Sivaraj Patchaiappan1, Sudhakaran D2
BACKGROUND
Airway management is of prime importance to the anaesthesiologists. Unanticipated difficult laryngoscopy and endotracheal intubation remains a primary concern for the anaesthesiologists. The reported incidence of a difficult laryngoscopy or endotracheal intubation varies from 1.5% to 13% in patients undergoing surgery. Failure to intubate is detected in 0.05-0.35% of the patients. Thus, preoperative airway assessment is of pivotal importance for the anaesthesiologist to predict difficult intubation.
The aim of the study is to study the usefulness of two different airway assessment predictors, a clinical and radiological tool to predict difficult intubation.
MATERIALS AND METHODS
Two hundred and eight patients in the age group of 15-75 years of either sex were included in the study. We assessed the clinical variable: modified Mallampati classification and radiological variable: the atlanto-occipital distance, in all the patients. Patients with tumours or malformations of head and neck and oral cavity, edentulous patients, pregnant patients and those requiring emergency surgeries were excluded. A Cormack-Lehane grade of I and II were considered as easy intubation and III and IV were considered as difficult intubation.
RESULTS
Thirty eight patients had difficult intubation. The sensitivity and specificity of the clinical model were found to be 97.2% and 95.3%, respectively. The sensitivity and specificity of the combined clinical and radiological model were found to be 100% and 95.3%, respectively. The area below the ROC curves measures the probability of the correct prediction of the clinical and the combined models. It was found to be 0.992 and 0.993, respectively. This means that the clinical and combined models correctly predicted the outcome with a probability of 99.2% and 99.3%, respectively.
CONCLUSION
From this study, we found that- 1. Clinical models- Modified Mallampati classification is an important predictor of difficult intubation. 2. Radiological imaging- Atlanto-occipital distance is also an important predictor, but with less sensitivity than the clinical model. 3. The radiological predictor is of more value when it is combined with clinical variable, but of less value as a single predictor.
