Correlative Value of Airway Assessment by the Modified Mallampati Classification and Cormack and Lehane grading in Patients with Goitre Scheduled for Thyroidectomy Under General Anaesthesia

Background: Patients with goitres may present with difficult airway. The Modified Mallampati test (MMP) assists the anaesthetist in planning airway management. Aim of the study was to determine the correlative value of the MMP and Cormack and Lehane (CL) in goiter patients scheduled for thyroidectomy. Methodology: Patients recruited were 250. MMP was assessed preoperatively and CL grading at laryngoscopy. MMP and CL 1 and 2 were rated easy intubations while MMP and CL 3 and 4 were rated difficult intubations. Data collected: number of patients in MMP and CL, true positive (TP), false positive (FP), true negative (TN) and false negative (FN). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and correlation were derived. Results: Highest percentage of patients in MMP were in class II, 45.6% and the lowest were in class IV, 4.8%. Highest percentage of patients in CL were in grade 1, 42.8% while the lowest were in grade 4, 13.2%. There were 37, 36, 131 and 46 patients that had TP, FP, TN and FN respectively. Sensitivity, specificity, PPV, NPV and diagnostic accuracy were 50.68%, 74.01%, 49.22%, 75.12% and 66.27% respectively. Pearson’s correlation coefficient was 0.192, p = 0.002. Three patients had failed intubation. Conclusion: MMP had low sensitivity of 50.68% and low positive predictive value of 49.22% in goitre patients scheduled for thyroidectomy under general anaesthesia. Though there was positive correlation between MP and CL, it was negligible Addition of other tests may improve predictive accuracy when there is a high index of suspicion.