Dataset from a Cohort study assessing the association between difficult laryngoscopies and two new features (the Upper Airway Angle and the Glottic Height)

Published: 26 August 2021| Version 1 | DOI: 10.17632/vvkx4hjmp3.1
Clístenes Carvalho,


Dataset collected from a cohort study assessing the association between difficult laryngoscopies and two new measures: the Upper Airway Angle and the Glottic Height. A summary of our work is presented as follows: ABSTRACT Background: Predicting difficult direct laryngoscopies remains challenging and improvements are needed in preoperative airway assessment. We conceived two new tests (the upper airway angle and the glottic height) and assessed their association with difficult direct laryngoscopies as well as their predictive performance along with the performance of other available bedside tests. Methods: A prospective cohort was conducted with 211 patients – based on a sample size estimation - undergoing general anaesthesia for surgical procedures. We collected preoperatively data on sex, age, weight, height, body mass index (BMI), ASA physical status, modified Mallampati test (MMT), upper lip bite test (ULBT), mandibular length (ML), neck circumference (NC), mouth opening (MO), sternomental distance (SMD), thyromental distance (TMD), upper airway angle (UAA), and glottic height (GH). The main outcome was difficult laryngoscopy defined as Cormack and Lahane classes 3 or 4. Bivariate analyses were performed to investigate mainly the association between variables and alternatively calculate their predictive values. Results: Difficult laryngoscopy was presented by 12 patients (5.7%). Six tests reached statistically significant association with difficult laryngoscopies: the UAA (p < 0.001), the GH (p < 0.001), the ML (p = 0.001), the NC (p = 0.005), the MO (p = 0.036), and the MMT (p = 0.006). The area under the ROC curve and their 95% CIs for these six tests were as follows: UAA = 88.82 (81.86-95.78); GH = 86.43 (72.67-100); ML = 83.75 (72.77-94.74); NC = 79.17 (64.98-93.36); MO = 65.58 (45.13-86.02); and MMT = 77.89 (68.37-87.41). The UAA presented yet the highest sensitivity (100%) and negative predictive value (NPV = 100%), whilst the GH presented the highest overall (91%) and balanced (87.4%) accuracies as well as the highest positive predictive value (PPV = 37%). Conclusion: We have found two new features (the UAA and the GH) to be significantly associated with the occurrence of difficult direct laryngoscopies. They also presented the best predictive performance amongst the nine evaluated tests in our cohort of patients. We cannot ensure, however, these tests to be superior to other regularly used bedside tests based on our estimated 95% CIs.



Health Sciences, Anesthesia, Airway Management, Airway, Perioperative Care