One of the simplest and most valuable devices to help with a difficult intubation is the bougie. The primary use is a difficult intubation, when you cannot see the larynx well but are able to predict where the glottic opening should be based on anatomy. However bougies must be used with care to avoid patient injury.
The bougie is an endotracheal introducer that is made of a braided polyester base with a resin coating, giving it both flexibility and stiffness at body temperature. The standard size for intubation is 15 Fr, which is 60 cm long. There is a 10 Fr pediatric version which can be used for endotracheal tubes as small as 4 to 6mm. A bougie will retain the curvature given to it, making it very useful for anterior airways. I highly recommend that you have a bougie in the room whenever you intubate because it is a quick and easy aide when the unexpected difficult intubation occurs. However, like so many of our tools you you have to use it wisely or you can seriously hurt your patient.
Sir Robert MacIntosh, the anesthesiologist who invented the Mac laryngoscope blade, created the original straight gum elastic bougie in 1949 to solve a particular problem. During intubation, especially difficult intubations, the view of the larynx was often hidden behind the distal tip of the endotracheal tube, making aiming the tube into the glottis that much more of a challenge. The bougie, being slender, firm and easily manipulated, could be passed into the trachea first and then used to guide the endotracheal tube. Bougies are no longer made of gum, despite their name, and now have a curved tip, called a coude tip, that is very useful for intubating an anterior larynx.
Two Bougie Techniques Depending on Availability of a Helper
Using a Helper
During laryngoscopy, pass the bougie forward into the larynx if seen, or toward the probable location of the laryngeal opening under the epiglottis if the larynx is not visible.
If you can’t see the glottic opening, correct placement into the trachea is felt as “clicks” as the bougie slides over tracheal rings. You won’t feel clicks if the bougie is in the esophagus. Advance the bougie past the cricoid ring and down the trachea. The device may rotate as it encounters the main stem bronchus or stop when the smaller bronchi are reached. Never force a bougie.
Fix the bougie and laryngoscope in position. Have your helper load the ETT onto the bougie and feed it down to you until you can grab it. Your helper needs to be gentle to avoid twisting the bougie out of the trachea or bumping your laryngscope which lies close to the teeth. Once loaded, you should gently continue to push the tube down the bougie through the mouth and into the trachea. The action is often called “railroading” the tube down the bougie – presumably because the tube is following the “track” into the target.
Without a Helper
Preload the endotracheal tube onto the bougie. Slide it far enough down that you can stabilize both tube and bougie, but not so far down that it interferes with your ability to aim the bougie into the mouth and trachea.
Once you have the bougie in the trachea slowly “railroad” the bougie as above.
Always listen for breath sounds to verify tracheal placement, especially when intubating without a good view of the glottic opening.
Should I Remove the Laryngoscope Or Not Before Advancing the tube?
Some people prefer to remove the laryngoscope before advancing the endotracheal tube down the bougie and into the trachea. The rationale for removing the scope is to makes tooth damage less likely as you are manipulating bougie and tube.
Removing the laryngoscope prior to “railroading” the tube can cause potential problems:
- More likely to twist the bougie out during tube insertion and getting an esophageal intubation
- Higher risk of advancing the bougie at the same time, risking tracheal trauma
- Higher risk of tearing the Endortracheal tube cuff against the teeth
Depending on the situation, I usually wait to remove the laryngoscope until after I have stopped advancing the endotracheal tube.
Risk of Dangerous Complications Using a Bougie Is Rare But Real
Use a bougie in combination with laryngoscopy under direct vision rather than as a blind stent. The bougie is stiff enough to cause damage or perforation of the trachea, bronchi and potentially the esophagus and must be used with caution. Other laryngeal and pharyngeal structures could be injured as well. A bougie passed through the bifurcation at the carina can cause a bilateral tension pneumothorax: an event that is particularly difficult to diagnose because the trachea remains midline, the heart is usually not displaced, and the breath sounds, though poor, will often be equal.
Because of the risk of perforation, it is not recommended for routine use in exchanging endotracheal tubes. If you are exchanging endotracheal tubes, a standard tube exchanger should be used since it is softer and more flexible, plus the lumen is hollow and will allow insufflation or jetting of oxygen if necessary. The same caution exists for advancing a tube whose cuff is above the cords.
However, it is difficult to say “never” in medicine. In a life threatening situation where a tube exchanger is not present, you might decide in a particular patient that using a bougie is your best option. If you do decide to use a bougie in this way:
- be especially cautious that the bougie is inserted only to mid trachea (measure the distance against the outside of the patient before you start)
- direct a helper to hold it in position when you start to insert the endotracheal tube –so that it cannot inadvertently be shoved deeper along with the tube.
- check breath sounds and be alert to hemodynamic changes
- always be gentle
Tips For Success
When using a bougie, keep your eyes on the target. You may need to rotate the tube to allow passage through the vocal cords if the tip of the tube catches on the anterior commissure. Once the tube is in place, withdraw the bougie and laryngoscope and verify correct placement of the tube.
Occasionally it’s hard to make the tip of the bougie make the turn upward toward the trachea, especially if the patient can’t extend their neck well or if you can’t open the mouth widely. My good friend, anesthesiologist Steve Blum taught me his trick. Press the shaft of the bougie lightly against the upper teeth during insertion to force a shallow bend that curves the bougie tip upward toward the larynx. The more you press the more it bends, helping you aim around the corner and easing insertion.
One study(1) of patients requiring cervical spine precautions and stabilization showed that in the neutral position, the view of the larynx on direct laryngoscopy was reduced in 45% of the patients. Of these, 22% had views showing only the epiglottis. The patients in the bougie group were all successfully intubated within 15-20 seconds. On the other hand 5 patients in the laryngoscopy only group subsequently required the bougie and 5 required more than 50 seconds for intubation. Thus the bougie appears to be a good adjunct for difficult intubations. You should practice its use in routine intubations to gain experience before you need it in an emergency.
May The Force BeWith You
Christine Whitten MD
(1) Nolan, JP; Wilson, ME: Endotracheal intubation in patients with potential cervical spine injuries: An indication for the gum elastic-bougie. Anes. 1993; 49:630-633.