endotracheal tube

Diagram of an endotracheal tube (10) that has been inserted into the airway of a patient.

An endotracheal tube (also called an ET tube or ETT) is used in anaesthesia, intensive care and emergency medicine for airway management and mechanical ventilation. The tube is inserted into a patient's trachea in order to ensure that the airway is not closed off and that air is able to reach the lungs. The endotracheal tube is regarded as the most reliable available method for protecting a patient's airway.

Inventor

David S. Sheridan was the inventor of the modern "disposable" plastic endotracheal tube now used routinely in surgery. Previous to his invention, red rubber tubes were used, then sterilized, and re-used which often led to a high risk of infection. Mr Sheridan is credited with saving thousands of lives.

He also held more than 50 medical instrument patents. Mr Sheridan died April 29 2004 in Argyle, New York at the age of 95.

Procedure

Insertion of the endotracheal tube. The ET tube is held in this practioner's right hand and the laryngoscope is held in the left.

The tube is inserted into the trachea, generally via the mouth, but sometimes through the nares of the nose (e.g. in extensive mouth surgery) or even through a tracheostomy. The process of inserting an ETT is called intubation.

Intubation usually requires general anesthesia and muscle relaxation but can be achieved in the awake patient with local anaesthesia or in an emergency without any anaesthesia, although this is extremely uncomfortable and generally avoided in other circumstances.

It is usually performed by visualising the larynx by means of a hand-held laryngoscope that has a variety of curved and straight blades. The intubation can also be performed "blind" or with the use of the attendant's fingers (this is called digital intubation). A stylet can be used inside the endotracheal tube. The malleable metal stylet is a bendable piece of metal inserted into the ETT as to make the tube more stiff for easier insertion, this is then removed after the intubation and a ventilator or self-inflating bag is attached to the ETT. The goal is to position the end of the ETT 2 centimeters above the bifurcation of the lungs or the carina. If inserted too far into the trachea it often goes into the right main bronchus (the right main brochus is less angled than the left one).

Types

There are many types of Endotracheal tubes (ETT). Endotracheal tubes range in size from 3-10.5 mm in internal diameter (ID) - different sizes are chosen based on the patient's body size with the smaller sizes being used for pediatric and neonatal patients. Tubes larger than 6 mm ID tend to have an inflatable cuff. Special double-lumen endotracheal tubes have been developed for lung and other intra-thoracic surgery. These tubes allow one-lung ventilation while the other lung can be collapsed to make surgery easier. Another type of endotracheal tube has a second lumen with an opening situated right above the inflatable cuff, which can be used for suction.. This allows a suction system to be connected to the ETT to allow for suctioning of secretions which sit above the cuff. This has been proven to decrease the amount of bacteria which could grow in the secretions, which cause complications such as pneumonia and other infections.

External Links

• Kimberly-Clark* Microcuff* Endotracheal Tube
• Smiths Medical (Endotracheal tubes for Adults and Children)

Donate to Wikimedia