Accuracy of a smartphone to test laryngoscope's light and an audit to our laryngoscopes using an ISO standard

Laryngoscope is a key tool in anesthetic practice. Direct laryngoscopy is a crucial moment and inadequate laryngoscope's light can lead to catastrophic consequences. From our experience laryngoscope's light is assessed in a subjective manner and we believe a more precise evaluation should be used. Our objective is to compare the accuracy of a smartphone compared to a lux meter. Secondly we audited our Operating Room laryngoscopes. We designed a pragmatic study, using as primary outcome the accuracy of a smartphone compared to the lux meter. Further we audited with both the lux meter and the smartphone all laryngoscopes and blades ready to use in our Operating Rooms, using the International Standard form the International Organization for Standardization. For primary outcome we found no significant difference between devices. Our audit showed that only 2 in 48 laryngoscopes complied with the ISO norm. When comparing the measurements between the lux meter and the smartphone we found no significant difference. Ideally every laryngoscope should perform as required. We believe all laryngoscopes should have a practical but reliable and objective test prior to its utilization. Our results suggest the smartphone was accurate enough to be used as a lux meter to test laryngoscope's light. Audit results showing only 4% comply with the ISO standard are consistent with other studies. The tested smartphone has enough accuracy to perform light measurement in laryngoscopes. We believe this is a step further to perform an objective routine check to laryngoscope's light. O laringoscópio é uma ferramenta essencial na prática anestésica. A laringoscopia direta é um momento crucial e uma luz inadequada do laringoscópio pode levar a consequências catastróficas. De acordo com nossas pesquisas, a luz do laringoscópio é avaliada de forma subjetiva e acreditamos que uma avaliação mais precisa deve ser feita. Nosso objetivo foi comparar a precisão de um smartphone com a de um luxímetro. Depois, fizemos uma auditoria de nossos laringoscópios em sala de operação. Estudo pragmático usando como desfecho primário a precisão de um smartphone em comparação com a de um luxímetro. Subsequentemente, fizemos uma auditoria tanto com o luxímetro quanto com o smartphone de todos os laringoscópios e lâminas prontos para uso em nossas salas de cirurgia, usando as normas da International Organization for Standardization (ISO). Para o desfecho primário não encontramos diferença significativa entre os