Endotracheal Intubation in the Rabbit

Introduction

Intubation of the rabbit is challenging because it difficult to directly visualize the tracheal opening in all but the largest individuals. Rabbits have a long, narrow oral cavity and the larynx, which sits on a ventral slope, is prone to spasm. The rabbit mouth does not open very wide at all, and it also has a relatively large tongue paired with large incisors and cheek teeth.

 

Video


Video produced by Dr. M. Scott Echols and narrated by Dr. Natalie Antinoff.

 

Equipment needed

  • Endoscope tube 2.0-4.0 mm
  • Stethoscope
  • Roll gauze
  • Water-soluble sterile lubricant
  • Topical anesthetic in gel, solution, or spray form
  • Drugs for pre-medication and/or induction are extremely helpful

To visualize the airway:

  • Long narrow layrngoscope blade (i.e. size 0 or size 1 Miller or Wisconsin blade)
  • Stylet such as a modified polypropylene catheter or a 2.7-mm rigid laparoscope

Potential complication

Difficult intubation can potentially cause tracheal inflammation that can lead to asphyxiation and death. To minimize the risk of iatrogenic damage, limit intubation attempts to two or three tries then maintain the rabbit on a tightly fitting facemask.  Since rabbits are obligate nasal breathers the mask may be fitted over only the nose when necessary.

Blind endotracheal intubation in the rabbit

Blind intubation requires patience and careful positioning.

  • Place the rabbit in ventral recumbency.
  • Hyperextend the head and neck to allow the larynx and trachea to line up with the oral cavity (Fig 1).

 

Hyperextend head

Figure 1. Hyperextend the head. Click image to enlarge. Click image to enlarge.

  • Slide an uncuffed endotracheal tube measuring 2.0 to 2.5 mm though the diastema, or the gap between the incisors and cheek teeth.
  • Pass the tube over the tongue until resistance is met.
  • If the tube is aligned correctly, condensation will collect in the tube as the rabbit breathes.
  • On inspiration advance the tube with a gentle twist (Fig 2). Never force the tube.

 

Pass the tube over the tongue

Figure 2. Pass the tube over the tongue until resistance is met, then on inspiration advance the tube with a gentle twist. Click image to enlarge.

  • Confirm tube placement by ausculting lung sounds bilaterally during positive pressure ventilation.
  • Secure the tube with gauze.

Endotracheal intubation in the rabbit using visualization

Although the blind technique is popular in rabbits, it is also important to be able to intubate rabbits using direct visualization, since in an emergency, the patient may not be breathing!

  • An assistant places trips of gauze behind the upper and lower incisors to open the mouth and maintain the head and neck in an extended positon (Fig 3).

 

Place loops of gauze around incisors

Figure 3. Place loops of gauze around the incisors to open the mouth. Click image to enlarge.

  • Place the laryngoscope blade over the tongue towards the back of the mouth then use the blade to pull the tongue forward exposing the tracheal opening.
  • Once the glottis is visualized, apply topical anesthetic then wait 15 to 30 seconds
  • Gently pass an endotracheal tube, loaded with a stylet into the oral cavity.
  • Gently introduce the stylet into the tracheal opening (Fig 4).

 

Gently introduce the stylet

Figure 4. Gently introduce the stylet into the tracheal opening. Click image to enlarge.

  • Then feed the endotracheal tube over the guide and into the trachea, while holding the stylet in place.
  • Remove the stylet.
  • The tube should pass easily once it is within the tracheal opening. If resistance is met, pull back slightly and advance the tube with a gentle twist. Never force the tube.
  • Confirm tube placement by ausculting lung sounds bilaterally during positive pressure ventilation.
  • Secure the tube with gauze.

References