Overview of Nasotracheal Intubation
Nasotracheal intubation, or NTI, is a procedure usually performed after a person has been put under general anesthesia in an operating room. In this procedure, a tube is inserted through the nose and into the windpipe to help the patient breathe. This technique is often used during dental, mouth and jaw surgeries because it allows doctors to administer the gases to keep the patient asleep without blocking access to the mouth area.
This skill is very important for those who administer anesthesia, but it should only be carried out by a professional who knows how to do a similar procedure called an orotracheal intubation. This is because there could be potential complications if it’s done wrong. An orotracheal intubation involves inserting a tube through the mouth instead of the nose. In summary, unless you’re skilled in inserting this tube through the mouth, it’s generally recommended that you don’t attempt to insert it through the nose.
Anatomy and Physiology of Nasotracheal Intubation
To perform nasal intubation successfully, it’s important to know about the structure and arrangement of the nasal area and throat. This includes the nasal cavity, which makes up the inside of the nose, as well as the nasopharynx, oropharynx, hypopharynx, and larynx, parts of your throat where air and food pass. Here’s a breakdown of these structures:
Nasal Cavity
This cavity is the space within your nose. It begins at your nostrils (nares) and ends at the back of the nasal wall, where it connects to your throat through an opening called the posterior nasal aperture (choanae). This cavity sits above the mouth and hard structure in the roof of the mouth (hard palate) and below the base of the skull.
Hard Palate
This is the bony structure that forms the floor of the nasal cavity, behind the nostrils. The roof of the nasal cavity is made up of the ethmoid bone with a structure called the cribriform plate at its center. The left and right walls of the cavity are made up of the orbital walls (the walls of the eye sockets) at the top and the structures of the sinus cavity at the bottom.
Lateral Nasal Walls
The side walls of the nasal cavity contain the turbinates, which are soft tissue and bone ridges sticking out into the cavity. They help to control the temperature and moisture in the nasal cavity.
Inferior Turbinate
The inferior turbinate is the largest and can sometimes block airflow if it becomes swollen or inflamed. Middle and superior turbinates also exist, with the superior one usually being the smallest and attaching to the skull area and the nasal wall. Some people have a fourth set of turbinates above the superior ones, but these usually do not have a lot of practical importance.
Nasal Septum
This is the structure that separates the nasal cavity, dividing it into left and right sides. At the back of the nose, the two sides join to form a single cavity known as the nasopharynx.
Respiratory Mucosa
The nasal cavity has a special type of lining that helps to moisten the air you breathe. This lining, known as respiratory mucosa, can sometimes lead to nosebleeds if it’s disturbed.
In some people, the structure of the nasal cavity is abnormal; for example, the nasal septum might be deviated due to injury or birth defects. These variations can sometimes cause issues, such as partial blockages, which could affect the process of nasal intubation.
Why do People Need Nasotracheal Intubation
Nasotracheal intubation (NTI) is a medical procedure often used when a patient’s airway is at risk of being blocked. This might be due to various reasons, but in short, NTI involves placing a tube through the nose into the windpipe (trachea) to help the patient breathe. In certain situations, performing NTI while the patient is awake can be beneficial. This is because it can prevent the loss of natural reflexes that protect the airway during the process of putting the tube in (intubation).
NTI is better tolerated by awake patients because it causes less gagging compared to the oral intubation (a similar procedure where the tube is placed through the mouth). This is why it’s the preferred method in cases where there’s a serious risk of airway compromise – a situation where the normal breathing process is at risk of being blocked or interrupted.
There are other situations in which NTI is useful too. This includes during oral and throat (oropharyngeal) surgeries, complex procedures involving reconstruction of the lower jawbone (mandible), and during examination of voice box (rigid laryngoscopy).
NTI can also be used during dental surgery and during surgeries involving the teeth, jaw, or face (maxillofacial or orthognathic surgery).
When a Person Should Avoid Nasotracheal Intubation
There are certain situations where it’s absolutely not safe to undergo certain medical procedures. These situations are referred to as absolute contraindications. In the case of some procedures, these include:
- If there’s a suspicion of a serious throat infection commonly known as epiglottitis
- If the middle part of the face isn’t stable
- Past incidents of both old and recent fractures at the base of the skull
- Any bleeding disorder that might increase the patient’s risk of severe nosebleeds (epistaxis)
- Choanal atresia, a condition where the back of a newborn’s nasal passage is blocked
- Fractures at the front base of the skull, which may cause the tube to accidentally enter the brain area (intracranially)
There are also what we call relative contraindications. These are conditions where the procedure could still be done but might come with higher risks. These include:
- If there’s a blockage in the nasal airway (like large nasal polyps or foreign bodies)
- If the patient had recent nasal surgery
- If the patient has a history of frequent nosebleeds
In both cases, the doctor needs to weigh all factors before deciding on the best course of action for the patient’s health.
Equipment used for Nasotracheal Intubation
To carry out a medical procedure known as nasotracheal intubation, which is a way to place a special tube into a person’s windpipe through the nose, certain tools and equipment are needed. Let’s break down these items so that you can understand what each one does:
* An Endotracheal tube (also known as a nasal RAE or standard endotracheal tube) – This is a flexible tube that’s inserted through the nose and into the windpipe to help a person breathe.
* Lidocaine jelly or a water-soluble lubricant – These substances are used to make insertion of the tube easier and more comfortable.
* Magill forceps – These are a special type of tweezers used by doctors to guide the tube into the right spot.
* Intubating laryngoscope – This is a tool with a light and camera that helps doctors see inside the throat during intubation.
* Vasoconstricting nasal spray (for example, oxymetazoline 0.05% or phenylephrine nose drops 0.25% to 1%) – These types of sprays shrink blood vessels in the nose to help reduce bleeding and swelling during and after the procedure.
* Syringe to inflate the cuff – a cuff is a small balloon-like attachment at the end of the tube, inflating it helps to keep the tube in place.
* Video laryngoscope – This is an advanced version of a laryngoscope that gives doctors a better view of the vocal cords and surrounding area.
Who is needed to perform Nasotracheal Intubation?
During a procedure known as nasotracheal intubation (NTI), which is performed to help you breathe, an anesthesia provider – a specialist who ensures you don’t feel pain during surgery – plays the main role. However, a nurse can also assist, passing tools like the Magill forceps (a special type of tong used during medical procedures), applying pressure to a part of your throat called the cricoid cartilage, or removing a guide from the breathing tube if needed. A second anesthesia specialist can help prevent related complications such as swelling caused by fluid buildup (angioedema).
An ear, nose, and throat specialist may also help by guiding a thin, lighted instrument called a fiberoptic scope through your nose. If the NTI process is not successful and the situation is critical, this specialist may also create a new air passage – a procedure called a surgical airway. This is how the medical team will work together to ensure your safety during the procedure.
Preparing for Nasotracheal Intubation
Before giving general anesthesia for a surgery or medical procedure, doctors do an assessment to better understand each patient’s potential health risks. This also helps in creating the best management plan for each individual. Sometimes, patients may have one-sided nasal blockage or congestion, and this information is crucial for doctors in deciding which side of the nose is best for inserting the Nasotracheal Tube (NTI) – a tube passed through the nose for giving anesthesia.
If a patient’s feedback does not make it clear which side of the nose is more open, a physical examination can help the doctor decide. Doctors may also use a tool called an anterior rhinoscope (though this is not often done) to see the front part of each nostril from the inside. However, this tool has its limitations as it can’t give a clear picture of the back part of the nostril. In such cases, doctors might use a flexible nasopharyngoscope or a bronchoscope – special devices that can be inserted into the nostril to thoroughly assess the nasal pathway.
How is Nasotracheal Intubation performed
Firstly, the decision must be made about which nostril to use for the procedure. Once this is decided, medicine that constricts (narrow) the blood vessels (vasoconstricting) is applied to both nostrils. To help numb the area, a local anesthetic is also applied, either by spray or mixed with a lubricating jelly. You might hear the medical names oxymetazoline hydrochloride 0.05%, phenylephrine hydrochloride 1%, and cocaine 4% mentioned – these are common options. However, it’s worth noting that only the last one has a numbing effect, so if either of the first two options is used, an additional numbing agent (like 2 to 4% lidocaine) would also need to be given.
After that, there’s some debate about whether a device should be used to expand the nostril area before proceeding. This idea is controversial and there’s not currently any strong evidence either way, so it’s not typically recommended.
Before the procedure begins, the patient will be provided with a high concentration of oxygen to breathe, and we need to make sure that the patient is breathing normally before the muscle relaxant is given. It’s also important to apply lubrication to the tracheal tube – this tube will be inserted through the nostril into the windpipe.
This procedure can sometimes be done while the patient is awake, such as in cases where swelling from a throat injury is developing. Additional numbing spray can be given to the vocal cords, and they can numb the area around the voice box. They might also use a thin, flexible scope with a light and camera to guide the tube placement. A medication called glycopyrrolate can help to reduce the body’s natural secretions and improve visibility through the scope. It can be helpful to have the patient sitting up slightly during this part of the procedure.
The tube is inserted gently into the nostril and guided in the direction of the back of the nose and throat. The tube may require some adjustment as it’s being passed through the nasal cavity, and there might be some resistance encountered. If this resistance feels substantial, the tube may be adjusted in position or a smaller tube may be required. The size of the tube used is determined by the patient’s age and sex.
Once the tube is in place past the soft palate into the back of the throat, the doctor will use a special instrument, called Magill forceps, to guide the tube into the windpipe through the vocal cords. After the tube is in place, they will listen to your chest and check the carbon dioxide level at the end of your breath to confirm that it’s in the right position.
It’s important to note that the position of the patient’s head can affect the positioning of the tube. Flexing the neck can cause the tube to go deeper into the windpipe, which isn’t usually a problem. Extending the neck, however, can pull the tube up, risking damage, balloon herniation, or removal of the tube altogether.
Possible Complications of Nasotracheal Intubation
When a tube is inserted through the nose and into the windpipe to help with breathing (a process called nasotracheal intubation), the most common issue that arises is a nosebleed, which can occur to some degree nearly every time a nasotracheal intubation is done. Additional risks include the introduction of bacteria from the nose into the body through the tube, which could cause an infection in the bloodstream, and the potential for the tube to cause a tear or hole (perforation) in areas of the throat.
It’s especially important to avoid this procedure in patients who have experienced severe injuries from high-speed incidents or trauma to the face. This is because these patients could have damage to the base of the skull, and there’s a risk that the tube could mistakenly be placed inside the skull.
What Else Should I Know About Nasotracheal Intubation?
Nasotracheal intubation is a helpful method used by doctors to ensure a patient’s airway is open and secure before beginning mouth surgery. When done right, this technique is extremely safe and effective. For those administering anesthesia, it’s essential to understand the body’s structure, when and where to use this approach, where not to use it, and the possible complications that might occur.