Endotracheal Intubation - The Art and Science of Securing the Airway

Introduction

Endotracheal intubation refers to the medical procedure performed in an emergency hospital setting to provide oxygenation and ventilation. Two types of approaches are used for endotracheal intubation. The primary indication for this procedure is to be performed on unconscious patients or persons who cannot breathe independently. The process helps maintain the open airway and prevents suffocation.

What Is an Endotracheal Tube?

In its simplest form, the endotracheal tube is a polyvinyl chloride (PVC) tube that is put through the trachea and between the vocal cords to bring oxygen and gases into the lungs. It also keeps stomach acid and blood from getting into the lungs and making them sick. Improvements in anesthesia and surgery have led to improvements in the endotracheal tube. Changes have been made to make aspiration less likely, separate a lung, give medicines, and stop airway fires.

What Are the Indications of Endotracheal Intubation?

• The primary goal of endotracheal intubation is maintaining the open airway and obtaining first-pass success.

• There are several indications to perform this procedure, and these include:

• Altered mental status.

• Hypoxia (poor oxygen levels).

• Questionable airway patency.

• Hypercarbia (increase in carbon dioxide levels in the blood).

• The indications are assessed by analyzing factors such as the patient’s mental status, consciousness level, oxygenation level, conditions that compromise the airways, respiratory acidosis, and respiratory rate.

• In the case of trauma, a Glasgow coma scale value of eight or less indicates endotracheal intubation.

What Are the Contraindications of Endotracheal Intubation?

• Some orofacial traumas due to the disruption of facial and upper airway anatomy or bleeding may obstruct the procedure.

• In the case of spine injury and immobility, cervical spine manipulation during intubation is harmful.

• In the case of the requirement for a definitive airway, preparation for a surgical airway is recommended.

• The patient’s clinical condition can determine the requirement for a definitive airway.

What Are the Types of Equipment for the Intubation Procedure?

Various types of equipment are needed for both direct and video laryngoscopy, and these include:

• Preparation.

• Intravenous access.

• Stethoscope.

• Hemodynamic monitoring.

• Pulse oximeter.

• Suction catheter attached to continuous suction.

• End-tidal carbon dioxide (Et CO2) monitor.

• Defibrillator.

• Rapid sequence intubation medications.

• Pre-oxygenation Procedure:

• Bag-valve masks of various sizes.

• A nasal cannula or high-flow nasal cannula.

• Oral and nasal airways of multiple sizes.

• Supplemental oxygen.

• Non-rebreather mask.

• Positive end-expiratory pressure (PEEP) value.

• For direct laryngoscopy

• Laryngoscope handles have batteries.

• Endotracheal tubes of various sizes.

• Malleable stylet.

• 10 cc syringe.

• Tape.

• Laryngoscope blades of different sizes and shapes.

• For video laryngoscopy

• Video laryngoscope with a power source.

• Rigid or malleable stylet.

• Backup Equipment:

• Laryngeal mask airway.

• Cricothyrotomy tray.

• Magill forceps.

How to Prepare For Endotracheal Intubation Before the Procedure?

Airway Evaluation:

• Airway evaluation is the primary step in preparation for intubation, including a history of previous or difficult intubations.

• Patients with facial or neck trauma, obesity, and restricted cervical motion present with difficult airways during external anatomy evaluation. Thus, alternative modes of intubation are followed in these situations.

• “LEMON” - is a common mnemonic to represent the airway evaluation.

• Look for external signs of trauma, neck masses, dentures, or a large tongue.

• Evaluate for the 3-3-2 rule. It represents less than three fingers between the incisors, three fingers between the hyoid bone and mental protuberance, and two fingers between the hyoid bone and the thyroid cartilage, which may represent difficult airways.

• “Mallampati” score (a simple test used to predict the ease of intubation and predictor of obstructive sleep apnea), equal to or greater than three, indicates difficult intubation.

• “Obesity” or “obstruction” restricts vocal cord visualization.

• “Neck” mobility or restriction indicates difficulty in passing the endotracheal tube.

• Positioning:

• After completing the external evaluation, one should fix the head position to receive the best view of the vocal cords.

• The “sniffing position” is a familiar position that aligns all the pharyngeal, laryngeal, and oral in the same axis.

• Elevating the patient’s head, lifting the head to the neck, and positioning the ears horizontally with the sternal notch provide the exact head position.

• Endotracheal Tube:

• For women, the ideal size of the endotracheal tube is seven, and eight for men.

• The variations in the size of the patient's height and the need for bronchoscopy.

• In children, cuffed endotracheal tubes are mostly preferred.

What Happens During Endotracheal Intubation?

• Endotracheal intubation is usually carried out under anesthesia.

• Once sedated, a small instrument with a light called a laryngoscope is introduced into the mouth, giving an inner picture of the larynx or voice box.

• Once the vocal cord is located, a flexible tube is placed into the mouth and passed beyond the vocal cords and the lower portion of the trachea.

• A stethoscope assesses breathing and ensures the tube is placed correctly.

• The tube is removed once extended; help is not needed for breathing.

• The tube is connected to the ventilator or breathing machine in the intensive care unit or during surgical procedures.

• Sometimes, it may be attached to a bag from which the oxygen is pumped into the lungs.

Why Is Endotracheal Intubation Done?

• Primarily to open the airways and receive anesthesia, oxygen, or medication.

• In the case of difficulty breathing or when breathing stops.

• To protect the lungs.

• If a patient requires machine support to breathe.

• Head injury and inability to breathe on their own.

• In the case of extended sedation, to recover from a severe injury or illness.

What Is the Risk of Endotracheal Intubation?

Certain risks associated with intubation include:

• Injury to the throat or trachea.

• Damage to the teeth or dental prosthesis.

• Accumulation of too much fluid in organs or tissues.

• Lung injury or complications.

• Bleeding.

• Aspiration.

• Anesthesia Risks:

• Healthy people do not have any complications with general anesthesia; few cases may present with long-term complications.

• These risks are manifested based on the type of procedure and general health.

• Specific factors that may increase the risk of complications with general anesthesia include:

• Diabetes.

• History of seizures.

• Family history of adverse reactions to general anesthesia.

• Obesity.

• Smoking.

• Alcohol use.

• Age.

• Allergies to food or medications.

Medical conditions that increase the risk of general anesthesia include:

• Lung infection.

• Heart attack.

• Stroke.

• Mental confusion.

Conclusion:

Endotracheal intubation is an essential skill for emergency medicine and critical care providers. A better understanding of endotracheal intubation's risk and complications is significant for candidates. Proper positioning, pre-oxygenation, and team preparation are mandatory for endotracheal intubation. Practice and preparation are essential factors for successful intubation in the emergency setting.