Abstract
Objective
The classical radiographic signs in acute epiglottitis are qualitative. The purpose of our study was to identify objective radiographic parameters to aid diagnosis of acute epiglottitis in Chinese adults.
Methods
A case-control study of Chinese adult patients attending the accident and emergency department (AED) who were subsequently diagnosed to have acute epiglottitis from 1st January 2009 to 31st December 2013 in a public hospital in Hong Kong. Controls were one-to-one age- and sex-matched patients who attended the AED during the study period for orthopaedic problems with cervical spine radiographs taken. Cases and controls were retrieved from the hospital computer system and their radiographs were interpreted by two specialist radiologists with various pharyngeal and laryngeal parameters, including the dimensions of the third cervical vertebral body, epiglottis, aryepiglottic fold, hypopharynx, retropharyngeal soft tissue and retrotracheal soft tissue, measured and analysed. Sensitivity, specificity, positive and negative likelihood ratios were calculated for each of the parameters.
Results
Twenty-six patients and 26 age- and sex-matched controls were included in the study. Epiglottis width of 5.5 mm or more was found to be 96.2% sensitive and 100% specific in diagnosing acute epiglottitis. Positive and negative likelihood ratios were infinity and 0.04 respectively. Aryepiglottic fold width of 5.9 mm or more was 92.3% sensitive and 80.8% specific. Positive and negative likelihood ratios were 4.80 and 0.10 respectively.
Conclusion
The identified objective radiographic parameters should aid in the diagnosis of acute epiglottitis in Chinese adults. (Hong Kong j. emerg.med. 2016;23:168-175)