Tag Archives: intubation

The April 2021 Trauma MedEd Newsletter Is Live! Potpourri

This issue is devoted to an uncommon yet potentially devastating problem, blunt carotid and vertebral artery injury.

In this issue, learn about:

  • Who’s Better At Invasive Procedures? Advanced care providers or residents?
  • How Many Salt Tabs In A Liter Of Saline?
  • Mainstem Intubation In Pediatric Patients
  •    And How To Avoid It!
  • Giving TXA Via An Intraosseous Line?

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Is Intubation For Low GCS Necessary? Dangerous?

More dogma? I was taught that as the Glasgow Coma Scale (GCS) score drops toward 8, the higher the consideration of intubating the patient. And that a GCS 8 was pretty much an absolute indication for inserting the endotracheal tube. The rationale was that the more obtunded the patient was, the less able they were to protect their airway.

Even ATLS, our trauma textbooks, and practice guidelines from the likes of EAST recommend intubation for GCS 8 and less.

Having said that, I know many of you have been in a situation where you have a patient with GCS 8 or so, and they are lying there breathing peacefully with good oxygenation and ventilation. Do you really need to put in that tube? And we also tend to be very forgiving with obtunded children, avoiding premature intubation there as well.

Intubation is not a benign procedure. There is the potential for mayhem during the process, ICU admission will be required, and a host of ventilator and sedation-related complications are possible once the patient arrives there.

The trauma group at LAC + USC decided to look into this. They performed a five-year retrospective study of data from the TQIP database. A subset of patients was selected with isolated blunt head injury and GCS 7-8 who did not require immediate operation upon arrival. They were divided into intubation and non-intubation groups, and these were further subdivided into intubation within an hour of arrival, intubation after an hour, and never intubated groups.

Here are the factoids:

  • A total of 2,727 patients were studied; about two thirds were intubated within an hour, a quarter were never intubated, and the remaining 9% were intubated after the first hour
  • Immediately intubated patients were significantly younger and had fewer comorbidities
  • Mortality was 19% in the immediate intubation group vs 27% in the delayed group vs 11% in the never intubated group
  • Complications were significantly higher after immediate intubation, particularly DVT and ventilator associated pneumonia (VAP)
  • Regression analysis indicated that immediate intubation was independently associated with mortality compared to late or never intubated patients
  • Using additional regression testing, the authors concluded that the following two subsets of patients would benefit most from early intubation:
    • Younger patients (age < 45) with head AIS 5
    • Patients age <65 with head AIS 5

The authors recommend that “future research focus on more adequate parameters to identify patients requiring immediate intubation and should avoid an isolated fixed GCS threshold.”

Bottom line: This is a difficult paper to understand (at least for me). It looks like the authors are saying we should avoid immediate intubation of severe TBI patients with depressed GCS to reduce mortality and complications.

But you need to read the whole paper closely to really get it. First, let’s look at those mortality figures. The mortality in the three groups was:

  • intubated < 1 hour after arrival – 18.7% (from n = 1,866)
  • intubated > 1 hour after arrival – 27.4% (from n = 223)
  • never intubated – 11.4% (from n = 638)
  • If you combine the last two lines you get the mortality in the non-immediate intubations = 15.5% (from n = 861)

The authors then claim that the mortality for immediate intubation is greater than non-immediate intubation (the other two groups). This may be somewhat misleading, because the delayed intubation group actually has a higher mortality than the immediate group (27%)! This fact is covered up by combining delayed intubation with the never intubated group, bringing the number down to 15.5%!! Why shouldn’t you say that intubating the patient at any time is bad, immediate or delayed??

They suggest some criteria to try to focus in on the patients who really need intubation: younger patients (age < 45 or < 65) with head AIS 5 and GCS 7. Unfortunately, you can’t determine which patients have an AIS 5 in their head without a head CT, which may push them into the higher mortality delayed intubation group.

Remember, this type of study can only show an association, not cause and effect. The authors suggest that early intubation results in more deaths and complications. My suspicion is that patients with severe TBI don’t do poorly because they were intubated. I believe that they were intubated because the clinicians feared that they would do poorly. Unfortunately, this is information that can only be gleaned from a prospective study, not a retrospective database review.  And no amount of statistical manipulation or regression analysis can make up for this shortcoming.

This is yet another one of those studies that ends by concluding that a better study should be done. That would be okay if this one actually provided a hint that the endeavor would be worthwhile. But it doesn’t. I didn’t really learn anything from it, unfortunately.

So I still heartily recommend using your existing training, guidelines, and judgement to intubate these patients early and safely!

Reference: Isolated traumatic brain injury: Routine intubation for GCS 7 or 8 may be harmful! J Trauma, publish ahead of print, DOI: 10.1097/TA.0000000000003123, Feb 16, 2021.

COVID-19 Thinking Cap: How To Protect Personnel During Intubation (Video)

There is a fascinating letter in the New England Journal of Medicine submitted by authors from the Boston Medical Center and Brigham and Women’s Hospital. Like all trauma professionals, they were concerned with droplet contamination produced during the intubation process. Most hospitals have modified their intubation procedures to try to protect personnel as much as possible.

The authors designed a Plexiglas box with two holes for the arms of the intubator that is placed over the patient’s head. This should serve to shield them, and other personnel in the room if the patient unexpectedly coughs during the process. They tested this concept using an intubation mannequin. First, they placed a balloon filled with fluorescent dye in its mouth and slowly inflated until it burst. Here was the result when viewed under ultraviolet light. Sputum everywhere!

Next, they placed the intubation shield over the patient. Here is a drawing of its dimensions.

The device is open on the bottom and on the side away from the intubator. The arm holes are 10cm in diameter.

The authors then repeated the balloon experiment with the shield in place and the intubator’s arms inserted through the holes. The resulting contamination was limited to their hands and forearms, and the inside of the shield.

Bottom line: This is a very interesting yet simple and cheap device that can be built by just about anyone and should protect personnel from droplet contamination. It will not have much effect on aerosols escaping into the room, but that’s what our other PPE are for! It’s a great example of how creativity is key in keeping us all safer during this pandemic.

You can view the video on the NEJM website at:
https://www.nejm.org/doi/full/10.1056/NEJMc2007589

Reference: Barrier Enclosure during Endotracheal Intubation. NEJM DOI: 10.1056/NEJMc2007589, April 4 2020.

Mainstem Intubation In Pediatric Patients: How To Avoid It

In my last post, I reviewed a simple technique utilizing a reminder card and provider feedback loops to reduce deep intubations in pediatric patients. Today, I’ll review three other techniques and discuss a paper that compared their efficacy.

A variety of techniques for determining and/or confirming endotracheal tube position exist. Use of one or more of them is important in children due to their short trachea and increased likelihood of deep intubation. Some, like the confirmatory chest x-ray, are obvious. However, it’s more desirable to apply techniques during the intubation in order to avoid deep intubation in the first place. Hyperinflation of one lung, especially in very small children, can cause a host of impairments and complications that may compound their other injuries.

A paper from the University Hospital Basel in Switzerland evaluated three techniques: bronchoscopic insertion to a specific depth, cuff palpation in the sternal notch, and intentional right mainstem intubation followed by slow withdrawal during auscultation.  Each of 68 children ranging in age from 0 to 4 years were studied using all three techniques.

Each endotracheal tube was marked at the ideal insertion point that would ideally be placed just beyond the vocal cords. The distance from this mark to the mouth end of the tube was measured so actual intubation depths could be compared.

Bronchoscopic insertion was always performed first to obtain a baseline depth measurement, essentially the gold standard. The other two techniques were performed in random order. For the cuff palpation technique, the trachea was palpated while the balloon was intermittently partially inflated until it could be felt at the suprasternal notch. For the mainstem intubation technique, the uninflated tube was advanced until breath sounds in the left axilla disappeared. It was then slowly withdrawn until sounds reappeared.

Distances from the tip of the tube to the carina was calculated using the insertion depth at the incisors and the initial ideal intubation depth mark. Here are the factoids:

  • Insertion to a depth mark on the tube via bronchoscope technique resulted in the highest tube tip with respect to the carina, and also with the greatest depth variability
  • The cuff palpation technique resulted in less distance to the carina (about 19mm vs 36 for the mark technique) and less variability
  • Use of the mainstem intubation with pullback technique resulted in the tube tip resting within just a few mm of the carina, but tube depth was very consistent

Bottom line: What to make of all this? Which technique is “best?” First, it’s not practical or advisable to use a bronchoscope for every pediatric intubation. It’s invasive and adds complexity and time to a critical procedure. The cuff palpation technique also takes additional time due to the repeated cuff inflation/deflation that is required. However, the tube position is fairly accurate and safe.

The intentional right mainstem intubation with pull-back seems a bit sketchy. It requires some type of ongoing ventilation while the tube is being inserted, as well as someone who can listen to the left chest. Additionally, it results in a tube position that is so low that neck positioning may move it into the mainstem bronchus again.

In my mind, estimation of the proper depth pre-intubation is probably the best. Strict attention must be paid to the final depth of the tube once it is inserted, as measured by the distance marker at the incisors. This number must match the one decided upon at the start of the procedure. A good exam of the chest should be carried out to quickly identify an inadvertent mainstem intubation. And finally, a quick confirmatory chest x-ray should always be obtained for objective information on tube position. 

The fancy techniques described in this paper add too much time and complexity for intubation in a trauma situation. They may very well have a place in the OR where the situation is more controlled and there is more advanced equipment and support. But stick to the basics when intubating children in your trauma bay!

Reference: Assessment of three placement techniques for individualized positioning of the tip of the tracheal tube in children under the age of 4 years. Ped Anesthesia 25:379-285, 2014.

Mainstem Intubation In Pediatric Patients: How Common?

Mainstem intubation in the pediatric patient is a common problem. There are two major issues: the trachea is shorter than in an adult, and the angles are different making intubation of the right mainstem bronchus much easier. Frequently, the intubator watches the balloon slide between the cords, then pushes the tube in “just a little further.”

Unfortunately, that “little bit” can vary significantly. An abstract from my hospital was presented at the Pediatric Trauma Society in 2016. Subjectively, we noticed that mainstem intubation was occurring with some regularity in our pediatric trauma patients.  It seemed as though insufficient attention was being paid to the depth of the tube.

A major difference between adult and pediatric intubations is that in adults, optimal tube depth is locked into a relatively narrow range. In children, the depth varies considerably based upon child age and size. And small variances in depth can have major implications for tube position.

We decided to implement a PI project to change our intubation policy. In order to focus the entire team on tube depth, a color coded card was attached to each size of endotracheal tube. This card listed the optimal depth for insertion. Once the provider inserted the tube, the final depth was called out for the team and documentation scribe to hear. This had the added advantage of allowing multiple team members confirm the appropriateness of tube depth. A chest x-ray was immediately obtained to confirm position.

We retrospectively reviewed our seven year experience with pediatric intubations, from 2009-2015. Here are the factoids:

  • Nearly 2,000 pediatric trauma patients were admitted during the study period
  • 94 patients (5%) required intubation in the ED
  • Prior to implementation of the new protocol, 6 of 68 patients (8.8%) had confirmed right mainstem intubation 
  • After the change, only one further mainstem intubation occurred in 26 procedures (3.8%)

Bottom line: Unfortunately, this series is too small to determine statistical significance. There is a definite trend toward fewer mainstem intubations. It appears that by calling more attention to the proper tube depth, fewer deep placements occur. Our numbers  have remained low since this change.

Are there other methods to ensure proper ET tube placement in small patients? In my next post, I’ll review a paper that compares three additional different techniques that can be used.

Reference: Eliminating the Preventable Occurrence of Right Mainstem Intubation in the Pediatric Trauma Patient: A Quality Performance Improvement (PI) Initiative. Pediatric Trauma Society Poster Abstract #1, 2016.