2015 Volume 37 Issue 3 Pages 261-266
Background. Influenza (H1N1)2009 spread on a pandemic scale in 2009, which resulted in a large number of infected cases in Japan. Even in 2010, numerous cases of influenza (H1N1)2009 infection were reported. Those afflicted were predominantly children. Many children were admitted to our hospital, some of whom experienced respiratory failure and required artificial respiration. Objective. To determine the factors of respiratory failure associated with (H1N1)2009 infection. Subjects and Methods. Between September 2009 and March 2010, 116 children were admitted to our hospital, and 71 children (52 boys and 19 girls) had pneumonia or bronchitis associated with influenza (H1N1)2009. Among these, 5 suffered respiratory failure that required bronchial intubation and artificial ventilation, and bronchoscopy was performed for all of these cases. Results. The 5 cases included 4 boys and 1 girl. Two cases had a past history of asthma, and 3 cases had accompanying infection. The bronchoscopic findings showed mucus plugs occluding the lobar and sublobar bronchi. After removing the mucus plugs, their respiratory condition improved. The microscopic findings of the mucus plugs showed fibrin and inflammatory cells mainly consisting of eosinophils, and we diagnosed plastic bronchitis type. Though 4 cases were discharged, 1 died due to myocarditis. Conclusions. A high incidence of plastic bronchitis was observed among pediatric patients with influenza (H1N1)2009 infection. Bronchoscopy should be considered for treating cases when plastic bronchitis is present.
