A study of the brightness of laryngoscope light.
We have measured the brightness (luminance) of the light spot produced by 105 Macintosh 3 laryngoscope blades (33 bulb, 72 fibrelight) using a Hagner photometer. An estimate of the minimum luminance required for laryngoscopy (circa. 100 cd.m-2), was determined using a laryngoscope adapted to provide a variable light output. Five (15%) of bulb blades and 24 (33%) of the fibrelight blades failed to meet this minimum level. A new bulb blade produced brighter lighting conditions (maximum 700 cd.m-2) than a new fibrelight blade (max. 500 cd.m-2). In total, 61 (84%) of the fibrelight blades and three (9%) of the bulb blades were found to provide a light spot that encompassed areas of luminance below 30 cd.m-2, which is a level for comfortable reading. The light spot from a mains-powered fibreoptic bronchoscope was found to be four times brighter (2000 cd.m-2) than a new battery-powered fibrelight laryngoscope.
Skilton
R W
RW
Maelor Hospital, Clwyd.
Parry
D
D
Arthurs
G J
GJ
Hiles
P
P
D020680:Bronchoscopes; D005336:Fiber Optic Technology / Q000295:instrumentation; D006801:Humans; D020704:Laryngoscopes; D008029:Lighting; D010783:Photometry