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

- Rogue Medic

Delayed Sequence Intubation (DSI)

There is a fascinating podcast, although it is not really relevant to EMS in the US, yet. It feels as if this is something that will be part of EMS in the future. EMCrit Podcast 40 – Delayed Sequence Intubation (DSI). There is also a short video (less than 5 minutes) covering DSI and a couple of other airway/preoxygenation topics.

I know. I am a research guy, so why am I going on feelings?

There is a lot of research out there on ketamine, and much more in the works. All of it appears to be producing positive results as far as efficacy and safety. I would be surprised if there is a discovery of some unknown danger.

It is certainly possible that a problem turns up. There have been cases of apparently safe drugs that have been shown to have significant dangers after being used for a while. However, outside the US, ketamine has been used extensively. How extensively? Even EMS uses ketamine. We appear to be way behind the times in doing what is best for patients. Not because it is fashionable. not because others are doing it. Not because it is the cool thing to do. Because it seems to provide a lot of benefits that our current treatments lack.

Ketamine sedates.

Oh no! The hypotension!

Not with ketamine.

Oh no! The respiratory depression!

Not with ketamine.

Oh no! The depressed airway reflexes!

Guess what?

Not with ketamine.

Ketamine is not perfect, but it appears to be a much better drug for dealing with unstable patients in awkward circumstances.

What is more challenging for EMS, than an unstable patient in awkward circumstances?

Where does EMS make a big difference in outcomes? One place is with the unstable patients in awkward circumstances.

In Etomidate in procedural sedation, I wrote about etomidate, which is another drug that is not a cardiac depressant and can be used for sedation under similar circumstances.

When RSI (Rapid Sequence Intubation/Induction) may not be the right thing to do for a variety of reasons, DSI may be the right thing to do. Maybe EMS can use etomidate for these patients, until we finally realize that ketamine is safe and efficacious.

Ketamine does sometimes produce nausea and/or emergence reactions, but in the podcast, Dr. Weingart gives a good reason for not worrying about these with DSI. The nausea only seems to be a problem in a minority of patients and then only on emergence from the dissociative state. These patients would be kept sedated with ketamine for an extended period – at least until after transfer of care in the ED (Emergency Department).

In an earlier podcast on ketamine, Dr. Weingart explained that he thinks that the problem with emergence from ketamine sedation is similar to the problem with bad LSD (Lysergic Acid Diethylamide – LSD, because Acid is Saure in German) trips.

Should the answer be DSI?

I think that this is coming to the more progressive systems, but another way of using sedation with ketamine (or etomidate) may be to use DSA (Delayed Sequence Airway). Why does airway control need to be with intubation?

It doesn’t.

This article presents a case in which an air medical flight crew encountered a potentially difficult airway when a trauma patient deteriorated in-flight. The crew elected to sedate and paralyze the patient and place a laryngeal mask airway without a prior attempt at direct laryngoscopy and endotracheal intubation. The term Rapid Sequence Airway (RSA) is coined for this novel approach. This article describes and supports this concept and provides definitions of alternative and failed airways.

Rapid Sequence Airway (RSA)–a novel approach to prehospital airway management.
Braude D, Richards M.
Prehosp Emerg Care. 2007 Apr-Jun;11(2):250-2.
PMID: 17454819 [PubMed – indexed for MEDLINE]

The sad thing is that this may still be a novel approach to prehospital airway management almost 4 years later.

But there is a YouTube about it, so how novel can RSA be?

The YouTube is from the medical center where Dr. Braude and Dr. Richards work. When others are doing RSA, then RSA may no longer be a novelty.

Does an extraglottic airway mean increased aspiration?

Maybe not. If we work on ways of monitoring the airway, we may not have any greater incidence of aspiration with extraglottic airways than with intubation. If we become comfortable with extraglottic airways, we may even find that we have a lower incidence of aspiration with extraglottic airways.

What about DSA (Delayed Sequence Airway) with CPAP (Continuous Positive Airway Pressure)?

Why not?

But the patient has to be fully alert for CPAP.

Maybe we will be able to write some more flexible protocols for CPAP and EMS. We are still not using CPAP enough to become as familiar with it as we will need to for innovation.

If you have not done so, yet – Go listen to the podcast.


High Flow Nasal Oxygen During Intubation

High flow oxygen by nasal cannula to improve intubation outcomes?

Crazy or intelligent and aggressive.

During pre-oxygenation, applying nasal oxygen in addition to a non-re-breather face mask can significantly boost the effective inspired oxygen. After apnea created by RSI the same high flow nasal cannula will help maintain, or even increase, oxygen saturation during efforts securing the tube (oral intubation). The use of nasal oxygen during pre-oxygenation and continued during apnea can prevent hypoxia before and during intubation, even in extreme clinical cases.[1]

Yes. High flow oxygen by nasal cannula.

15 LPM (Liters Per Minute) oxygen by nasal cannula.

Nasal oxygen doesn’t affect the choice of oral intubation technique (direct or video laryngoscopy). The short time use of non-humidified oxygen has minimal risk of bleeding or irritation. Decreasing respiratory drive in patients with chronic hypercarbia is irrelevant after the decision to intubate. There is no risk of barotrauma, even at combined face and nasal oxygen flow rates exceeding 30 lpm. Air can leak out of a face-mask through the exhalation ports (rubber flaps) or from the pressure release valves built into a bag-mask resuscitator. The only challenge to the routine use of nasal oxygen is the availability of a second oxygen source.[1]

We should have a spare oxygen regulator on every ambulance.

Small changes in FiO2 create dramatic changes in the availability of oxygen at the alveolus, and these increases result in marked expansion of the oxygen reservoir in the lungs prior to the induction of apnea.[1]

What he does not state is that the reverse should also be true. We tend to be cavalier with oxygen, up until the point where we panic and decide to intubate. If we are more aggressive with patients who desaturate quickly before they desaturate, maybe we will not even feel the need to intubate some of these patients.

The net result is that during apnea, oxygen insufflated into the upper airway will be “drawn” down the trachea and into the alveolus. Oxygenation can be maintained in non-breathing humans for 100 minutes through apneic diffusion, even as carbon dioxide builds up in the blood.[1]

Oxygenation can be maintained in non-breathing humans for 100 minutes

Perhaps this is a part of the reason some patients survive unrecognized esophageal intubations.

If oxygen is being aggressively delivered to the patient’s stomach, some of that high concentration atmosphere will progress from the stomach to fill the airway, then expand down the trachea, and diffuse into the alveoli.

Dr. Levitan is one of the more creative airway management people around. Go read the whole article.


Emergency Physicians Monthly
by Rich Levitan, MD on December 9, 2010


Experts Debate Paramedic Intubation – JEMS.com

In JEMS, there is an article by almost all of the top people in EMS airway management. There are several omitted, who contribute to the understanding of airway management, such as Richard Levitan, MD[1] and Kelly Grayson, CCEMT-P.[2] This is not that much of a criticism, since the people they included are definitely among the top airway management experts.

The article points out some of the problems we have in teaching paramedics/nurses/doctors to use critical judgment. We do a very poor job of educating people to make good decisions. Then we conclude that our failure means that the alternative is rigid protocols – even for doctors.

That is just another example of bad judgment.

What is wrong with the following paragraphs?

An EMT listens over the chest and abdomen with a stethoscope. He says he hears breath sounds over the chest but doesn’t say anything about the presence or absence of breath sounds over the abdomen. An ECG monitor with capnography is attached to the patient. The EMT operating the monitor is unsure how to set the device to measure waveform capnography.

Approximately a minute later, the EMT states, “There’s something wrong with the monitor.” The paramedic quickly checks the monitor and re-checks placement of the ET tube. He says, “Looks like the monitor’s not working. But the breath sounds are good, so let’s go ahead and get this guy to the hospital.” The patient is then moved to the ambulance and transported to St. Joseph Hospital with mechanical ventilation continued.[3]

When the monitor does not produce a waveform, or confirm what the EMT expected to see, the conclusion is that There’s something wrong with the monitor.

This is bad, because the EMT is already deciding where the problem is. He has made a statement that he will probably feel the need to defend later on. He doesn’t even appear to be considering operator error.

As the patient becomes less stable, the operator error rate increases.

The EMT operating the monitor is unsure how to set the device to measure waveform capnography. Still, he concludes, not that he doesn’t know what he is doing, but that the equipment is wrong.

I’m not the problem! The equipment I don’t understand is the problem!

Not to worry. We still have a paramedic, trained in the use of waveform capnography and drilled in intubation until he talks about it in his sleep. Sorry. Paramedic programs do not seem to drill paramedics on intubation that much, nor do employers, EMS systems, or even medical directors. Intubation is just not taken seriously. Tube placement confirmation and waveform capnography are taken even less seriously

Looks like the monitor’s not working. But the breath sounds are good, so let’s go ahead and get this guy to the hospital.

This is the motto of a serial killer.

It is only a matter of time until someone, who thinks like this, kills and kills again.

Who taught this guy to think like this?

Who hired him to think like this?

What EMS system licensed him to think like this?

What medical director authorized him use this kind of thinking to go out and kill patients?

His paramedic instructor from the local community college is subpoenaed and, during his deposition, reports that it was very difficult for his students to gain access to local hospitals to practice intubation, explaining that students simply learned the procedure on manikins.[3]

So what?

You can learn to intubate competently on mannequins.

You do not need real live dead people to learn to use critical judgment.

The lack of human intubation practice is a pathetic excuse for poor education.

Would this medic have made a better decision about the obvious lack of waveform during his intubation attempt if he had practiced on dozens of live patients?


The education he received does not appear to have included thorough coverage of tube placement confirmation. And that is not even the most important part of intubation.

We spend too much time worrying about intubation, when the real issue is airway management. This medic does not understand airway management – not even a little bit.

This is a systemic problem.

This lack of understanding of airway management begins in EMT/paramedic school, continues with employers, is certified by EMS systems, and is given the Dominus vobiscum of the medical directors.

Then the medic has his license to kill. The question is, Why is anyone surprised when the medic does kill?

We all seem to believe that this series of failures – school to employer to EMS system to medical director – works.

How many people are killed by this misunderstanding?

How many people are killed by this ignorance?

Am I being too harsh on these failures?


Am I going too easy on the medic?

Calling him a serial killer is not exactly killing him with kindness. This is similar to Murder on the Orient Express. There are plenty of fingerprints on the murder weapon. There is plenty of guilt to go around.

Marc Eckstein, MD, MPH, FACEP, EMT-P: The take-home point here is that we need prehospital research that involves prospective randomized controlled trials (RCTs) with meaningful outcome variables, which are decreased morbidity and mortality.[3]

Essential to the study of intubation and airway management is that the researchers control for the quality of the paramedics.

We need to stop looking at intubation as something that is not affected by the quality of the people attempting intubation.

Dr. Eckstein: These alternative airway devices, particularly the King airway, can be placed quickly, and they provide good oxygenation and ventilation. However, they don’t protect against aspiration, which of course is a major concern with emergency airway management, especially in the field.[3]

I disagree about the major concern of aspiration.

Where is the research to support this?

In the studies comparing intubation with basic BVM use, where is the flood of emesis worsening outcomes?

I think that intubation protecting against aspiration is mostly just another EMS myth.

William E. Gandy, JD, NREMT-P: I wholeheartedly agree with Dr. Wang. Yes, the emphasis should be on ventilation—not intubation. Paramedics should be thoroughly schooled in airway evaluation and should have a variety of airway adjuncts, such as bougies, video laryngoscopy and supraglottic airways, available and be willing to use them.[3]

If you have heard Gene (William E. Gandy) talk about airway management, you have heard this over and over.

You may get tired of hearing that airway management is about ventilation, not intubation or oxygenation. If that is the case, then you really do not understand airway management.

If you do not understand airway management, then you do not understand intubation.


[1] Laryngeal view during laryngoscopy: a randomized trial comparing cricoid pressure, backward-upward-rightward pressure, and bimanual laryngoscopy.
Levitan RM, Kinkle WC, Levin WJ, Everett WW.
Ann Emerg Med. 2006 Jun;47(6):548-55. Epub 2006 Mar 14.
PMID: 16713784 [PubMed – indexed for MEDLINE]

Free Full Text Free PDF

[2] The Airway Continuum
The Ambulance Driver’s Perspective
by Kelly Grayson

[3] Experts Debate Paramedic Intubation – Should paramedics continue to intubate?
Bryan E. Bledsoe, DO, FACEP, FAAEM | Darren Braude, MD, MPH, FACEP, EMT-P | David K. Tan, MD, FAAEM, EMT-T | Henry Wang, MD, MS | Marc Eckstein, MD, MPH, FACEP | Marvin Wayne, MD, FACEP, FAAEM | William E. Gandy, D, LP, NREMT-P
Thursday, July 1, 2010