Expiratory air trapping during XXXX exacerbation: Relationships with clinical indices and proximal airway morphology.

@entity1 @entity565 @entity996
OBJECTIVES: To semi-quantitatively assess expiratory air trapping (ATexp) and structural changes in the proximal airways in @entity565 during @entity565 exacerbation (AE) and to explore the relationships among ATexp, clinical indices, and proximal airway changes. METHODS: Paired inspiratory-dynamic forced expiratory CT scans of 36 asthmatics (30 @entity1 , 6 @entity1 ; mean age, 49.2  18.9 years) performed during AE were retrospectively reviewed for the total ATexp score (summed scores [extent grading (0-4)*pattern grading (1-4)] of the twelve lung zones), morphologic parameters and expiratory bronchial collapse (BCexp) of the proximal airways. The relationships of the score with clinical indices and proximal airway morphology (normalized by body surface area [BSA]) were analyzed. A p value of <0.05 was considered statistically significant. RESULTS: The mean total ATexp score was 110.1  43.4 (range, 8-166). It was higher in the lower zones and in @entity1 older than 60 years, having BMI of <27.5kg/m(2), and peak expiratory flow rate (PEFR) of <60% predicted. Correlation existed between the score and age (r=0.331), BMI (r=-0.375), BSA (r=-0.442), % predicted PEFR (r=-0.332), right upper lobe apical segmental bronchus ( @entity996 )-wall area (WA)/BSA (r=0.467), % @entity996 -WA (r=0.395), and @entity996 -bronchial wall thickness (BWT)/BSA (r=0.378). The score showed no correlation with BCexp and other morphologic bronchial parameters. Area under receiver-operating-characteristic curve 0.724 (95% CI) showed that the score of 110 could discriminate @entity1 with PEFR of <60% predicted from those with PEFR of >= 60% predicted. CONCLUSION: During AE, there was a high prevalence of extensive ATexp which was correlated with @entity1 's age, BMI, BSA, AE severity and @entity996 morphology but not correlated with BCexp.
