A Study of the Lma C - Trach Tm Guided Intubation With Special Reference to the Conventional Laryngoscopic Cormack and Lehane Grading System

Abstract

BACKGROUND AND AIMS: Laryngeal Mask Airway (LMA), one of the supraglottic airway devices, has become a standard fixture in airway management, filling a niche between the face mask and tracheal tube in terms of both anatomical position and invasiveness. Here we tried to correlate between the Cormack and Lehane view grading achieved by rigid laryngoscopy and the view of larynx achieved by the LMA CTrach TM system, the success rates of LMA CTrach TM insertion and of endotracheal intubation with this system, a modification of the original LMA with integrated fiberoptic system. SETTINGS AND DESIGN: A randomized, controlled study. MATERIALS AND METHODS: The study comprised 100 consenting patients of ASA class I(95) and II(5), posted for elective surgical and gynecological procedures under general anesthesia after having institutional ethics committee approval. After achieving optimum anesthesia and muscle relaxation, an anesthesiologist with more than 5 years of experience did the Cormack and Lehane grading by rigid laryngoscopy but did not reveal that to the second anesthesiologist who carried out the CTrach TM procedure and graded laryngeal view as per Endoscopic View Grading System (EVGS). The success rates of ventilation and intubation using CTrach TM were determined. Adjusting maneuvers were undertaken to improve the laryngeal view. STATISTICAL ANALYSIS AND RESULTS: Inter-rater agreement between the 2 procedures was found to be 0.107 using Cohen's Kappa statistics with a 95% Confidence Interval of (-) 0.0475-0.262, which signifies minimal agreement or correlation between the 2 procedures. We found statistically significant difference present in the Initial view & Final view group (p <0.0001). CONCLUSION: There was minimal correlation between Cormack and Lehane (C-L) grading achieved by direct laryngoscopy and the view of larynx achieved by the LMA CTrach TM system, thereby aiding successful ventilation and intubation.