CORRELATION OF PALM PRINT SIGN AND DISTANCE FROM SKIN TO EPIGLOTTIS AS ASSESSED BY CORMACK-LEHANE GRADING IN PATIENTS UNDERGOING GENERAL ANAESTHESIA: A PROSPECTIVE OBSERVATIONAL STUDY

Abstract

Background and Aims: Prediction and preparation for difficult airway management is important in minimising peri-operative airway complications. This study aimed to evaluate the correlation between palm print sign (PP sign), distance from skin to epiglottis (DSE) and hyomental distance ratio (HDMR) with Cormack-Lehane (CL) grading in patients receiving general anaesthesia. Methods: After IEC clearance, CTRI registration and patient consent, a prospective observational study was conducted on 42 patients aged 18-65 years requiring tracheal intubation. Patients were randomised into two groups (n=21). Anaesthesiologist blinded to study assessed PP sign in Group A and performed airway ultrasonography in Group B to measure DSE and HDMR. Laryngoscopy was performed by single anaesthesiologist in both groups and CL grade noted, easy airway (CL-1,2a) and difficult (CL-2b,3,4). Principal investigator who is blinded analysed parameters of Group A and B with CL grading. DSE>2.5cm and HDMR< 1.2cm predicted difficult airway. Statistical analysis was done using Kendall’s Tau Correlation test and Chi square test. Results: The diagnostic performance of DSE, HDMR and PP sign was compared with Cormack-Lehane grading. HDMR showed highest diagnostic accuracy with sensitivity and specificity of 69.4%, positive predictive value (PPV) of 46.9% and negative predictive value (NPV) of 66.1%. PP sign demonstrated intermediate accuracy (sensitivity 54.5%, specificity 50.2%, PPV 38.9%, NPV 53.8%), while DSE showed lowest performance (sensitivity 36.5%, specificity 30.5%, PPV 28.9%, NPV 34.6%). Conclusion:  Sonologically measured HDMR is relatively better predictor of difficult laryngoscopy than DSE and PP sign. Airway ultrasound represents a useful and emerging tool for predicting difficult airway.