Endotracheal intubation is a necessary, life-saving procedure involving the placement of a flexible breathing tube (ETT) through the mouth and into the trachea (windpipe). This tube secures the airway and allows a machine to assist or control breathing, often required during general anesthesia or for patients in intensive care units with respiratory failure. While this intervention is common and generally safe, the tube must navigate the larynx, where the delicate vocal cords reside. Therefore, irritation and potential injury to the laryngeal structures are recognized risks associated with the procedure.
The Physical Mechanics of Injury
Damage to the vocal cords occurs through two primary mechanisms: dynamic forces during insertion and removal, and static pressure while the tube is in place. During insertion, the ETT or guiding instruments can cause friction against the mucosal lining of the vocal cords. If the procedure is difficult or the patient coughs, the risk of surface trauma, such as scrapes or abrasions, increases significantly. The second mechanism involves sustained pressure from the ETT against the tissues of the larynx once the tube is secured. The inflated cuff near the tip can press against the posterior part of the vocal cords. This constant pressure can lead to a localized lack of blood flow (pressure ischemia), which can result in tissue damage or necrosis if the pressure is too high or the duration is too long.
Specific Forms of Vocal Cord Trauma
The physical strain on the larynx can manifest in several distinct forms of trauma, ranging from temporary swelling to permanent structural changes. The most common reaction is laryngeal edema, a temporary swelling of the vocal cord tissue due to irritation. This swelling is typically mild and resolves on its own, but severe cases can narrow the airway and cause breathing difficulties.
Structural Injuries
More serious complications include mucosal abrasions and ulcerations (open sores) where the tube rested. The healing response to these ulcers can lead to the formation of vocal process granulomas or polyps, which are small masses of scar tissue that interfere with normal vibration. A less common injury is vocal cord paralysis, which occurs when the recurrent laryngeal nerve is damaged by ETT cuff compression, resulting in a non-moving cord.
What to Expect Immediately After Extubation
Once the endotracheal tube is removed, patients can expect immediate symptoms, most of which are temporary and reflect simple irritation. Hoarseness (dysphonia) is extremely common due to mild vocal cord swelling and irritation, ranging from a rough voice to a weak, breathy quality. A sore throat (pharyngitis) is also a universal complaint, arising from the tube passing through the mouth and pharynx. Patients may also experience a mild cough or difficulty swallowing (dysphagia) as throat muscles recover. These uncomfortable symptoms are transient and fully resolve within 24 to 72 hours following extubation.
When to Seek Medical Assessment for Persistent Issues
While temporary throat discomfort is normal, certain signs indicate the need for a medical assessment for a lasting injury. The most important indicator is the persistence of symptoms beyond the expected recovery period, generally defined as more than one week. If hoarseness, pain, or difficulty swallowing continues for several weeks, a specialist evaluation is warranted. Any sign of severe breathing difficulty, particularly noisy breathing upon inhalation (stridor), requires immediate medical attention. Stridor suggests significant airway narrowing and is a medical emergency.
For persistent voice changes, an Ear, Nose, and Throat specialist will typically perform a laryngeal examination, such as a flexible nasolaryngoscopy, to visually inspect the vocal cords. This procedure identifies structural problems like granulomas, severe ulceration, or vocal cord immobility. Management for lasting issues can include voice rest, anti-inflammatory medications, or in rare instances, minor surgical intervention like laser removal of scar tissue.