Laryngoscope Illuminance in a Tertiary Care Medical Center: Industry Standards and Implications for Quality Laryngoscopy

Abstract

Objective: To test the hypothesis that a substantial proportion of laryngoscopes exhibit substandard illuminance by comparing laryngoscope illuminance in a tertiary-level medical center to established standards and identifying features associated with poor illuminance.

Study design: Cross-sectional observational study.

Setting: Academic tertiary care medical center (level 1 trauma center, specialty cardiac hospital, and general hospital).

Subjects and methods: Laryngoscopes from main, cardiac, and outpatient operating rooms; emergency department; and code carts were tested using a standard technique. Illuminance (lux) was chosen as the outcome measure. Benchmarks were derived from the International Standards Organization and medical literature. Light types included incandescent bulb, light-emitting diode, and xenon. Personnel were surveyed regarding maintenance practices.

Results: Across all hospitals, 691 laryngoscopes were tested. Mean (SD) illuminance was 810 (700) lux for incandescent bulb-on-blade designs (n = 237), 1860 (1220) lux for incandescent bulb in-handle designs (n = 79), 4730 (3210) lux for LED (n = 354), and 28,800 (34,500) lux for xenon (n = 21). Seven percent of units failed to turn on (n = 45). Using an established threshold of 867 lux, 28% of devices (47% of incandescent, 12% of LED, and 10% of xenon) were substandard. All laryngoscopes were cleaned according to standard protocols following use; no preventive maintenance was reported.

Conclusion: Twenty-eight percent of laryngoscopes in a tertiary care hospital exhibit substandard illuminance; these results corroborate the findings of our inaugural study on this subject. Consequently, our hospital is instituting changes to reduce the likelihood of substandard performance by laryngoscopes in circulation.

Keywords: airway management; device failure; device performance; emergency medical services; intratracheal; intubation; laryngoscopy; light; lighting; quality assurance; quality control.