Laryngoscopes

Although blind or tactile tracheal intubation of awake patients could be mastered with extensive practice, an improved technique to accomplish tracheal intubation was developed by Alfred Kirstein^{[417] [418]} (1863–1922), Chevalier Jackson^[419] (1865–1958), and Gustav Killian (1898–1912), all contributors in the introduction of the hand-held laryngoscope. Before the pioneering efforts of these innovators, the only way to visualize the larynx was with indirect laryngoscopy, a technique introduced by the Spanish singing instructor Manuel Garcia (1805–1868). In 1854, Garcia read a paper before the Royal Society entitled "Observations on the Human Voice," wherein he described his use of mirrors to view his student's and his own larynx during vocalization.^[420] Alfred Kirstein was charting unknown territory in 1895, when he boldly suggested that the larynx could be directly visualized with instruments similar to the commonly used esophagoscope.^[417] Although he abandoned the procedure in 1 year, it was revived 13 years later by Gustav Killian,^[421] whose portable laryngoscope was remarkably like the current instrument, but with no light attached.

Direct laryngoscopy did not gain in popularity among anesthesiologists until Chevalier Jackson promoted the use of his hand-held laryngoscope for insertion of tracheal insufflation catheters. Even then, the technique was slow to gain acceptance, but the accelerated use of muscle relaxants eventually required the anesthesiologist to be adept at rapid placement of tubes within the trachea. The first hand-held laryngoscopes, as perfected by Jackson, were U-shaped and had no curve at the tip. A light at the end of the blade was a unique contribution by Jackson that has been retained, with the modification that some instruments today use a fiberoptic bundle in the blade.

Anesthesiologists soon began to design their own laryngoscopes that were more suitable for insertion of endotracheal tubes. Robert A. Miller^[422] designed a new blade that was remarkably similar to Killian's instrument, except for a slight curve at the distal end. Robert R. Macintosh's (1897–1989) (see Fig. 1-18C ) improved laryngoscope featured a short, curved blade that elevated, instead of retracted, the epiglottis. ^[423] This promoted a new concept in laryngoscopy, specifically designed for the anesthesiologist for timely tracheal intubations. Many intubations were then performed without muscle relaxants, and the Macintosh blade was able to expose the glottis without coming into contact with the sensitive posterior surface of the epiglottis. By this time, a detachable joint had been placed between the blade and the handle. The batteries were located in the handle, conveniently avoiding the trailing wires attached to the distal bulb.