Sudden cardiac arrest is common and, obviously, very bad. In the US, there are about 500,000 cardiac arrests each year. About half of these cardiac arrests are out of hospital cardiac arrest (OHCA) and the survival rate is pretty poor. The most recent survival estimates put it at 7 – 9.5% in most communities. About 10-12 years ago, the American Heart Association built the 4-step “chain-of-survival.”
Step One – Early access to emergency care
Step Two – Early CPR
Step Three – Early defibrillation
There is little debate about these three steps as the sum of the data supports that they lead to better outcomes.
The 4th step in the chain, however is slightly more controversial; early advanced care. This basically means rapid access to ACLS type resuscitation skills (intubation and intravenous drug therapy). Despite it being the 4th step, ACLS has little evidence to defend it.
What was the effect on survival in OHCA of adding ACLS to BLS?
All persons > 16 yo who had an OHCA and for whom resuscitation was attempted.
Advanced-life-support program whereby paramedics were trained in inutbation, IV line placement and IV medication administration.
Basic-life-support – defibrillation + CPR
Primary: Survival to hospital discharge (defined as patient leaving hospital alive).
Secondary: ROSC, admission to hospital and cerebral performance category.
Multicenter, controlled clinical trial that was conducted in a before and after model.
< 16, persons who were dead, patients with trauma, disorders of clearly noncardiac cause.
5638 patients over 48 months in 17 communities and 11 hospitals
1391 Rapid-defibillation phase (no ACLS) over 12 months
4247 Advanced-life-support phase over 36 months
Initial cardiac rhythm not significantly different between groups.
Medications (ACLS phase)
- ROSC: 12.9% vs. 18.0% (absolute change 5.1% p < 0.001)
- Admission to hospital 10.9% vs. 14.6% (absolute change 3.7% p < 0.001)
- Survival to hospital discharge 5.0% vs. 5.1% (absolute change 0.1% p 0.83)
- Survivors’ Cerebral-performance category level 1 – 78.3% vs. 66.8% (p 0.73)
- Large, multicenter trial
- Study asked a clear clinical question that was patient centered
- Minimal exclusions increasing applicability
- Outcome measures were objective reducing bias
- Follow up was complete and appropriately long
The results of the OPALS study did not show any incremental benefit of introducing a full advanced-life-support program to an emergency-medical services system of optimized rapid defibrillation.
The institution of ACLS into OHCA care improved the rate of ROSC without improving the return of neurologic function (RONF). Increasing ROSC without improving RONF means that there are more patients “alive” without good neurologic outcomes. This is not the goal of OHCA management. Epinephrine, the cornerstone drug in ACLS, in its current recommended regimen may be a major culprit in getting back the heart but not the brain.
Addition of an advanced life support algorithm to BLS management did not increase the survival to hospital discharge for patients with OHCA.