Predictors of difficulty in intubation in patients with obstructive sleep apnoea

• Published in: Medical journal of Malaysia Vol. 74; no. 2; pp. 133 - 137
• Main Authors: Wang, C M Z, Pang, K P, Tan, S G, Pang, K A, Pang, E B, Cherilynn, T Y N, Chan, Y H, Rotenberg, B W
• Format: Journal Article
• Language: English
• Published: Malaysia 01.04.2019
• Subjects: Adolescent; Adult; Age Factors; Aged; Body Mass Index; Female; Humans; Intubation, Intratracheal - adverse effects; Intubation, Intratracheal - methods; Male; Middle Aged; Prospective Studies; Sleep Apnea, Obstructive - complications; Surgical Procedures, Operative; Young Adult
• ISSN: 0300-5283

To evaluate predictors of difficult intubation in patients with obstructive sleep apnoea (OSA). Prospective series of 405 OSA patients (350 males/55 females) who had upper airway surgery. Procedures included functional endoscopic sinus surgery, septoplasty, turbinate reduction, palate/tonsil surgery, and/or tongue base surgery. Intubation difficulty (ID) was assessed using Mallampati grade, Laryngoscopic grade (Cormack and Lehane), and clinical parameters including BMI, neck circumference, thyromental distance, jaw adequacy, neck movements and glidescope grading. Mean age was 41.6 years old; mean BMI 26.6; mean neck circumference 44.5cm; mean Apnea Hypopnea Index (AHI) was 25.0; and mean LSAT 82%. The various laryngeal grades (based on Cormack and Lehane), grade 1 - 53 patients (12.9%), grade 2A - 127 patients (31.0%), grade 2B - 125 patients (30.5%), grade 3 - 93 patients (22.7%) and grade 4 - seven patients (1.7%); hence, 24.4% had difficulties in intubation. Parameters that adversely affected intubation were, age of the patient, opening of mouth, retrognathia, overbite, overjet, limited neck extension, thyromental distance, Mallampati grade, and macroglossia (p<0.001). Body mass index (BMI) (p=0.087), neck circumference (p=0.645), neck aches (p=0.728), jaw aches (p=0.417), tonsil size (p=0.048), and AHI (p=0.047) had poor correlation with intubation. BMI-adjusted for Asians and Caucasians, showed that Asians were more likely to have difficulties in intubation (adjusted OR = 4.6 (95%Confidence Interval: 1.05 to 20.06) (p=0.043), compared to the Caucasian group. This study illustrates that difficult intubation can be predicted pre-surgery in order to avert any anaesthetic morbidity.