Awake Intubation Jed Wolpaw MD, M.Ed

References  Based primarily on Collins SR and Blank RS. Fiberoptic Intubation: An Overview and Update. Respiratory Care. June 2014: 59;6( ).

Outline  Indications  Approaches  Patient preparation  Nasal  Oral  Nerve blocks  Sedation  Other approaches

History  Peter Murphy, in England, in 1965 used a fiberoptic choledocosope to intubate nasally a pt with Still’s disease.

Indications for Awake Intubation  Need for intubation where ability to ventilate via mask or supraglottic airway is unlikely or poses an aspiration risk  History of need for awake intubation  Anatomic features that are worrisome  Limited mouth opening, reduced neck mobility, cervical spine instability, anatomic malformations of mandible or larynx, congenital deformities (Pierre Robin), head and neck cancers, trauma to the face, airway.

How common are difficult airways  Review of 50,000 records excluded planned fiberoptics  Found impossible to mask was only 0.15%, and 25% of those were difficult to intubate

Neck movement  When compared with DL or glidescope FOI causes less movement of cervical spine

Techniques: Nasal  Preferred when:  large tongue, limited mouth opening  receding lower jaw, or tracheal deviation  or in cases in which an unobstructed surgical field is beneficial (eg, dental surgery).  This approach is also anatomically favorable in that the laryngeal opening is more easily seen with the fiberscope as it courses past the nasopharynx with less obstruction by the tongue

Nasal  Anti-sialogogue: Glycopyrollate mg  Afrin or phenylephrine and lidocaine to nare, ask which is more open  Inhaled nebulized lidocaine at 5l/min flow for correct droplet size, not trying to get into lungs, have pt stick out tongue  Spray additional high concentration lidocaine through atomizer into back of throat and directed down on cords  5% lidocaine ointment onto tongue depressors with 4x4 attached, paint back of throat and let drip down while pt bites on tongue blade  Plus/minus trans-tracheal injection of lidocaine, more concentrated is better  Can also “spray as you go”

Nasal continued  Dilate nare with increasing size of lubed NP airways  Insert tube with gentle pressure until passes into oropharynx, then inflate balloon and draw back until resistance is felt  Insert fiber and pass into cords, deflate cuff and advance tube  Ideally use smaller tube, 6-5 or 7-0 better than 7-5 or 8-0 due to ease of passage into trachea  If you cannot visualize cords, try having someone do a jaw thrust and/or pull the tongue out of the mouth with a 4x4  If scope is in trachea but tube won’t pass, withdraw slightly and rotate 90 degrees and try again, then another 90 degrees. If necessary try corkscrew  Parker Flex tip tube has curved tapered distal tip to slide past cords more easily

Oral  Harder due to tongue, more anterior path needed to get to cords  No nasal prep needed, otherwise the same  Can use special oral airway such as Ovassapian with central channel to pass scope  Jaw thrusts and tongue out can really help here  Key is staying midline, walk along the tongue, manipulate ETT

Nerve Blocks  Glossopharyngeal nerve supplies sensory to posterior third of tongue, vallecular, anterior epiglottis, walls of pharynx, tonsils  Block by holding pledgets with lidocaine at tonsillar pillars or injecting at mandible and mastoid processes.  Superior laryngeal nerve provides sensory to base of tongue and posterior surface of epiglottis to arytenoids.  Block by injecting local at cornua of hyoid bone  Vagus nerve branches (recurrent laryngeal) supply sensory innervation to the underside of epiglottis and trachea  Transtracheal block  1% lido can last 75 minutes, up to 400 minutes with 1:200,000 epi

Sedation  Depends on how scary the airway is, okay to use no sedation  Versed +/- fentanyl  Remi bolus vs drip (0.5-1mcg/kg and mcg/kg/min)  Ketamine bolus vs drip ( mg/kg and 10mcg/kg/min)  Precedex, load and drip (0.4-1mcg/kg bolus over 10 min mcg/kg/HR)  General anesthesia with spontaneous ventilation, inhaled or propofol  More hypoxia with propofol  Remi vs. Prop: Remi better conditions, better tolerated, patients breathed when told to  Precedex vs prop: Precedex superior in terms of hemodynamic stability and not having airway obstruction  Precedex vs remi: Precedex better in terms of desaturations Johnston KD and Rai MR Consious Sedation for awake fiberoptic intubation: a review of the literature. Can J Anesth (2013) 60:

Other techniques  Fiber through LMA  Awake glidescope  Awake DL  DL and fiber or glidescope and fiber