Review of: Cheung KW, Kovacs G, Law JA, et al: "Illumination of bulb-on-blade laryngoscopes in the out-of-hospital setting." Academic Emergency Medicine. March 28, 2007.
I generally don't comment on studies that are still in press, because it makes it more difficult for you to find them. However, in this instance I felt the study abstract alone had sufficiently compelling information that we could make some useful inferences from it.
The authors of this study chose to examine the brightness of the laryngoscopes in their service. They randomly visited each station and measured each scopes' brightness using a standard light meter. They then measured its brightness after placing new batteries in it, then placing a new bulb using the original battery, and with a new battery and new bulb. As a final test, they attached a disposable blade to the scope with fresh batteries.
They measured 51 scopes. Mean illumination was 624 lux. New batteries increased the brightness by 168 lux. A new bulb increased the brightness by 679 lux, and the combination of new batteries and a new bulb by 937 lux. The disposable blade with its built in light source (not fiber-optic) resulted in an increase of 2401 lux.
They concluded that, "Optimal changing of lightbulbs and batteries in the out-of-hospital setting will have to be more clearly defined."
Again, we have another study that would appear to be a "no-brainer." New batteries? New bulb? Brighter light! Remarkable! However, could poor lighting be contributing to failed endotracheal intubations? Wouldn't it have been interesting if they could track the experience of a given scope and it's brightness?
Regardless, with the increased awareness of the vital need to get the tube in on the first attempt and make that attempt as short as possible, the role of brightness may very well be an issue we should consider when purchasing equipment. The authors' conclusion did not address the most revealing part of their results. The disposable blade was the brightest.
Rather than worry about changing batteries and bulbs, why not just suggest that all intubations be performed with single-use disposable blades? There are a growing number of such devices on the market, including those that can be attached to a video display to enable a more comfortable approach to intubation. These devices also provide the capability of recording the intubation for both risk management and quality improvement purposes.