Endotracheal intubation is used to ventilate unconscious or anesthetized patients in emergency and trauma medicine and in anesthesia. An endotracheal tube is used, which is inserted into the trachea through the mouth or nose. Complications can arise during intubation if it is performed incorrectly.
What is endotracheal intubation?
Endotracheal intubation is used to ventilate unconscious or anesthetized patients. An endotracheal tube is used, which is inserted into the trachea through the mouth or nose. Endotracheal intubation is the standard method for artificial ventilation of emergency patients and anesthetized patients. Shortened, this method is also called intubation. The basis of this procedure is the insertion of an endotracheal tube through the nose or mouth into the trachea. It is passed between the vocal folds of the larynx. The endotracheal tube consists of a plastic tube for the oxygen supply. It usually also contains a so-called cuff, which is inflated to prevent the aspiration of foreign bodies into the lungs. There are tubes with two lumina (double lumen tube). They are able to ventilate both lungs separately. When intubation is difficult, alternatives to endotracheal intubation are used in the form of laryngeal masks, laryngeal tubes, and combination tubes.
Function, effect, and goals
Endotracheal intubation is used in patients who are unable to breathe independently due to disease, inadequate reflexes, or anesthesia. Intubation prevents obstruction of the upper airway and aspiration of foreign bodies into the lungs. It works by inserting a 20- to 30-cm-long tube (hollow plastic probe) through the mouth or nose via the larynx into the trachea (windpipe). A connection piece for the ventilator is attached to the mouth end of the tube. At the other end, the tube is slightly beveled. Just in front of it is a so-called cuff. This cuff can be inflated as a balloon and ensures that the trachea is closed off from the nasopharynx to prevent the inhalation of foreign bodies such as blood, vomit or other matter. Thus, when the balloon is inflated, the gaps between the tube and the wall of the trachea close. Before inserting the tube, the patient is placed in the so-called Jackson position. In this position, the head lies high and the neck is hyperextended. This provides the best view of the glottis through the mouth. The spatula of a laryngoscope is used to pull the epiglottis caudally and upward. The tube is pulled through the vocal folds until the cuff has passed through them. The cuff is then inflated and the patient is listened to. If everything is correct, ventilation can be continued. Endotracheal intubation is used in a variety of situations. For example, in patients with cardiovascular arrest, anesthetized patients, or patients with severe poisoning, the protective reflexes no longer function during breathing. Their ventilation is urgently required. Patients with inadequate respiration also often require artificial ventilation. Furthermore, artificial respiration is also often necessary during bronchoscopies, endoscopic operations on the respiratory tract, injuries to the upper respiratory tract or insect sting allergies. Depending on the area of application, different endotracheal tubes are also used. Thus, there are flexible or also rigid tubes. It is true that most tubes have an inflatable cuff. However, this is not true for all of them. The cuff can lead to necrosis if it rests on the mucosa for too long, so cuffs are often not used for long-term ventilation. A cuff is also not used in children because their mucosa swells so quickly that this already ensures that the trachea is sealed. A spiral tube does not kink easily and is therefore often used in goiter operations. Endotracheal intubation requires a great deal of experience and therefore causes difficulties for many physicians in its application. Many hospitals have a special resuscitation team for this reason.
Risks, side effects, and hazards
A variety of complications can occur when performing endotracheal intubation, especially since many physicians lack experience in this area. One common complication is esophageal intubation failure, which can even be fatal.In this case, the stomach is ventilated instead of the lungs. If the error is not recognized in time, the patient dies of asphyxiation. For this reason, it is now standard practice to carry out monitoring to prevent this type of incorrect intubation. Aspiration is also feared. Foreign bodies such as blood or stomach contents enter the lungs via the trachea. If there is an increased risk of this aspiration, a special form of induction of anesthesia (the Rapid Sequence Induction) is performed, whereby an accelerated induction of anesthesia occurs. Another complication is injury to the vocal cords. If the tube is advanced too far, there is a risk that only one lung will be ventilated. By listening, this incorrect intubation can be quickly detected. Correction is made quickly by retracting the tube. Long-term ventilation can have negative effects on the tracheal mucosa. Necrosis and ulceration may occur due to pressure on the mucosa. Therefore, cuff pressure must be constantly monitored in intensive care units. In rare cases, teeth may break out of the upper jaw. Very rarely, reflex cardiac or respiratory arrest is also possible due to irritation of the parasympathetic nervous system of the autonomic nervous system. Furthermore, vomiting may occur during intubation if anesthesia is inadequate. For this reason, it is important that the patient remain fasting before a planned anesthetic.
