Intubation: securing the airways

If the patient cannot maintain breathing himself, the doctor secures the airways by intubation - either with a tube or a laryngeal mask

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The medical staff practice intubation and ventilation on simulator manikins

© A1PIX / Your Photo Today / BSIP

What is intubation?

Intubation keeps the airway open by inserting a tube through the mouth or nose. It is an indispensable aid in emergencies and in the intensive care unit. Medicine also uses intubation for operations or diagnostic interventions.

As early as 1543, the Flemish anatomist Vesalius reported for the first time about intubation in animals. He already realized that this measure can be life-saving. However, his method went unnoticed for a long time. It was not until 1869 that the German surgeon Friedrich Trendelenburg performed an intubation on humans using a tracheostomy. In 1878 the Scottish doctor William Macewen intubated a patient for the first time via the mouth.

When is intubation necessary?

The most common reason for intubation is surgery under anesthesia. With general anesthesia, the person's consciousness is switched off and the function of the respiratory center in the brain is impaired. Medicines such as strong pain relievers, which may be necessary during an operation, also dampen the respiratory center. Artificial ventilation is also mostly necessary because drugs relax the muscles and thus hinder breathing.

In contrast to an oxygen or ventilation mask, intubation prevents foreign substances from entering the airways from the stomach and causing severe inflammation. The backflow of food residues and digestive juices is particularly dangerous. Furthermore, medication and anesthetic gases can also be administered via the tube (tube).

Apart from operations, intubation is always necessary when a patient's breathing and thus the oxygen supply to the body is disturbed and a simple oxygen mask is not sufficient. For example, if the airways are swollen or injured, or if there is bleeding. Even if those affected lose consciousness, for example due to shock, poisoning or in a coma, intubation is necessary.

Location of a tube in the windpipe (purple is an inflatable cuff, the cuff)

© W & B / Jörg Neisel

How does intubation work?

There are several types of intubation. The safest, but also the most complex, is intubation into the windpipe, also known as endotracheal intubation. It is usually done during major surgery. For interventions in body cavities (abdomen, chest) and in the ear, nose and throat area, endotracheal intubation is almost always necessary.

Endotracheal intubation

With endotracheal intubation, a thin, flexible plastic tube (endotracheal tube) about 25 to 30 centimeters long is inserted through the larynx into the windpipe. This can be done through the mouth or nose, depending on the procedure. A laryngoscope - a metal spatula and lamp - is used as an aid, through which the specialist staff can guide the tube and see the patient's larynx. So-called video laryngoscopy is also increasingly being used. In addition to a light source, the spatula is also equipped with a camera that can display the entrance of the windpipe (the glottis) on a screen by means of video transmission. Vidoelaryngoscopy makes it easier to insert the tube, especially when intubating a difficult airway (see below), and increases safety.

If the tube is properly seated, it is "blocked" with the help of an inflatable cuff. The cuff prevents the tube from slipping in the windpipe and seals the entrance to the windpipe. This prevents the air from escaping sideways and foreign substances such as stomach contents from entering the lungs. The ventilator or resuscitation bag is connected to the end of the tube on the mouth side.

The intubation usually takes place after the anesthesia has been initiated, so the inturbated do not notice anything.

Intubation with a laryngeal mask (purple)

© W & B / Jörg Neisel

What is a laryngeal mask, Guedel tube and Wendl tube?

Laryngeal mask

If a brief procedure is performed on an empty person, a laryngeal mask may be used. This is a plastic tube with a soft mask on one end that is placed directly over the larynx. The surgical team inserts it like the tube through the mouth, but does not need a laryngoscope. A laryngeal mask is gentler because it does not have to pass the vocal cords. However, it is also less dense and can slip more easily. It is therefore less suitable for longer interventions or emergencies in which those affected are not sober.

Guedel tube and Wendl tube

When ventilating with a mask bag, the Guedel tube (oropharyngeal tube) can also be inserted through the mouth. This tube is shorter and extends to the lower throat. It keeps the upper airway free and prevents the tongue from sinking back onto the back of the throat, which would impede breathing. However, it does not protect against stomach contents from getting into the airways. The Wendl tube (nasopharyngeal tube) has a similar function, but is inserted through the nose. If it lies correctly, it triggers less gag stimulus than the Guedel tube.

What are the side effects?

The most common side effects after tracheal intubation are sore throats and a hoarse voice, as the friction of the tube can irritate the larynx and vocal cords. These symptoms usually disappear after a few days, and the vocal cords are rarely injured. Sometimes teeth can be damaged or broken out, especially with difficult intubations. This happens especially with previously damaged teeth. Therefore, the condition of the teeth should be assessed before anesthesia.

Absolutely sober

The most feared complication of intubation is aspiration. This means the penetration of gastric juice, food residues or other liquids into the airways.If something was eaten or drunk shortly before intubation, acidic food pulp and juices from the stomach can penetrate into the trachea and lungs during intubation, causing strong inflammatory reactions up to pneumonia.

In the preliminary discussion you should therefore be informed in detail about how long you have to be sober before the procedure and what you are allowed to consume.

If the patient is not sober, surgeries that are not urgent are usually postponed. When there is an emergency, there are several techniques, such as lightning initiation, that can help reduce the risk of aspiration.

What is difficult intubation?

Some people may find it difficult to intubate because of their physique or medical history. If this is already known from previous interventions, you will receive a "Difficult intubation" card. You should definitely present this at the preliminary interview.

Our advisory expert:

Dr. med. Julia Sadgorski is a specialist in anesthesia and works as a senior physician at the Rotkreuzklinikum Munich.

Swell:

  • Stiebel, HW, Die Anesthesie: Volumes I and II, Schattauer, Stuttgart, 3rd edition, 2010
  • Bause H, Kochs E, Scholz, J, Dual Series: Anesthesia: Intensive Care Medicine, Emergency Medicine, Pain Therapy, Thieme, Stuttgart, 4th edition, 2011
  • Schäfer R, Söding P, Clinic Guide Anesthesia, Urban & Fischer Verlag / Elsevier GmbH, Munich, 6th edition, 2010

Important NOTE:
This article contains general information only and should not be used for self-diagnosis or self-treatment. It cannot replace a visit to the medical practice. It is unfortunately not possible for our experts to answer individual questions.

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