Prediction of difficult intubation using tongue mobility

Abstract

Aim: The aim of study is to determine the possible usage of tongue movements out of the mouth in the prediction of difficult intubation. Methods: Two hundred twenty-three patients undergoing abdominal surgery under general anesthesia, between 2014 and 2015, were enrolled in this study. Difficult intubation was evaluated using the intubation difficulty scale (IDS) score. All intubations were performed by the same anesthesiologist to eliminate the differences in the anes­thesiologists` experience. IDS scores were evaluated by anesthesiologists who had no idea about the measurements of the tongue movements and performed laryngeal intubation in all patients. To define the tongue movements, horizontal lines were used. Horizontal lines were passed through the mid points of the mandible and upper lip height. Patients were asked to protrude the tongue maximally and upward (PTMU), to protrude tongue maximally and downward (PTMD) in anatomically neutral position when sitting down on a chair. Results: Mallampati III and IV score in the difficult intubation group was significantly higher than in the groups without difficulty in intubation (p<0.001). Similarly, Cormack-Lehane III and IV score in the difficult intuba­tion group was significantly higher than in the groups without difficulty in intubation (p<0.001). PTMU and PTMD in the difficult intubation group was significantly higher than in the groups without difficulty in intuba­tion (p=0.001 and p=0.002, respectively). Patients who could not reach and pass target of PTMD OR=7.3 (95% CI: 2.1 - 25.0) had a higher risk of difficult intubation than the ones who could reach and pass the target (p=0.001). Patients who could not reach and pass the target of PTMU OR=4.5 (95% CI: 1.7 - 11.4) had a higher risk of diffi­cult intubation than the ones who could reach and pass the target (p=0.001). Conclusion: We investigated the relationship between difficult intubation and tongue movements, which has some advantages like easy application and objectivity.