Intubation is performed to secure a patient’s airway when they cannot breathe effectively on their own. This procedure involves placing a flexible plastic endotracheal tube (ETT) through the mouth and into the trachea. The ETT connects to a ventilator, delivering oxygen directly to the lungs. A stylet is a malleable wire temporarily inserted inside the ETT. Its primary function is to provide rigidity and a customized curve, helping the clinician guide the tube past the vocal cords and into the correct position.
The Role of the Stylet in Airway Management
Standard endotracheal tubes are made of soft, flexible plastic to minimize trauma to delicate airway tissues. However, this flexibility makes the tube difficult to maneuver during insertion. The stylet, typically a malleable aluminum wire encased in a plastic sheath, acts as an internal skeleton for the ETT to address this issue.
The stylet serves two main mechanical functions. First, it increases the tube’s overall rigidity, allowing the operator to push the ETT forward accurately without the tip collapsing or bending unpredictably. Second, the malleable core allows the clinician to pre-shape the tube into a specific curve, often called the “hockey stick” or “C-curve.” This shaping enables the operator to navigate the patient’s upper airway and direct the tube’s tip toward the trachea.
Clinical Scenarios Where a Stylet is Necessary
The stylet is necessary when direct visualization of the larynx is difficult or impossible, a situation often termed a “difficult airway.” Anatomical factors can obstruct the view, including a receding jaw, a short neck, limited mouth opening, or restricted neck mobility. Using a stylet in these scenarios increases the likelihood of a successful intubation attempt by allowing the operator to manipulate the tube’s angle to circumvent obstacles.
The stylet is also important when using certain video laryngoscopes, which offer an indirect view of the larynx via a camera. These devices often use a highly curved blade that requires the ETT to be shaped to a corresponding angle to match the blade’s trajectory. The pre-shaped, rigid tube allows for guided placement, steering the ETT toward the vocal cords even if the tip is not perfectly visible. In emergency settings, the stylet improves the first-attempt success rate of intubation, helping to reduce patient complications.
Step-by-Step Stylet Intubation Technique
The initial step involves preparation, where the clinician inserts the malleable wire into the ETT until the stylet tip is completely recessed. This safety measure ensures the tip does not protrude beyond the plastic tube, preventing trauma during insertion. The ETT and stylet assembly is then bent into the required shape, typically forming a curve in the distal third of the tube to facilitate maneuvering past the anatomy.
During insertion, the shaped tube is guided through the patient’s mouth and into the pharynx under visualization, either direct or via a video screen. The rigidity provided by the stylet allows the operator to precisely direct the tube tip through the vocal cords and into the trachea. Once the tube tip is confirmed to have passed through the cords, the withdrawal phase begins.
The clinician must hold the ETT securely while carefully and smoothly pulling the stylet out of the tube. This withdrawal must occur before the ETT is advanced further into the trachea, ensuring the rigid metal tip does not injure the delicate inner wall of the airway. Correct placement is then confirmed, usually by observing exhaled carbon dioxide, and the small balloon cuff on the ETT is inflated to secure the tube’s position.
Avoiding Complications During Stylet Use
While the stylet significantly aids in successful tube placement, its use introduces specific risks that must be carefully managed. The primary concern is potential trauma to airway structures, including the vocal cords, larynx, or trachea, caused by the rigid tip. This risk increases if the stylet tip is not properly recessed within the ETT or if excessive force is used during insertion.
To mitigate trauma, the stylet is manufactured with a plastic coating and often a specialized soft distal tip. Protection is further ensured by keeping the tip well inside the bevel of the ETT.
Another potential issue is the stylet becoming stuck within the ETT or bending improperly during the withdrawal phase, which can delay the procedure. Clinicians reduce this risk by using lubricated stylets and ensuring the curvature is appropriate for the tube size, allowing for smooth, clean removal once the ETT is correctly positioned.