AIRWAY VISUALIZATION – EXTERNAL “CEPHALIC” MANIPULATION

Here is a potential airway technique that may help with visualization: hold the laryngoscope in the left hand (the usual) but the right hand, instead of being at your side, is behind the patient’s head. You then move it around until you get the best view. Then you have an assistant hold the head in that spot.

 

A hospital in Southern California started doing that. The technique deserves some exploration. The work of Richard Levitan reminds us that the airway is most patent in the sniffing position. Extension does not really help but true sniffing position does. Sometimes you think you have enough and you need more.

 

I have not seen this technique studied but it probably deserves some attention.

 

TAKE HOME POINTS

-Consider external cephalic manipulation as an analogy to “external laryngeal manipulation” as a way of fine tuning the visualization during a tough intubation

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JAW THRUST MASK GRIP

You are intubating a critically ill patient. The first intubation attempt fails and the patient experiences rapid oxygen desaturation. The respiratory therapist tries to ventilate the patient but air leaks out around the mask with each breath. The chest does not rise and the saturation is dropping.

 

What is the problem?

Sometimes the problem is an insufficient seal around the mouth but more often the problem is soft tissue obstruction. We intubate supine. The tongue occludes the airway. The air follows the path of least resistance, which is out the face, leaking around the mask.

 

What are the choices of grip?

  1. One handed grip, aka C or CE grip (generally acknowledged to be less optimal).
  2. Classic two handed grip – taking the problematic one handed grip, and doing it with the other hand too. Similar to the grip you would have if holding a soda can.
  3. Jaw thrust grip – similar to the grip you would have if lifting a gurney or plank, thumbs on top, fingers below doing the work of lifting. Or if you will, taking your soda can and dumping it out forward.

 

Some studies say CE grip or jaw thrust grip are equally effective. So why do you say jaw thrust is better?

Most of the time airway resistance (A) is lower than mask resistance (M). Anything will work in that situation. What really matters is what happens when A is greater than M. That isn’t addressed in most of these studies.

 

What happens when A is higher than M?

When airway resistance is higher than mask resistance, the operator grips harder to raise mask pressure. The fingers often compress the submandibular space. This presses the tongue against the posterior airway, and raises airway pressure further. The harder you grip, the more you close off the airway.

 

What is a better way?

JAW THRUST MASK GRIP

The best way to grip the mask is to press the mask to the face with the thumbs pointing forward. The fingers then fit over the angle of the jaw. If you want more pressure, you pull the fingers, which not only increases the seal pressure but also performs a jaw thrust maneuver. It pulls the tongue off of the palate.

 

Is there anything else that will help?

NASAL AND ORAL AIRWAYS

Place two nasal trumpets and an oral airway. Whether you have great technique or bad technique this will help. Don’t be afraid to “waste” some plastic here. I suspect that nasal trumpets also improve the effectiveness of apneic oxygenation via high flow rate nasal cannula.

 

Back to the case. You put the thumbs pointing forward on the mask and pull jaw thrust with digits 2-5. The leak is gone and the patient is re-oxygenated before your second attempt.

 

TAKE HOME POINTS

-Use the jaw thrust mask grip technique for ventilation

-Good mask ventilation is a crucial airway skill. Invest in it.

-If you are have ANY trouble, place nasal and oral airways

 

Suggested references:

Efficacy of facemask ventilation techniques in novice providers.

Gerstein NS, Carey MC, Braude DA, Tawil I, Petersen TR, Deriy L, Anderson MS.

J Clin Anesth. 2013;25:193-7

USE THE SWALLOW PROVOCATION TEST TO ASSESS AIRWAY PROTECTION

A patient presents obtunded. You wonder about airway protection and consider intubation. Is there any way at the bedside to gather more information before choosing to intubate?

 

This has not been well studied in the ED population mentioned above, but if you are wondering whether the patient is going to aspirate oropharyngeal liquids, you could consider a safe trial of seeing how they handle liquids.

 

Called the “swallow provocation test” it is done by injecting a “swallowful,” (ie 10 cc) of water into the mouth of the patient.

 

I have had patients leave the secretions there (so I suctioned them out) and proceeded to intubation. I recall one severely alcohol intoxicated patient swish it around in his mouth like he was seeing what it was, then lean over and spit it on the floor (I wondered what he would have done if it were a drink more of his choosing). He did not get intubated, needless to say.

 

While this approach is not validated, neither is your current approach! So consider using this in situations where you are not sure what they need.

 

Take home points:

-If you are wondering how the patient will handle liquids in the mouth, inject water and find out.

SUPINE POSITIONING CAUSES AUTO-PEEP

Why do some critically ill patients, when they are laid flat for intubation, either get worse or sometimes even go into cardiac arrest?

Patients with CHF, COPD, and morbid obesity are considered susceptible. I am not sure what I have read in the literature is correct in explaining it. I suspect that anyone who lays flat has more air trapping. This can crowd out venous return. In a patient on the brink of dying, impairing venous return might put them over that brink.

An interesting corollary of this idea is that patients with high autoPEEP on a ventilator can be placed in the upright position and this significantly reduces their autoPEEP.

So in summary, supine positioning appears to exacerbate auto-PEEP, and in the peri-arrest state can precipitate cardiac arrest apparently through crowding out venous return

Take Home Points

-Supine positioning causes autoPEEP

-In the patient with a respiratory life threat, keep the patient upright as long as possible.

-Consider 30 degrees elevation (reverse Trendelenburg) for intubating patients thought to have potential for arrest during intubation

-In the ventilated patient who develops auto-PEEP, use reverse Trendelenburg or upright posture as a treatment

Head-Elevated Patient Positioning Decreases Complications of Emergent Tracheal Intubation in the Ward and Intensive Care Unit.

Khandelwal N, Khorsand S, Mitchell SH, Joffe AM.

Anesth Analg. 2016 Apr;122(4):1101-7

DIFFICULT AIRWAY: MODIFIABLE?

A patient presents in cardiac arrest, morbidly obese, her face covered in blood and vomit. As the paramedics bag her, froth sprays out to the sides. You place an oral airway and 2 nasal trumpets, while the resident pulls a jaw thrust and the ventilations get better. On a tough intubation you want the resident to have the best shot at first pass success. What can be done at the bedside?

 

This is a difficult airway, no doubt, but it is interesting that when difficult airway is defined as Cormack grade III (unable to visualize the vocal cords) the studies often show that a simple bedside maneuver will resolve the problem.(eg Takenaka Can J Anesth 1999) In that sense, the difficult airway can be thought of in relative terms, dependent on modifiable anatomical factors.

 

Richard Levitan recommends horizontally aligning the ear canal to the sternal notch as the ultimate standard. This has not been universally accepted but it does seem to offer a reasonably uniform standard.

 

After the initial positioning, if we encounter a problem we can reassess the anatomy:

 

Head: Additional elevation may sometimes improve the view (Schmitt J Clin Anesth 2002)

Neck: Extremes of extension and flexion impair the view

Cheek: Can block vision, pull it away when needed (left molar instead of right molar approach accomplishes this with the blade). (Yamamoto Anesthesiology 2000)

Jaw: Jaw thrust maneuver can open up pharynx for visualization (Corda J Anesth 2012)

Larynx: External laryngeal manipulation (Benumof J Clin Anesth 1996)

“Back up” position – partially sitting up may improve the view (Khandelwal Anesth Anal 2016)

 

The bottom line is that during a case, any of the variables might need to be manipulated, and the emergency physician should be prepared to try any of these.

 

The resident fails on the first attempt, but realizing the folds of soft tissue are part of the problem, the attending physician asks that the pannus and soft tissue be retracted. This retracts the tissues around the neck, and the second attempt is a success.

 

Take home points:

The difficult airway is by definition an anatomical problem

The anatomy of the cheek, jaw, head, neck, larynx, and thorax can often be manipulated

NEONATAL INTUBATION: POSITION FOR AN ANTERIOR AIRWAY

Case: No time, no visible larynx

You are seeing a patient in the hallway when suddenly a mother rushes in with a pallid blue lifeless infant. The nurses start CPR and bag mask ventilation as you grab a Miller blade and 4.0 tube. Your first look is all secretions. After using the adult Yankauer suction you clear that out fast and look again….esophagus. You pull back but still the larynx is nowhere to be seen. What do you do next?

Neonatal airway is a difficult airway

Success rates for pediatric emergency airway, as published, are limited. Pediatric senior residents had a 40% success rate, 47% with more experience, and 68% for fellows.(Leone 2005) Among emergency physicians, success on first attempt was 60%.(Sagarin 2002) This is markedly different from adults, where success rates are commonly well above 90%. Why is it so low? Can we prevent this?

Kids are little adults? Sniffing position

I have heard dozens of lectures on how kids are anatomically different, so we make interventions to address that. Then at the bedside I see that taken to extremes. An example is the idea that they have big heads so we need a towel behind the shoulders, and pretty soon intubation is being performed with distorted anatomy. Infants need the sniffing position just like adults. Richard Levitan recommends aligning the ear canal to the sternum as a more universal standard that applies to children, adults, and the obese. A ramp of towels behind both the shoulders and head can achieve good sniffing position.

Secretions

I have had cases where the respiratory therapist hands me the floppy small endotracheal suction. That usually doesn’t work. Use the adult Yankauer suction, and get those secretions out.

Back to the case

In this case you place towels behind the head and neck, extend the head slightly, and suction with Yankauer. Your next look is all tongue, but a gentle sweep to the left shows the arytenoids and you pass the tube just anteriorly. Capnography turns yellow through 6 tidal breaths, confirming success. You proceed with resuscitation.

Take home points:

-Neonates, like adults, need the sniffing position

-Neonatal secretions, like adult secretions, are best removed with Yankauer suction