Endotracheal Tube and Its Uses

For people interested in knowing about endotracheal tubes, the most important questions they have are: what is an endotracheal tube, what is the construction of an endotracheal tube, and what are the uses of an endotracheal tube? This article is intended to be informative and provides answers to those key questions.

Background Information: What Is the Human Airway

The human airway is a complex system that facilitates the intake and expulsion of air during respiration. It comprises several distinct sections, each with its unique anatomical features and functional roles.

Nasal Cavity

This is the starting point of the respiratory tract, located in the face. The nasal cavity filters, warms, and humidifies inhaled air, reducing the irritants that would otherwise reach the lower respiratory tract. Its intricate structure, including nasal hairs, mucous membranes, and sinuses, contributes to these functions.

Pharynx

Serving as a common passage for both the respiratory and digestive tracts, the pharynx is divided into three main regions: nasopharynx, oropharynx, and laryngopharynx. Each of these regions has specialized roles in swallowing, voice production, and protecting the airway from foreign bodies.

Larynx (Voice Box)

Located below the pharynx, the larynx contains the vocal folds (also known as vocal cords), which are crucial for sound production. Additionally, the larynx acts as a gatekeeper, preventing food and liquids from entering the lungs during swallowing.

Trachea (Windpipe)

The trachea is a rigid, cylindrical tube that connects the larynx to the lungs. It is composed of rings of cartilage reinforced by smooth muscle, which allows it to maintain its shape while also being flexible enough to accommodate changes in air pressure during breathing. The trachea's lining is covered with ciliated epithelium and mucus-secreting glands, which help clear debris and pathogens from the airway.

Bronchial Tree

The trachea branches into the right and left main bronchi upon entering the lungs. These bronchi further divide into smaller and smaller bronchioles, eventually terminating in tiny alveoli where gas exchange occurs. The bronchial tree's intricate branching pattern ensures that air is distributed evenly throughout the lungs. Like the trachea, the bronchi and bronchioles are lined with ciliated epithelium and mucus-producing glands, which are vital for maintaining airway health.

What Is an Endotracheal Tube

An endotracheal tube (ETT) is a flexible, plastic tube that is inserted through the mouth or nose into the trachea (windpipe) to establish and maintain an open airway during medical procedures or in critically ill patients who require mechanical ventilation. It serves as a conduit for delivering oxygen and removing carbon dioxide from the lungs, ensuring adequate gas exchange and preventing airway obstruction.

A typical endotracheal tube

Construction of an Endotracheal Tube

The construction of an endotracheal tube (ETT) typically involves several key components and features, as outlined below.

Tube Material

ETTs are commonly made of flexible, medical-grade plastics such as PVC (polyvinyl chloride) or silicone. These materials are chosen for their durability, flexibility, and biocompatibility.

Tube Diameter and Length

The diameter and length of the ETT are carefully selected based on the patient's age, size, and medical needs. Smaller ETTs are used for pediatric patients, while larger ETTs are required for adults. The length of the ETT is sufficient to extend from the patient's mouth or nose to the distal end, which sits within the trachea.

Cuff Design

Most ETTs have an inflatable cuff near the distal end. This cuff can be inflated with air or gas to create a seal between the ETT and the tracheal wall, minimizing the risk of aspiration and improving ventilation efficiency. The cuff is typically made of a soft, compliant material to minimize tracheal trauma.

Distal End Shaping

The distal end of the ETT is shaped to facilitate insertion through the vocal cords and into the trachea. It may have a rounded or beveled tip to reduce trauma to the vocal cords and trachea. Additionally, the distal end may be tapered to conform to the triangular-shaped space between the vocal cords, making insertion easier.

Ports or Perforations

Some ETTs have small ports or perforations in the walls of the tube, particularly in the tapered section near the distal end. These ports allow for the passage of air and secretions, reducing the risk of obstruction and improving ventilation.

Proximal End Components

The proximal end of the ETT remains outside the patient's body and connects to a ventilator or breathing circuit. It typically includes a connector for attaching to the ventilator tubing, a pilot balloon for monitoring cuff inflation, and a valve for adjusting cuff pressure.

Additional Features

Some ETTs may have additional features designed to improve patient comfort, safety, and ease of use. For example, some ETTs have a soft, rounded Murphy eye (a small indentation or notch in the wall of the tube) to reduce the risk of tracheal injury during insertion. Others may have an X-ray opaque line running through the length of the tube to aid in its visualization during radiographic procedures.

Uses of an Endotracheal Tube

An endotracheal tube (ETT) is used in various medical situations, primarily when there is a need to secure and maintain an open airway for a patient who is unable to breathe adequately on their own. Here are some specific scenarios where an endotracheal tube might be utilized:

General Anesthesia

During surgical procedures that require general anesthesia, an ETT is inserted to ensure that the patient's airway remains open and unobstructed, allowing for controlled ventilation with oxygen-rich gases. This prevents hypoxia (lack of oxygen) and ensures proper anesthesia depth.

Airway Obstruction

In cases where a patient's airway is obstructed due to various reasons (e.g., foreign body, trauma, swelling, or anatomical abnormalities), an ETT can be placed to bypass the obstruction and establish a patent airway.

Critical Illness

Critically ill patients, such as those with respiratory failure, pneumonia, or acute respiratory distress syndrome (ARDS), may require mechanical ventilation through an ETT to support their breathing.

Trauma or Resuscitation

In emergency situations, such as trauma or cardiac arrest, an ETT may be inserted to facilitate resuscitation efforts and ensure adequate ventilation.

Long-term Ventilation

In some cases, patients may require long-term mechanical ventilation due to chronic conditions. An ETT may be used in these situations.

Our Intentions

By discussing what is an endotracheal tube, the construction of an endotracheal tube, and the uses of an endotracheal tube, we have made you more acquainted with endotracheal tubes so that you have a better comprehension of the device. This enhanced knowledge might be of help to your future inquiries (You can take a look at this website if you want to dig into more details of the tubes: www.bevermedical .com).