Correlation of Neck Circumference with Difficult Mask Ventilation and Difficult Laryngoscopy in Morbidly Obese Patients: an Observational Study.

PURPOSE: Mask ventilation and laryngoscopy can be challenging in morbidly obese patients because of excessive fat tissue. There are studies suggesting that neck circumference is associated with difficult mask ventilation, difficult laryngoscopy, and difficult intubation. The primary aim of our study is to evaluate predictive value of neck circumference for difficult mask ventilation and difficult laryngoscopy in female and male morbidly obese patients separately.

METHODS: This observational cross-sectional study was performed in the period between March 2015 and December 2015. One hundred and twenty (37 male and 83 female) patients undergoing elective surgery were included. Neck circumference, BMI, Mallampati scores, neck movements, dentition, upper lip bite test, breast, thorax, waist, hip circumferences, mouth opening, and sternomental and thyromental distances were evaluated preoperatively. Mask ventilation was graded using four-grade classification. Laryngoscopy was evaluated by Cormack Lehane score.

RESULTS: The incidence of difficult mask ventilation was 13.5% in male and 3.6% in female patients. Mouth opening ≤ 6.5 cm and inadequate flexion were found as significant predictors for difficult mask ventilation in male patients. The incidence of difficult laryngoscopy was 10.8% in male and 4.8% in female patients. Mallampati score > II was found as a significant predictor for difficult laryngoscopy in both male and female patients. Sternomental distance ≤ 16 cm and inadequate flexion were also significant predictors for difficult laryngoscopy in male patients. Neck circumference was not found statistically significant predictor for difficult mask ventilation and laryngoscopy in morbidly obese patients in our study.

CONCLUSION: Neck circumference is not a statistically significant predictor for difficult mask ventilation and laryngoscopy in morbidly Turkish obese male and female patients.

CLINICAL TRIALS REGISTRATION NUMBER: NCT02589015.