Jun 132018
 

Bougies are long, stiff plastic wands inserted into the trachea through the glottis during direct laryngoscopy (DL), providing a "guidewire" over which an endotracheal (ET) tube can then be more easily advanced into the trachea. Bougies have traditionally been used after one or more failed intubation attempts with direct laryngoscopy, at which point the airway is declared “difficult.”

The problem: after more than two attempts at endotracheal intubation, the rate of complications skyrockets. Patients may already have experienced severe stress from hypoxemia, are rendered paralyzed and apneic by rapid sequence induction medications, and may be developing airway edema that can make subsequent intubation attempts even more difficult. Severe hypoxemia, cardiac arrest and death occur far more often after two failed airway attempts.

So why not use bougies on every first intubation attempt by direct laryngoscopy? (Bougies are not useful during video laryngoscopy with hyperangulated blades, in which the tongue tends to block smooth passage of the bougie.)

In a randomized trial, the routine use of bougies on every DL intubation led to a higher rate of first-pass intubation success. And even allowing for the two-step technique (bougie insertion followed by ET tube insertion), the bougie technique required less total time to intubate the patient, on average, by reducing the time spent guiding the ET tube into the airway.

Authors affiliated with the University of Minnesota randomized 757 patients requiring intubation in one emergency department to be intubated with or without a bougie on the first attempt. All patients were intubated by video-augmented direct laryngoscopy with a Macintosh (slightly curved) blade, by either an attending or a senior emergency medicine resident. About half the patients had at least one predictor of a difficult airway (obesity, short neck, small jaw , large tongue, copious pharyngeal secretions or blood, airway edema or other obstruction, facial trauma, or cervical spine immobilization).

The laryngoscopes used had Macintosh blades allowing direct visualization of the glottis (traditional DL), along with a video screen which the intubating physician could use, or not. (The devices were the Karl Storz C-Mac blade and the Glidescope Titanium MAC blade; the bougie was a 70-cm long, 15 French / 5-mm diameter, single-use with a coudé tip made by SunMed. Bougie bending was allowed.)

First-pass intubation success was higher overall among the bougie-first group (98% vs. 87%). Among the 380 patients with predicted difficult airways, 96% were intubated on the first attempt with a bougie, vs. 82% of those intubated without a bougie.

Endotracheal intubation with direct laryngoscopy is becoming more difficult in the developed world, owing to the increasing prevalence of obesity. At the same time, the advent of video laryngoscopy with hyperangulated blades (recommended for expected difficult intubations) has reduced physicians’ experience and skills with direct laryngoscopy. Given the increasing awareness of the importance of first (or second) pass success, critical care training programs are increasingly reluctant to allow learning physicians to fail with DL often enough to learn the technique. At least one respected critical care training program has abandoned training DL skills altogether. The result is an emerging generation of intensivists -- many of whom will become teachers themselves -- with inadequate skills at direct laryngoscopy. Because DL is still an essential salvage method after failed video laryngoscopy, this puts patients at risk.

By adopting a “DL with bougie first” approach, using devices with Macintosh blades with video screens for teaching, training programs could address these issues. Incorporating video-supported DL would allow critical care physicians in training to gain the needed skills in DL intubations, without putting patients at excess risk during learning attempts.

Source: JAMA

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Bougies for all intubations led to high success rates, even on difficult airways