title: Is ultrasonic investigation of transverse tracheal air shadow diameter reasonable for evaluation of difficult airway in pregnant women: A prospective comparative study.
abstract: OBJECTIVE
  The aim of this study was to compare clinical screening tests (modified Mallampati score, Cormack-Lehane score, thyromental distance, and sternomental distance) with ultrasonic measurements of the upper airway in predicting difficult intubation in pregnant women whose Body Mass Index (BMI) is higher and lower than 30 kg m-2.
  
  
  METHODS
  This study was designed as a prospective observational trial, and consisted of 40 pregnant women of American Society of Anesthesiologists (ASA) 1-2 groups. Patients with a BMI lower than 30 kg m-2 were included in Group 1 (n=20), and patients with a BMI higher than 30 kg m-2 were included in Group 2 (n=20). In the supine position with head in mild extension, the diameter of the transverse tracheal air shadow in the subglottic area of the front neck was measured using ultrasonography. Modified Mallampati score, Cormack-Lehane score, thyromental distance and sternomental distance measurements were recorded.
  
  
  RESULTS
  No statistically significant difference was detected between groups regarding mean age, mean number of pregnancy, ASA scores and comorbid disease. Mean body weight (p=0.0001) and mean pre-pregnancy weight (p=0.0001) were significantly higher in Group 2. There was no statistically significant difference between groups regarding mean modified Mallampati score, thyromental distance, sternomental distance measurements, Cormack-Lehane score, and mean ultrasonic measurements.
  
  
  CONCLUSIONS
  It was found that BMI higher or lower than 30 kg m-2 has no effect on ultrasonic measurements and clinical airway tests. We thought that ultrasonic measurement could not give us valuable information in obese or non-obese pregnant women.
authors.affiliation: Dr. Meltem Turkay Aydogmus, Department of Anesthesiology and Reanimation, Bagcilar Training and Research Hospital, Turkey.
authors.forename: Meltem
authors.initials: M
authors.lastname: Turkay Aydogmus
authors.affiliation: Dr. Kerem Erkalp, Department of Anesthesiology and Reanimation, Bagcilar Training and Research Hospital, Turkey.
authors.forename: Kerem
authors.initials: K
authors.lastname: Erkalp
authors.affiliation: Dr. Sitki Nadir Sinikoglu, Department of Anesthesiology and Reanimation, Bagcilar Training and Research Hospital, Turkey.
authors.forename: Sitki
authors.initials: S
authors.lastname: Nadir Sinikoglu
authors.affiliation: Dr. Taner A. Usta, Department of Obstetrics and Gynaecology, Bagcilar Training and Research Hospital, Turkey.
authors.forename: Taner A
authors.initials: TA
authors.lastname: Usta
authors.affiliation: Dr. Gunes O. Ulger, Department of Anesthesiology and Reanimation, Bagcilar Training and Research Hospital, Turkey.
authors.forename: Gunes
authors.initials: G
authors.lastname: O Ulger
authors.affiliation: Research Assistant.
authors.forename: Aysin
authors.initials: A
authors.lastname: Alagol
keywords: Pregnancy; airway evaluation; body mass index; diameter of transverse tracheal air shadow; obesity; ultrasonography