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

- Rogue Medic

What Laryngoscope Blade Do You Use? – Why?

Mon, 06 May 2013 13:35:24 -0400 by

 

Which laryngoscope blade is your favorite?

Does length matter?

Does strength matter?[1]

Dr. Minh LeCong asks this at his blog PHARM – PreHospital And Retrieval Medicine.

There is also a video that provides some information on blade size.
 


 

One of the problems with the video is the hand position. The laryngoscope should be held so that the hand is touching the blade. I prefer to have my ring finger touching the blade.

The higher the hand is on the handle, the more likely that the handle is used like a slot machine handle, as I demonstrate below.
 


 

The way to intubate is to position the patient before even picking up the laryngoscope (and premedicating with oxygen and whatever else is appropriate), then only advance the blade as far as necessary for each step of laryngoscopy.

1. Find the tongue.

Yay! That was easy.

2. Advance the laryngoscope and find the epiglottis.

Not as easy, but just more important.

3. Lift up (either in the valecula or under the epiglottis – it does not matter) and find the arytenoid structures. The vocal cords are above the arytenoid structures, so there is no need to lift up any farther.

4. Advance the bougie/tube over the arytenoid structures without touching anything else. It isn’t about cleanliness. The biggest problem I see people have when trying to intubate is that they do not avoid everything else in the mouth and end up trying to force the tube.

Force should never be used in the airway.

We should not arm wrestle with the airway. We will lose.

Go ahead and try to force this airway. I double dog dare you.
 


Image credit. It is all in the positioning.
 

The goal of airway management is to out-think the airway, not to out-muscle the airway.

As with martial arts, strength improves with repetition due to the development of muscle memory, even if there is no increase in strength. Technique requires a lot of repetition.

If you have not intubated a mannequin over a thousand times, you are still learning technique. We can always learn more.

We tend to be satisfied with very little practice, as if the patient owes it to us to inhale the tube.

This is ridiculous, but I find that for almost every class I have taught, I intubated the mannequin more times than everyone else in the class combined. I offer to let students practice as much as they want. I offer to help or to leave them alone.

Why is intubation of the airway of another human being so unimportant to so many of us?

Why do so many of us pretend that we are good at intubation?
 

Intubation shouldn’t be that hard, but research repeatedly shows us that we become airway stupid when things do not go as planned – and we are often the cause of the problems with our plan. Even if our plan is not just having the patient inhale the tube.
 

Most adults can be intubated with a #2 Mac or a #2 Miller. A longer blade is only necessary for a patient with an unusually long mandible.

Understanding of the airway is more important than blade size. Any spatula will do.

A blade should be relatively wide and flat. A tongue depressor would work well, but this would require some practice to manipulate the tongue with a tongue depressor. A tongue depressor is wider and flatter than a Miller, so a tongue depressor is better designed than a Miller to lift the tongue out of the way.

Why isn’t the Miller blade designed to lift the tongue out of the way? Was Miller in cahoots with the trial lawyers?

I prefer a Grandview, but a lower profile Grandview would be nice.
 


 

This is from Dr. Richard Levitan’s Airway Cam series.

Dr. Levitan is one of the top airway doctors in emergency medicine. Notice how low his hand is on the blade. It may be someone else manipulating the laryngoscope, but probably someone who has received input from Dr. Levitan on intubation technique.

The wrist is lower than the blade. This makes it more difficult to pull back on the blade and easier to lift up with the blade.

Intubation is not about a long blade, or a strong arm, or pulling back, but many people attempt to intubate using all three of these mistakes.

Intubation is about thinking, preparation, positioning, technique, and lifting the tongue up.

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Footnotes:

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[1] PHARM Poll : Blade choice in direct laryngoscopy – does length or strength matter?
by rfdsdoc
on May 2, 2013
PHARM – PreHospital And Retrieval Medicine
Article

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Filed Under: Airway Management, Heresy, Intubation, Video Laryngoscopy

Will IV Oxygen Save Lives?

Thu, 02 May 2013 16:30:43 -0400 by
ResearchBlogging.org
Image credit.
 

Intravenous oxygen delivery that works?

Maybe temporary oxygenation, but not yet.

Will this change the approach to CICV (Can’t Intubate, Can’t Ventilate) patients?

No, but it may change the approach to CICO (Can’t Intubate, Can’t Oxygenate) patients.

The distinction is important. If we can deliver oxygen without ventilation, we can avoid some of the problems of hypoxia, but we will still have to deal with the acidosis that results from the inability to eliminate CO2 (Carbon DiOxide).
 

In the early 1900s, intravenous administration of oxygen gas was used in attempts to relieve refractory cyanosis (4–7). Most reported that spontaneously breathing, cyanotic animals exhibited signs of pulmonary embolism at infusion rates in excess of 0.2 to 1 ml/kg per minute and required frequent pauses in the infusion (4, 5); . . . None of these studies documented an increase in oxygen content in the blood as a result of the intervention.[1]

 

Try walking up several flights of stairs while only breathing through your nose. You will become short of breath very quickly.

Unless you are in truly horrible shape, it is not a lack of oxygen that is causing you to become short of breath. It is the inability to remove CO2 (Carbon DiOxide) that is the problem.

Most of us breathe because of a buildup of CO2, not because of a lack of oxygen.
 

The reflexive response of some people might be to give the anti-acidosis drug NaHCO3 (sodium bicarbonate). We will ignore the sodium, which at 5.8% in NaHCO3 is over 6 times the concentration of the NSS (Normal Saline Solution – 0.9% sodium) we routinely give. The sodium in NaHCO3 may be effective for treating sodium channel blocking drugs, such as antidepressnts, antiseizure medications, antiarrhythmics, and antivirals.[2]

The sodium is not the real danger. The bicarbonate (HCO3–) is the problem. When binding with the excess hydrogen ions to neutralize metabolic acidosis, CO2 is produced.
 

HCO3– + H+

Produces:

CO2 + H2O
 

a patient with complex airway anatomy and difficulty maintaining oxygenation using basic airway maneuvers could avert a hypoxemic crisis during a prolonged intubation attempt. To date, safe and effective intravascular delivery of oxygen gas has not been realized.[1]

 

In the cute little bunnies used in the study (7 LOM [Lipidic Oxygen–containing Microparticles] and 6 Control), these were the results.
 


Click on images to make them larger.
 

Oxygen saturation remained between 40% and 60% with the LOM, but that was much better than the less than 20% for the controls. since the study animals received LOMs titrated to an arterial oxygen tension of greater than 30 mmHg, this is not a surprise. The controls just received fluid at a similar rate.
 


 

CO2 more than doubled for both groups.

Providing oxygen does nothing to remove CO2.
 


 

When CO2 increases, the pH will decrease (acidosis will increase).

Sodium bicarbonate will not decrease the acidosis for these patients.

Sodium bicarbonate will increase the acidosis for these patients.

Sodium bicarbonate produces CO2, which must be removed by ventilation. If we are giving LOM to patients we can adequately ventilate, maybe we do not understand what we are doing.

We should only give sodium bicarbonate to a patient who is well ventilated – unless we are trying to kill the patient.
 


 

In (F) and (G), data are means ±SEM. The blue lines end at 10.2 min because no animals treated as controls had spontaneous circulation after that time and received chest compression–only cardiopulmonary resuscitation (CPR) during the remainder of asphyxia. (H) Kaplan-Meier plot of animals experiencing cardiac arrest during asphyxia (left; P =0.0002, log-rank test), restoration of mechanical ventilation (shaded box), and subsequent recovery and observation (right).[1]

 


 

None of the bunnies reported any near-death experiences.

Consider the time involved. Many in the media have been reporting this as a way to provide half an hour of apneic oxygenation. That is ridiculously optimistic. This will be something that might provide an extra 5-10 minutes to manage a hypoxic patient, if the patient has not already died due to the hypoxia.

5-10 minutes can be the difference between life and death.

Don’t believe me?

Hold your breath for 10 minutes. Just stop breathing and hold your breath.[3]

Without LOMs, all of the bunnies were pulseless after a little more than 10 minutes, but at 15 minutes, when ventilation was resumed, almost all of the LOM bunnies still had pulses (6 out of 7).

LOMs are not just to make it possible to deliver a patient with a pulse to the hospital, so that we can say that They didn’t die in the ambulance.

That is not changing anything.

LOMs are to provide time for us to provide an airway – if this ever demonstrates safety and efficacy in humans.

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Footnotes:

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[1] Oxygen gas-filled microparticles provide intravenous oxygen delivery.
Kheir JN, Scharp LA, Borden MA, Swanson EJ, Loxley A, Reese JH, Black KJ, Velazquez LA, Thomson LM, Walsh BK, Mullen KE, Graham DA, Lawlor MW, Brugnara C, Bell DC, McGowan FX Jr.
Sci Transl Med. 2012 Jun 27;4(140):140ra88. doi: 10.1126/scitranslmed.3003679.
PMID: 22745438 [PubMed – indexed for MEDLINE]

Free Full Text Download in PDF format from medlive.cn
 

At the end of the asphyxial period, mechanical ventilation was restored with 100% oxygen until return of pulsations (in animals receiving chest compressions) and then titrated downward to achieve arterial saturations of >92%. Animals achieving return of spontaneous circulation after relief of asphyxia were treated with standard intensive care management, including inotropic support (dopamine, 2 to 10 mg/kg per minute, intravenous infusion) to maintain MABP of at least 40 mmHg during the follow-up period. Hyperthermia was avoided by passive ambient cooling (goal, 34 to 35° C). Animals were sacrificed 90 min after the end of asphyxia for lab and histology sampling.

Everyone seems to be using therapeutic hypothermia and trying to avoid giving too much oxygen.

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[2] Management of sodium-channel blocker poisoning: the role of hypertonic sodium salts.
Di Grande A, Giuffrida C, Narbone G, Le Moli C, Nigro F, Di Mauro A, Pirrone G, Tabita V, Alongi B.
Eur Rev Med Pharmacol Sci. 2010 Jan;14(1):25-30. Review.
PMID: 20184086 [PubMed – indexed for MEDLINE]

Free Full Text in PDF format from EuropeanReview.org
 

As more substances having sodium-channel blocking properties become available, the incidence of this poisoning may be expected to increase, and clinician, particularly the emergency physician, should be familiar with this potential fatal condition.

A little evidence supports the treatment with hypertonic sodium salts, and current recommendations have not been based on randomized clinical trials.

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[3] Longest time breath held voluntarily (male)
Guinness World Records
Web page.
 

The longest time holding the breath underwater was 22 min 00 sec by Stig Severinsen (Denmark) at the London School of Diving in London, UK, on 3 May 2012.

Stig was allowed to hyperventilate with oxygen prior to the attempt, and did this for 19 minutes and 30 seconds.

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Kheir, J., Scharp, L., Borden, M., Swanson, E., Loxley, A., Reese, J., Black, K., Velazquez, L., Thomson, L., Walsh, B., Mullen, K., Graham, D., Lawlor, M., Brugnara, C., Bell, D., & McGowan, F. (2012). Oxygen Gas-Filled Microparticles Provide Intravenous Oxygen Delivery Science Translational Medicine, 4 (140), 140-140 DOI: 10.1126/scitranslmed.3003679

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Filed Under: Heresy, Intubation, Oxygen, Pharmacology, Research Blogging

Bougies and ALS Airways

Tue, 05 Mar 2013 16:30:46 -0500 by
ResearchBlogging.org
 

The last paper we were working on for the EMS Research Podcast was this paper on the use of a bougie in the intubation of a simulated patient with spinal immobilization.

Is BAI (Bougie-Assisted Intubation) an improvement over traditional intubation (ETI or EndoTracheal Intubation)?
 

For this study, we had three separate hypotheses: The first was that BAI would be more successful than ETI in a difficult airway scenario; the second was that BAI would take no more time to complete than ETI in a difficult airway scenario; and the third was that BAI would be perceived by providers to be as easy to perform as traditional intubation.[1]

 

1. Better.

2. As fast.

3. As east to use.

That is a lot.
 

The study was done inconjunction with an annual skills competency assessment session. Each participant was being assessed for competence in nine different out-of-hospital procedural skills, and the study involved only one of the skill stations. The participants gave written consent to participate, but they were blinded to which skill was being assessed and what data were being obtained during the study. At the ETI station, a brief explanation and demonstration of BAI was given to each participant.[1]

 

An intubation mannequin had its neck strapped down to simulate motion restriction that would be consistent from intubation attempt to intubation attempt.

 

Before and during the study, three experienced emergency physicians verified that the best obtainable view by direct laryngoscopy was a partial glottis opening of approximately 20%—equivalent to a grade III Cormack and Lehane glottic view.[1]

 


Image credit.[2]
 

Grade III is a lovely view of the epiglottis, but that is as good as it gets with Grade III. A good view of the airway is going to involve a glimpse of arytenoid. More than that is just gratuitous. As with the rest of medicine, our goal is not to do as much as possible, regardless of the harm. Our goal is to do as little as possible, realizing that doing more often means doing more harm.

Since Cormack-Lehane Grade III means that the glottis is not visible, is it appropriate to call this a Grade III glottic view?
 

The participants were not aware that they were being timed. Timing began when the laryngoscope blade entered the mouth and ended with ventilation through the ETT with the BVM (evidence of successful ventilation as determined by manikin lung inflation or evidence of failed placement as determined by manikin stomach inflation).[1]

 

I do have problems with both of these.

Timing should begin when the last ventilation is delivered, rather than when the blade enters the mouth. The patient does not care why there is a delay in oxygen delivery, only that there is a delay in oxygen delivery. If we want to use hypoxia as a guide, then hypoxia also has nothing to do with when the blade enters the mouth.

The timing should end with successful ventilation either through a properly placed tube or through the BVM after recognizing incorrect placement. They did not record times for incorrectly placed tubes, but this information is relevant when dealing with real patients.

Also, is placement as easy to identify as with Fred The Head, where the lungs are visible? A requirement for a good assessment should be a part of the study. From the end of the paper, the reference to this method being similar to what could be done with the SimMan, suggests that this is Fred, or a close relative of Fred.
 

We found this model to be an easy and inexpensive way to provide EMS personnel with a difficult airway experience without the use of a high-fidelity simulator,[1]

 

This is not a criticism of Fred the Head or SimMan. We need to pay attention to what they are there for. They are there to assist us in creating a simulation of a real world environment, not to assist us in creating scenarios that are easy to measure. Their utility is that we can do both, when we address the reality of the simulation first. Otherwise, we begin to teach bad techniques.[3]

We can use low fidelity equipment to teach people to do the right thing, but we can also use high fidelity equipment to teach people to do the wrong thing. We need to understand what we are teaching.

Should we be teaching that time is not important if we do not place the tube between the cords?
 

Upon completion of the two techniques, each participant was asked to complete a five-point Likert-style survey to assess his or her overall ease of intubation with both techniques in this particular difficult airway model.[1]

 

How did the bougie do?
 

41% rated the ease of intubation the same for the two methods (asterisked values in Table 2), 50% rated the BAI to be easier than traditional ETI, and 9% rated traditional ETI to be easier than BAI. The participants perceived the BAI to be easier than traditional ETI in this difficult airway model (Jonckheere-Terpstra exact p = 0.0006).[1]

 

It is interesting that for a supposedly very difficult intubation, 16/35 participants (just under half) rate this simulated difficult airway as easy or as very easy.

There are many possible explanations, arrogance, excellence, not really very difficult, great airway education, et cetera.
 

3. As east to use?

Yes.
 

There was no significant difference in the average time to successful intubation (20.4 seconds for BAI [standard deviation (SD) = 9.1 seconds] versus 16.7 seconds for ETI [SD = 9.6 seconds], paired t-test p = 0.102). When controlling for order of techniques attempted, the difference between the groups remained nonsignificant (p = 0.0901). The analysis was limited to the 27 participants who were successful with both methods.[1]

 

This is one of the reasons that airway management should be seen as more complicated than just in the hole/not in the hole. The subjects who were least successful had their times eliminated from this comparison of times.

Does that bias the results?

I do not see how it can be considered as anything other than introducing a bias to the results.

Time from last ventilation to first ventilation is the time that matters. Whether the ventilation is through an endotracheal tube or a BVM is not as important as the ventilations.

If the tube is placed incorrectly, the amount of time until this is recognized does matter to the patient. This is one of the reasons why we should always listen over the stomach first.[4],[5]
 

2. As fast?

They did not come up with a statistically significant difference in times, but they only compared times when the subject was successful with both methods. Since almost all of the failures were when the bougie was not used, this would seem to preferentially eliminate the worst times for the traditional intubation.

The trend was toward a difference in favor of traditional intubation, but the method of time keeping had what appears to be a strong bias built in toward whichever method had the most failures.

The most failures turned out to be with the traditional intubation.

2. As fast?

There was no statistically significant difference in what was measured, but what was measured is not what should have been measured.

Maybe faster. Maybe as fast. Maybe slower. We do not know.
 

There was significantly greater success in intubating the simulated difficult airway with BAI than with ETI (94% vs. 77%, McNemar’s exact p = 0.0313). The order of techniques attempted did not influence this conclusion.[1]

 
94% success vs. 74% success.

If we are to continue using intubation, maybe we should use bougies all of the time.
 

1. Better?

Much better.
 
 

The problem with the bougie is that it is too long to be carried by EMS without bending it. Management tends not to approve of bending equipment that is not supposed to be bent. At 2 feet long, or longer, my excuse has been that the bougie is impractical in my gear.
 


 

This is the pocket bougie by Bomimed.

That will easily fit in my airway bag, or even a cargo pocket.

I have run out of excuses for not having a bougie with me.

I do not have any financial connections with anyone manufacturing or selling bougies. I just like the way this makes it much more practical for those of us in EMS to improve our intubation first pass success rates.

Dr. Scott Weingart (EMCrit) and Dr. Minh Le Cong (PHARM) have both covered the Pocket Bougie.

EMCrit.

PHARM.

 


 

Notice that when you use a bougie, you keep the laryngoscope in place until the tube is placed. Holding the bougie with the same hand that is holding the laryngoscope makes this an easy one person procedure.

–

Footnotes:

–

[1] Comparison of bougie-assisted intubation with traditional endotracheal intubation in a simulated difficult airway.
Messa MJ, Kupas DF, Dunham DL.
Prehosp Emerg Care. 2011 Jan-Mar;15(1):30-3. doi: 10.3109/10903127.2010.519821. Epub 2010 Nov 10.
PMID: 21067319 [PubMed – indexed for MEDLINE]

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[2] Rapid airway access
Sérgio L. AmantéaI; Jefferson P. PivaII; Malba Inajá RodriguesIII; Francisco BrunoIV; Pedro Celiny R. GarciaV
Print version ISSN 0021-7557
J. Pediatr. (Rio J.) vol.79 suppl.2 Porto Alegre Nov. 2003
doi: 10.1590/S0021-75572003000800002
Free Full Text Article from Jornal de Pediatria.

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[3] On Combat
by Lt. Col Dave Grossman (with Loren Christensen)
Chapter Two
Whatever is drilled in during training comes out the other end in combat–no more, no less

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[4] Intubation Confirmation
Fri, 25 Apr 2008
Rogue Medic
Article

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[5] More Intubation Confirmation
Sun, 27 Apr 2008
Rogue Medic
Article

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Messa, M., Kupas, D., & Dunham, D. (2011). Comparison of Bougie-Assisted Intubation with Traditional Endotracheal Intubation in a Simulated Difficult Airway Prehospital Emergency Care, 15 (1), 30-33 DOI: 10.3109/10903127.2010.519821

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Filed Under: Airway Management, Bougie, Heresy, Intubation, Research Blogging

Does Intubation Prevent Aspiration of Stomach Contents?

Wed, 27 Feb 2013 23:55:12 -0500 by
ResearchBlogging.org
 

This is a study that looked at the rate of aspiration among patients intubated in the PH (PreHospital or EMS) setting and compared them to patients intubated in the ED = (Emergency Department) setting.
 


Image credit.
 

There is one huge difference between these settings – EMS was not authorized to use any form of chemically assisted intubation or RSI (Rapid Sequence Induction/Intubation). At the time of this study, the only drugs available to snow the patient would have been morphine, midazolam (Versed) and/or diazepam (Valium).

One of the reasons for using RSI is to prevent aspiration. If the hurl muscles are paralyzed, will there be a technicolor yawn?
 

Tracheal aspirates were obtained using a standard Leukens trap as soon as endotracheal tube position was confirmed using visualization, auscultation, and end-tidal CO2. If no aspirate could be obtained, 3 mL of normal saline solution was instilled into the endotracheal tube. Each patient was ventilated for several breaths and the sample was then collected. Tracheal aspirates were collected and marked with a study number, and no further patient identifiers other than the study number were used after this point.[1]

 

This was a good way to make this unbiased, but I would have liked to see a repeat of the ED test about 15 and again at about 30 minutes after the original intubation. In Philadelphia, it would be reasonable to expect that the packaging and transport of patients would result in a similar time from intubation to sample collection. A review of the documented times could give a better estimate of the time from intubation to the time of the collection of the pepsin assay sample.

Would this difference in time from intubation to sample collection affect the results?

This is a variable that can be controlled for, so this variable should be controlled for.

How much is cost a factor?

I don’t know, but we draw conclusions from bunches of studies that have asterisks next to them to describe the variables that might have affected the results, when we should be drawing conclusions from much fewer studies that do not need these asterisks.
 

Of the 148 patients intubated in the ED, 33 (22%) had positive pepsin assays, as opposed to 10 (50%) of the 20 patients intubated in the PH setting (OR, 3.5; 95% CI, 1.34-9.08; χ2 P = .008). No patient was excluded owing to inability to obtain a tracheal aspirate.[1]

 

How many of the PH patients aspirated after the endotracheal tube was placed?

How many of the PH patients aspirated during the intubation?

How many of the PH patients aspirated before the intubation?

These are things we really want to know, because there are plenty of people who promote the myth that intubation prevents aspiration.

In a randomized study, with endotracheal tubes and extraglottic airways on the trucks on even days (or odd days), would the incidence of aspiration be lower with intubation or with only BVM ventilation?
 

It is important to note that there is no way of knowing whether the aspiration occurred immediately before, during, or after the actual act of ETI. However, it has been shown that pepsin’s activity in lung secretions diminishes over time, with pepsin testing losing much of its sensitivity after 30 to 60 minutes[14]. Thus, we can be fairly certain that the aspiration events occurred in the peri-intubation period.[1]

 

More than double the rate of aspiration of stomach contents with EMS intubation, but . . .

Would it be better without EMS intubation?

Would it be better with EMS intubation with RSI?

Would it be better with extraglottic airways?

We do not know.

A lot of people will claim that an extraglottic airway will not prevent aspiration, but . . .

Endotracheal tubes do not show any signs of preventing aspiration.
 

Although it is possible that the ETI skills of the paramedics were less than those of the ED staff, it is equally possible that the absence of adjunctive medications (such as RSI medications) may account for some, if not all, of the increase in aspiration rates in the PH setting.[1]

 

The number of PH intubations was very low, so this may be a statistical variation among a very low number of patients. The number of ED intubations was much larger and agrees with a larger study of ED intubations and aspiration performed by the same authors several years earlier.
 

Results: Tracheal aspirates were obtained from 225 patients. The pepsin assay was positive for aspiration in 57 of these patients (25.3%). Only 22 of these 57 patients (38.6%) were deemed definitely or likely to have aspirated by the intubating physician. Of the 105 patients thought unlikely or definitely not to have aspirated clinically, 21 patients (20%) tested positive for aspiration.[2]

 

How good is our opinion of whether aspiration is likely?

Horrible.

Even doctors, working in the much more controlled setting of the ED, do not recognize when aspiration is present or when aspiration is happening.

Even in the more ideal setting of the ED, intubation does not prevent aspiration.

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Footnotes:

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[1] Aspiration of gastric contents: association with prehospital intubation.
Ufberg JW, Bushra JS, Karras DJ, Satz WA, Kueppers F.
Am J Emerg Med. 2005 May;23(3):379-82.
PMID: 15915418 [PubMed – indexed for MEDLINE]

Free Full Text Download in PDF format from IEP.org.

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[2] 128 Incidence of Aspiration after Emergency Endotracheal Intubation and Association with Clinical Suspicion
Joseph S Bushra, Jacob W Ufberg, David J Karras, Friedrich Kueppers;
Temple University School of Medicine: Philadelphia, PA
Academic Emergency Medicine 2002; 9:405. abstract issue

Free Full Text Download in PDF format from Academic Emergency Medicine

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Ufberg, J., Bushra, J., Karras, D., Satz, W., & Kueppers, F. (2005). Aspiration of gastric contents: association with prehospital intubation The American Journal of Emergency Medicine, 23 (3), 379-382 DOI: 10.1016/j.ajem.2005.02.005

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Filed Under: Airway Management, Heresy, Intubation, Research Blogging

Post-Intubation Package and Alarms

Thu, 18 Oct 2012 15:05:35 -0400 by
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What do we do after the tube is in?

 

No. It is not time to use the laryngoscope blade as a bottle opener. There is a lot still to do.

The quotes are some of the points Dr. Weingart makes. The comments here are mine.
 

Achieve Adequate Analgesia and Sedation
 

I won’t belabor this, because I’ve discussed it in so many other podcasts, such as the one about not leaving your patient in a nightmare[1]

 

Even a hypotensive trauma patient, who is not adequately sedated, will be worse off without sedation.

Pain is not an appropriate pressor.
 

Hook Up the ETCO2
 

You read NAP4 right? Continuous waveform ETCO2 until the ET tube gets pulled[1]

 

Maybe we can get away with the carelessness of not using continuous waveform capnography for a long time, but carelessness often shows up in other areas of patient care.

The foolishness of not recognizing the benefit of continuous waveform capnography is the bigger problem.

Alarms do not make up for incompetence.
 

Have a Plan for Vent Alarms
 

Treat them like a cardiac arrest announced overhead.[1]

 

Alarms are annoying.

That is the idea. If the alarm is not annoying, we tend to ignore it.

Why do we ignore alarms?

There are a variety of reasons.

We may leave all of the alarms on – even the ones we know that we do not care about.

If we are not going to do something about an alarm, because we do not think that the alarm is warning of anything important, we are only training ourselves to ignore alarms.

We become accustomed to alarms going off almost continuously, so the alarms become ironic. They are anything but alarming, when they are alarming.

If an alarm is not going to produce an instant response from staff, turn it off.

The purpose of an alarm is to produce a response.

The response is not to ignore the alarm.

The response is also not to just reset the alarm.

As with pulse oximetry, the response is not to just do something temporary, like turn up the oxygen in response to a low oxygen saturation.

The response is to address the cause of the alarm.

If the sat is low, why is it low?

Why is the same amount of oxygen no longer producing adequate oxygenation?

Or is something decreasing the amount of oxygen the patient is receiving?

Is the patient agitated and in need of more sedation, rather than just turning the oxygen up to meet the increased oxygen demands of an agitated patient?

If we want people to ignore alarms, the best way is to put alarms on every function possible. If it can alarm, it will alarm – then nobody will take alarms seriously.

If those of us responding to the alarms are not smart enough to be able to decide which alarms we should have turned on, then we aren’t smart enough to respond appropriately to the alarms.

Some places already require this level of continuous alarm incompetence.

Alarms on everything – dumbing down patient care to the point where competence is punished.

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Footnotes:

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[1] Podcast 84 – The Post-Intubation Package
by EMCRIT
October 16, 2012
Web page with links to supporting information and link to mp3 download of podcast

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Filed Under: Airway Management, EMCrit, Heresy, Intubation, NAP4

The cricoid cartilage and the esophagus are not aligned in close to half of adult patients

Thu, 06 Sep 2012 16:00:26 -0400 by
ResearchBlogging.org
–

Cricoid pressure has been used to keep the stomach contents in the stomach, and out of the airway, since Dr. Brian A. Sellick wrote about it in 1961.[1] The problem is that the evidence does not show that it works.

This study looked at cervical CT (Computed Tomography) scans to see what anatomic relationship exists between the cricoid ring and the esophagus in a group of patients with some sort of reason to have a neck CT. These are people with necks that may have some abnormalities, but they do give us some information on whether cricoid pressure should be expected to work and how cricoid pressure would be expected to malfunction. About half of the CTs showed masses displacing the esophagus or cricoid ring and were excluded.
 

Lateral esophageal displacement was seen in 49% (25/51) of the CT images. Of those displaced, 92% were displaced leftward and 8% were displaced right-ward. When present, the length of displaced esophagus relative to the midline of the cricoid was 3.3 mm ± SD 1.3 mm (range 1.4 mm to 5.7 mm).[2]

Of the patients without masses displacing the anatomy, half of patients still did not have the esophagus directly alinged behind the cricoid ring.
 

Based on anatomy and common sense, an assumption has been made since Sellick introduced the technique of cricoid pressure in 1961: the esophagus lies directly posterior to the cricoid. While this relationship has been assumed to be true in the majority of the population, we have identified some degree of lateral esophageal displacement in 25 of 51 subjects.[2]

The displacement is not large, but how much displacement is required for it to be significant?

The purpose of cricoid pressure is to prevent gastric contents from entering the airway (and maybe to improve glottic view), but does it work? This study only looked at the anatomy, but we have other reasons for doubting the efficacy of cricoid pressure from other studies.
 

FIGURE 2 Computed tomography of the neck and line drawing demonstrating 1.5 mm of leftward lateral esophageal displace-ment. AJ = anterior jugular vein; C = carotid artery; Cr = cricoid cartilage; E = esophagus; IJ = internal jugular vein; SCM = stern-ocleidomastoid muscle; Th = thyroid gland; VB = vertebral body.[2]

Although there is only 1.5 mm displacement, would pushing straight back on the cricoid ring obstruct that esophagus?
 

However, previous reports of its failure to prevent regurgitation have never been explained adequately. Its use has also been associated with serious complications including distorted laryngeal view, increased difficulty with intubation, laryngeal trauma, cricoid fracture, and esophageal rupture.
11-15 [2]

Distorted laryngeal view?

All inadequately studied procedures should encourage caution.

A maneuver that makes it even harder to place an endotracheal tube should have received much more examination in the first four decades of use.

–

Footnotes:

–

[1] Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia.
SELLICK BA.
Lancet. 1961 Aug 19;2(7199):404-6. No abstract available.
PMID: 13749923 [PubMed – indexed for MEDLINE]

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[2] The cricoid cartilage and the esophagus are not aligned in close to half of adult patients.
Smith KJ, Ladak S, Choi PT, Dobranowski J.
Can J Anaesth. 2002 May;49(5):503-7.
PMID: 11983669 [PubMed – indexed for MEDLINE]

Page with link to Free Full Text Download in PDF format from Springerlink.

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Smith KJ, Ladak S, Choi PT, & Dobranowski J (2002). The cricoid cartilage and the esophagus are not aligned in close to half of adult patients. Canadian journal of anaesthesia = Journal canadien d’anesthesie, 49 (5), 503-7 PMID: 11983669

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Filed Under: Airway Management, Heresy, Intubation, Mythology, Research Blogging, RSI

Does experience matter – Part I

Sun, 02 Sep 2012 08:00:37 -0400 by
ResearchBlogging.org
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In response to some of what I have recently written about the problems with too many medics, people have claimed that I don’t have any evidence to support my statements.[1],[2],[3]

This will cover just one of the many studies that demonstrate that less experience is bad for patients. For those who think that having all medic crews run all 911 calls, your problem will be burnout, since only a minority of patients are likely to benefit from any ALS (Advanced Life Support) providers. I will address that lack of critical judgment separately.
 

This is from a paper using video to review the quality of intubation with the documentation of the quality of intubation. It is not surprising that the actual quality was not as good as what was documented.

Humans are not good at memory. We document errors with a recall bias, but we pretend that this bias does not exist.
 

Figure 3.First-attempt success by physician type (nsubjects per type). “Attending” is comprised of both attending physicians from Pediatric Emergency Medicine and providers from Anesthesiology. First attempt success was 88% (6 of 7 subjects) for PEM attendings and 91% (10 of 11 subjects) for providers from Anesthesiology. Two study subjects, whose first attempts were performed by a neonatology fellow and an otolaryngology resident, respectively, are not included in this figure. 95% confidence intervals for the first attempt success of each physician type are indicated by the “error” lines: Attending (67%, 97%), PICU Fellow (40%, 89%), EM Resident (30%, 75%), PEM Fellow (25%, 64%), and Pediatric Resident (23%, 50%).[4]

 

The doctors at the top of the graph have the most experience. Those at the bottom have the least experience. If we want to determine the odds of successful intubation, we need to look at intubation experience.

Are we supposed to believe that experience has nothing to do with the success rates appearing in the graph?

A little detail about the actual experience of these doctors shows that they have about the same amount of experience as paramedics.
 

In trying to explain the difference between these results and the results from other studies of physician intubation and physician pediatric intubation, Dr. Green sees the primary point as the differences in the acuity of the patients and the differences in amount of experience available in a general ED as compared with a pediatric ED.
 

There are notable acuity differences between a general ED and a pediatric ED, with the latter demonstrating significantly fewer resuscitations and critical care procedures.8, 9 General emergency medicine residents perform an average of 146 intubations during their training,10 rendering them substantial comfort with the procedural sequence, equipment, anatomic features, techniques for endotracheal tube placement verification, and strategies for backup management.[5]

 

We don’t really want an inexperienced medic managing our child’s airway, but we demand less experienced medics. The fewer skills the medics perform, the less skilled they are.

The fewer procedures the doctors perform, the less skilled they are.
 

Pediatric emergency physicians, on the other hand, can learn and refine their ED intubation skills only on the rare children who require the procedure, and even at high-volume children’s hospital EDs, trainees are exposed to a low number of critically ill children.11 In a 2008 survey, pediatric emergency medicine fellows reported performing a median of 3.5 intubations per year, with some reporting that they performed zero.12 In a 2008 survey of pediatric ED directors, 62% reported that their volume of intubations was insufficient to maintain ongoing competency.13 [5]

 

The average number of intubations per medic per year was found to be 1 per year in Pennsylvania.[6] Pennsylvania does not require dual medics (some systems do use dual medics, but many do not). Pennsylvania also does not require responder-only paramedics on non-transport trucks as a way to dilute skill frequency even more. Some places are having not just 2, but half a dozen medics show up on calls.

This almost appears to be an attempt to prevent any medic from ever becoming experienced.

Why?

Some people pretend that being in the room while a patient is being intubated is the same as intubating the patient.

This study makes it clear that this is a lie. There are plenty of inexperienced doctors in the room, but they are still inexperienced.
 

This low-volume dilemma can be readily illustrated with data from the current article. The authors’ ED treated 90,000 children over the 12-month study period, during which there were 145 total intubations (of which 123 were rapid sequence).1 The program has 12 pediatric emergency medicine fellows, who performed just 21 of these intubations primarily. This averages to less than 2 intubations per fellow per year! During the fellows’ 3 years of training, they would average barely 5 total primary ED intubations.[5]

 

More than 1/4 of patients required 3 or more intubation attempts.

Skill dilution in action.

More medics equals more dilution of skills.

It is simple math. More medics available to perform the same number of skills means less experience.
 

How can any fellow become expert in such a setting? If techniques and strategies for managing difficult airways are not used frequently enough, they cannot be retained and effectively applied.[5]

Exactly.
 

Training and practice in difficult airway algorithms and rescue devices should be routine.[5]

 

Even if we do not have a medic in every seat, we should be regularly practicing airway management.

Before each shift, intubate Fred the Head 5 times in a row in less than 30 seconds each.

Before every shift.

That is silly of me. That is really only something that serious medics should do, not people who think that quantity is more important than quality.
 

When an airway must be secured, one must already know how to act, do it without hesitation, and have a well-thought-out backup plan should that first attempt fail. Action must be instinctive and reflexive but not mindless.[5]

 

Every week, we can practice a scenario of managing difficult airways.

Is this really too difficult?

Does a the tube automatically go in when enough paramedics are in the room?

Of course not.
 

Regardless, it suggests that a culture of command over airway management may not develop in locations with insufficient intubation volume.[5]

 

If we do not get enough tubes, we probably are not good at intubation.

The more medics the tubes are divided among, the worse we will be at intubation.

–

Footnotes:

–

[1] Allentown EMS will remain an all-paramedic squad
Rogue Medic
Sun, 19 Aug 2012
Article

–

[2] I ignore it when NJ calls me a Semi-Medic, but it hurts when you point it out
Rogue Medic
Fri, 10 Aug 2012
Article

–

[3] Long Beach Fire Department considers single paramedic response system
Rogue Medic
Thu, 09 Aug 2012
Article

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[4] Rapid sequence intubation for pediatric emergency patients: higher frequency of failed attempts and adverse effects found by video review.
Kerrey BT, Rinderknecht AS, Geis GL, Nigrovic LE, Mittiga MR.
Ann Emerg Med. 2012 Sep;60(3):251-9. Epub 2012 Mar 15.
PMID: 22424653 [PubMed – in process]

Free Full Text from Annals of Emergency Medicine.

There will probably be a podcast by David H. Newman, MD, and Ashley E. Shreves, MD. covering this paper, but the current issue podcasts usually do not get posted until a few weeks after the current issue. Annals Podcast page.

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[5] A is for airway: a pediatric emergency department challenge.
Green SM.
Ann Emerg Med. 2012 Sep;60(3):261-3. Epub 2012 Apr 19. No abstract available.
PMID: 22520991 [PubMed – in process]

Free Full Text from Annals of Emergency Medicine.

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[6] Procedural experience with out-of-hospital endotracheal intubation.
Wang HE, Kupas DF, Hostler D, Cooney R, Yealy DM, Lave JR.
Crit Care Med. 2005 Aug;33(8):1718-21.
PMID: 16096447 [PubMed – indexed for MEDLINE]

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Kerrey BT, Rinderknecht AS, Geis GL, Nigrovic LE, & Mittiga MR (2012). Rapid sequence intubation for pediatric emergency patients: higher frequency of failed attempts and adverse effects found by video review. Annals of emergency medicine, 60 (3), 251-9 PMID: 22424653

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Green SM (2012). A is for airway: a pediatric emergency department challenge. Annals of emergency medicine, 60 (3), 261-3 PMID: 22520991

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Filed Under: Experience, Heresy, Intubation, Research Blogging

How Accurate are We at Rapid Sequence Intubation for Pediatric Emergency Patients – Part II

Wed, 29 Aug 2012 14:30:15 -0400 by
ResearchBlogging.org
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Continuing from Part I,

Do we accurately report errors and success with pediatric RSI (Rapid Sequence Intubation/Induction)?

Should we trust our memories?

–

The leading indications for tracheal intubation were a failure of oxygenation (22 subjects) or ventilation (20 subjects), followed by head injury (17 subjects), seizure (16 subjects), apnea caused by infection (12 subjects), and altered mental status (11 subjects). None of the 114 subjects died in the ED; 5 died during the corresponding hospitalization.[1]

There is good variety among the patients studied, so there should not be any claims that this just looked at other pediatric patients. This appears to be representative.

–

All but 1 subject were tracheally intubated by the fifth attempt (1 required 9 attempts) in the ED.

. . . .

No rescue methods, eg, laryngeal mask airways, were used for any subject and no surgical airways were performed.[1]

1 required 9 attempts

That is so unreasonable, that it distracts us from the rest of the sentence –

All but 1 subject were tracheally intubated by the fifth attempt

5 intubation attempts are not considered to be unreasonable.

A patient doesn’t require 9 attempts. The patient is abused by 9 attempts by doctors who refuse to manage the airway by other means.

Taking 5 attempts, without switching to other means, is similarly unreasonable. The difference appears to be that the tube coincidentally ended up in the trachea in 5 moves or less.


Original image credit.

Hold onto this nut, while I take a shot at that intubation.

But you’re bind – and a squirrel!

But nothing – I can probably intubate in fewer than 9 attempts.
 

Well, we don’t know about that particular patient, but we do know that 31% of patients had more than one adverse effect.

52% intubation success on the first attempt. I could almost make an argument that there are two holes, so the probability is 50-50 regardless of training, but that is not the way probability works. that is just the appearance – if we were to judge a book by its cover. Let’s not be that foolish.

In their defense, some of these unsuccessful intubations were right mainstem intubations, which are providing some oxygenation and ventilation and (if correctly identified) only need to have the tube pulled out a small distance. A mainstem intubation is significantly less of a problem than an esophageal intubation.

–

Seventy subjects (61%; 95% CI 52% to 70%) experienced at least 1 adverse effect during RSI, and 35 (31%; 95% CI 23% to 40%) experienced more than 1.[1]

 

61% at least 1 adverse effect.
 

31% more than 1 adverse effect.
 

–

The depth of desaturation was available for 29 of the 38 subjects with an episode identified during RSI. Among these 29 subjects, 22 (76%) had desaturation to below 80% and 10 (29%) to less than 60%.[1]

 

10 patients had desaturation to 59% or less.
 

They give this as 29%, but that is 29% of the patients who desaturated. These are actually 9% of all RSIs.

One out of every 11 patients had SpO2 drop to 59% or less.

While hypoxia alone is not harmful, these patients had other medical problems that would probably not do well in the presence of hypoxia.

I usually have to tie a patient down and place a pillow over the airway to drop their sat into the 30s, 40s, or 50s.

Did anyone hit the 20s?

We don’t know, but if we assume that they hit 60% and stopped, we are lying to ourselves. Less than 60% does not include 60%. Also, this is not a PaOO2 of less than 60 torr, which also indicates hypoxia, just a much milder hypoxia.

An SpO2 of 59% or less is an adorable little Smurf, but this is not a cartoon and I don’t like Smurfs.

Was there any other bad news?

4 patients with some hypotension, 4 patients with some bradycardia, and 2 patients with some CPR.

How much of this would have been avoided by a maximum number of intubation attempts (2?, 3?) before requiring use of an extraglottic airway?

–

We did not identify any occurrences of aspiration, pneumothorax, or pneumomediastinum for any subject.[1]

That is some good news.

–

Focused review of the written record revealed marked variation in the documentation of important aspects of the RSI process, as well as notable discrepancies with findings from video review.[1]

Is anyone surprised that the documentation of these adverse events is more optimistic than what really happened?

There is more to write about this, because this is an important paper, so there will be at least a Part III.

–

Footnotes:

–

[1] Rapid sequence intubation for pediatric emergency patients: higher frequency of failed attempts and adverse effects found by video review.
Kerrey BT, Rinderknecht AS, Geis GL, Nigrovic LE, Mittiga MR.
Ann Emerg Med. 2012 Sep;60(3):251-9. Epub 2012 Mar 15.
PMID: 22424653 [PubMed – in process]

Free Full Text from Annals of Emergency Medicine.

There will probably be a podcast by David H. Newman, MD, and Ashley E. Shreves, MD. covering this paper, but the current issue podcasts usually do not get posted until a few weeks after the current issue. Annals Podcast page.

–

Kerrey BT, Rinderknecht AS, Geis GL, Nigrovic LE, & Mittiga MR (2012). Rapid sequence intubation for pediatric emergency patients: higher frequency of failed attempts and adverse effects found by video review. Annals of emergency medicine, 60 (3), 251-9 PMID: 22424653

.

Filed Under: Airway Management, Heresy, Intubation, Research Blogging, RSI
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