Use of the 'L-E-M-O-N' score in predicting difficult intubation in Africans

Background: Endotracheal intubation is an integral part of airway management and is key to the practice of safe anesthesia. Prediction of a difficult airway can help reduce the incidence of failed or difficult intubation. We studied the use of 'L-E-M-O-N' (Look-Evaluate-Mallampati-Obstruction-Neck mobility) scoring system to predict difficult intubation and determine the prevalence of difficult intubation among adult surgical patients. Materials and Methods: One hundred and sixty (160) consecutive ASA I-III surgical patients between 18 and 65 years of age were recruited from October to December 2011. A variety of airway tests using the 'L-E-M-O-N' scoring were done during preoperative assessment; and at induction of anesthesia, airway assessment using Cormack and Lehane was performed and the results were recorded by a standardized record sheet. The variables evaluated were gender, age, weight, height, body mass index (BMI), dentition and a variety of airway tests using the 'L-E-M-O-N' scale. SPSS version 17.0 was used for statistical analysis; and a P value <0.05 was considered significant. Results: Prevalence of difficult intubation using Cormack and Lehane score only was found to be 8.1%. The 'LOOK' features had sensitivities of 99.1%, 96.6%, and 92.5% for facial trauma, large incisors, and beard or moustache, respectively, and positive predictive values of 0%. Combination of predictors in the 'L-E-M-O-N' score showed that, as the mean 'L-E-M-O-N' score of the patients increased, the likelihood of difficult visual laryngoscopy also increased. Conclusion: Combination of airway predictors in the 'L-E-M-O-N' scoring system significantly improves the ability to predict difficult intubation.