Cannula

Definition

Definition

Small tube made of plastic, metal, sometimes rubber, allowing the passage of air or liquid through an orifice, whether natural or obtained after surgery.

Generalities

A cannula is either rigid or flexible, straight or curved, but of variable length and caliber depending on the use. There are several types of cannula:

  • The tracheostomy tube, also called the Krishaber tube, which, after insertion into the trachea, allows breathing when there is an obstruction in the larynx. The tracheostomy tube is connected to an artificial ventilation device allowing air to be insufflated into the patient's lungs. A bronchial tube can also be passed inside the tracheostomy tube in order to suction secretions that may be blocking the lungs, and more specifically the bronchi.
  • The tracheostomy tube is either permanent and in this case made of silver or used episodically and in this case is made of rubber. The silver tracheostomy tube is likely to remain in place for several years in patients suffering from chronic respiratory failure, among other things. The Mayo cannula or Guedel cannula is a flattened cannula that allows air to pass through the trachea after its introduction into the patient's mouth in individuals with a coma. It helps prevent suffocation by the tongue falling backward.

  • The rectal or vaginal cannula fits onto a rubber tube and is used to administer enemas or injections.