M2E Too! Mellick's Multimedia EduBlog

The M2E Too! Blog by Larry Mellick, MD, presents important clinical pearls using multimedia.

By its name, M2E Too! acknowledges that it is one of many emergency medicine blogs, but we hope this will serve as a creative commons for emergency physicians.

Wednesday, July 2, 2014

My Difficult Airway

Looks can be deceiving. I was not supposed to have a difficult airway, but we found out the hard way that wasn’t true. I was about to undergo an exploratory laparotomy for suspected appendicitis in 1989, and my wife was adamant that an attending anesthesiologist perform my intubation. The anesthesiology resident at a large Midwest teaching hospital made a claim that I suspect many of us did as we advanced through training and began to feel procedurally invincible. He claimed that the attending anesthesiologist rarely did intubations, and that the residents who performed them daily were more prepared. Unaware of any unique issues with my airway and wanting to be a good patient, I didn’t attempt to override the resident.

I woke up from anesthesia with a swollen, bleeding, and extremely painful pharynx, and my right central incisor was abraded and roughened. We learned that the resident made four attempts before the attending took over and successfully placed the airway. The soft tissue injury to the pharynx resolved with time, and my dentist filed the tooth smooth again. Subsequent surgeries, however, included a successful bougie intubation and a not-so-pleasant awake intubation.

This May, my shoulder pain reached a point where I knew it was time for surgery again. My left rotator cuff muscle needed to be repaired, just like the right one had years before. Intubation methods were a necessary topic of conversation with my anesthesiologist again.

My “3-3-2” airway assessment is abnormal on two counts. Instead of three fingers, my mouth will only open to allow two and maybe part of a third finger between the upper and lower incisors. The second “3” is the distance between the mentum and the hyoid bone. This gives an idea of how much space is available for the tongue to be displaced during laryngoscopy. My facial anatomy appears fine in this regard. The “2” refers to the position of the larynx in relation to the base of the tongue. Two or more fingerbreadths between the hyoid bone and the upper anterior edge of the thyroid cartilage are ideal. This signifies that the larynx is located sufficiently beyond the base of the tongue. I barely get one fingerbreadth with this measurement. These two variances add up to a markedly anterior larynx and a difficult-to-visualize airway. I have never been told what my Cormack-Lehane classification is, but my Mallampati score is a Class II.

Visualization of Glottis: Cormack-Lehane Classification
Grade 1:
Full view of glottis and vocal cords
Grade 2: Vocal cords and glottis are partially visible
Grade 3: Only epiglottis seen; glottis is not visible
Grade 4: Glottis and epiglottis are not visible


Visualization of Upper Airway: Mallampati Class
Class I:
Faucial pillars, soft palate, and uvula visualized
Class II: Faucial pillars and soft palate visualized; uvula not seen (masked by tongue)
Class III: Only soft palate and base of uvula visualized
Class IV: Faucial pillars, soft palate, and uvula not visualized (only hard palate visualized)

The anesthesiologist who agreed to take my case chose a fiberoptic intubation using nebulized lidocaine, a Parker Flex-Tip endotracheal tube with the unique beaked tip, and the endoscope plastic oral airway guide. In fact, we agreed to make a teaching video of my procedure, even knowing it might not be pretty. It wasn’t. Everything the anesthesiologist did was technically correct. Unfortunately, the lidocaine nebulization failed to anesthetize my airway. That, however, was my fault. Instead of consistently inhaling the 4% lidocaine, I stopped multiple times to greet acquaintances in the operating room and to direct the filming of my video. My reward was vigorous coughing and bucking as the endotracheal tube and fiberoptic scope were inserted.

The intravenous midazolam also caused a short period of apnea, and it was a little unnerving to listen to the pulse oximetry monitor alarm drop in pitch when I reviewed the video later. I couldn’t actually tell how low my oxygen saturation went, but the oxygen was turned up, and the first reported reading was of 93%. Thankfully, I have no memory of these events.

The truth is that events like this happen all the time despite our best-laid plans, and they are the substance of life in the ED that keeps us simultaneously on our guard (paranoid) and humble. I love the video because it shows a few of the realities of difficult airway management that can be instructional for learners. Click here to watch a video of the interscalene brachial plexus block used for my shoulder surgery.

Have you ever had a patient with a difficult airway like mine? How did you manage it? What tips do you have for difficult intubations?