Description and Overview

A laryngoscopy is a diagnostic procedure performed to examine the back of the throat, as well as the vocal cords, the glottis, and the larynx to determine the causes of various symptoms including breathy, hoarse, or weak voice, as well as the loss of voice. It is also recommended if the patient is feeling a lump in the throat, coughing up bloody mucus, or is suffering from injuries following an illness or accidents. It can also be used to determine the gravity of throat stricture or investigate airway obstructions.

Aside from being used as a diagnostic tool, a laryngoscopy can also be performed to facilitate tracheal intubation during cardiopulmonary resuscitation, procedures requiring general anaesthesia, and treatment procedures that involve the larynx and other parts of the upper tracheobronchial tree.

Who Should Undergo and Expected Results

A laryngoscope can be recommended for patients with:

  • Problems with voice, including (but not limited to) uncharacteristic breathiness or hoarseness, weak voice, or complete loss of voice
  • Unexplained pain in the throat or ear
  • Difficulties in swallowing
  • A palpable lump in the throat
  • Coughing up bloody mucus
  • Injuries to the throat
  • Narrowing of the throat
  • Obstructions in the airway
  • Signs and symptoms of cancer in the voice box (larynx)

How is the Procedure Performed?

A laryngoscopy, which can be either direct or indirect, is performed in an ENT (ear, nose, and throat) specialist's office in a hospital or specialty clinic.

Direct laryngoscopy, also called micro-suspension laryngoscopy, is the most common procedure performed on the larynx under general anaesthesia and can be used for a wide variety of applications and purposes. These include the removal of obstruction and foreign objects lodged in the throat, biopsy, removal of polyps in the vocal cords, or to facilitate laser treatment for different conditions in the larynx. Direct laryngoscopy involves the use of a conventional laryngoscope, which features a light source (to assist the doctor in viewing the larynx) and a set of interchangeable blades for different types of patients (i.e. large adult, small adult, paediatric, infant, and neonate patients). These blades have mirrors to enlarge the doctor's field of view and oxygen ports to assist the patient in breathing.

Direct laryngoscopy is generally uncomfortable and is seldom performed on a conscious patient, which is why hospitals and clinics require that it is performed under general anaesthesia.

Before the actual procedure, the patient's teeth and gums are protected. The laryngoscope, a hollow, rigid barrel, is then introduced into the mouth and throat. In some cases, the laryngoscope is suspended using other instruments to allow the doctor to perform the procedure using both hands. Depending on the goal of the procedure, lasers and operative microscope are also used.

Meanwhile, indirect laryngoscopy is much less invasive and requires only anaesthetic spray to the throat to prevent gagging during the procedure. It involves pulling the patient's tongue while it is covered in gauze and pressing a small mirror against the soft palate and uvula. The patient is then asked to make loud sounds so the doctor can examine the vocal cord activity.

An indirect laryngoscopy takes only a couple of minutes, while a direct laryngoscopy takes around five to 45 minutes, depending on the complexity of the procedure.

Possible Risks and Complications

  • Inflammation of the throat
  • Obstruction of the airways during the procedure
  • Bleeding
  • Infection
  • Perforation of the airway and surrounding structures

    References

  • Pagana KD, Pagana TJ (2010). Mosby's Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.

  • Weinberger PM, Terris DJ (2010). Otolaryngology-Head and Neck surgery. In GM Doherty, ed., Current Diagnosis and Treatment: Surgery, 13th ed., pp. 224-258. New York: McGraw-Hill.

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