Emergency Airway Management Part 1: Optimizing the basics

Case

A 55 year old man was found unconscious in the bathroom by his family. He has a GCS of 7. His vital signs are a heart rate of 130, a blood pressure of 90/55, a respiratory rate of 28, and an oxygen saturation of 89% on room air. He is lying flat on the resuscitation stretcher and making some sonorous breath sounds. You resident grabs a laryngoscope and says, “ABCs… let’s get this guy intubated”…

My approach

Although many airway talks start at intubation, immediate intubation is rarely the first step in resuscitation. Basic airway maneuvers are essential. Many patients can be managed with simple maneuvers alone, preventing what seems like an otherwise necessary endotracheal tube. Even when the tube is ultimately necessary, starting with basic airway maneuvers stabilizes the patient, and gives you time to resuscitate, gather information, and effectively pre-oxygenate.

Airway positioning

Any patient being resuscitated should be positioned such that their airway is as open as possible. For awake patients, this generally means allowing them to assuming their position of comfort. In comatose patients, oxygenation is most efficient when the patient is upright, so elevate the head of the bed to at least 30 degrees when possible. (Frerk 2015; Ramkumar 2011; Altermatt 2005; Dixon 2005; Boyce 2003) In order to maximize the patency of the upper airway, position the patient so that their external auditory meatus aligns at or above their sternal notch. This is achieved by flexing the neck and extending the head (the face remains parallel with the stretcher). The simple jaw thrust is an essential airway maneuver to master. Place your fingers behind the angle of the mandible and apply a forward force, elevating the mandible, and with it the tongue. (Russo 2013)

If simple airway positioning is not sufficient, insert an oropharyngeal or a nasopharyngeal airway. Frequently, more than one is required. It is reasonable to place 2 nasopharyngeal airways and an oropharyngeal airway at the same time time to facilitate bag valve mask ventilation.

Oropharyngeal airway

• Ensure that an oropharyngeal airway is appropriate for the patient. The patient should be unconscious, without a gag reflex.
• To choose the correct sized airway, place one end at the tip of the chin, and the other end should reach the angle of the mandible.
• Open the patient’s mouth with your non-dominant hand, using a scissors action.
• Insert the oral airway with the curve upside-down, sliding the tip along the hard palate.
• When the tip of the airway reaches the back of the mouth, rotate it 180 degrees. (Russo 2013)

Nasopharyngeal airway

• To choose the correct sized tube, place one end at the tip of the patient’s nose and the opposite end should reach their external auditory canal.
• Apply lubricant.
• With the longer, beveled tip against the septum, insert the tube into the nare. It should enter at a 90 degree angle to the face (much like an NG tube). Insert completely, until the flared end is against the patient’s nare. (Russo 2013)
• If required, repeat with a second tube in the opposite side.

Suction

Seemingly simple, the mighty suction has rescued many an airway. Have two available if possible. The Yankauer tip is always attached, but not very good for the clotted blood or chunky vomit that frequently accompany emergent airways. Using an endotracheal tube attached to a meconium aspirator is one option in such situations. (Kei 2016) Perhaps easier is simply removing the Yankauer and inserting the suction tubing directly into the patient’s mouth. (Note: there are two types of Yankauers available; with and without a pilot hole that requires covering by the operator’s thumb to suction. If your Yankauer sounds like it’s suctioning but isn’t, look for this, tape it over, and order new ones that don’t require this extra silly-step for next time. )

Using a BVM

Despite our obsession with laryngoscopy, the most important skill in airway management is bag valve mask ventilation. If you can oxygenate and ventilate the patient, you can take all the time you need to ultimately pass the endotracheal tube.

Make sure you have an appropriately sized mask. It should cover the nose, mouth and chin, but not cover the eyes. (Russo 2013) If the mask you are handed is the only one available and is too big, consider using an oral airway to make the facial profile larger.

It is perfectly fine to use the standard one hand “CE” bag valve mask technique in a stable patient whose oxygen saturation is 100%. It is fine for the healthy non-obese patient undergoing elective surgery. However, for sick patients in the resuscitation room, I always use a 2 hand grip, with an assistant squeezing the bag. I think the best two hand grip is achieved by placing the thenar eminences of both hands along the sides of the mask, and gripping the ramus of the mandible with the fingertips. (Gerstein 2013) The goal is to pull the face up into the mask, not push that mask down onto the face.

When performing bag valve mask ventilation, how you squeeze the bag is also important. High pressures will inflate the stomach. High rates will increase intrathoracic pressures. Bag slowly and gently. Aim for 6-8 breaths a minute and slowly squeeze the bag so that only 500 ml (6-7 mL/kg) of air is delivered over 1-2 seconds. (Most adult ‘bags’ for BVM hold 2 litres; tidal volumes should depress the bag volume by about 25%.)

Hyperventilation does not treat hypoxia. If the patient is hypoxic, you need to increase the fiO2 or add PEEP. (Weingart 2012)

How do you know you are actually delivering breaths? I think the best answer is to use quantitative, waveform capnography whenever you are bagging a patient for immediate and accurate feedback.

Know the equipment that is available in your emergency department. Most BVM systems have an opening designed for a PEEP valve, but unless the PEEP valve is attached, room air can enter through that opening resulting in the delivery of much less than 100% oxygen to your patient. This is very well explained in these 2 videos by George Kovacs: Oxygenation – Understanding your BVM Device

If you really want to understand the design of the BVM, this post on EMCrit, in which Scott discusses the design of his ideal BVM, is great.

BVM troubleshooting

There are some patients who are predictably difficult to bag valve mask ventilate. The classic (although not necessarily helpful) mnemonic for these patients is MOANS:

• M: Mask seal (beard, facial trauma)
• O: Obesity/  Obstruction of the airway
• A: Age (generally listed as >55)
• N: No teeth
• S: Sleep apnea / Stiff lungs

BVM ventilation in the emergency department should probably always be performed with nasopharyngeal airway, oropharyngeal airway, or both in place. If you started without these adjuncts and are having trouble, put them in. Similarly, if you didn’t start by using a two hand grip, switch to that.

The next step is to optimize patient positioning. Usually, the ideal position is the ear to sternal notch position, but you can also try an exaggerated head tilt chin lift as well. Assuming there are no concerns about the c-spine, another option is turning the head 45 degrees to the side, which increases the retroglossal space and may increase the efficiency of BVM ventilation. (Itagaki 2017; Ono 2000) If the patient is resisting BVM, they may require added sedation. It is also always important to consider the possibility of laryngospasm.

Facial hair is a common cause of difficult bag valve mask ventilation. Numerous solutions have been suggested. You can apply vaseline or lubricant to flatten the hair and improve the seal. (Saddawi-Konefka 2015) You can apply a large tegaderm over the beard, with a hole cut for the mouth. (El-Orbany 2009; Johnson 1999) However, this often still leaves leaks around the edges of the tegaderm, so another option that has been described is wrapping cling-wrap around the entire head, with a hole cut out for the mouth. Shaving the facial hair is often described, but is unlikely to be an appropriate option in the emergency department. (El-Orbany 2009) Finally, the best option for ventilation in the presence of a beard may be to proceed directly to a LMA.

Mask ventilation is also frequently difficult in edentulous patients. If the patient has dentures, they should be left in place during attempts at mask ventilation. (El-Orbany 2009; Saddawi-Konefka 2015) You can ask an assistant to squeeze the patient’s cheeks up into the mask (like a “fish face”) to improve the seal. Another option is to place the lower end of the mask into the mouth against the lower gums instead of on the chin. (Racine 2010) Packing the cheeks with gauze, around an oral airway, has also be described. (Golzari 2014; Saddawi-Konefka 2015) Again, a supraglottic airway (LMA) may be the most appropriate temporizing measure in these patients.

Using an LMA

Although discussion of supraglottic airways is usually reserved for the end of algorithms, as rescue devices, they can also be used early in the algorithm as the primary means of ventilation. (Braude 2007; Mosier 2015)

The LMA can only be placed in patients without airway reflexes – the same patients who will tolerate an oral airway. You can use medications to facilitate LMA placement. Darren Braude has described using classic RSI medications, but proceeding directly to an LMA rather than intubation as “rapid sequence airway”. (Braude 2007) (This is not news to any of our anaesthetic colleagues, as this is routine for many procedures in the OR.)

The appropriate technique for placing an LMA will vary depending on the model you are using. Even for a single device, there are a wide variety of opinions about the optimal technique. This is my approach for the traditional LMA:

• Check the cuff for leaks, and then completely deflate it prior to insertion. (Some people think inserting a partially inflated LMA is easier, and prevents the LMA from folding back on itself.)
• Lubricate the posterior aspect of the LMA.
• Having an assistant provide a jaw thrust facilitates proper placement of the LMA.
• Place 2 fingers in the front of the LMA (the surface that will face the larynx), open the mouth, and slide the LMA along the palate into the pharynx. The insertion can be facilitated by elevating the tongue with a laryngoscope or tongue depressor.
• Inflate the cuff. The appropriate volume of air should be printed on the side of the LMA.
• Check for adequate ventilation using quantitative, waveform capnography. (Takenaka 2013)
• Secure the LMA.

As always, it is important to know what equipment you have available. Most experts recommend using a second generation LMA, meaning that it will have a gastric port. Personally, I am a big fan of intubating LMAs. These devices allow you to pass an endotracheal tube directly through the LMA. You can see how this is done in the video below, courtesy of Dr. Andy Sloas. If you use a bronchoscopy port, you can continue to ventilate the patient throughout the entire procedure, as is demonstrated by Dr. Darren Braude in the second video.

Troubleshooting the LMA

If you are having trouble getting the LMA to sit in the proper position, you can attempt a bougie assisted LMA placement. (Howath 2002) This requires an LMA with a gastric port. Pass the bougie into the esophagus, as you would an orogastric tube. Pass the LMA over the bougie, through the gastric port. This should keep the LMA midline and prevent the tip of the LMA from folding back on itself. (Note: If I was using the LMA as a rescue device, I would still attempt to pass the bougie into the trachea. If the bougie holds up, I would railroad an endotracheal tube over it. If it doesn’t, I would use it to guide my rescue LMA.)

If you cannot easily ventilate through the LMA, try pulling it back a until it sits on the tongue, keep it fully inflated, perform a jaw thrust, and then pushing it back in (the Chandry maneuver). You can also try elevating the head or extending the neck. Occult laryngospasm is an important consideration in patients who are only lightly sedated, and may require increased sedative doses or paralytics.

If you experiencing an air leak, place a LMA one size larger, or use a different style of device, if you have one available. If you are attempting to use a ventilator, the weight of the vent tubing can twist the LMA and cause a leak. Make sure the LMA is well secured.

The rest of the airway series:

Part 1: Optimizing the basics

Part 2: Is this patient ready for intubation?

Part 3: Intubation

Part 4: Cricothyroidotomy

Part 5: Post intubation care

Notes

A special thanks to Dr. Laura Duggan (@drlauraduggan) and Dr. Casey Parker (@broomedocs ) for providing peer review for this post.

Be sure to check out the airway app designed for reporting cases of front of neck airway access, as well as the 3D printed Cric trainer by Dr. Duggan: http://www.airwaycollaboration.org/

Other FOAMed Resources

Tim Leeuwenburg: Basic airway adjuncts:

EMCrit episode 65: A Primer on BVM Ventilation with Reuben Strayer

EM Updates: BVM Ventilation of the Edentulous Patient

Resus.me: Head rotation for mask ventilation

PlumCrit: Facial hair, airway management, and Movember

Supraglottic airway workshop at SMACC gold

Face mask ventilation workshop at SMACC gold

Bougie guided LMA (Brimacombe technique)

Open Airway: Using supraglottic airways

References

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