Laryngoscopy

Laryngoscopy may be performed to facilitate tracheal intubation during general anaesthesia or cardiopulmonary resuscitation or for surgical procedures on the larynx or other parts of the upper tracheobronchial tree.

[citation needed] Indirect laryngoscopy is performed whenever the provider visualizes the patient's vocal cords by a means other than obtaining a direct line of sight (e.g. a mirror).

[citation needed] Some historians (for example, Morell Mackenzie) credit Benjamin Guy Babington (1794–1866), who called his device the "glottiscope", with the invention of the laryngoscope.

[1] Philipp von Bozzini (1773–1809)[2][3] and Garignard de la Tour were other early physicians to use mouth mirrors to inspect the oropharynx and hypopharynx.

[7][8] All previous observations of the glottis and larynx had been performed under indirect vision (using mirrors) until 23 April 1895, when Alfred Kirstein (1863–1922) of Germany first described direct visualization of the vocal cords.

[15] An American anesthesiologist practicing at Bellevue Hospital in New York City, Janeway believed that direct intratracheal insufflation of volatile anesthetics would provide improved conditions for surgery of the nose, mouth and throat.

Incorrect usage can cause trauma to the front incisors; the correct technique is to displace the chin upwards and forward at the same time, not to use the blade as a lever with the teeth serving as the fulcrum.

[28] In an attempt to address some of these limitations, Jon Berall, a New York City internist and emergency medicine physician, designed the camera screen straight video laryngoscope in 1998.

The first true video laryngoscope Glidescope was produced in 1999 and a production version with 60 degree angle, an onboard heater, and a custom screen was first sold in dec 2000.

In a 2003 study, the authors noted that the GlideScope provided adequate vision of the glottis (Cormack and Lehane grade I-II) [30][31] even when the oral, pharyngeal and laryngeal axes could not be optimally aligned due to the presence of a cervical collar.

The Verathon design team later produced the Ranger Video Laryngoscope for a United States Air Force requirement that is now rolling forward into EMS and military use.

The Cobalt series of GlideScope then introduced a single-use variant that encompasses weights from 1000 grams to morbid obesity and is successful in many airway syndromes as well.

The GlideScope Ranger is a variant designed for use in pre-hospital airway management including air, land, and sea applications.

The GlideScope Cobalt is a variant that has a reusable video camera with light-emitting core which has a disposable or single use external shell for prevention of cross infection.

In August 2009, the team at Verathon collaborated with Professor John Sakles from the University of Arizona Emergency Department in achieving the world's first tracheal intubation conducted with the assistance of telemedicine technology.

During this demonstration, Sakles and the University of Arizona Telemedicine service guided physicians in a rural hospital as they performed a tracheal intubation using the GlideScope.

[44] Other "noninvasive" devices which can be employed to assist in tracheal intubation are the laryngeal mask airway[45][46][47][48][49][50][51] (Some types of which may be used as a conduit for endotracheal tube placement), the lighted stylet,[52][53] and the AirTraq.

[54] Due to the widespread availability of such devices, the technique of blind digital intubation[55] of the trachea is rarely practiced today, though it may still be useful in emergency situations under austere conditions such as natural or man-made disasters.

Anatomical parts seen during laryngoscopy
The laryngoscopy. From García , 1884
Laryngoscope handles with an assortment of Miller blades (large adult, small adult, pediatric , infant , and neonate )
Laryngoscope handle with an assortment of Macintosh blades (large adult, small adult, pediatric , infant , and neonate )
Intubation Macintosh Blade Sagittal View
Vie Scope Direct Line of Site Laryngoscope by Adroit Surgical
Glidescope video laryngoscope, showing 60-degree angulated blade. The CMOS active pixel sensor (CMOS APS) video camera and light source are located at the point of angulation of the blade. An anesthesia machine is visible on the high resolution LCD monitor .
Anesthesiologist using GlideScope video laryngoscope to intubate the trachea of a patient with challenging airway anatomy