A laryngoscope is an instrument designed to provide a direct view of the larynx (the voice box) for endotracheal intubation. This procedure involves placing a breathing tube into the trachea (windpipe) to secure a patient’s airway during surgery or critical illness. This guide details the foundational steps for proper use, but it is not a substitute for supervised, hands-on clinical training.
Essential Components and Blade Selection
The laryngoscope is composed of two main parts: a handle and a blade. The handle contains the power source, typically batteries, which illuminates a small light at the tip of the attached blade. The blade is the component used to manipulate the patient’s anatomy to create a line of sight to the vocal cords.
Two primary blade designs exist, used for different anatomical considerations and patient populations. The Macintosh blade is curved and is the most common choice for adult patients. Its design allows the tip to be placed into the vallecula, a space between the base of the tongue and the epiglottis, where an upward lift indirectly raises the epiglottis to expose the vocal cords.
The Miller blade features a straight design. This blade is frequently preferred for infants and young children because their epiglottis is often larger and more flexible. The Miller blade is advanced further to directly lift the epiglottis, providing a clear view of the glottic opening. Selecting the correct blade type and size is a prerequisite for successful visualization.
Optimizing Patient Alignment
Achieving the appropriate patient position is necessary before inserting the laryngoscope. The goal is to align three anatomical lines: the oral, pharyngeal, and laryngeal axes. When these axes are aligned, they form a straight path from the operator’s eye to the glottic opening.
This alignment is typically accomplished by placing the patient into the “sniffing position.” This position involves neck flexion, achieved by elevating the head with a cushion or blanket, and head extension at the atlanto-occipital joint. The combined effect mirrors the posture of a person sniffing the air, hence the name.
In a properly positioned adult patient, the ear canal should be horizontally aligned with the sternum (breastbone). Optimizing this alignment reduces the angle the laryngoscope must overcome to view the larynx, significantly improving the procedural success rate. Proper positioning minimizes the need for excessive force, which can lead to complications.
Mastering the Laryngoscope Grip and Insertion
Regardless of the operator’s handedness, the laryngoscope must always be held in the left hand. This technique frees the right hand to manipulate the patient’s mouth and insert the breathing tube once the vocal cords are visible. The handle should be grasped firmly, often with the fingers closer to the blade hinge, which provides better fine motor control and leverage.
The blade is gently introduced into the right side of the patient’s mouth, carefully avoiding contact with the teeth and lips. It is advanced along the right side of the tongue and used to sweep the tongue tissue toward the left side of the mouth. This lateral sweeping motion is essential for clearing the tongue out of the line of sight.
As the blade is advanced, the operator looks for key anatomical landmarks, the epiglottis. Once the tip of the curved Macintosh blade is seated in the vallecula, or the tip of the straight Miller blade is positioned over the epiglottis, the lifting action begins. The force must be applied up and away from the patient’s feet, along the axis of the laryngoscope handle. This pure lifting motion elevates the jaw and tongue, bringing the vocal cords into view.
Avoiding Common Procedural Mistakes
One of the most frequent errors is using the patient’s upper teeth or gums as a fulcrum to leverage the laryngoscope. This action, often described as a “rocking” motion, transfers significant force to the mouth, which can cause serious dental damage. Force must be directed purely along the long axis of the handle, lifting the entire lower jaw anteriorly.
Another common mistake involves a technique called wrist flexion, where the operator curls their wrist inward during the lift. This technique directs the lifting force incorrectly, often resulting in poor visualization and an increased risk of dental trauma. The wrist should remain relatively straight and locked, using the entire arm and shoulder to generate the necessary lifting force.
Inserting the blade too deep is a frequent pitfall. Advancing the blade too far can push the epiglottis or larynx out of the visual field, leading to a view of only the esophagus. The technique should be incremental, advancing the blade slowly while identifying landmarks until the glottic opening is centered in the field of view.