A laryngoscope (
larynx+ scope) is a medical instrument that is used to obtain a view of the vocal folds and the glottis, which is the space between the cords.
There are many types of laryngoscopes. A rigid laryngoscope utilized by anesthesia personnel for intubation typically consists of a handle (incorporating two batteries) and an interchangeable blade with a bulb
light source. Laryngoscopes used by otolaryngologists are found in many variations, used for various specialized tasks during endoscopy or surgery of the upper aerodigestive tract.
The original anesthesiologists' laryngoscope used a straight "Magill" [http://en.wikipedia.org/wiki/Ivan_Magill] blade, and this design is still the standard pattern veterinary laryngoscopes are based upon; however the blade is difficult to control in adults and can cause pressure on the vagus nerve, which can cause unexpected cardiac arrhythmias to spontaneously occur in adults.
There are many types of laryngoscope blades used by anesthesia personnel. The two main types are the curved Macintosh blade and the straight Miller (or Robertshaw) blade. The Macintosh blade sits anterior to the epiglottis and raises it out of the visual pathway, while the Miller blade sits posterior to the epiglottis, trapping it while exposing the glottis and vocal folds. Incorrect usage can cause trauma to the front Incisor teeth; the correct technique is to lift the chin upwards and forward at the same time, not to use the blade as a lever with the teeth serving as the fulcrum.
The Miller and Robertshaw blades are usually used for infants, this is due to the larger comparative size of the epiglottis, which makes the Macintosh blade less effective.
Direct laryngoscopy, generally performed by an otolaryngologist (ear, nose, throat, head and neck surgeon) is carried out (usually) with the
patientlying on his or her back; the laryngoscope is inserted into the mouthon the right side and flipped to the left to trap and move the tongueout of the line of sight, and, depending on the type of blade used, either inserted anterior or posterior to the epiglottisand then lifted with an upwards and forward motion. This move makes a view of the glottispossible. There are at least ten different types of laryngoscope used for this procedure, each of which has a specialized use for the otolaryngologist. This procedure is most often employed in direct diagnostic laryngoscopy with biopsy. It is extremely uncomfortable and is not performed on conscious patients, or on patients with an intact gag reflex.
Laryngoscopy is performed to facilitate
endotracheal intubationas part of general anesthesia or CPR ( cardiopulmonary resuscitation) during cardiac arrest, or, more specifically, for procedures on the larynx or other parts of the upper aerodigestive tract.
The invention of the laryngoscope is hotly disputed; some claim it was invented by
Manuel Patricio Rodríguez García, Professor of Music, and singing teacher for Jenny Lind, the "Swedish Nightingale"; whilst other medical giants (Morell Mackenzie writing in 1865) claim it was Benjamin Guy Babington.
Another type of procedure performed by many
ENTspecialists in clinics, called an indirect laryngoscopy. It utilizes a straight rod mounted mirror ("laryngeal mirror"; vide Instruments used in otolaryngology) that is inserted into the throat and used to look at the laryngeal inlet.
Transnasal Flexible Laryngoscope
A transnasal flexible laryngoscope can be used for office-based diagnostics.The patient remains wide awake during the procedure, so the vocal fold can be observed during speech or singing. Surgical instruments passed through the scope can be used for performing procedures such as biopsies of suspicious masses.
* [http://homepage.mac.com/changcy/endo.htm Photos of Flexible Laryngoscopy and Its Variations]
* [http://health.yahoo.com/ency/healthwise/hw232056/hw232059;_ylt=Amgb8b_Qd0FDsxd1rMIryuXogrMF Yahoo Health on Laryngoscopy]
* [http://www.entcolumbia.org/tfl.htm Transnasal Flexible Laryngoscopy (TFL)]
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