Rapid Sequence Awake Intubation

Awake Intubation

Jess Mason MD, Mel Herbert MD, Scott Weingart MD and Drew Merriman MD

 

Take Home Points

❏      Patients with an anticipated difficult airway but sufficient respiratory reserve to allow preparation may be candidates to perform awake intubation.

❏      Use 4% lidocaine and an atomizer device to anesthetize the airway.

❏      Patients may be sedated with 1-2mg of midazolam or small aliquots of ketamine.

 

CASE

Drew Merriman, an emergency medicine resident, had experienced a sore throat for several weeks. He woke up in the middle of the night in a puddle of drool. He was unable to swallow. His voice sounded like a hot potato. He couldn’t believe it was epiglottitis. He drove himself back to the hospital because he didn’t want to be that emergency medicine resident who called an ambulance for a sore throat.

 

●      He arrived at the triage desk and it was immediately apparent that something was wrong. The attending physician took one look at him and shoved him into a front room.  They put him on the monitor and placed on IVs. He realized that his fears were true. Everyone was starting to look frantic.

 

●      Prior to the H. influenza vaccination, epiglottitis was primarily a pediatric disease. Rates have dropped to less than 1 per 100,000. However, in adults, the incidence has remained the same between 1-2/100,000.

 

●      The traditional teaching for pediatrics is to keep them calm, transport them to the OR and intubate them under anesthesia. Adults may be able to cooperate. Some rural settings may not have alternatives and the ED physician will be responsible for the airway.

 

●      Who should be intubated while awake?

o      Any patients who may be a difficult airway but are breathing enough to allow you time to prepare for an awake intubation.

o      A patient who is apneic or nearly dead won’t allow enough time for preparation of the intubation. These patients need RSI.

o      Patients with breathing issues and an airway presumed to be difficult secondary to anatomy (such a morbidly obese patient with pneumonia) can be temporized with BiPAP while you prepare for intubation. Patients with epiglottitis or other disease states affecting their airway are in a different category. You need rapid sequencing of your awake intubation. You can’t take longer than 5 minutes.

 

●      What are the steps of a rapid sequence awake intubation?

o      You need to grab the highest concentration of a viscous type lidocaine and a tongue depressor.

o      Get a bottle of 4% lidocaine and something to atomize the 4% lidocaine. Weingart previously recommended the MADgic device, which is a flexible tube that attaches to any syringe and turns liquid into a thin spray. Now, he uses the EASY-spray. This is a reservoir that hooks up to air or oxygen and it puts out an atomized jet of the lidocaine with a tip you can direct. The nebulized lidocaine works quickly.

o      You need arm restraints, intubation devices and all of your failed airway equipment.

o      How do you prepare the patient? Put the patient in a position of comfort. Don’t make things worse by lying the patient flat.

▪       Merriman was only comfortable on all fours looking down.

o      Put a nasal cannula on the face and BiPAP or a non-rebreather mask depending on the situation to preoxygenate the patient.

o      Talk to the patient and put them in soft arm restraints. You don’t want them reaching up and grabbing at the tube.

o      Dry out the patient. Glycopyrrolate will take 5-10 minutes. Don’t bother. You don’t have time. Suction out the airway as best you can and pat dry their mucosal surfaces.

o      Put a blob of viscous lidocaine or lidocaine paste on a tongue depressor. Paint the back of their tongue. You can grab the tongue with a 4x4 gauze. Let this drop on their epiglottis. Use the EASY-spray or MADgic device to aerosolize the lidocaine over the posterior oropharynx. Use at least 5cc of the lidocaine for this. Direct the tip down and spray the epiglottis.

o      If you can time your spray, you may be able to achieve subglottic anesthesia. If you can’t, don’t worry about it. If you have to go through the nose, you need to give a lot of the lidocaine spray through the nostril. Take some more viscous lidocaine on your gloved pinky finger and put it in the patient’s nostril. If you can’t get it in, it probably won’t work for fiberoptic intubation through the nose. This can dilate the structures. The tube is about the same size as your pinky.

▪       They took a look at Merriman’s airway with the fiberoptic scope. He was gagging a little bit.

o      Sedation is a double edged sword. It makes the patient more comfortable and enhances the effects of topical anesthesia. However, you don’t want to do anything to worsen the respiratory status or cause apnea. You could use 1-2 mg of midazolam. This will cause very little sedation but causes amnesia. An alternative is to use small aliquots of ketamine (10mg at a time). This will cause some degree of dissociation. However, sometimes dissociation can lead to agitation and this is the last thing you want. If they are exhibiting increased agitation, you may want to give them a dose to fully dissociate them (probably 1-2 mg/kg). Try to avoid this if possible.

▪       They were unable to pass a 7-0 tube. They downsized to a 6-0 tube.

o      Ondansetron may help with the gag reflex. It probably won’t hurt. Give the patient 8mg of ondansetron.

▪       Once they got the tube in, they inflated the cuff and pushed midazolam. 

o      If you have video bronchoscopy available, use it. It is the least likely to cause airway irritation. However, many don’t have this available. Video laryngoscope and a bougie is another option. The patient will start coughing when the bougie goes in.  If nothing else, you can do these with standard laryngoscopy.

o      However, you should be very reluctant to use a laryngoscope in the setting of epiglottitis. You don’t want to inflame the epiglottis more. Fiberoptic bronchoscopy is the best option.

o      If you can’t pass the tube, try rotating it. Start small with a 6.5 endotracheal tube.

 

●      Merriman woke up in the ICU. He was extubated within 12 hours. He was discharged home the following morning.