Morphometric and ultrasonographic determinants of difficult laryngoscopy in obese patients: A prospective observational study

Abstract

Background: Obese people have a higher risk of difficult laryngoscopy due to their thick neck, large tongue, and redundant pharyngeal soft tissue. However, there is still no established predictive factor for difficult laryngoscopy in obese population. Methods: We conducted a prospective assessor-blind observational study to enroll adult patients with a body mass index of 30 kg·m-2 or higher undergoing laparoscopic sleeve gastrectomy at a medical center between May 2020 and August 2021. Conventional morphometric characteristics along with ultrasonographic airway parameters were evaluated before surgery. The primary outcome was difficult laryngoscopy, defined as a Cormack and Lehane’s grade III or IV during direct laryngoscopy. Logistic regression analyses were performed to evaluate the association between included factors and difficult laryngoscopy. Discrimination performance of predictive factors was assessed using area under the receiver operating characteristic curve (AUC). Results: A total of 80 patients were evaluated, and 17 (21.3%) developed an event of difficult laryngoscopy. Univariate analyses identified five factors associated with difficult laryngoscopy, including age, sex, hypertension, neck circumference, and cross-sectional area of tongue base. After adjusting for these variables, neck circumference was the only independent influential factor, adjusted odds ratio: 1.227 (95% confidence interval, 1.009–1.491). Based on Youden’s index, the optimal cutoff of neck circumference was 49.1 cm with AUC: 0.739 (sensitivity: 0.588, specificity: 0.889; absolute risk difference: 0.477, and number needed to treat: 3). Conclusion: Greater neck circumference was an independent risk factor for difficult laryngoscopy in obese patients. This finding provides a way of reducing unanticipated difficult airway in this high-risk population.

Introducing the First Distal Pharyngeal Airway

“…10 Notably, patients with obesity and OSA have greater neck circumference and more anterior neck soft tissues, which may predispose them to having a difficult airway. [11][12][13] Due to the unique airway difficulties in these groups, there is a growing need for an airway device that addresses obstructing distal pharyngeal tissues.…”

Pelvic adhesion: A challenge of all gynecologic surgeries

“…1 Besides conservative treatment, surgical lysing procedures, called as adhesiolysis sometimes cannot be totally avoided in these subjects with adhesion, since either emergency, such as intestinal obstruction complicated by adhesions or the other indications for further surgery, such as recurrent uterine myomas, adenomyosis, chocolate cysts, or others may occur. Minimally invasive procedures, such as hysteroscopic, laparoscopic, and robotic approaches, are very popular in the management of subjects with various indications for surgeries, 5,8,9 and additionally, these approaches are also reported as the preferred options for adhesiolysis. 1,10 However, it is believed in long term that history of any of myomectomy, cystectomy, electrofulguration for endometriosis, appendectomy, or bowel surgery is considered as a “contraindication” for laparoscopic surgeries, 11 although this hypothesis is worthy of being tested.…”