Improving outcome after out-of-hospital cardiac arrest by strengthening weak links of the local Chain of Survival; quality of advanced life support and post-resuscitation care

Background: Survival after out-of-hospital cardiac arrest (OHCA) depends on a well functioning Chain of Survival. We wanted to assess if targeted attempts to strengthen the weak links of our local chain; quality of advanced life support (ALS) and post-resuscitation care, would improve outcome.

Materials and methods: Utstein data from all OHCAs in Oslo during three distinct 2-year time periods 1996-1998, 2001-2003 and 2004-2005 were collected. Before the second period the local ALS guidelines changed with increased focus on good quality chest compressions with minimal pauses, while standardized post-resuscitation care including goal directed therapy with therapeutic hypothermia and percutaneous coronary intervention was added in the third period. Additional a priori sub-group analyses of arrests with cardiac aetiology as well as bystander witnessed ventricular fibrillation/tachycardia (VF/VT) arrests with cardiac aetiology were performed.

Results: ALS was attempted in 454, 449, and 417 patients with OHCA in the first, second and last time period, respectively. From the first to the third period VF/VT arrests declined (40% vs. 33%, p=0.039) and fewer arrests were witnessed (80% vs. 72%, p=0.022) and response intervals increased (7+/-4 to 9+/-4 min, p<0.001). Overall survival increased from 7% (first period) to 13% (last period), p=0.002, and survival in the sub-group of bystander witnessed VF/VT arrests with cardiac aetiology increased from 15% (first period) to 35% (last period), p=0.001.

Conclusions: Survival after OHCA was increased after improving weak links of our local Chain of Survival, quality of ALS and post-resuscitation care.