King LT Airway - The Supraglottic Airway Device

What Is King LT Airway?

The King LT (Laryngeal Tube) airway is a supraglottic airway device used to manage airway obstruction during resuscitation and anesthesia. The King LT airway is a popular alternative to the endotracheal tube (ETT) due to its ease of use, lower risk of complications, and versatility in various clinical scenarios.

The King LT airway is a single-use, latex-free device made of medical-grade silicone. It is supplied as a clean, non-sterile device and should be sterilized. The device has a curved tube with ventilation apertures between two inflatable cuffs. These cuffs are inflated using a pilot balloon.

The distal cuff seals the esophagus, and the proximal cuff seals the oropharynx. The proximal end of the tube is attached to the connector connected to the standard breathing circuit.

What Are the Indications for King LT Airway?

King LT Airway is indicated in the following situations:

• Difficult and emergent airway cases.

• For ambulatory and office-based anesthesia.

• For airway management in individuals over 4 feet in height in those having respiratory arrest or cardiac arrest.

• In cases where endotracheal intubation fails even after two attempts.

What Are the Contraindications for King LT Airway?

King LT Airway is contraindicated in the following cases:

• In individuals with hiatus hernia except in cases where measures are taken for gastric emptying.

• Patients who have not fasted.

• In patients whose fasting history is not confirmed.

• Patients with retained gastric contents like morbid obesity, pregnancy, abdominal injury, massive injury, and conditions with delayed gastric emptying.

• Patients who are unable to understand the instructions.

• Patients with inadequate medical history.

• Patients with extensive airway burns.

• Patients with a height of less than 4 feet.

• In cases of laryngectomy with a stoma.

What Are the Precautions to Be Taken While Using King LT Airway?

The following precautions should be taken while using King LT Airway:

• High airway pressure should be avoided as it can divert gas into the stomach or the atmosphere.

• Only the posterior surface of the King LT should be lubricated. This is to avoid ventilation aperture blockage.

• King LT Airway does not protect from regurgitation and aspiration.

• Failure to properly clean and rinse the device results in the retention of hazardous residues.

• Caution should be taken while using King LT on patients with decreased pulmonary compliance, like pulmonary fibrosis.

What Are the Types of Equipment Needed for King LT?

The equipment needed for King LT includes the following:

• Suction equipment (suctioning device, tubing, regulator, etc).

• Personal protection equipment.

• Mouth-to-mouth resuscitation.

• Appropriate size King airway based on the patient’s height.

• Tongue depressor.

• Water soluble lubricant.

• Suitable syringe for cuff inflation.

• End-tidal carbon dioxide device.

What Are the Steps Involved in the Insertion and Removal of King LT?

The steps involved in the insertion of King LT are:

• The correct king airway is initially selected based on the patient’s height.

• The cuff inflation system is tested, and all the air in the cuff is removed before insertion.

• A water-based lubricant is applied to the distal and posterior aspects of the tube.

• Preoxygenation is done.

• After preoxygenation, make sure that an adequate level of anesthesia is achieved.

• The patient’s head is positioned in a neutral or sniffing position before insertion.

• Using the dominator's hand, the clinician holds the connector end of King LT.

• Using the other hand, the clinician opens the patient's mouth and does a chin lift.

• King airway is rotated laterally, and the tube tip is introduced into the mouth and advanced behind the tongue base.

• As the tube tip passes under the tongue, the tube is rotated back to the midline.

• The tube is still advanced, and the base of the connector aligns with the teeth.

• The cuffs are fully inflated using the maximum volume of the syringe.

• A bag valve mask device is attached to the connector, and bagging is done to assess ventilation.

• The depth reading determines the approximate distance to the vocal cords.

• The position is confirmed by chest movement, auscultation, and waveform capnography.

• The King airway is secured using an accepted method and a bite block.

The steps involved in the removal of King LT are:

• Once King LT is appropriately positioned, it will be well tolerated until protective reflexes occur.

• Suction should be used while the King LT airway is removed.

• Before King LT airway removal, both cuffs should be completely deflated.

• When protective reflexes appear, remove King LT.

• While removing the airway, carefully avoid the teeth.

What Are the Steps Involved in the Sterilization of King LT?

The following are involved in the sterilization procedure of King LT:

• The cuffs of King LT should be completely evacuated before autoclaving—failure to evacuate completely results in the rupture of the cuffs.

• The valve actuator is tightly attached to the inflation valve.

• The tube is placed in an appropriate autoclavable bag.

• The autoclave manufacturer’s recommendation should be followed.

• Steam autoclaving is done in a pre-vacuum cycle at 132 to 135 degree Celsius.

• Sterilization is done in up to fifty cycles.

• Avoid using formaldehyde, ethylene oxide, glutaraldehyde, etc., for sterilization as it gets absorbed by silicone rubber, resulting in patient exposure.

• Before using, King LT should be cooled to room temperature.

King LT is a reusable device and should be sterilized and cleaned before each use.

The following should be considered during the cleaning of King LT:

• Use mild alkaline or neutral pH cleansing agents and warm water for cleaning.

• Avoid using stiff brushes to clean as it damages the silicone cuff.

• Appropriate-sized test tube brushes should be used to clean the foreign matter.

• Use running warm water to remove the residue of the cleaning agent.

• Make sure that all visible foreign matter is eliminated before starting sterilization.

Before using King LT, it should be checked for the following:

• Ensure that the device has been properly sterilized.

• Make sure that there is no visible damage to the components.

• Ensure that there is no blockage or loose particles on the interior of the tube.

• Remove the valve actuator from the inflation valve.

Conclusion

The King LT (Laryngeal Tube) airway is a supraglottic airway device used to manage airway obstruction as a popular alternative to endotracheal intubation. Ease of use, lower risk of complications, and versatility have increased their use in different clinical conditions.