Overview of Endotracheal Tube
The endotracheal tube, or ETT, is a tube made out of a plastic material called polyvinyl chloride (PVC) that is placed through the voice box into the windpipe to deliver oxygen and other necessary gases to the lungs. It was first reliably used in the early 1900s. Apart from providing an oxygen supply, the tube also guards the lungs against harmful substances like stomach fluids or blood.
As medical techniques improved over time, the endotracheal tube was also improved. Changes were made to the tube to help prevent things like choking on vomit, isolating a lung, delivering medicines, and preventing fires in the airway during procedures. But, even though the endotracheal tube has been updated over the years, there’s still a need for more research to make it better. For instance, there are concerns that the endotracheal tube could be a primary cause for lung infections associated with using a ventilator.
When it comes to children, the size of the endotracheal tube used depends on the child’s age. They range in size from ones suitable for premature babies to those for teenagers approaching adult size. In the past, uncuffed tubes were used in kids because there was a fear that the cuff could damage the windpipe due to pressure necrosis, which is tissue death caused by pressure. This is because in kids, the airway just below the vocal cords, known as the cricoid cartilage, is the narrowest part. On the other hand, in adults, the vocal cords are the narrowest part of the airway. But today, except for newborns, this practice of using uncuffed tubes in kids has mostly been replaced with cuffed tubes. There are certain established guidelines to help doctors decide the right size of the ETT to use.
Anatomy and Physiology of Endotracheal Tube
The endotracheal tube, sometimes referred to as the “ETT,” is a device that is used in medical procedures that require assistance with your breathing. To understand what it looks like, think of it as a small plastic tube. The size of the endotracheal tube, when you hear something like “give me a 6.0 tube,” actually refers to the internal diameter of the tube, measured in millimeters (mm). The tube mentions both the inner diameter and the outer diameter, so a 6.0 tube means that the inner diameter is 6.0mm, and the outer diameter is 8.8mm. The skinnier the tube, the harder it is for air to pass through. It is, therefore, important for medical staff to choose the largest suitable tube for the patient, especially for patients who are breathing on their own, as they would have to work harder to breathe with a narrower tube.
The length of the tube is also measured, often in 2 cm steps from the end of the tube, the farthest point inside the patient. After the patient is intubated (the process of inserting the tube), the doctor or nurse will note how deep the tube is, at the patient’s lips or teeth. This is a reference point to make sure the tube doesn’t move too far in or out of the windpipe with the patient’s movement or transport. The endotracheal tubes are not visible in x-rays, so they often have a special material running along the tube that can be seen in x-rays, making it easier to check the position of the tube.
To help with breathing or certain medical procedures, the end of the ETT needs to be a specific distance from a part in your airway called the carina. In adults, this is usually somewhere around 4 cm, give or take 2 cm. If a bronchoscopy, a procedure to look inside your airway, is needed, a larger tube may be required. For men, the average tube size is 8.0, while for women it’s usually 7.0, although this can vary slightly from place to place.
For children, the tube sizes are determined by a formula which considers the age of the child. Once the tube is in place, it’s typically taped at a depth which is three times the size of the tube.
At the end of the ETT nearest to the patient (the distal end), there’s an inflatable section known as a ‘cuff’. This can be filled with air to create a tight seal against the wall of the windpipe, which helps to stop anything unwanted from getting into the lungs and helps to ensure efficient delivery of breaths when connected to a ventilator. When assessing whether the cuff is inflated properly, the doctor or nurse may feel the small balloon on the outside of the tube, known as the ‘pilot balloon’, which provides a rough estimate of the pressure in the cuff.
The ETT also has a beveled edge, or slant, making it easier to insert through the vocal cords and to provide a better view of the area ahead. You might also hear about something called the ‘Murphy’s Eye’ – this is a safety addition to the tube, an extra hole near its end that allows for air flow even if the main tube becomes blocked somehow.
Lastly, the ETT has a connector which attaches the tube to the ventilator or a hand-held breathing bag. Usually, this is a standard size so it can fit with other medical equipment.
Why do People Need Endotracheal Tube
An endotracheal tube is mainly used to create a safe passage for air to flow into and out of the lungs. This air path, also known as a definitive airway, involves putting a tube into the windpipe (trachea) and inflating a small balloon (cuff) on the tube below the voice box (vocal cords). This process is needed when someone is having trouble keeping their airway open, safeguarding their airway from food or fluid entering (aspiration), or when they not able to properly inhale oxygen or exhale carbon dioxide. It is also used when it seems that a person’s condition might worsen and lead to a breathing failure.
When a Person Should Avoid Endotracheal Tube
There are several reasons why a doctor may decide not to insert an ETT (a tube that helps you breathe) into the oropharynx (the middle part of your throat). One reason could be if you have serious throat injuries or blockages that make it unsafe to place the ETT. If you have a severe neck injury that requires you to keep your neck still, this could be another reason. Some patients may have a Mallampati score of III or IV, which suggests that managing their airway might be difficult.
In some cases, it’s best not to place an ETT through your nose and into your windpipe. If you have facial injuries, bleeding from your nose, a swelling blood clot in your neck, injures in your mouth and throat, severe head injury that could involve the base of your skull, or if you’re not breathing, it’s generally not safe to place the ETT in this way.
Equipment used for Endotracheal Tube
Here’s a list of tools doctors need to properly use and function an Endotracheal Tube (ETT), which is a flexible tube placed into the windpipe (trachea) through the mouth or nose to help a patient breathe:
* A Stylet, which is a thin, flexible rod that’s inserted in the ETT to give it shape and help guide it into the trachea.
* A Syringe, which is used to inflate the cuff or the pilot balloon. The cuff is a device that seals off the windpipe to prevent air leakage or aspiration, and the pilot balloon indicates whether the cuff is inflated.
* A Universal 15 mm connector, which helps attach the ETT to auxiliary equipment such as a ventilator (breathing machine).
* An End-tidal CO2 Device, used to measure the amount of carbon dioxide in the exhaled air to verify that the tube is placed correctly in the lungs.
Who is needed to perform Endotracheal Tube?
In the emergency room, it’s pretty usual to have a registered nurse (RN) on hand who can administer medications if necessary. The RN also provides additional support and can call for backup in case there are unforeseen difficulties, such as trouble with a patient’s breathing. In some hospitals, a respiratory therapist (RT) may step in to help secure the breathing tube and assist with providing breaths once a patient has been intubated (a process where a tube is placed through the mouth into the windpipe to assist with breathing).
Preparing for Endotracheal Tube
Choosing the right size breathing tube is a crucial step in the process. The selected tube is taken out of its packaging and the end that goes inside the windpipe, and its inflatable cuff, is coated with a lubricant. This is unless it’s an emergency where time is of the essence.
The medical team attaches a small, filled air pump (10 to 20 cc) to a little balloon attached to the tube. They then inflate and deflate the balloon to test it works properly. A metal guide, called a stylet, is then inserted into the tube and bent to the right shape that suits the patient’s airway.
After these steps, the tube, with the inserted stylet and attached air pump, are kept back in the packet, ready for use. This entire process is repeated with a slightly smaller tube just in case the first tube is too difficult to insert.
Moreover, there will be a device set aside to monitor the patient’s carbon dioxide levels during the procedure. This device is known as an end-tidal CO2 detector and it helps the healthcare providers assess the patient’s breathing throughout the procedure.
Possible Complications of Endotracheal Tube
There might be some technical issues with the breathing tube (also known as endotracheal tube or ETT) that can cause it to stop working properly. For instance, if the balloon attached to the tube is not functioning, it can prevent the tube from protecting your airway from foreign materials and can also make it difficult to help you breathe with a machine. If the standard 15 mm connector on the tube is missing or not working, this essentially makes the ETT unable to connect to a breathing bag or machine.
There might also be complications from inserting the tube. These could include bleeding, infection, or even perforation (a hole or tear) in the area at the back of your throat, especially if a stiff wire (known as a stylet) is used. Other potential issues might include hoarseness due to injury to the vocal cords, damage to the teeth or lips, or mistakenly placing the tube in the food pipe (esophagus) instead of the windpipe.
Breathing tubes are not meant to stay in forever—they’re usually removed after a surgery or once you’ve recovered from a severe illness. Most of the time, they should be taken out within two weeks. If you still need help breathing after this period, a different procedure called a tracheostomy might be required, where a new opening is made in your neck for a breathing tube.
What Else Should I Know About Endotracheal Tube?
Intubation, which involves placing a tube into a person’s windpipe, is a critical procedure that can save lives. It’s especially important for medical personnel working in emergency rooms, operating rooms, and intensive care units to understand how to do this. This understanding is vital for setting up breathing machines (ventilators) correctly and taking care of critically ill patients.
