During many surgical procedures, doctors will place a tube in the patient’s throat to help them breathe while under anesthesia. This tube is called an endotracheal tube (or ET tube). The ET tube serves several crucial functions:
Why do they put a tube down your throat during surgery?
There are a few key reasons why an endotracheal tube is used:
- To keep the airway open and unobstructed. The tube helps prevent the tongue and tissues of the airway from collapsing and blocking airflow to the lungs.
- To deliver oxygen and anesthetic gases. The ET tube is connected to the anesthetic breathing circuit so that oxygen and anesthetic gases can be administered directly into the lungs.
- To protect the lungs from aspiration. The ET tube creates a seal over the trachea which helps prevent gastric contents, secretions or blood from being aspirated into the lungs during surgery.
- To allow controlled ventilation. The anesthesiologist can manually assist or control the patient’s breathing via the ET tube if necessary.
Having a securely placed ET tube is vital for patient safety and ensures the airway is protected while the patient is under general anesthesia.
When is an endotracheal tube used?
Endotracheal intubation is performed for almost all major surgeries requiring general anesthesia. This includes:
- Abdominal surgery
- Thoracic surgery
- Neurosurgery
- Cardiac surgery
- Head and neck surgery
- Orthopedic surgery
- Plastic surgery
- Transplant surgery
- Emergency surgery
Reasons it may also be used for non-surgical procedures include:
- For patients on a ventilator in the ICU
- During procedures like endoscopies or bronchoscopies
- When a patient cannot protect their own airway like during a seizure
- For trauma cases where the airway needs to be secured
What does the endotracheal tube look like?
An endotracheal tube is a thin, flexible plastic tube that ranges from 2mm to 10mm in diameter depending on the size of the patient. Adult sizes generally range from 6.0mm to 8.5mm. There are a few key parts of an ET tube:
- Distal tip – This is the end of the ET tube that sits in the trachea.
- Cuff – This is a balloon-like sac around the distal end that can be inflated to create a seal against the tracheal wall.
- Murphy’s eye – A small opening at the distal tip that allows airflow if the main lumen gets obstructed.
- Main shaft – The main length of the tube that sits in the airway.
- Proximal end – The end outside the patient’s mouth that connects to the breathing circuit.
ET tubes usually have a curved shape to follow the natural anatomy of the airway. The cuff, when inflated, blocks off the esophagus so that air only goes to the lungs.
How is an endotracheal tube inserted?
Endotracheal intubation is performed after the patient has been induced into anesthesia and is fully relaxed with muscle relaxants. The process involves these basic steps:
- The patient’s head is placed in the “sniffing” position – neck slightly flexed, head extended, to align the airway.
- The mouth is opened and a laryngoscope is used to visualize the vocal cords.
- The ET tube is inserted through the mouth and advanced past the vocal cords into the trachea.
- The cuff is inflated to seal the airway.
- The tube position is confirmed by exhaled CO2 detection and auscultation of breath sounds.
- The tube is secured in place by tape or other devices.
Intubation is performed by the anesthesiologist or nurse anesthetist. Correct tube depth is estimated based on the patient’s height. Placement is confirmed after intubation using a CO2 detector and by listening over the lungs with a stethoscope.
What does it feel like to have an ET tube during surgery?
Patients do not feel any discomfort from the ET tube itself during surgery because they are under anesthesia. However, it is common to experience a sore throat after surgery due to irritation from the tube. This usually resolves within a few days.
Some other sensations patients may experience after extubation include:
- Hoarse voice
- Swallowing discomfort
- Dry mouth
- Pain with coughing or talking
Proper lubrication of the tube before insertion as well as gently suctioning the mouth and throat after removal can help reduce post-operative soreness.
What are the risks of intubation with an endotracheal tube?
Endotracheal intubation is generally very safe when performed by experienced providers. However, there are some risks to be aware of:
- Failed intubation – Difficulty visualizing or passing the tube can lead to failed intubation attempts. This can cause low oxygen levels.
- Esophageal intubation – Placing the tube accidentally into the esophagus instead of trachea. This is dangerous as the lungs will not receive air.
- Endobronchial intubation – When the tube is advanced too far and enters one bronchus instead of mid-trachea. This will only ventilate one lung.
- Displaced tube – The tube can move out of proper position, especially with patient movement or coughing.
- Trauma – Excessive pressure on the teeth and airway structures can potentially lead to damage. Most tubes have an introducer that protects the tube from biting.
Overall, serious complications from ET tubes are rare when proper protocol is followed. Doctors take precautions to verify correct tube placement and secure it well.
What’s the process for removing the endotracheal tube?
The endotracheal tube is removed once surgery is complete and anesthesia wears off enough that the patient can breathe adequately on their own. This process involves:
- Suctioning the airway to remove secretions
- Deflating the endotracheal tube cuff
- Removing any oral airway devices or retainers
- Gently pulling the tube as the patient coughs or breathes out
- Suctioning the mouth and airway again after removal
- Providing supplemental oxygen via a facemask
- Closely monitoring oxygen levels, breathing, and patient status after extubation
Most patients will breathe spontaneously and maintain good oxygen levels after the ET tube is removed. Rarely, some patients may have respiratory depression or lack protective airway reflexes if anesthesia has not worn off sufficiently and may need to remain intubated longer or even be reintubated.
What alternatives are there to endotracheal intubation?
There are a few alternatives to placing an ET tube, including:
- Laryngeal mask airway (LMA) – This is a supraglottic device that sits over the laryngeal opening. Less invasive than an ET tube, but does not fully protect the airway.
- Nasal intubation – Passing the tube through the nose instead of mouth. Can be useful for operations involving the mouth or throat.
- Regional anesthesia – Using an epidural or spinal block instead of general anesthesia may preclude the need for an ET tube.
- Conscious sedation – Minimal or no sedation so patient can breathe on their own without an ET tube.
For major surgeries requiring general anesthesia and controlled ventilation, however, endotracheal intubation remains the gold standard for airway management.
Conclusion
The endotracheal tube is a vital part of airway management and safety during surgery. It helps keep the airway patent, delivers oxygen and anesthesia, prevents aspiration, and allows mechanical ventilation. While largely safe, proper technique and continuous monitoring are needed to avoid complications. A sore throat and hoarseness are common temporary side effects after extubation. Overall, endotracheal intubation is an essential component of general anesthesia care, improving patient outcomes and reducing anesthesia-related mortality.
