Grading of Bag-Mask Ventilation Difficulty and Association with Unanticipated Difficult Laryngoscopy/Intubation in Children at a Training Center University Hospital: A Prospective Cohort Study

Abstract

Objective: In children, the grading of Bag-Mask Ventilation (BMV) difficulty and its association with difficult laryngoscopy/intubation has not been well established. This study aimed to evaluate the grading for BMV difficulty and determine its association with difficult laryngoscopy/intubation in a normal airway pediatric population. Methods: This prospective cohort study was conducted in children aged ≤9 years who underwent general anesthesia and oroendotracheal tube intubation between September 2008 and December 2012. Difficult laryngoscopy was defined as a Cormack-Lehane laryngoscopic view grade of 3 or 4. Difficult intubation was defined as the occurrence of at least two of the following: 1) at least three intubation attempts using direct laryngoscopy by experienced personnel (excluding first intubation attempts); 2) intubation time >300 s; and 3) occurrence of desaturation (SpO 2 <95%). The use of open airway maneuvers, including continuous positive airway pressure (CPAP), oropharyngeal airway (OPA), and two-person ventilation (TPV), or unsuccessful BMV were also considered. The association between BMV difficulty and difficult laryngoscopy/intubation was assessed using multivariate logistic regression with adjusted odds ratios (OR), 95% confidence intervals (CIs), and area under the receiver operating characteristic curve (AUC). Results: The incidence of difficult laryngoscopy/intubation was 6.4% (49/765). The categories of BMV difficulty were grade 0 (easy BMV without requiring an open airway maneuver, n=308), grade 1 (easy BMV after applying CPAP, n=368), grade 2 (successful BMV after inserting an OPA, n=16), grade 3 (successful BMV after applying TPV, n=71), and grade 4 (unsuccessful BMV after applying all airway maneuvers, n=2). Difficult BMV was defined as a BMV grade of 3 or 4 (v/s grades 0-2). After adjusting for age, body weight, history of snoring, type of operation, use of neuromuscular blocking agents, and first laryngoscopist, BMV difficulty was significantly associated with difficult laryngoscopy/intubation (adjusted OR [95% CI]=2.5 [1.1-5.5], sensitivity 0.59, specificity 0.74, AUC=0.70). Conclusion: A BMV grade of 3 (requiring TPV) or 4 (unsuccessful BMV) was associated with difficult laryngoscopy/ intubation in a pediatric population.

Pre-epiglottic Space and Epiglottis to Vocal Cord Ratio in Order to Predict Difficult Intubation in Adults: A Multivariate Analysis

“…The incidence of difficult intubation in our study was 14%. We used the combination of high grade Cormack-Lehane classification 4,6 , which corresponded to difficult laryngoscopy in children 15 and criteria of difficult intubation in adults 1,2 to establish the criteria of difficult intubation. According to previous airway ultrasound studies, researchers used high grade CL (2b up) to represent difficult laryngoscopy and difficult intubation 16 .…”