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Wales
Last updated 18/06/01

Difficult intubation protocol: use of the endotracheal tube introducer (gum-elastic bougie)

Woollard, M., Pitt, K. Internal document. Welsh Ambulance Services NHS Trust.

Description

The Eschmann tracheal tube introducer (formerly known as the gum elastic bougie) is a 60cm long, 15 French Gauge flexible device with a J angle at its distal tip. During use a curve is also formed towards its distal end. The device should be clinically clean prior to use but does not need to be sterile. Both re-usable and disposable versions are available.

Rationale for use

The tracheal tube introducer is used to facilitate difficult intubation. It should not be confused with the more rigid stylet, which is inserted into the ET tube and used to alter its shape prior to intubation. Unlike the stylet a bougie is inserted independently of the ET tube and is used as a guide. Since the bougie is considerably softer, more malleable, and blunter than a stylet this technique is considered to be a relatively atraumatic procedure.

Indications

Difficult intubation with a restricted view of the glottic opening. This may occur due to:

  • Short, thick (bull) neck;
  • Pregnancy;
  • Laryngeal oedema (anaphylaxis, burns);
  • Normal anatomical variation;
  • Supra-glottic neoplasms (tumours above the glottic opening);
  • Inability to position patient appropriately (e.g. entrapment, confined space).

Contra-indications

  • Paediatric patients under the age of 14.

Method

Where a difficult intubation is anticipated, or a poor view of the glottic opening has been confirmed on laryngoscopy:

1) Hyperventilate the patient with 100% oxygen for at least one minute prior to each intubation attempt. Note, however, that this step should be omitted when ventilation (demonstrated by rise and fall of the chest) proves impossible.

2) Have suction running with the tip placed under the patient’s shoulder. Use wide bore tubing, not an endotracheal catheter.

3) Prepare the ET tube for a crash intubation: cut to length, and with a syringe, catheter mount, and tube-tie pre-attached.

4) Prepare a second ET tube one size smaller than normal, as above. This may be required in the event of laryngeal oedema.

5) Consider using a number four laryngoscope blade.

6) Use at least one pillow or equivalent to place the patient’s head in the ‘sniffing the morning air’ position.

7) Insertion of the laryngoscope may prove very difficult in pregnant or obese patients. This may be overcome by removing the blade from the handle, inserting it, and then re-attaching the handle with the blade in the mouth.

8) Each intubation attempt must take no more than thirty seconds from the point at which the last inflation is given. After this time has expired, if not successful, abandon the procedure and hyperventilate again for one minute with 100% oxygen prior to further attempts. If ventilation is not possible consider seeking more expert help.

9) Prepare the endotracheal tube introducer for use:

a) Curve the bougie and ensure the distal tip is formed into a J (coudé) shape;

b) Perform a laryngoscopy, obtaining the best possible view of the glottic opening. You should always be able to view the tip of the epiglottis and, ideally, the arytenoid cartilages;

c) Advance the bougie, continually observing its distal tip, with the concavity facing anteriorly;

d) Visualise the tip of the bougie passing posteriorly to the epiglottis and (where possible) anterior to the arytenoid cartilages;

e) Once the tip of the bougie has passed the epiglottis, continue to advance it in the mid-line so that it passes behind the epiglottis but in an anterior direction (figure 1);

f) As the tip of the bougie enters the glottic opening you will either feel ‘clicks’ as it passes over the tracheal rings or the tip will arrest against the wall of the airways (‘hold-up’). This suggests correct insertion, although cannot be relied upon to indicate correct positioning with 100% accuracy. HOWEVER, FAILURE TO ELICIT CLICKS OR HOLD-UP IS INDICATIVE OF OESOPHAGEAL PLACEMENT. If hold-up is felt, the bougie should then be withdrawn approximately 5cm to avoid the ET tube impacting against the carina.

g) Hold the bougie firmly in place AND MAINTAIN LARYNGOSCOPY.

i) Instruct your colleague to pass the endotracheal tube over the proximal end of the bougie.

ii) As the proximal tip of the bougie is re-exposed, the assistant should carefully grasp it, assuming control of the bougie and passing control of the ET tube to the intubator.

iii) The ET tube should then be carefully advanced (‘rail-roaded’) along the bougie and hence through the glottic opening, taking care to avoid movement of the bougie.

iv) SUCCESSFUL INTUBATION MAY BE CONSIDERABLY ENHANCED BY ROTATING THE ET TUBE 90º ANTI-CLOCKWISE, SO THAT THE BEVEL FACES POSTERIORLY. In so doing the bougie may also rotate along the same plane but should not be allowed to move up or down the trachea.

h) Once the ET tube is fully in place hold it securely as your colleague withdraws the bougie.

i) Withdraw the laryngoscope.

10) Inflate the cuff without delay. Then verify correct positioning of the ET tube using auscultation of the lung fields and epigastrium and observing for chest wall movement.

11) Tie the tube securely into place. The tip of the ET tube can move up to 6.0 cm once placed and this is certainly sufficient to dislodge it from the trachea.

12) Position an appropriately sized oro-pharyngeal airway alongside the ET tube to serve as a bite block should the patient’s level of consciousness change.

Special circumstances

Single-handed technique for use of bougie

Proceed as above but:

a) Curve the bougie and ensure the distal tip is formed into a J (coudé) shape.

b) Pass the ET tube over the proximal end of the bougie.

c) Hold the ET tube and the bougie together at the distal end of the ET tube.

d) Perform a laryngoscopy and proceed to advance the bougie as described above, maintaining a secure hold at the distal end of the ET tube.

e) Once the bougie is in position advance the ET tube over the bougie until it is in place. Great care must be taken not to displace the bougie.

f) Holding the ET tube securely in place, remove the Laryngoscope and then the bougie.

g) Continue as above.

Regurgitation

Where there is a high risk of regurgitation, or where liquid from the stomach continuously obscures the glottis despite suction, an assistant should apply Sellick’s manoeuvre. This differs from crico-thyroid pressure in that a hand must be placed under the neck as well as on the cricoid cartilage. This action helps to compress the oesophagus to minimise the risk of regurgitation, and has the additional benefit of bringing an anterior glottis into view. SELLICK’S MANOEUVRE MUST NOT BE DISCONTINUED UNTIL THE ET TUBE HAS BEEN CORRECTLY POSITIONED AND THE CUFF INFLATED.

This technique requires either a third assistant or the intubator must use the single-handed technique as described above.

Laryngeal oedema

Rarely, laryngeal oedema due to burns or anaphylaxis will be so severe as to result in swelling which obliterates the glottic opening. When nothing but inflamed swollen tissue is visible on laryngoscopy, instruct an assistant to push down slowly on the chest AND MAINTAIN THE COMPRESSION. This may result in a bubble of air becoming visible over the (hidden) glottis. Pass a bougie through the bubble and it should enter the larynx. Passage of an ET tube over the bougie should now be possible. Initial insertion of a bougie will facilitate trying various sizes of ET tube in the event of difficulty as the bougie can remain in position until success is achieved.

Figure 1: Technique for using tracheal tube introducer (Nocera, A. A flexible solution for emergency intubation difficulties. Ann Emerg Med, 1996;27(5):665-667.)

Bibliography

Pitt, K., Woollard, M. Should paramedics bougie on down? Pre-hospital Immediate Care. 2000;4:68-70.