Abstract: Objective To observe and compare pulmonary function changes of patients were between acute exacerbation of chronic obstructive pulmonary disease(AECOPD)group and pneumonia group assisted by portable spirometer, then to explore its benefit for diagnosis and treatment in AECOPD in-patients. Methods 20 patients with AECOPD and 15 contemporaneous patients with pneumonia were examined and underwent pulmonary function test through portable spirometer on the 1^st day, 3^rd day and the last day, respectively. Three indicators including FEV₁/FVC, FEV₁%pred, PEF were detected and compared with each other. Difference were calculated. Results The average of improvement in FEV₁ demonstrated significant difference between two groups. 6.60%±0.82% of FEV₁%pred improvement were shown in pneumonia group compared with 12.30%±1.66% in AECOPD group(P=0.009), which means FEV₁ elevation during the hospitalization. The variation of PEF demonstrated significant difference between two groups(P=0.002). 24.50%±4.01% of PEF variation was shown in pneumonia group while 45.37%±4.44% shown in AECOPD group, which means part of them have airway hyperreactivity. No significant difference of ΔFEV₁/FVC(difference of before and after)was shown between AECOPD group and pneumonia group(P=0.209).Conclusion AECOPD could cause decreasement of ventilatory function in inpatients, who would usually obtain a certain rehabilitation after stabilization. Therefore, it is necessary to fulfill pulmonary function test after recovery again and then helpful to accurate assessment for AECOPD patients.

Key words: portable spirometer, pulmonary function, chronic obstructive pulmonary disease, acute exacerbation