Clinical and Bronchoscopic Manifestations
In this study, disease course was assessed based on clinical manifestations, lung imaging, and bronchoscopic findings then was classified into three disease course categories: acute-stage, subacute-stage, and recovery-stage.
Symptoms during acute-stage SMPP included fever, elevated CRP, and large areas of consolidation detected via lung imaging. Generally, detection of bronchial mucosal congestion with or without airway mucosal follicular hyperplasia and bronchial secretions increased with use of bronchoscopy. Symptoms of subacute-stage SMPP were characterized by decreased or normal fever peak, improved signs as assessed via lung imaging, increased blood CRP, and decreased bronchial secretions and airway blockages accompanied by mucous membrane necrosis and exfoliation found via bronchoscopy. Symptoms of recovery-stage SMPP included normal body temperature, normal blood CRP, and either improved findings via lung imaging or atelectasis.
Bronchoscopic manifestations of acute-stage SMPP: all cases exhibited different degrees of congestion and roughness of tracheal and bronchial mucosa, mucosal longitudinal fold changes, and mucinous secretion. During the first bronchoscopy, follicular hyperplasia of airway mucosa was found in 162 cases (162/213, 76%), with lung lesions located in grade I and grade II trachea. Erosion of airway mucosa was found in 105 cases (49.2%), with lesions located in grade III or lower grade bronchi. Mucous plug blockages involving grade III or lower bronchi were found in 47 cases (47/213, 22.0%). The mean disappearance time of mucous plugs was 15 ± 1.7 days. The mean number of previous bronchoscopies was 2.6 ± 3.5. Of cases with mucous plugs, 8 cases (8/213, 3.8%) had severe mucous plug obstruction (with tree-like bronchial-shaped changes). Locations of lesions were as follows: lesions of 11 cases (11/213, 10.5%) were in the left upper lung, of 15 cases were in the left lingual lobe (15/213, 14.3%), of 48 cases were in the left lower basal segment (48/213, 45.7%), of 13 cases (13/213, 12.4%) were in the right upper lobe, of 10 cases (10/213, 9.5%) were in the right middle lobe, of 64 cases (64/213, 60.9%) were in the right lower basal segment, of 63 cases (63/213, 60%) were in one lobe, of 32 cases (32/213, 30.5%) were in two lobes, of 7 cases (7/213, 6.7%) were in three lobes, of 3 cases (3/213, 2.8%) were in four lobes; no cases involved five lobes.
Bronchoscopic manifestations in subacute and recovery stages: 22 cases (22/213, 10.3%) had OB, including 13 males (13/22, 59%) and 9 females (9/22, 41%). The median time to diagnosis of Sub-bronchial stenosis was 15 days [IQR 12-18]. The initial obstruction was a thin film that was easily broken with biopsy forceps in order to reopen the airway. With time, the untreated occluded airway section gradually thickened and the center became concave and became associated with a peripheral radial hyperplasia-like obstruction. Proximal tracheal examination revealed the presence of fishbone-like bronchiectases that were difficult to reopen using biopsy forceps (Figures 1 and 2).