Ultrasound measurements of anterior soft tissue thickness to predict difficult laryngoscopy in women undergoing elective cesarean section under general anesthesia.

• Register: ANZCTR
• Last refreshed on: 10 April 2017
• Main ID: ACTRN12617000482369
• Date of registration: 03/04/2017
• Prospective Registration: No
• Primary sponsor: Canan Yilmaz
• Public title: Ultrasound measurements of anterior soft tissue thickness to predict difficult laryngoscopy in women undergoing elective cesarean section under general anesthesia.
• Scientific title: Ultrasound measurements of anterior soft tissue thickness to predict difficult laryngoscopy in women undergoing elective cesarean section under general anesthesia.
• Date of first enrolment: 7/04/2014
• Target sample size: 140
• Recruitment status: Completed
• URL: http://www.anzctr.org.au/ACTRN12617000482369.aspx
• Study type: Observational
• Phase: Phase 4

Health Condition(s) or Problem(s) studied

difficult laryngoscopy

Intervention(s)

Prospective, observational study included 140 pregnant women (18-45 years old, ASA I-II) who underwent elective cesarean section under general anesthesia. A written informed consent was obtained from each patient. Patients with difficult airway anamnesis, history of neck surgery were not included in the study.
In addition, very urgent cases such as acute fetal distress and ablatio placenta were excluded from the study. Mallampati test, mouth opening, sternomental distance, thyromental distance, upper lip bite test, neck circumference were recorded one day before operation. The distance from the skin to the anterior aspect of the trachea was measured at five different levels: hyoid bone (zone 1), tirohyoid membrane (zone 2), vocal cords (zone 3), thyroid isthmus (zone 4) and suprasternal notch (zone 5). An anaesthesiologist who were unaware of the clinical screening variables and ultrasonography results performed laryngoscopy.