Relationship of neck circumference and difficult endotracheal intubation in obese patients

Abstract

Background and Objectives:Patient identification with difficult intubation is important in planning anesthetic management and one major factor for difficult intubation in the obese patients is large neck circumference. The need for prediction of a potentially difficult airway received great importance as it plays a significant role in reducing morbidity and mortality. Therefore, this study was done to glimpse the effect of neck circumference on endotracheal intubation and to determine the frequency of difficult intubation. Material and Methods:The study was cross sectional descriptive study and convenient sampling technique was used. Seventy patients of age between 19-50 years of both sexes were enrolled. Neck circumference was measured at the level of cricoid cartilage along with other airway assessments. Direct laryngoscopy was done and checked whether it is difficult one or easy using Intubation difficulty scale. Data were entered and analyzed by using statistical software SPSS version 15.0. Results:Mean BMI was noted as 33.02±2.30 kg/m2 and the mean neck circumference was 43.64±2.30 cm. Difficult intubation was observed in 23 (32.86%) patients with mean neck circumference of 45.44±1.88 cm and normal intubation observed in 47(67.14%) patients with mean neck circumference of 42.77±1.98 cm. Linear correlation was found between the neck circumference and Intubation Difficulty Scale score with value of Pearson correlation=0.617. Conclusion:Neck circumference of patient was found to have significant effects on difficult intubation. Frequency of difficult intubation was found in almost one third of obese patients with increasing neck circumference.

Clinical Relevance of Mallampati Grading in Predicting Difficult Intubation in the Era of Various New Clinical Predictors

“…The diagnostic value of TMD was found to be unsatisfactory as an individual predictor in Meta-analysis performed by Shiga et al [ 17 ]. It has been observed in many previous studies [ 21 ], that neck circumference of obese patients was found to have significant effects on difficult intubation at 40 cm of neck circumference, the probability of difficult intubation was approximately 5%, and at 60 cm of neck circumference, the probability of difficult intubation was approximately 35% and concluded that increase in neck circumference was associated with difficult intubation in obese patients [ 22 ]. The disparity in the present study and study done by others can be explained by the exclusion criteria of the present study which did not include the patients with BMI>35 kg/mt2.…”

Effectiveness and Validity of Preoperative Ultrasonographic Airway Assessment and Clinical Screening Tests to Predict Difficult Laryngoscopy: A Prospective, Observational Study

“…Shiga et al also found the diagnostic value of TMD unsatisfactory as an individual predictor [6]. However, many previous studies [17][18] concluded that an increase in neck circumference significantly affected difficult intubation and was directly proportional to difficult intubation, especially in obese patients. And since we excluded the patient with BMI > 35 kg/m2 in the present study, this disparity in results is expected.…”