Effects of Laryngoscopy
Using either indirect or direct laryngoscopy helps a doctor:
- Detect causes of voice problems, such as a breathy voice, hoarse voice, weak voice, or no voice.
- Discover causes of throat and ear pain.
- Evaluate difficulty in swallowing, a persistent sensation of a lump in the throat, or mucous with blood.
- Detect injuries to the throat, narrowing of the throat (strictures), or obstructions or masses in the airway.
Direct rigid laryngoscopy may be used to perform surgical procedures, including removing foreign objects that may get caught in the throat, collecting tissue samples (biopsy), removing polyps from the vocal cords, or performing laser treatment. Direct rigid laryngoscopy may also be used to help diagnose cancer of the voice box (larynx).
Candidates for Laryngoscopy
Laryngoscopy is an examination a doctor uses to look at the back of the throat, including the voice box (larynx)and vocal cords. If biopsy samples of suspicious areas or growths are taken and sent to a laboratory for analysis, it may take several days for your doctor to receive the results.
- Normal: A normal throat (larynx) shows no evidence of inflammation, injury, narrowing (strictures), or foreign bodies. Your vocal cords show no abnormal scar tissue, growths (tumours), abnormal movement, or signs of paralysis.
Abnormal: There is evidence of inflammation, injury, strictures, tumours, or foreign bodies in the larynx. Your vocal cords show signs of scar tissue, abnormal movement, or signs of paralysis.
Direct rigid laryngoscopy is usually recommended instead of indirect laryngoscopy for:
- People who gag easily because of abnormalities in their throat structure.
- People who may have symptoms of laryngeal or pharyngeal disease.
- People who have not responded to previous short-term therapy for laryngeal symptoms.
Before a rigid laryngoscopy, tell your doctor if you:
- Are allergic to any medications, including anesthetics.
- Are taking any medications.
- Have any bleeding problems or take blood-thinning medications.
- Are or might be pregnant.
You will also be asked to sign a consent form. Talk to your health professional about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will indicate. To help you understand the importance of this test, fill out the medical test information form (What is a PDF document?).
Rigid laryngoscopy requires a general anesthetic. Do not eat or drink for at least 6 to 8 hours before the procedure. If you are scheduled to have this test in your doctor’s office or a hospital’s outpatient surgery centre, arrange to have someone drive you home after the procedure.
The examination usually takes 15 to 30 minutes. You may be given an ice collar to wear to reduce the risk of swelling in your throat. After the procedure, you will be watched closely for a few hours until you are fully awake and able to swallow.
- Do not eat or drink anything for about 2 hours or until you are able to swallow without choking. After that time, you may resume your normal diet, starting with sips of water.
- After the procedure, spit out your saliva. Do not swallow it.
- Avoid clearing your throat or coughing vigorously for several hours after the procedure.
The Laryngoscopy Procedure
Laryngoscopy is a procedure that a physician uses to examine a patient’s vocal chords to see if they are functioning normally. It is usually performed by one of two methods. With direct laryngoscopy a thin flexible tube containing fiber optics is inserted into one of the patient’s nostrils and is then pushed forward and angled downward towards the throat and vocal cords.
The physician is then able to look through an eyepiece to directly examine the vocal cords while the patient speaks. With indirect laryngoscopy a small circular mirror on a long thin handle is inserted into the patient’s mouth and turned so that the vocal cords are reflected on the surface. The physician is able to shine a bright light on the mirror to examine the reflection of the vocal cords while the patient speaks.
Indirect laryngoscopy is done in a doctor’s office using a small hand mirror held in the mouth at the back of the throat, a head mirror worn by the doctor, and a light source. The mirror worn by the doctor reflects light into the mouth. Some doctors now use headgear equipped with a bright light.
Indirect laryngoscopy has been largely replaced by newer direct fibre-optic laryngoscopic techniques that provide better views and greater comfort during the examination.
Direct fibre-optic (flexible or rigid) laryngoscopy
Direct laryngoscopy uses a fibre-optic scope that allows the doctor to see deeper into the throat than during indirect laryngoscopy. The laryngoscope is either flexible or rigid. Fibre-optic scopes provide better views and are better tolerated than older, rigid scopes. Rigid scopes are still used in surgery.
You will sit straight up in a chair and stick out your tongue as far as you can. The doctor will hold your tongue down with some gauze. This allows the doctor to see into your throat more easily. If you gag easily, the doctor may spray a local anesthetic into your throat to numb the area.
The doctor will then hold a small mirror at the back of your throat while wearing a head mirror to reflect light into your mouth; or the doctor may wear headgear with a bright light to see into the back of your throat. He or she may ask you to make a high-pitched “e-e-e-e” sound or a low-pitched “a-a-a-a” sound. Making these noises helps the doctor see your vocal cords.
The entire examination takes only 5 to 10 minutes.
If a local (topical) anesthetic is used during the examination, its effects will last about 30 minutes. You can eat or drink according to your doctor’s instructions after the anesthetic has worn off.
Direct flexible laryngoscopy
The doctor may also use a pencil-thin, flexible fibre-optic instrument to look at your throat. You will be given a medication to dry up the secretions in your nose and throat and allow the doctor to see more clearly. A local anesthetic may be sprayed on your throat to numb it.
The scope is put in your nose and then threaded down your throat. As the scope is passed down your throat, the doctor may spray more anesthetic to keep your throat numb during the examination. The doctor will also swab or spray a medication inside your nose that dilates your nasal passages to provide a better view of your airway.
Direct rigid laryngoscopy
Before you have a rigid laryngoscopy, remove all your jewellery, dentures, and eyeglasses. You may want to empty your bladder before the examination. You will be given a hospital gown to wear.
Direct rigid laryngoscopy is done in an operating room. A specially trained doctor and several assistants will perform the procedure. You will be given general anesthetic to make you sleep through the procedure. Since you will be given a general anesthetic, you will need to fast for 6 to 8 hours before the examination.
You will lie on your back during this procedure. An assistant will position your head so that the laryngoscope can be easily placed down your throat. After you are asleep, the rigid laryngoscope will be inserted through your mouth and down your throat. Once the scope is in place, the doctor will be able to view your voice box (larynx).
The rigid laryngoscope may also be used to remove foreign objects that may get caught in your throat, collect tissue samples (biopsy), remove growths from the vocal cords, or perform laser treatment.
In the recovery time after the procedure:
- If your vocal cords were actually cut during the laryngoscopy, rest your voice completely for at least 3 days after the procedure.
- If you speak, do so in your normal tone of voice and keep your conversations short. Whispering or shouting can strain and damage the vocal cords as they are trying to heal.
- You may have hoarseness for up to 3 weeks after the procedure.
- Resume your normal diet when you are comfortable doing so.
After the procedure, you may experience some nausea, general muscle aches, and may feel tired for 1 to 2 days. You also may have a sore throat and some hoarseness for a few days. Sucking on throat lozenges or gargling with warm salt water may help soothe your sore throat.
Laryngoscopy is usually a very safe procedure. Although complications don’t occur very often, you should discuss the risks in your particular case with your doctor.
All types of laryngoscopy have a slight risk of triggering a life-threatening blockage of the airway. This risk may be greater if you already have a partially blocked airway because of tumours, polyps, or severe inflammation of the tissues at the back of the throat (epiglottitis). If complete blockage of the airway should occur, the doctor may have to make an incision in your neck to help you breathe (a tracheotomy). This complication is very rare.
If biopsy samples were taken, there is a very slight risk of prolonged bleeding, infection, or perforation of the airway. In very rare cases, death may occur from the general anesthetic used during direct laryngoscopy.