The EMS community is all a-twitter with the results of the trial published in the latest issue of JAMA- Internal Medicine.
Sanghavi, et al (2014) published an observational study of over 32,000 cases of out of hospital cardiac arrest. The study examined relevant outcomes such as survival to hospital discharge and neurological outcome. Not surprisingly, patients treated by BLS crews experienced a higher rate of overall survival AND better neurologic functioning. Sanghavi's study affirms the results of the landmark Ontario Prehospital Advanced Life Support (OPALS) study in which the introduction of advanced life support services failed to demonstrate improvement in survival rates from out of hospital cardiac arrest.
So, what are the take home points of this study? Are we to heed calls to mothball ALS ambulances? Do paramedics make any difference at all? What's the value of ALS in cardiac arrest?
First of all, this study is consistent with decades of resuscitation research. Interventions associated with survival from cardiac arrest have remained relatively constant: high quality, minimally interrupted compressions, early defibrillation, hypothermia, and possibly percutaneous coronary intervention. The reflexive, historical practice of intubating every arrest simply to "secure" an airway has no basis in evidence. Its not that the presence of a paramedic is harmful. Rather, the routine addition of advanced life support interventions to a prehospital resuscitation event continually fails to confer additional benefit. The value of a paramedic rests with his/her ability to orchestrate resuscitative efforts and prioritize those things most likely to achieve ROSC. Survival has inched ever higher in the wake of high performance and bystander CPR initiatives- the EMS community should take notice and embrace a "BLS centric" approach to the problem of out of hospital cardiac arrest.
Practice patterns shouldn't change on the basis of one study- that's why we'll follow this discussion up by highlighting recent articles focusing on the role of epinephrine and advanced airways in cardiac arrest management.
PubMed abstract
Outcomes After Out-of-Hospital Cardiac Arrest Treated by Basic vs Advanced Life Support.
Abstract
IMPORTANCE:
Most out-of-hospital cardiac arrests receiving emergency medical services in the United States are treated by ambulance service providers trained in advanced life support (ALS), but supporting evidence for the use of ALS over basic life support (BLS) is limited.
OBJECTIVE:
To compare the effects of BLS and ALS on outcomes after out-of-hospital cardiac arrest.
DESIGN, SETTING, AND PARTICIPANTS:
Observational cohort study of a nationally representative sample of traditional Medicare beneficiaries from nonrural counties who experienced out-of-hospital cardiac arrest between January 1, 2009, and October 2, 2011, and for whom ALS or BLSambulance services were billed to Medicare (31 292 ALS cases and 1643 BLS cases). Propensity score methods were used to compare the effects of ALS and BLS on patient survival, neurological performance, and medical spending after cardiac arrest.
MAIN OUTCOMES AND MEASURES:
Survival to hospital discharge, to 30 days, and to 90 days; neurological performance; and incremental medical spending per additional survivor to 1 year.
RESULTS:
Survival to hospital discharge was greater among patients receiving BLS (13.1% vs 9.2% for ALS; 4.0 [95% CI, 2.3-5.7] percentage point difference), as was survival to 90 days (8.0% vs 5.4% for ALS; 2.6 [95% CI, 1.2-4.0] percentage point difference). Basic life support was associated with better neurological functioning among hospitalized patients (21.8% vs 44.8% with poor neurological functioning for ALS; 23.0 [95% CI, 18.6-27.4] percentage point difference). Incremental medical spending per additional survivor to 1 year for BLS relative to ALS was $154 333.
CONCLUSIONS AND RELEVANCE:
Patients with out-of-hospital cardiac arrest who received BLS had higher survival at hospital discharge and at 90 days compared with those who received ALS and were less likely to experience poor neurological functioning.
Unfortunately this study does not confirm anything regarding the false dichotomy of ALS versus BLS. Billing codes used without matching prehospital data cannot possibly inform agencies looking to improve. This is especially true when we consider they looked at old data under a period of mixed AHA guidelines. Also, given it was just medicare beneficiaries what does this mean for 45 year old patients?
ReplyDeleteNichol et al 2008, also published in JAMA (PMID: 18812533), established the presence of regional outcome disparity in US EMS; something of which we're well aware. When similarly situated systems feature a five-fold difference in outcomes it cannot possibly be about "ALS" versus "BLS". A casual glance at up to date NEMSIS, CARES, and ROC data shows that many ALS systems are outperforming the "BLS billing" data in this study.
Steill's OPALS study had better methodology and actionable conclusions, both of which are lacking in this study. Sanghavi wasted an important opportunity to delve deeper into outcome disparity and focused their efforts on old irrelevant data. Systems are what matter in OHCA. Systems which integrate effective treatments are what matter. CMS Level of Service and ICD-9-CM codes are not treatments for OHCA and cannot inform our opinion (which you note).
I'll be honest, I would not have given this study a second glance after reading its design. Meaningless and/or bad research in resuscitation is common due to the difficulties inherent in studying OHCA. However, the JAMA media team's PR Blitz that we should slap OHCA patients on stretchers and perform CPR on the way to the hospital necessitated a response (their suggestion is downright negligent given the body of real evidence out there).
I'm disappointed that I let JAMA get me so worked up, but we're finally making headway in survival to discharge in many areas of the US and this is the sort of bad press which gets in the way.