Sonographic Measurement of the Epiglottis in Normal Chinese Adults

Abstract

Objectives: (1) To assess the normal range of thickness of the epiglottis by means of ultrasound measurement. (2) To evaluate inter-observer agreement in measuring the thickness of the epiglottis of normal individuals by ultrasound. (3) To assess the association between biological factors and the thickness of the epiglottis. Methods: Fifty adult volunteers working at a local accident and emergency department were recruited. The thickness of the epiglottis was measured by means of ultrasound examination, which was performed twice by two emergency physicians at different time. The study subjects' age, sex, height and body weight were recorded. Results: The mean thickness of the epiglottis was 0.236 cm and the standard deviation was 0.020. Male subjects had thicker epiglottis. Interobserver agreement of the two emergency physicians who performed the ultrasound scan was very good. Multiple regression models showed that sex and height were useful predictors of the thickness of the epiglottis. Conclusions: Bedside ultrasound assessment of the epiglottis is an easy, rapid and reliable method to evaluate its thickness. Further studies are needed to evaluate the thickness of the epiglottis in patients with epiglottitis before it can be put into clinical use.

Ultrasound as an Assessment Method in Predicting Difficult Intubation: A Prospective Clinical Study

“…This parameter is important because tongue can get displaced during laryngoscopy, and hence it may cause difficult laryngoscopy in patients' with thick submental region. Epiglottis was visualized by placing the linear transducer probe at the level just above the thyroid cartilage [12]. With a little tilting of the probe or asking the patient to extend his neck slightly, the standard view can be located.…”

Feasibility of sonographic access to the cricothyroid membrane in the presence of a rigid neck collar in healthy Chinese adults: A prospective cohort study

“…Although it is operator‐dependent, desirable image capture can often be achieved on superficial structures such as the upper airway through the anterior neck approach. A local study at a major local hospital showed it was quick and straightforward to locate the epiglottis of healthy Chinese adults with little interobserver difference …”

Appearance of the Epiglottis During Upper Airway Sonography

“…Sonography is increasingly being explored as a tool for evaluation of upper airway anatomy and pathologic characteristics, with clinical use developing in areas as broad as the diagnosis of laryngeal and swallowing abnormalities, guidance for percutaneous tracheostomy and cricothyrotomy, prediction of difficult intubation and postextubation stridor, and measurement of epiglottal enlargement during acute epiglottitis 1 – 5 . However, few studies have compared sonograms acquired for these purposes to those of well‐established upper airway imaging modalities such as computed topography (CT) and magnetic resonance imaging.…”

“…7,8 Since this initial report, there have been several studies using these characteristics to identify the epiglottis without direct comparison to reference standard imaging modalities. [3][4][5]8 However, in a recent study by Prasad et al, 6 sonographic and CT measurements of several pharyngeal and hypopharyngeal airway parameters, including the depth of the epiglottis and thyrohyoid membrane, were compared in 15 adult patients with normal neck anatomy. On the basis of their measurements, the authors concluded that the pre-epiglottic fat appears hypoechoic and had been mislabeled as the epiglottis in previous studies using Böhme's method of identification.…”

“…[1][2][3][4][5] However, few studies have compared sonograms acquired for these purposes to those of wellestablished upper airway imaging modalities such as computed topography (CT) and magnetic resonance imaging. In some instances, such as in the identification of the epiglottis, the anatomy described in the ultrasound literature has failed to match images obtained by CT. 6 The purpose of this report is to clarify and confirm the sonographic appearance of the epiglottis and to describe the surrounding anatomy as depicted on sonography.…”