Tracheal intubation and airway management

The purpose of endotracheal intubation is to establish a patent, stable airway for ventilation. Establishing and maintaining a patent airway is the first step in all emergency procedures. Endotracheal intubation is widely used in emergency departments, ICUs, anesthesia departments, various wards, and various emergency response sites outside the hospital. Therefore, every clinician should master this technique.

Tracheal intubation involves a wide range of content, including preoperative assessment, equipment conditions, induction methods, intubation techniques, complication prevention and difficult airway management.

1. Correct intubation position: Laryngoscopy is most easily performed with the neck flexed and the atlas joint extended.

2. Depth of the Endotracheal Tube
The tip of the tube should be in the mid-trachea, 4 cm from the carina.
Men: No more than 22 cm from the incisors.
Women: 21 cm.
Children: 12 cm + (age/2) between the lips.

3. Requirements for Intubation

Oxygen and ventilation equipment or devices:
-Simple, mobile breathing bag and mask.
-Complete, fixed anesthesia machine (ventilator) and high-pressure oxygen source.
-Ventilation and oxygenation monitoring equipment.
-Pulse oximeter, end-tidal carbon dioxide.
-Intubation equipment.

4. Equipment for Intubation

-Laryngoscope and various blades (with adequate power supply).
-Various endotracheal tubes.
-Endotracheal tube introducers (stylet or bougie).
-Oropharyngeal or nasopharyngeal airway, mouthpiece, and intubation forceps.
-Reliable suction device.
-Trained assistant.

5. Patient Preparation

Preoxygenation: Preoxygenating the patient before induction and intubation improves safety during laryngoscopy. Anesthesiologists should ensure that the patient is receiving supplemental oxygen at all times.

6. Ventilation and Oxygenation

Ventilation and oxygenation are the goals, while intubation is a means to an end. Ventilation is more important than intubation.

7. Monitoring

-Respiratory: rate, amplitude, pattern.
-Color of lips, nail beds, and skin and mucous membranes.
-Blood pressure, pulse.
-Oxygen saturation (SaPO2).
-End-tidal carbon dioxide (ETCO2).

8. Anesthesia Induction and Tracheal Intubation

-The pharyngeal and tracheal mucosa are richly distributed with autonomic nerves.
-Adverse reflexes can easily develop: hypertension, tachycardia or bradycardia, or even cardiac arrest.
-Patients experience pain and struggle due to hypoxia and the irritation of the intubation tube, clenching their jaws and making intubation difficult.
-Forced intubation causes significant trauma to the airway and is prone to complications.
-Anesthetic induction is a necessary step in tracheal intubation.

9. Anesthesia Induction Methods

-Topical Anesthesia and Awake Intubation: Thoroughly explain the situation and obtain the patient's cooperation. Appropriate sedation and analgesia are used. Topical anesthesia is applied to the mouth, pharynx, larynx, and trachea. Features: Consciousness is maintained, airway tone (patency) is maintained, and spontaneous breathing is maintained. Safe, with room for maneuver. If the patient is in pain and uncooperative, intubation may be difficult.

-Rapid Induction: General anesthetics and muscle relaxants. Features: Rapid induction results in loss of consciousness, respiratory arrest, and loss of airway tone. Aspiration may occur. The patient is pain-free, making intubation easier.

-Slow induction: Sedatives and analgesics, topical anesthesia. Characteristics: Slow induction is somewhere in between: unconscious but breathing spontaneously.

-General anesthesia induction: (Based on preoperative medication).

10. Choice of Induction Method

-Normal airway: Induction with general anesthesia;
-Patients at risk of aspiration: Rapid induction with a short-acting general anesthetic and a muscle relaxant; or topical anesthesia and awake intubation;
-Difficult endotracheal intubation: Topical anesthesia and awake intubation.

Summary of endotracheal intubation

●  Preoperative assessment should be based on a comprehensive assessment of multiple parameters; both anatomical abnormalities and pathophysiological changes should be assessed.

● Preoperative preparation should include: comprehensive intubation and ventilation equipment; a difficult airway plan based on the ASA rules; patient preparation (preoxygenation); and well-trained anesthesiologists and assistants.

● Accurate, gentle, and skillful techniques can reduce complications.

●  The fundamental goal of airway management is to ensure ventilation and oxygenation and prevent hypoxia. The patient should not be placed in respiratory arrest unless the anesthesiologist has determined that ventilation is feasible. When intubation becomes difficult, one must not focus solely on intubation and forget about ventilation; this is the most common mistake. Therefore, it should be emphasized that patients will only die from ventilation and oxygenation failure, not from intubation failure.

● The intubator's three primary responsibilities:
-Recognize potential airway problems;
-Plan preventive measures;
-Ensure patient safety after intubation fails.