Endotracheal Intubation Using a Flexible Intubation Endoscope as a Standardized Model for Safe Airway Management in Swine

This protocol provides a standardized approach for endoscopically-guided endotracheal intubation in swine. This allows securing the airway easier and safer than conventional endotracheal intubation. Compared to the standard, conventional endotracheal intubation, this technique is easier to learn with a steeper learning curve and allows direct supervision by an experienced examiner.

We highly recommend that inducing anesthesia to be performed only by specially-trained personnel or under their direct surveillance. By using a video monitor, direct correction by a supervisor is possible. To begin endotracheal intubation, have an assistant standing on the left side of the head of an anesthetized pig.

Have the assistant's left hand open the mouth, pinch the tongue outward and left with a compress. Instruct the assistant to press down on the right upper lip with the right index finger for better mouth opening. To perform direct laryngoscopy, insert the laryngoscope into the right side of the mouth and push it forward while pushing the tongue to the left.

Advance the tip of the laryngoscope until it rests in the epiglottic vallecula. Carefully push the epiglottis aside with a tube-guiding wire with a gentle scooping motion from the right piriform recess to the left along the soft palate. Pass the handle of the laryngoscope to the assistant to fix it in the current position.

Next, take the flexible intubation endoscope onto which an endotracheal tube has already been mounted and is connected to a video monitor. Insert the endoscope orally and advance it over the base of the tongue until the glottis is visualized. Advance the endoscope between the vocal ligaments into the trachea.

Confirm the anatomy of the trachea by visually identifying the cartilaginous rings and the pars membranacea. Continue advancing the endoscope until it rests above the carina. Do not touch the sensitive mucosa to avoid swelling and bleeding.

While maintaining the endoscope position, advance the endotracheal tube until it becomes visible in the camera image. After positioning, remove the flexible intubation endoscope while maintaining the endotracheal tube. Next, use a 10-milliliter syringe to inflate the cuff with 10 milliliters of air.

Control the cuff pressure with a cuff manager. Confirm the correct placement of the endotracheal tube and adequate ventilation by periodic and regular exhalation of carbon dioxide via capnography and double-sided ventilation via auscultation. After connecting the tube with the ventilator, start mechanical ventilation.

The number of intubation attempts and time required for carbon dioxide detection in flexible intubation endoscope or FIE, and conventionally-intubated or CI groups, is shown here. In the FIE group, every intubation attempt was successful whereas in the CI group, it took an average of 1.4 attempts. In the FIE group, a longer duration was required for carbon dioxide to be detected in the ventilator compared to the CI group.

In the unlikely event that the glottis is not well visualized with the endoscope, it is important that mask ventilation is resumed as soon as there's a relevant drop in oxygen situation.