Awake Endotracheal Intubation

Authors: Gregory Nabers, MD (EM Chief Resident, LSUHSC-Shreveport) and Adam Canion, MD (EM resident physician, LSUHSC-Shreveport) // Edited by: Alex Koyfman, MD (@EMHighAK) and Brit Long, MD (@long_brit, EM Chief Resident at SAUSHEC, USAF)

Scenario 1

You are working in a rural ED when a 52 year-old patient is brought in by EMS with the complaint of facial swelling. The patient’s vital signs are BP 146/94, HR 85, RR 18, SpO2 97%. On your examination, the patient appears to be resting comfortably and in no acute distress. His tongue is slightly enlarged, he has poor dentition, and his submandibular space is erythematous and firm. You suspect the patient has Ludwig’s angina. Your facility does not have the resources to manage this patient so you decide to transfer to a larger hospital, two hours away by ground. During transport the patient’s swelling worsens. He loses his airway and goes into respiratory arrest and dies after unsuccessful attempts at intubation by the ambulance crew. What could have been done differently?

Awake endotracheal intubation is a critical skill for the Emergency Physician and can be utilized in many different situations to help control a potentially unstable airway. Awake intubation does not require any additional skills above and beyond standard intubation skills and the ability to manage a difficult airway or perform a surgical airway if needed. Aside from a crash airway, awake intubation can be considered in most other patients requiring airway control. At the most basic level the more difficult the airway and the less urgent the need for airway control, the better awake intubation becomes as an option.

What patient is a candidate?  As noted above, any patient except for the acutely crashing patient can be considered a candidate for awake intubation. However, the ideal candidate is a non-crashing patient with a presumed difficult airway in which the loss of airway reflexes during RSI could lead to dire consequences if intubation is unsuccessful. Also, patients with likely loss of airway over time are good candidates for awake intubation (as in the case presented above).

Who should not be considered?  Absolute contraindication => acutely crashing patients. Relative contraindications => patients unable to cooperate with the procedure.

Supplies:

Airway supplies: Oxygen, endotracheal tube, suction, oral and nasal airways, laryngoscope blade, End-Tidal CO2 monitor or other confirmation device, cricothyrotomy kit if presumed difficult airway.

Medications: Atropine or glycopyrrolate, lidocaine, ketamine or other sedative.

How to do it: In the most simplistic of terms the procedure follows the course of Dry, Topicalize, Sedate, Intubate.

Dry: Use of 0.2mg glycopyrrolate or 0.01mg/kg atropine will decrease oral secretions. Give this about 15 minutes to work, then allow patient to suction oral cavity and pat dry with gauze. This is an integral part of the procedure in order for the next step to work appropriately.

Topicalize: Nebulized 4% lidocaine at 5 lpm given over a few minutes will anesthetize the oral cavity and oropharynx. Follow this with additional atomized lidocaine down the oropharynx using a mucosal atomization device. Then give a 2-4% viscous lidocaine gargle. At this point the airway should be well anesthetized, but you may want to have additional lidocaine for atomization to use as needed during the procedure. You may also consider injecting 3cc of 2-4% lidocaine through the cricothyroid membrane to further anesthetize the cords.

Sedate: Use of low-dose ketamine is the agent of choice, as this will sedate without loss of airway reflexes. Give the patient 20mg Ketamine aliquots. You may also use low-dose versed or 1-2cc of ketofol (50mg of each in a 10cc syringe).

Intubate: During the above procedure the patient should be preoxygenated with either a non-rebreather (NRB) alone, NRB with nasal cannula, or non-invasive positive pressure ventilation (NIPPV). Switch the patient over to nasal cannula oxygenation for the intubation. Quickly survey to ensure that all the equipment is at bedside and nothing was forgotten. Position the patient with external auditory canal at the level of the sternal notch. Discuss with the patient the need to put on loose restraints to avoid the reflex of reaching for the tube during the intubation. In fully cooperative patients this may be unnecessary. Proceed with standard orotracheal intubation with direct versus video laryngoscopy. Utilize the additional lidocaine via atomization as needed. Once the cords are visualized, you can intubate in normal fashion or pass a bougie through the cords and then thread the ETT over the bougie through the cords under constant visualization. You may need to give additional sedation if the patient has difficulty tolerating this, and you are now safe to do so as the airway is secure.

Pearls and pitfalls

Pearls: Place the patient at 30 degree head elevation to decrease the chance of passive regurgitation. If the patient is obese, he/she will be more prone to desaturation and regurgitation, so you may want to attempt intubation with the patient sitting up fully. The technique is reversed in that you will hold the blade with the right hand and intubate with the left. This should be practiced beforehand using an airway dummy in order to get used to the technique and get comfortable handling the equipment in this fashion.

Pitfalls: The biggest pitfall is not thinking about awake intubation early enough. Remember to consider awake intubation in any patient that is not acutely crashing. Failure to educate and prepare the patient adequately will often lead to an anxious, gagging patient and a failed attempt.

Scenario 2

You are alerted by nursing staff that an angioedema patient is being roomed. Vital signs include HR 108, RR 26, BP 136/86, SpO2 94%. You walk into the room to see your patient sitting up on the bed in marked distress. Her tongue is protruding from her mouth with marked swelling to the tongue and lips. The patient is protective of her position and cannot tolerate lying back or being supine. The patient appears to be maintaining her airway and is able to speak in short sentences; however, she appears on the cusp of respiratory failure.

What will you consider for definitive airway management in this patient?

This patient, like any other in respiratory distress, should be in a room with cardiopulmonary monitoring. Airway equipment should be immediately available and respiratory therapy should be called if available. The patient’s oral edema makes traditional orotracheal intubation difficult if not impossible. As is the case with any patient in acute respiratory distress without a definitive airway, surgical airway should be considered.

This patient is known to the service for frequent angioedema presentations and is strongly against a surgical airway if it can be avoided.

Is this patient a candidate for nasotracheal intubation?

Blind nasotracheal intubation (BNTI) has changed little since it was first described in the 1920s. It has fallen into disuse due to training in and benefits of RSI in the ER. However, in specific situations (and especially in pre-hospital settings) BNTI is a valid option for definitive airway in the awake and spontaneously breathing patient. Particular benefits for this patient and situation include the ability to intubate in the sitting (sniffing) position while awake, without need for heavy sedation.

As you continue to assess the patient, you notice she is progressing in her respiratory distress and you need to act expeditiously to secure the airway. You decide to attempt nasotracheal intubation and prepare the patient.

What supplies do you need?

Little change in supplies is needed from orotracheal intubation to nasotracheal intubation. A 6.0 or 7.0 mm ET tube (or 0.5 to 1 mm smaller than the tube you would use for orotracheal intubation) is used. Oxygen, suction, and surgical cric kit should be available. Constricting the nasal mucosa with phenylephrine or oxymetazoline spray is beneficial, and topical anesthesia with 2-4% viscous lidocaine and cocaine mixture is also helpful. In the non-emergent setting, placing a lubricated nasal airway to physically dilate the passageway is also helpful. Often a nasal airway can be placed early and left in place while preparing for intubation. Use a nasopharyngeal airway that is the same size as the intended nasotracheal tube. As with any airway management, it is important to be prepared for complications and/or failure of the airway, and surgical airway equipment should be readily available.

The technique

Choose the most patent nare, either by closing each nare independently and asking the patient to breath or exhale, or by visual inspection. A gloved small finger lubricated with viscous lidocaine can be used to determine patency if needed. Prepare the patient by instilling 1-2 cc of the lidocaine/cocaine mixture in each nare; repeat this step 1 to 2 times. Lubricate a nasopharyngeal airway with your lidocaine/cocaine mixture and place in the most patent nare. When ready to proceed with intubation, lubricate your ET tube (Endotrol or similar preferred, but standard ETT is sufficient) and insert into the nare following the floor of the nasal cavity. Confirm placement.

As you insert the ET tube you orient the bevel of the tube towards the septum to avoid injury to the inferior turbinate. At about 6 to 7 cm you feel a “give” in the insertion of the tube. You know you have reached the nasal choana and are negotiating the abrupt 90° curve needed to enter the nasopharynx. As you continue, you note louder breath sounds and fogging in the tube. You are just above the vocal cords and on deep inspiration you make one smooth move to pass the cords. The patient begins to cough and you note a stridulous quality to her breathing.

Successful Intubation

Upon passing through the vocal cords, stridulous breathing and reflex coughing can be noted. This serves to verify proper passage to the level of the cords. Absence of this response should alert to possible esophageal intubation. Vocalization should cease after the tube is passed through the cords. If continued vocalization occurs you have most likely entered the esophagus. Reflex swallowing can lead the tube towards the esophagus. In this instance, have the patient stick out their tongue to avoid swallowing and pass through the cords in one smooth movement. Optimum distance from the nare to the tip of the tube is about 28 cm in males and 26 cm in females.

You note the patient is unable to make any vocalizations, breath sounds are heard bilaterally, and you inflate the cuff and secure the tube verifying placement. You successfully intubated your awake patient and avoided a surgical airway.

Complications

Epistaxis is the most common complication of BNTI and can be lessened or avoided with pretreatment as discussed above with phenylephrine drops or oxymetazoline spray. Sinusitis can be an often unrecognized source of infection or even sepsis in nasotracheally intubated patients. Also, laryngospasm can be common during NT intubation but is usually transient. If encountered, the tube is withdrawn slightly and time given for the patient’s first “gasp.”  Advancement of the tube at that precise moment is frequently successful due to the vocal cords being widely abducted during the forced inhalation.

Modifications

There are many modifications described. A few worth noting are placement under direct visualization and fiberoptic nasotracheal intubation. Visualization can be accomplished by opening the mouth and noting the ET tube’s location. A pair of Magill forceps can be used to assist in placement of the tube. This requires a patient where opening of the mouth can be accomplished and can take more time, although in a failed BNTI it can allow for successful intubation. Fiberoptic nasotracheal intubation is virtually identical to BNTI in technique with the exception that the scope can be placed inside the ET tube and both guided in under fiberoptic visualization. If equipment and time permits, this can be an effective NT intubation technique.

Summary

Awake orotracheal and nasotracheal intubation are two skills that all emergency medicine physicians should have in their airway “tool kit.” All emergency medicine residency trained physicians will be well-trained in the ins and outs of rapid sequence intubation, but rarely utilize this integral skill. Much of this is due to the accessibility of a specialist such as surgeon, ENT, or anesthesiologist to assist with airway control in more difficult patient scenarios; however, this will not always be the case in actual practice. Being able to identify the difficult airway and when RSI may cause significant morbidity and mortality as well as the alternate options of awake intubation is paramount to the success of every EM physician. During my 3^rd year of residency we had a patient being transferred to our facility from a small outlying hospital with the presentation and outcome of the first scenario above. I discussed with my attending why this patient was not intubated using a technique such as awake intubation and the reply was simple. Many community physicians, EM trained or not, don’t know how to do it. It is our responsibility to not only treat patients in response to pathology, but to also anticipate a patient’s course and intervene early to prevent decompensation. Awake intubation should be utilized to prevent a difficult airway from becoming an impossible airway.

References / Further Reading:

– Tintinalli, Judith E. “Resuscitative Procedures.” Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York: McGraw-Hill, 2011. 205. Print.

– Custalow, Catherine B. “Tracheal Intubation.” Roberts and Hedges’ Clinical Procedures in Emergency Medicine. 6th ed. Philadelphia, PA: Elsevier/Saunders, 2013. 99-101. Print.

– Levitan, Rich. “Nasal Intubation.” Nasal Intubation. Emergency Physicians Monthly, 6 June 2011. Web. 14 May 2015.

– “Nasotracheal Intubation .” Nasotracheal Intubation. Medscape. Web. 14 May 2015.

– “Emergency Medicine.” NASOTRACHEAL INTUBATION. Web. 14 May 2015.

– Bailenson G, Turbin J, Berman R. Awake intubation – indications and technique. Anesthesia Progress. 1967;14(10):272-278.

– http://emcrit.org/podcasts/awakeintubation/

– http://lifeinthefastlane.com/tag/awake-intubation/

– http://emupdates.com/2013/07/07/awake-intubation-a-very-brief-guide/