Look Before You Leap - Awake Fiberoptic Intubation
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Look Before You Leap, Drive Your Ferrari Like it is a Wheelchair, Harken Ye to the Wicked Witch of the West!
A 37 year-old woman presents with stridor, drooling, tachypnea and accessory respiratory muscle use. She has an adequate blood pressure, but is tachycardic to 120. Her oxygen saturation on room air is a reassuring 97%. She cannot answer questions, appears to have an altered mental status though she follows commands, and suddenly has a brief period of either myoclonus or seizure with unresponsiveness. No post-ictal period is noted after this episode.
What the heck is going on? You have no idea, but the presentation is worrisome for an impending airway disaster. A decision is made to manage her airway. Why? Let’s go over the indications for intubation: 1) Failure to oxygenate? No.2) Failure to ventilate? Unclear, but not suspected to be an issue. You could toss on the ETCO2 monitor or send a VBG [time permitting] to assess this further, but the decision should praobably be mage clinically. 3) Inability to protect and maintain the airway? This is VERY unclear, but the early signs are worrisome (drooling, stridor, respiratory distress).4) Projected clinical course would be improved by definitive airway management? Bingo! We have no idea why this woman looks the way she does, but whatever it is occurred acutely, and must be assumed to be a progressive, downwardly-bound process. The decision to manage the airway is a righteous one.
How to manage her?
This decision in clarified by applying the Universal Airway Algorithm. Is she a Crash Airway? No. We have time to optimize our efforts. Is she a Difficult Airway? We have no idea, but the assumption must be that she has upper airway obstruction. Anatomically she has no unfavorable external characteristics, but her LEMON Law is worrisome for the “O”...obstruction. The potential for a high-grade, upper-airway obstruction also must play into our assessment of the ability to bag her (the “O” of MOANS), or rescue her by an extra-glottic device (the “O” of RODS). How about rescue by cricothyrotomy? The new mnemonic for this is SMART (S = prior Surgery, M = Mass obscuring the CTM or in the trachea, A = Anatomy of the patient and Access to the neck, R = prior Radiation, and T = Traumatic alteration of the airway. Her SMART is a little scary for the M...does she have an aspirated foreign body in the airway? A tracheitis? A vocal cord tumor? We have no idea. You must assume that she will be a Difficult Airway. Proceed to the appropriate algorithm.
Thus far in this story, I have used the phrase, “You have no idea” three times. This should telegraph a key point, and forms the basis for the following multiple-choice question –
When you don’t know what is down a dark, dangerous hole, you should:
- A. Jump in feet first heedless of the potential for monsters or poison-tipped spikes at the bottom?
- B. Dive in head first, because it will be better to die quickly if you are proven wrong?
- C. Cautiously look down the hole to get more information?
- D. Run away screaming?
The answer, of course, is “D”....er, “C”. You need more information. RSI is not the way to get more information, it is the way to dive down the hole. Look before you leap! This patient is a poster child for an Awake Look. Recall that an Awake Look is a pharmacologic strategy that renders the patient cooperative by judicious sedation, and removes troublesome airway reflexes by topical anesthesia. The method of looking is an independent decision, and could be DL, VL, optically-enhanced DL, or fiberoptic. Here, fiberoptic was (wisely) chosen. Alluding to the title, fiberoptics are the Ferrari of airway management.
The patient has her airway fogged with 4% aqueous lidocaine, and receives some benzodiazepine, then a sub-induction dose of Ketamine. She mellows out a bit, and a 7.5 mm ETT is introduced through her nose to 19 cm. KEY POINT!This is too deep! Introduce the ETT to 12 to 15 cm (about at the decimal point of the size label on the tube) to ensure that you are supraglottic). Back it up to this marker. A spaghetti-sucker is readied to assist with clearing any secretions from the tube, and the fiberoptic scope is introduced into the ETT. The airway is a wet mess, and several rounds of suctioning are necessary. The cords are then glimpsed. The resident revs his Ferrari, shifts into 1st, and in a single, deft motion, dives toward the glottis...and crashes! The scope is removed and cleaned, the process repeated in the same manner, with the same result. What is happening?
KEY POINT!Drive your Ferrari like a wheelchair – slowly and in measured steps. The method for successful intubation with a fiberoptic is to identify the target, then center it horizontally on the screen (or in the eyepiece) through rotation of the hand, then center it vertically by flexion or extension using the thumb-toggle. Then advance slightly, re-center, advance, re-center and finally advance through the cords when they are close, and centered. Keep in mind, the view will be dynamic since the patient is (thankfully) breathing. You must accommodate movements of the target. This process is followed, and the fiberoptic is passed through the cords to the carina. TOUCHDOWN DANCE!!!
But, no! Resistance is encountered as the tube is passed over the scope by Seldinger technique. The patient is now coughing and thrashing a bit, but maintaining sats. KEY POINT! When the tube won’t pass the cords, it is likely that the point of the bevel is catching on the right arytenoid cartilage or aryepiglottic fold, or in the vestibule above the cords. Since the bevel is cut of the left-hand side of the tube, back the tube up a centimeter and rotate the tube counterclockwise about 90 degrees to disengage it, then advance. If this doesn’t work (...it didn’t) consider that the direction that the tube wants to take is posterior. To make the tip move anteriorly relative to the glottis, extend the neck and retry. SUCCESS! Kudos to Bill Hinckley for pulling out this gem of a solution in a moment of stress. Now do your touchdown dance!
Remember always the wise counsel of the Wicked Witch of the West, who said, “These things must be done delicately, or it hurts the spell!”. Never force a tube, or a bougie, or a blade, or a scope.
