Overview of Double-Lumen Endobronchial Tubes
A double-lumen tube, also known as a DLT, is a special type of breathing tube used to manage airflow to each lung separately. This tube is often the chosen tool to ensure each lung can breathe independently when needed.
When only one lung needs to be operated on, or if there’s a disease in just one of the lungs, a DLT can be used to keep the other lung working freely. This method is called one-lung ventilation or lung isolation. In simple terms, this process separates the function and airflow of both lungs so that only one lung is being ventilated, or breathed for. The other lung that isn’t receiving air then either naturally lets air out or is moved aside by the surgeon. This is to make enough room for surgeries that are not related to the heart but are within the chest area, like surgeries on the thorax, esophagus, aorta, or spine.
Double-lumen tubes can also be used during heart surgeries that use minimal interference techniques, as well as controlling disease spread from one lung to the other. Apart from these, DLTs also let doctors clean the bronchial tubes (the main passageway for air in the lungs) without disrupting the patient’s breathing.
Anatomy and Physiology of Double-Lumen Endobronchial Tubes
The proper positioning of a Double-Lumen Tube (DLT), which is a special type of tube used in lung surgeries, requires understanding the structure of the trachea and bronchi. The trachea, also known as the windpipe, starts at a level of the cricoid cartilage, a ring-shaped structure in your neck, and continues up to a point called the carina, where it splits into two main bronchi (tubes), one for the right lung and one for the left lung. The trachea is about 12 cm long in adults and is made up of 18 to 22 C-shaped rings of cartilage on the front and sides, while the back part consists of a flexible muscle and a membrane wall.
The right bronchus is more vertical, shorter (about 1.9 cm in men and 1.5 cm in women), and wider than the left bronchus. The left bronchus is more horizontal and is longer, about 4.9 cm in men and 4.4 cm in women.
The left lung, which is slightly smaller than the right, is divided into two sections, the upper and lower lobes, while the right lung has three sections – the upper, middle, and lower lobes. Each of these lobes is further divided into smaller sections known as bronchopulmonary segments. These segments can be individually removed in a procedure known as a segmentectomy without affecting the others. Each lung typically has 10 of these segments.
Normally, the airflow and blood flow (ventilation and perfusion) in the lungs are closely matched so all areas of the lung receive the right amounts of oxygen and blood. However, one-lung breathing during surgery disrupts this balance by stopping the airflow to one lung, creating a shunt, which is a condition where blood flow continues but there is no airflow. The left lung is smaller, and so it causes less disruption when it is the one collapsed during surgery.
Why do People Need Double-Lumen Endobronchial Tubes
A double-lumen tube (DLT) is used for surgeries or procedures where it’s important to keep the lungs separate. This could be for a few reasons.
Absolute Uses
– To keep one lung safe and clean:
– For example, if there’s a lung abscess (a pocket filled with pus), a DLT can stop the pus from spreading to the healthy lung.
– Also, if one lung is bleeding, a DLT can avoid blood spilling over into the other lung.
– To regulate breathing:
– If there’s a broncho-pleural fistula present (an abnormal tunnel in the chest that makes it hard to breathe), a DLT can be used to manage the airflow to the lungs.
– A DLT can help out if there’s a bronchial disruption from trauma, which means the airway is damaged and needs to be corrected.
– If there’s a major cyst (a sac filled with fluid or air) or bulla (a large air-filled space within the lung tissue) in one lung, the DLT can be used to protect that lung or the healthy lung.
– During video-assisted thoracoscopic surgery (VATS), which is a type of lung surgery done through tiny cuts in the chest, a DLT can give doctors a better view.
– For single lung lavage, which is a treatment for lung conditions like pulmonary alveolar proteinosis (a rare disorder where a type of protein builds up in the lungs) or cystic fibrosis (a genetic disease that causes sticky mucus to build up in the lungs and other organs), a DLT can be helpful.
Relative Uses
– To decrease movement in one lung and improve the surgical view during certain surgeries:
– These surgeries could include thoracic aortic surgery (surgery on the large artery in the chest), mediastinal surgery (surgery in the middle part of the chest), esophageal surgery (surgery on the tube from the mouth to the stomach), or open pulmonary resection (surgery to remove part or all of the lung).
When a Person Should Avoid Double-Lumen Endobronchial Tubes
Intubation, or inserting a tube into a person’s airway, can be tricky. This is especially true when using a double lumen tube (DLT), which is larger and more complex than a single lumen tube (SLT). The DLT can sometimes be harder to use, especially in people with:
- A hard-to-manage airway
- An existing hole or tube in the windpipe
- A narrow windpipe
- A limited ability to open their mouth
If the airway is distorted due to twists or growths, using a DLT may not be the best option. This is also true in cases where an SLT may be needed during surgery, or if a tube needs to be re-inserted after an operation. This is because the airway can become swollen, making the use of an SLT risky.
Thankfully, there are special DLTs made for people with a tracheostomy, which is a surgically made hole in the windpipe. These tubes look like regular DLTs but are shorter and bent in between the inside and outside portion of the windpipe. However, these are not used very often.
Equipment used for Double-Lumen Endobronchial Tubes
Double-lumen tubes (DLTs) are a special type of medical equipment used to allow each lung to breathe separately. In simpler terms, they are two breathing tubes joined together, each one designed to go into a specific lung. These tubes can either be for the left or right lung, based on their design and length. The longer breathing tube is designed to reach the main part of the lung while the shorter one ends in the windpipe.
There are several different kinds of DLTs, but they are all made from the same material called Polyvinyl chloride. They usually have color-coded cuffs and small balloon-like parts. The part of the tube that goes into the lung and its balloon are usually blue, while the part entering the windpipe and its balloon are clear.
These DLTs are usually supplied in a package that contains the tube, a guiding wire called a stylet, a connector, and suction tubes. Sometimes, they may also come with a device to provide continuous air pressure to the lung which isn’t being ventilated. They are made by different companies.
In terms of their shape from a cross-sectional perspective, each tube is shaped like a ‘D’. A variety of sizes are available depending on the patient’s age and size of the airway. Smaller tubes can sometimes move further into the lung than needed, causing difficulty in ventilation and suction. On the other hand, larger tubes can also potentially damage the airway.
Usually, left-sided DLTs are safer to place due to the longer length of the left main lung branch. Placing a DLT on the right side can be more challenging because of the shorter length of the right main lung branch. Therefore, a special modification is made to the right-sided DLT to allow ventilation of the right upper lobe.
Before placing a DLT on the right side, it can be helpful to examine a chest X-ray, CT scan, or MRI scan to better understand the lung anatomy. Despite the higher safety associated with a left-sided DLT, a right-sided DLT may be preferred when there’s a need to avoid manipulating the left lung branch, or if the patient has had certain lung procedures or anomalies.
Who is needed to perform Double-Lumen Endobronchial Tubes?
The team that places a double-lumen endotracheal tube (DLT) — a special tube used to control breathing during certain surgeries — includes an anesthesiologist, a certified registered nurse anesthetist (CRNA), or a certified anesthesiologist assistant (CAA). These are special health professionals trained in managing your breathing and keeping you comfortable during surgery. Sometimes, a doctor-in-training (resident) or a student nurse or anesthesiologist assistant might also help place the DLT, but they will always do this under the guidance of an experienced anesthesiologist. This team is responsible for your safety and comfort during the procedure.
Preparing for Double-Lumen Endobronchial Tubes
When using a double-lumen tube (DLT), which is a device used to manage airflow into your lungs during surgery or when you’re critically ill, certain steps need to be followed to prepare it properly. First, the parts of the tube that go into your windpipe and bronchial tubes should be filled with air to make sure there are no leaks and that they fill evenly. It might also be helpful to put a water-based lubricant on the insert that goes into your bronchial tube to make it smoother and easier to insert, making sure that it’s not sticking out from the end of the tube. It’s also important to have all parts that link the DLT to the breathing machine fully assembled and ready to use before starting the process.
A specialized type of scope, known as a fiberoptic bronchoscope, should be available to help the doctors confirm that the DLT is correctly placed inside your airways. A good understanding of the anatomy of the airways is key to making sure that the DLT is positioned correctly.
The correct size of a DLT may vary for men and women. Usually, 39-French and 41-French tubes are used for adult men while a slightly smaller 35-French or 37-French tubes are used for adult women. The right DLT size should be able to pass easily through your voice box and windpipe, as well as into the desired bronchus (the tubes that carry air to your lungs) without any difficulty.
How is Double-Lumen Endobronchial Tubes performed
There are two methods used for inserting double-lumen endobronchial tubes (DLT) – either without seeing the tube going down the throat or with the help of a very small fiber-optic camera.
With the first method, the doctor inserts the DLT without seeing its exact path. This process involves using a tool to check the vocal cords inside your throat to make sure they are placed accurately without any complications. Once the doctor has seen the vocal cords, they can start inserting the DLT into the throat, then slightly turn the tube to fit the shape of the throat. After the tube is placed properly, it’s anchored in place by filling a part of the tube (the tracheal cuff) with air to inflate it like a balloon. Then, they’ll check to make sure air is flowing properly and both lungs are working well. It’s important for your doctor to isolate or separate the working of one lung to ensure that the tube is placed correctly.
The DLT can also be placed with the help of a fiber-optic camera. The camera guides the DLT, which makes sure the tube is placed in exactly the right place.
Once inserted, the tube is then attached to a breathing machine to help you breathe. Carbon dioxide will come out from a part of the tube (ETCO2) to show that the tube is placed correctly inside the trachea or the windpipe. They’ll then make sure that the bronchial cuff (another part of the tube that can also be filled with air like a balloon) is working correctly, ensuring that around 3mL of air should be enough to create a good windpipe seal. To avoid damage to the throat from the inflated bronchial cuff, its pressure is monitored by the doctor. They make sure the tube is placed correctly by listening to your breath sounds or by using the fiberoptic camera. By stopping the air from flowing into one lung, they can check if breath sounds are absent on that side. The absence of breath sounds shows that the DLT is in the correct main bronchus or the main airway leading to the lungs.
To confirm the placement of the tube, your doctor uses the fiber-optic camera and looks to see if the bronchial cuff is just visible without it pushing against the carina (the area where the windpipe splits into the two lungs). They should also be able to see certain features that tell them which lung the camera view is showing.
Using a fiberoptic bronchoscope or the small camera, they will look through the lung tube to make sure everything is ok and just where it should be. They make sure the DLT is placed correctly depending on if it’s a left-sided or right-sided DLT.
Fiberoptic bronchoscopy or looking directly at the lungs with a small camera is the best way to confirm that the DLT is placed correctly, as just listening to your breath sounds may not be totally reliable.
If there’s a problem with getting the DLT in the right place, your doctor might use the fiber-optic camera to help guide the tube, use a stiff wire to help guide the DLT, check the placement of the tube if the patient’s position changes or if they switch between breathing with both lungs or a single lung, and rotate the tube, turn the patient’s head to the other side and then gently move the tube until it’s in the right place.
When the doctors need to work with only one lung, say during a surgery, they inflate the bronchial cuff, stop the air flow to the lung that needs to be isolated and then let it slowly deflate. The quickest way to deflate the lung is by starting at the end of a breath.
Inside the body, the bronchial cuff should be kept deflated (unless the doctor needs to prevent blood or an infection from spreading) and should only be filled with air to isolate the lung, to stop the bronchus (the passage of airway in the respiratory tract) from getting damaged.
Possible Complications of Double-Lumen Endobronchial Tubes
The deadliest risk from using a double lumen tube (DLT) – a special tube used for certain types of lung surgeries – is the airway rupturing from rough placement. This tube can also cause harm to the tongue, lips, and teeth from the use of the laryngoscope, a tool used to view the throat. Often, these types of airway injuries occurred when the DLT used was too small, especially in women with specific sized DLTs. Small DLTs could move too far into the larger airway or require more air, which could damage the lining of the airways.
Other complications can be caused by the tube being in the wrong position, being moved, or being blocked by body fluids or blood. There are also cases where the DLT has got caught in the stitching during surgery.
A misplaced DLT can have severe consequences. It can negatively impact breathing, leading to low oxygen levels, trapped gases, lung contamination, and can even interrupt the surgery being carried out.
There are several factors that could lead to airway damage, such as:
- Forcefully placing a DLT
- Using a DLT that’s too small
- Inflating the balloon in the lung airway too much
- Moving the DLT when the balloon is inflated
- Existing conditions in the airways, like tumors.
What Else Should I Know About Double-Lumen Endobronchial Tubes?
Double lumen tubes are important tools used in medical procedures, particularly ones that involve the lungs. So, what are these tubes exactly? Think of them as special types of breathing tubes that can control the airflow to one or both of your lungs separately. This is especially helpful in certain situations, let’s take a look at a few.
Firstly, they’re often used in lung surgeries. This is because they can make sure one lung gets air while the other one is being operated on. Secondly, they can help to separate a healthy lung from a diseased one. This separation could prevent several problems, like if one lung starts bleeding extensively, they make sure the blood doesn’t reach the other lung. They also help keep one lung clean when the other needs to be washed out as in the case of a condition called pulmonary alveolar proteinosis. Or if one lung has infectious secretions, the tubes ensure they don’t spill over into the healthy lung. Lastly, in the case of lung transplant patients, these tubes can allow tailored airflow to each lung based on its needs, enhancing the protective effect and support for the new lung.
So in essence, these tubes give doctors more control during lung-related medical procedures, ensuring the best possible care for their patients.