A laryngoscope is a medical instrument used to visualize the larynx (voice box) and surrounding throat structures. Its primary application is to facilitate endotracheal intubation, guiding a breathing tube into the trachea to secure an airway for mechanical ventilation or general anesthesia. Proper handling technique is fundamental to the procedure’s success, directly impacting patient safety and the speed of securing the airway. Mastering the correct biomechanics ensures a clear view of the vocal cords and smooth tube placement, as errors in grip or insertion can lead to failed attempts or injury, such as dental trauma.
Preparing the Patient and Equipment
Preparation of the equipment and patient is essential before the procedure begins. The operator must first ensure the laryngoscope is functional by checking that the blade’s light source is bright and securely locked into the handle. Blade type and size are determined by the patient’s anatomy; the curved Macintosh and straight Miller blades are the most common variations. The size must be appropriate for the patient’s age and build to ensure optimal viewing without causing trauma.
The patient’s position is equally important, as it helps align the three axes of the airway: the oral, pharyngeal, and laryngeal axes. The standard positioning for most adults is the “sniffing position,” achieved by placing a small cushion under the head to facilitate neck flexion and head extension. This maneuver brings the ear canal level with the sternal notch, the visual marker for proper alignment. For patients with complex anatomy or obesity, a ramped position may be required to achieve optimal alignment.
Mastering the Laryngoscope Grip
The foundational technique requires the instrument to be held exclusively in the operator’s left hand, regardless of hand dominance. This keeps the right hand free to manipulate the endotracheal tube or perform other maneuvers. The handle should be grasped firmly, often described as a pistol grip, though some practitioners hold it lower for maximum stability and leverage.
The force used to lift the tongue and soft tissues must be applied along the axis of the laryngoscope handle. The lifting motion should combine wrist and forearm movement, pulling the entire instrument upward and away from the operator’s body. The operator must strictly avoid using the patient’s upper teeth as a fulcrum to lever the blade, which can result in dental damage. Upward and forward traction creates the direct line of sight to the larynx, not a rocking motion.
Blade Insertion and Visualization Sequence
The process begins by inserting the blade into the right side of the patient’s mouth, carefully avoiding the lips and teeth. The operator uses the blade to sweep the tongue from the right side towards the left, establishing a clear working channel. This lateral approach helps control the bulk of the tongue, which can otherwise obstruct the view. The blade is then advanced until the epiglottis comes into view.
The technique for elevating the epiglottis varies based on the blade type. When using the curved Macintosh blade, the tip is advanced into the vallecula (the space between the base of the tongue and the epiglottis). Lifting the blade here indirectly elevates the epiglottis by stretching connecting tissues, exposing the vocal cords. Conversely, the straight Miller blade is advanced further to pass beneath and directly lift the epiglottis itself.
Techniques to Optimize Airway View
If the initial visualization of the vocal cords is suboptimal, several maneuvers can improve the view. External Laryngeal Manipulation (ELM) involves applying gentle pressure to the anterior neck structures. This external pressure moves the larynx backward, upward, and to the right (the BURP maneuver), bringing the glottic opening into the operator’s line of sight.
The most effective method of ELM is often bimanual laryngoscopy, where the operator uses their right hand to manually adjust the larynx while maintaining the laryngoscope grip with the left hand. Once the optimal position is found, an assistant can maintain that external pressure. Suctioning is also necessary if blood, secretions, or vomit obscures the view, ensuring the airway is clear before the tube is passed.