An analysis of laryngoscope blade shape and design: new criteria for laryngoscope evaluation

Abstract

Laryngoscope blade design has tended to be relatively arb#rary and so far scientific analysis has not allowed useful comparisons between blade shapes. A new theoretical method of analysing laryngoscope blades is introduced and uses the depth of in

Light intensity and area of illumination provided by various laryngoscope blades

“…]2 Differences in blade design can result in the laryngoscope fight being directed away from the larynx. 6 We have shown that differences in direct light intensity and field of illumination exist among various laryngoscope/blade combinations. These differences may make tracheal intubation more difficult.…”

Straight blades improve visualization of the larynx while curved blades increase ease of intubation: a comparison of the Macintosh, Miller, McCoy, Belscope and Lee-Fiberview blades

“…The curved tip of the MIL blade helps to obtain better intubation conditions than other straight blades because it increases the exposure of the vocal cords and the room in which to maneuver the tracheal tube. 9 In summary, a good laryngeal view with the intubating device did not equate with ease of intubation. Since the most important aspect of a laryngoscopic intubation is the correct placement of the endotracheal tube, and not the visualization of the larynx, based on our study of 500 patients, we recommend the use of a curved blade to improve intubating conditions.…”

“…We used the larger M blade #4 as theoretical and clinical observations have demonstrated its superiority to M #3. [8][9][10] The other blades were of similar sizes.…”

An evaluation of a modified Macintosh laryngoscope in a manikin

“…1 Instead, the majority of laryngoscope designers resort to subjective anecdotal recommendations ranging from modest claims to bold generalisations. 2 Among the factors which have contributed to this situation are our limited ability to quantify important aspects of the laryngoscopic procedure and the great variability in the anatomy of the upper airways of patients. The former problem has been greatly reduced with a recently introduced "measuring" laryngoscope handle, s The latter can be circumvented by using intubation manikins, which also enable measurements to be made which can not be performed in patients.…”