Abstract
Tracheal tube introducers or bougies and airway exchange catheters (AECs) are widely used airway adjuncts for facilitating airway management in difficult circumstances. They are easy to use, relatively inexpensive and have success rates of ≥ 90% in most settings. Both are included in many modern airway management algorithms. The use of bougies has expanded over the years, and they are now used to aid insertion of supraglottic airways (SGAs), videolaryngoscope-guided intubation and as adjuncts to emergency front of neck airway procedures. Stylets are rigid or semi-rigid airway adjuncts that are inserted into the tracheal tube before intubation. They maintain the tracheal tube in a particular shape and may therefore assist during intubation. AECs are semi-rigid hollow tubes designed to aid airway device (SGA, and single- or double-lumen tracheal tube) exchange or to manage ‘at-risk’ extubation. The risk of serious airway trauma associated with the use of bougies and airway exchange catheters, and the risk of barotrauma with the latter, invites cautious and educated use of these devices.
Tracheal tube introducers (commonly referred to as ‘bougies’), stylets and airway exchange catheters (AECs) are widely used airway adjuncts for facilitating airway management in difficult circumstances. They are easy to use, relatively inexpensive and have success rates of ≥ 90% in most settings.
Bougies are 60–80 cm long narrow tubes of 4–5 mm external diameter designed to assist during tracheal intubation. They are inserted into the trachea during laryngoscopy and then used as a guide over which to pass a tracheal tube (called ‘railroading the tracheal tube’). They often have a curved or angled (‘coudé’) tip (Figure 15.1). They are also used to aid supraglottic airway (SGA) insertion, videolaryngoscope (VL)-guided intubation and as adjuncts to emergency front of neck airway (eFONA) procedures.
Stylets are rigid or semi-rigid airway adjuncts, 30–50 cm long, that are inserted into the tracheal tube before intubation. They maintain the tracheal tube in a particular shape and may therefore assist during intubation (Figure 15.1).
AECs are semi-rigid hollow tubes of 80–110 cm designed to aid airway device (SGA, and single- or double-lumen tracheal tube) exchange or to manage ‘at-risk’ extubation (Figure 15.1).
The risk of serious airway trauma associated with the use of bougies, stylets and AECs, and the risk of barotrauma with the latter, invites cautious and educated use of these devices.
The usefulness of bougies and AECs is probably underestimated and, as a consequence, under-taught, perhaps due to the assumption that the basic techniques are easy and not worthy of the meticulous disciplined approach they deserve.
Tracheal Tube Introducers (Bougies)
Aid to Direct Laryngoscope-Guided Intubation
History
1949: Macintosh used a gum elastic urinary dilator (bougie) to facilitate tracheal tube placement in a patient with limited laryngeal view at laryngoscopy with a straight blade.
1973: Venn introduced the ‘Eschmann endotracheal tube introducer’, with a coudé tip and just the right balance between stiffness and flexibility.
1996: Frova designed the first hollow single-use introducer using stiffer material.
Current: there are numerous types of bougies described all differing somewhat (Table 15.1).
Bougies are highly effective aids to direct laryngoscope-guided intubation. Reported success rate is around 90% on first attempt rising to 94–100% with two attempts. During unexpected difficulty success rate is 80–90%.
Table 15.1 Tracheal introducers – bougies
| Device | Material | Colour | Length (cm) | OD/ID Fr (mm) | Hollow/ports | Tip | Notes |
|---|---|---|---|---|---|---|---|
|
| Golden brown | 60 | 15 Fr (5) | NO | Coudé (35) 38° |
|
| PVC |
|
| 15 Fr (5) | < 1 mm | Coudé | Hollow lumen < 1 mm |
| Intermediate density PET | Light blue | 70 | 14 Fr (4.7) / 3 | Yes (3 mm)/2 | Curved 2 × 2 cm |
|
| Polyurethane | Yellow | 35 | 8 Fr (2.7) / 2 | Yes/2 | Curved 1 × 1 cm |
|
| Stiff PET | Orange | 65 | 15 Fr (5) | Yes/2 | Coudé | For TT 6.0 mm ID |
| PVC – metal core | Light green | 40/65 | 8/12/14 Fr | NO | Flexible-coudé |
|
| PVC – plastic core | Dark green | 80 | 12/14 Fr | NO | Flexible-coudé | For TI and TI with TT ID 4.5/5.5 and larger |
| Stiff PET | Blue | 20→65 | 15 Fr | NO | Coudé | Folded, to be extended |
| PVC – partially metal reinforced |
| 65 | 15 Fr (5) | Yes/3 | Coudé 35° |
|
| Low density PET |
| 70 | 10/15 Fr | NO | Coudé/straight | |
| Bougie To Go (SunMed) | Low density PET | Light blue | 60 | 15 Fr | NO | Coudé | Rolled-up-packed |
| Introes Pocket Bougie | Special blend PTFE (Teflon) | White | 60 | 14 Fr (4.7) | NO | Flexible | Double-ended use, precurved |
| NA | Green | 53/70 | 6/10/15 Fr (2/3.3/5) | NO | Coudé | |
| Low density PET + metal inserts | White green dots | 65 | 15 Fr | NO | Coudé | Hexagonal section – stylet & bougie function |
| DEAS (DEAS) | Stiff PET | Light blue | 53.5/70/83 | 2/3.3/5 | Yes/2 | Coudé | |
| NA | Blue/yellow | 47/60/75/80 | 5/10/14/15 Ch | Yes/2 | Straight/angle/coudé | |
| Flexible Tip (P3) | Nylon + silicon tip | White-yellow | 66 | 15 Fr/5 | NO | Flexible/steerable tip; phosphorus coated (UV) | |
| PVC | Transparent-green/orange | 50/60/70 | NA | Yes (double) | Coudé 40° | |
| PET | Orange | 60 | 15 Fr | NO | Coudé | |
| PVC | Orange | 60 | 15 Fr | Yes/3 | Coudé/angled | Preshaped/shape-holding |
| PVC – wired | Orange | 60→73 | 15 Fr | NO | Adjustable | Wire-in-bougie to change shape/length |
| PVC | Yellow | 47/60/80 | 5/10/15 Fr | NO | Coudé | Barium tip |
| PVC | Blue | 75 | 14 Fr | Yes/2 | Curved | |
| NA | Orange | 75/80 | 10/14/15 Fr |
| Coudé luminescent | Luminescent tip; markers on left; memory & flexibility |
| Tracheal introducer (SUMI) | PVC | Blue or green | 60/70/100 | 3.3/5 | NO | Coudé |
Fr, French; ID, inner diameter; NA, information not available; OD, outer diameter; PET, polyethylene; PTFE, polytetrafluoroethylene; PVC, polyvinyl chloride; TI, tracheal intubation; TT, tracheal tube; UV, ultraviolet.
Bougies are most effective when the view at direct laryngoscopy is limited to the epiglottis only but this can be lifted (Cook’s modified Cormack and Lehane Grade 3a) or there is a better view but tube advancement is difficult. The use of a bougie in Grades 3b (epiglottis resting on the posterior pharyngeal wall over the glottic opening) and 4 (only the base of the tongue visible) is unlikely to be successful and may lead to airway trauma due to blind attempts at tracheal placement (Figure 15.2).
Bougies with a deflectable or steerable tip have been introduced relatively recently. These have the potential to improve success rates of bougie-guided direct and VL intubation. However, they are likely to require practice to master and to be relative rigid. It is therefore possible they will slow down during routine intubations and have increased risk of trauma. Their place in airway management practice is yet to be established.
