Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Resuscitation characteristics and outcomes in suspected drug overdose-related out-of-hospital cardiac arrest


This study is interesting for several reasons.

In a system that claims excellence, the most consistent way to identify the study group is by documentation of a protocol violation – but it is not intended as a study of protocol violations.

This may hint at some benefit from epinephrine (Adrenaline in Commonwealth countries), but that would require some study and we just don’t study epinephrine. We only make excuses for not studying epinephrine.

The atropine results suggest that the epinephrine data may be just due to small numbers, or that we may want to consider atropine for drug overdose cardiac arrest patients, or . . . .

The Sodium Bicarbonate (bicarb – NaHCO3) results suggest a flaw in EMS education (probably testing, too). If the patient is acidotic, this is one type of cardiac arrest where hyperventilation may be beneficial. Bicarb is the part of the drug that doesn’t do much, especially if the patient is dead. The sodium is what works, such as when the patient has taken too much of a sodium channel blocker, such as a tricyclic antidepressant or a class I antiarrhythmic. Acidosis is treated by hyperventilation. Use capnography.

Most important – antidotes probably don’t work as expected during cardiac arrest. Not even naloxone (Narcan).

Despite clear differences in the etiology of suspected OD [OverDose] and non-OD OHCA [Out of Hospital Cardiac Arrest], the International Liaison Committee on Resuscitation guidelines published in 2010 do not specify different treatments for suspected OD-OHCA patients during resuscitation,and state that there is no evidence promoting the intra-arrest administration of the opioid antagonist naloxone.8 [1]


What did they find in the study?

They may have located the highest concentration of heroin overdose in the country. 93% of OD-OHCA patients were treated with naloxone.

We relied on either naloxone administration or clear description of circumstantial evidence in the PCR [Patient Care Recod] to identify a suspected OD. Clear descriptions are also rare, and most (93%) of the cases were identified by naloxone administration. Naloxone during cardiac arrest is not part of any regional protocol, and all of these administrations are deviations from recommended practice. There may be other cases in which paramedics suspected OD, but did not deviate from protocol to administer naloxone. Therefore, it is impossible to be certain whether the actual number of OD cases is larger or smaller than the reported number. However, the use of naloxone as a proxy indicator of suspected OD has been supported in the literature.11 [1]


The EMS approach to naloxone still appears to be –

Image credits – 123

These results seem to show better response to the prehospital drugs in the OD-OHCA patients, but that ignores the ROSC (Return Of Spontaneous Circulation) rates.

Click on images to make them larger.

Why would OD-OHCA patients do better than non-OD-OHCA patients if they get a pulse back?

The average non-OD-OHCA patient is 20+ years older. These older patients may not be as capable of recovery nor as capable of tolerating the toxicity of the drugs they were treated with.

The change after ROSC is dramatic. Is that the important point of this study?

Are they doing anything special for OD patients in the hospital, or is it just a matter of That which does not kill me by anoxic brain damage, may allow me to recover twice as often as a typical cardiac arrest patient.

Do drugs (antidotes, antiarrhythmics, . . . ) work the same way in dead people as in living people?

Pharmacologic insults are just so massive and normal metabolism and physiology so deranged that no mere mortal can make a meaningful intervention. The seriously poisoned who maintain vital signs in the ED have the best, albeit never guaranteed, chance of rescue from a modicum of antidotes and intensive supportive care.[2]


We should understand that normal metabolism is irrelevant to cardiac arrest.

We should understand that we do not need to ventilate adult cardiac arrest patients, when the cause is cardiac. An absence of ventilation would not be appropriate in a living adult, but dead metabolism is not normal. If something as basic as oxygen changes, when the patient is dead, how much less do we understand the behavior of other drugs in dead patients?


[1] Resuscitation characteristics and outcomes in suspected drug overdose-related out-of-hospital cardiac arrest.
Koller AC, Salcido DD, Callaway CW, Menegazzi JJ.
Resuscitation. 2014 Jun 26. pii: S0300-9572(14)00581-4. doi: 10.1016/j.resuscitation.2014.05.036. [Epub ahead of print]
PMID: 24973558 [PubMed – as supplied by publisher]

[2] Dissecting the ACLS Guidelines on Cardiac Arrest from Toxic Ingestions
Emergency Medicine News:
October 2011 – Volume 33 – Issue 10 – pp 16-18
doi: 10.1097/01.EEM.0000406945.05619.ca
Roberts, James R. MD

Roberts, J. (2011). InFocus: Dissecting the ACLS Guidelines on Cardiac Arrest from Toxic Ingestions Emergency Medicine News, 33 (10), 16-18 DOI: 10.1097/01.EEM.0000406945.05619.ca

Koller, A., Salcido, D., Callaway, C., & Menegazzi, J. (2014). Resuscitation characteristics and outcomes in suspected drug overdose-related out-of-hospital cardiac arrest Resuscitation DOI: 10.1016/j.resuscitation.2014.05.036



  1. Rogue…. Mr. Medic….. Not sure of your correct title, but here goes. I’m new to following the EMS blogs and it’s refreshing to find bloggers like yourself pushing for empirical evidence to guide treatment decisions. My read of this article on Naloxone use during CPR and a quick Google search of related articles makes me think that we don’t have enough information to guide our decisions and our research studies are not asking the questions we really want to know the answers to. Retrospective studies such as this one inherently contain errors. While I know RCTs are difficult, I’d be much more moved by controlled animal studies than correlational or retrospective human studies. The animal studies seem to be mixed but some show good results for Naloxone for cardiac arrest following asphyxiation ( but I can;t see how anyone could asphyxiate a rat – I hope they were anesthetized).

    I come from a background doing fMRI research which is inherently correlational. My guess is that in the future most of the fMRI research will be thrown out as garbage.Similarly, it is a mistake to base clinical decisions on cardiac arrest care from studies like these. I believe in empirically based interventions but we need ot make sure the science backs up the interventions. To me, the first question is, does Naloxone during cardiac arrest cause harm or worsen outcomes. If we don;t have the answer to that, then how can we administer Naloxone during Cardiac Arrest

    • Nicholas Maltby,

      Theory (i.e. “science”) is important in designing a study, not a treatment. You develop the hypothesis/theory, then you determine a way to falsify it, then you determine if the experimental evidence fits the theory. Unfortunately, a lot of research (not just in healthcare for that matter) is done in the opposite order: find facts to fit the theory (hey, scientists are human). The complicating factor in human medicine is that some people use unproven theories to declare certain research unethical.

      Epinephrine in cardiac arrest is the classic example. Even the American Heart Association, who sets the guidelines that nearly all pre-hospital and ED providers follow, admits there is no hard evidence that epinephrine is effective in improving survival……but they still keep it in the guidelines anyhow because it’s “unethical” to deviate from the “standard of care”.

      As for the studies, I agree they’re not optimal. Ideally, these retrospective studies will be used to design RCT studies. However, these studies have one very important use: to cast enough doubt on the “standard of care” that it is no longer seen as unethical to deviate from “what we’ve always done.” Animal studies IMHO are just as flawed; too many assumptions on how a given animal’s physiology is or is not like human to make it any more useful than in designing RCTs.

  2. It is unfortunate that research tends to often be mining facts to fit the theory – I saw this all too often in my research career. Part of this is the bias against publishing negative results. It is very hard to publish a paper in which you don’t find significant difference – even if this conclusion is useful as with epi during SCA.

    RCTs on humans where denial of care is not an option as with SCA is very difficult to do and requires lots of circumstantial evidence and animal studies to overcome the ethical dilemma. Animals studies can serve as very good human anologues. They don’t replace human studies but they make human studies possible where ethical concerns might otherwise prohibit a human RCT.

    With that said, I am heartened but frustrated by the movement for empirically guided treatments in EMS. The movement has been going on so long and yet has gained so little traction. Maybe the dinosaurs need to die off in order to gain wide acceptance. Worse, I see a fair amount of turf protection guiding treatment beliefs. *** Momentary tirade warning *** EMS is it’s own worst enemy. We accept lousy pay which prohibits the growth of our profession. We allow ourselves to be called technicians who are only good enough to follow protocols. I can’t believe that we still debate whether we can diagnose. We need to demand pay commensurate with our sacrifices (read national union), fight back against the privatization of EMS which minimizes us in the eyes of the public since we can be relegated to the lowest bidder), and increase the professionalism and expertise of of our members in the process. ****End of Tirade ***


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