55) vs 74 (61-82)], had resuscitation attempted less (25% vs 48%), were less likely to have a shockable rhythm (1.6% vs 17.1%), were more likely to be witnessed (62.8% vs 38.1%) and were less likely to receive bystander CPR (10.2% vs 25.5%) (p<0.001, respectively). Multivariate logistic regression identified factors associated with EMS decision to attempt resuscitation. The odds ratio [OR (95% CI)] for 'presence of bystander CPR' was 5.94 (4.11-8.58) and for 'witnessed arrest' was 2.60 (1.86-3.63). CONCLUSION In this paramedic delivered EMS attempted resuscitation was not always futile in traumatic OHCA with a survival of 5.1%. The quality of survival needs further study.