Takashi Fujiwara1, Hiroshi Okamoto2, Yasuhiro Ohnishi3, Toshio Fukuoka2, Kazuyuki Ichimaru4. 1. Department of Otolaryngology Head and Neck Surgery, Ehime University, Toon City, Ehime, Japan. 2. Department of Emergency Medicine, Kurashiki Central Hospital, Kurashiki City, Okayama, Japan. 3. Department of Radiology, Kurashiki Central Hospital, Kurashiki City, Okayama, Japan. 4. Department of Otolaryngology Head and Neck Surgery, Kokura Memorial Hospital, Kitakyushu City, Fukuoka, Japan.
Abstract
OBJECTIVE: To assess the diagnostic accuracy of lateral neck radiographs (LNR) for acute supraglottitis in adults. DESIGN: A single centre prospective observational study. SETTING: Emergency department at Kurashiki Central Hospital, Japan. PARTICIPANTS: Adult patients who underwent LNR to detect supraglottitis. MAIN OUTCOME MEASURES: Presence of supraglottitis, based on nasopharyngeal laryngoscopy or a follow-up telephone call, 7-30 days after the visit. RESULTS: 140 patients had LNR during the study period. 35 patients were excluded from further analysis because of lack of consent. Of the 105 eligible patients, 21 patients (20%) were given the diagnosis of supraglottitis: 17 of 29 with a radiographic abnormality, and 4 of 76 patients without a radiographic abnormality. Three of the four cases where LNR was negative was grade 1, and all cases of grade 3 or higher had abnormal LNR. Sensitivity and specificity (95% CI) of LNR for supraglottitis were 81.0% (64.2 to 97.7) and 85.7% (78.2 to 93.2), respectively. The positive predictive value of LNR was 58.6% (40.7 to 76.5) and the negative predictive value was 94.7% (89.7 to 99.8). The positive likelihood ratio of LNR was 5.67 (3.27 to 9.82) and the negative likelihood ratio was 0.22 (0.10 to 0.51). CONCLUSIONS: LNR showed only moderate sensitivity and specificity for supraglottitis and would miss some cases of supraglottitis if the pre-test probability is high. LNR was very sensitive for grade 3 or higher supraglottitis, but would miss milder cases. TRIAL REGISTRATION: UMIN000011928. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
OBJECTIVE: To assess the diagnostic accuracy of lateral neck radiographs (LNR) for acute supraglottitis in adults. DESIGN: A single centre prospective observational study. SETTING: Emergency department at Kurashiki Central Hospital, Japan. PARTICIPANTS: Adult patients who underwent LNR to detect supraglottitis. MAIN OUTCOME MEASURES: Presence of supraglottitis, based on nasopharyngeal laryngoscopy or a follow-up telephone call, 7-30 days after the visit. RESULTS: 140 patients had LNR during the study period. 35 patients were excluded from further analysis because of lack of consent. Of the 105 eligible patients, 21 patients (20%) were given the diagnosis of supraglottitis: 17 of 29 with a radiographic abnormality, and 4 of 76 patients without a radiographic abnormality. Three of the four cases where LNR was negative was grade 1, and all cases of grade 3 or higher had abnormal LNR. Sensitivity and specificity (95% CI) of LNR for supraglottitis were 81.0% (64.2 to 97.7) and 85.7% (78.2 to 93.2), respectively. The positive predictive value of LNR was 58.6% (40.7 to 76.5) and the negative predictive value was 94.7% (89.7 to 99.8). The positive likelihood ratio of LNR was 5.67 (3.27 to 9.82) and the negative likelihood ratio was 0.22 (0.10 to 0.51). CONCLUSIONS: LNR showed only moderate sensitivity and specificity for supraglottitis and would miss some cases of supraglottitis if the pre-test probability is high. LNR was very sensitive for grade 3 or higher supraglottitis, but would miss milder cases. TRIAL REGISTRATION: UMIN000011928. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.