ET (EndotTracheal) drug administration in cardiac arrest is one resuscitation topic that refuses to die. People keep trying to bring ET drugs back to prominence in ACLS (Advanced Cardiac Life Support). In the absence of evidence of benefit of a treatment, the intervention should be studied in settings that are as controlled as possible. When the evidence suggests harm from the treatment, unless that apparent harm is outweighed by apparent benefit, the treatment probably should not even be used in controlled studies.
How does this apply to ET drug administration in cardiac arrest?
Before looking at the research, let's look at the theory behind this.
ALS (Advanced Life Support - drugs, IVs, intubation, . . .) improves outcome from cardiac arrest.
In one recent and very large study of this, Advanced Cardiac Life Support in Out-of-Hospital Cardiac Arrest[1], the claim that ALS saves lives in cardiac arrest is shown to be not supported, at least not with the ALS that was used at the time of the study. That ALS has not changed much, but the BLS (Basic Life Support - CPR, defibrillation, . . . generally non-invasive treatments) has changed significantly.[2] There is one ALS treatment that is promising, therapeutic hypothermia,[3] but that was not being used at the time and is not the reason for this post.
The research on ALS in cardiac arrest does not show an improvement in resuscitation. Resuscitation is the ability for the patient to leave the hospital with brain function similar to the brain function they had prior to the cardiac arrest. Resuscitation is not arriving at the hospital with a pulse.
While arriving at the hospital with a pulse is important for resuscitation, focus on this is bad patient care. If we were only interested in arriving at the hospital with a pulse, we could just shock the patient into asystole, use a pacemaker and drive fast. we might have to upgrade the pacemakers from milliAmps to Amps and use thicker rubber gloves, but this could improve the number of patients arriving at the hospital with pulses. That does not mean it would improve the number of patients leaving with good brain function. A focus on pulses is not good for patient care. Even Dr. Frankenstein would feel silly yelling, It's Alive, for a monster with just a pulse. Even the fictional doctor, in a book almost 200 years old, knew that the brain was essential to resuscitation.
If you think that arriving at the hospital with a pulse is a big deal, you probably would have done well as a banker up until this year, thinking that making reckless loans is conservative, because you wear a suit and tie. Either way, other people pay for your mistakes. With all of the increase in resuscitation rates following the improved focus on continuous good compressions, how many thousands of deaths have the get a pulse back crowd been responsible for by distracting paramedics, nurses, and doctors with ineffective and harmful drugs?
So, what research is there on ET drug administration in cardiac arrest?
One study does compare IV (Intravenous) medication administration with ET medication administration in cardiac arrest. Endotracheal drug administration during out-of-hospital resuscitation: where are the survivors?[4] There are some differences between the groups. The endotracheal drug group was 5 times larger, 5 years older, much more likely to be female, twice as likely to be in a nursing home, much less likely to have VF and much more likely to have asystole as the initial rhythm. The results still should not be ignored.
Why not?
Although this is a retrospective study with a lot of variables that have not been controlled for, it is the
Why does that matter?
There is no other study on ET administration worth looking at. Unless you are interested in something that looks at the change in blood level of epinephrine in a pig in a laboratory. Since I do not treat pigs in a laboratory, this is not really relevant to what I do. Even if I do find a pig in cardiac arrest under a spider web that reads, Humble, I will not be regretting that I am not more familiar with these studies. Besides the IO (IntraOsseous) needle has become standard in cardiac arrest treatment.
What were the results of the study?
Of the IV drug group, 5% survived to discharge.
That sounds typical for the resuscitation rates back then. What about the ET drug group?
Nobody survived.
If you have good circulation, you may absorb medication from the lungs without complication.
If you have circulation by way of chest compressions, that may not be the case.
If you have to stop the compressions in order to deliver the medication, you are doing more harm than any possible good that could come from providing these drugs that are not research based. Since none of the drugs are research based, apparently not even oxygen, that means all of the drugs are a problem.
There is not even evidence that providing oxygen down the ET tube is good for the patient, but we still have people who think that making Mr. Bubble in the lungs is good patient care.
Footnotes:
^ 1 N Engl J Med. 2004 Aug 12;351(7):647-56.
Comment in:N Engl J Med. 2004 Dec 9;351(24):2553-4; author reply 2553-4.
Advanced cardiac life support in out-of-hospital cardiac arrest.
Stiell IG, Wells GA, Field B, Spaite DW, Nesbitt LP, De Maio VJ, Nichol G, Cousineau D, Blackburn J, Munkley D, Luinstra-Toohey L, Campeau T, Dagnone E, Lyver M; Ontario Prehospital Advanced Life Support Study Group.
Free Full Text
One interesting aspect of the OPALS criteria is an attempt to evaluate the quality of the paramedics participating in the study. Listed among the criteria is "and paramedics had to successfully perform an endotracheal intubation in 90 percent of patients. These criteria were monitored regularly, and the three communities that failed to meet the standards were excluded."
^ 2 Just one example of the improved resuscitation rates is provided in this post from Ambulance Driver and the comments.
Does This Mean I'm Fully Assimilated?
^ 3 Therapeutic Hypothermia
Wikipedia article
^ 4 Niemann JT, Stratton SJ, Cruz B, Lewis RJ.
Endotracheal drug administration during out-of-hospital resuscitation: where are the survivors?
Resuscitation. 2002 May;53(2):153-7.
PMID: 12009218 [PubMed - indexed for MEDLINE]
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11 Comments:
Seeing as IO administration is preferred even over central line placement/administration, is faster than intubation (at least using the EZ-IO), and as IV/IO placement comes before advanced airway placement (doesn't interfere w/ CPR), just WHY is ET administration still being pushed so much?
I think the last time I gave any med down the ETT was Narcan, and that was some 9 or 10 years ago. For some reason the agency I was with did not allow IM Narcan, only IV & ETT, and we couldn't get an IV.
0.5 mg Narcan ETT & he sat up & pulled out the tube.
Thank God for technology.
Great post.
But there's a big difference between just providing some oxygen, and forcing massive quantities of it into the patients lungs.
RevMedic,
There are some people who just think that ET drug administration is cool, or something. I don't worry too much about why they are so fond of this. If I can give people some good references to show to medical directors, maybe the protocols will change to eliminate some of these procedures. Things that are not in the best interest of the patients, but remain in the protocols because they are traditional or just overlooked.
Anonymous,
Thank you.
You are correct. There is a big difference between a lot of oxygen forced in and just some oxygen.
We do not know what the best CPR will turn out to be, but it might be just compressions for the first 10 minutes. In a low flow state, maybe the administration of oxygen is more harmful than helpful. It does not make sense, but it may be an example of narrative fallacy misleading us.
We need supplemental oxygen to live, but we might not need any supplemental oxygen to be resuscitated - at least not initially. Maybe the compressions move enough air around to provide some oxygen/CO2 exchange, in spite of what we have been taught about the need to ventilate more volume than the dead space can hold.
On the other hand, one problem with the ET drugs is the fluid in the lungs can interfere with the movement of oxygen and CO2 between the alveoli and capillaries.
I know of one physician (brother to one of my past physician advisors), who is board certified in critical care and pulmonary disease, who claims that some 100-200ml of fluid can be safely infused into the lungs via the ETT.
Personally, the 'coolness' of ETT Rx administration was lost on my a long time ago.
Great post!
Well, as much as I hate to, you know I cannot resist the urge to 'poke the gorilla with the stick', so here goes.
I agree, that given the widespread use of alternative vascular access(IO), the ET route of medication administration during resuscitation is most likely of little value [and as you point out potentially harmful-although I would worry just as much about washing the 'Mr. Bubbles' away, as making it ;-) ]
However, you know my feelings on retrospective studies in general, and this one is particularly horrible! In addition to all the patient disparity between the treatment arms, the ET group was 1.5 times more likely to be in asystole at the onset than the IV group! Might this impact the results? Furthermore, since this was retrospective, the medics doing the treating were not randomizing which patients were going to get ET vs. IV. My guess is that this was most certainly NOT random at all. A myriad of factors such as length of downtime, ability to attain IV access, Single provider vs. double provider etc. etc. etc. may have determined which route a provider chose and would most certainly skew any data.
So I would say that this "study" should be ignored, at least for the purposes of "ruling-out" the potential benefits of ET administration. Poor research is poor research. Trying to make chicken soup out of this chicken-shit is, at best, Quixotic.
This is unfortunately the nature of the beast when it comes to quality research surrounding resuscitation- there is a dearth of good data. Half-truths, anecdotes, bad ideas, and untested theories abound.
On point of porcine lab testing- it has a valuable place in establishing that for certain formulations, the ET route can provide adequate absorption to approach blood levels established by IV routes - Charlotte and her web notwithstanding. Does this necessarily mean better outcomes? Of course not. Until we get some IRBs with a full compliment of testes*, this is the closest we are ever going to get to scientifically rigorous data on the subject.**
You do make a great point about arbitrary endpoints like presence of a pulse upon arrival.
Consider the pot stirred. It's been a while! ;-)
* sarcasm
** not sarcasm
Whoops, that's what I get for commenting right before going to sleep.
When I said "just providing some oxygen" I was thinking of the passive oxygen insufflation approach spelled out here.
But note also the discussion on gasping, it's entirely possible that passive insufflation is also unnecessary, and maybe even harmful.
RevMedic,
Living patients will tolerate quite a bit of fluid in the lungs. After each ET dose there is an apparent need to hyperventilate the patient back to baseline oxygen levels.
While we are moving away from ventilation in cardiac arrest, that does not mean that we should be doing things that block gas exchange.
In the ICU there will be patients who regularly receive medications down the ET tube. This is not what I am criticizing. The patients who, according to the latest research, seem to need continuous compressions for a chance at resuscitation, should not have those compressions interrupted to provide a treatment that appears to be harmful.
Vince,
You will find your response here. Endotracheal Drug Administration in Cardiac Arrest - comment. I guess you left the building, broke down the firewall, or used one of the many tunnels through the firewall.
Anonymous,
That article, Cardiocerebral Resuscitation: Could this new model of CPR hold promise for better rates of neurologically intact survival?, is an excellent one. I have been thinking about writing a post on it. There is a lot of information to consider and fortunately there is a lot of research being done that may help clarify what works.
We do need to be careful in deciding what is helpful and what is harmful, since it becomes almost dogmatic when these associations are made.
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