Role of flexible fiberoptic laryngoscopy in predicting difficult intubation.

BACKGROUND: The ability to precisely predict which intubations will be difficult during administration of anesthesia is an important part of preoperative preparation. This study's goal is to accurately identify patients who will be difficult to intubate using the number of tracheal rings observed preoperatively by fiberoptic laryngoscopy.

METHODS: We enrolled 994 adult patients in our study who required general anesthesia and orotracheal intubation for their elective surgeries. All patients received a Mallampati Test, a Wilson Risk-Sum Score, and fiberoptic laryngoscopy before operation. Each patient's age, Body Mass Index (BMI), and neck circumference was recorded preoperatively. Logistic regression analysis was applied to evaluate the association between the recorded risk factors and a potentially difficult intubation. The three preoperative assessments were compared using three parameters: positive predictive value, sensitivity, and specificity.

RESULTS: The risk factors which were determined to be predictive for difficult intubation were: BMI, neck circumference, Mallampati Test, Wilson Risk-Sum Score, and fiberoptic laryngoscopy (P<0.05). Fiberoptic laryngoscopy as a predictive factor in the preoperative setting had a higher sensitivity, specificity, and positive predictive value than did the Mallampati Test or the Wilson Risk-Sum Score (P<0.05).

CONCLUSIONS: Fiberoptic laryngoscopy is a more accurate and convenient preoperative method to predict difficult intubation.