Evaluation of Dynamic Hyperinflation with Negative Expiratory Pressure Method in Patients with Chronic Obstructive Pulmonary Disease
1Biruni University Faculty of Medicine, Department of Pulmonary Diseases, İstanbul, Turkey
2Haseki Training And Research Hospital, Clinic of Pulmonary Diseases, İstanbul, Turkey
Eur Arch Med Res 2019; 35(3): 147-152 DOI: 10.4274/eamr.galenos.2019.18209
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Abstract

Objective: Chronic Obstructive Pulmonary disease (COPD) is a disease characterized by progressive airflow limitation, which is not fully reversible. Expiratory flow limitation (EFL) is the most common cause of dynamic hyperinflation (DH) and increased respiratory workload in COPD. In our study, the relationship between negative expiratory pressure (NEP) and all pulmonary function tests, especially inspiratory capacity (IC), was investigated in the examination of DH in COPD patients.

Methods: Thirty four COPD patients with a mean forced expiratory volume in one second (FEV1) of 38.9±12.7% and 15 healthy subjects were included in the study. Pulmonary function tests and NEP were performed in all COPD patients.

Results: In 16 COPD patients (47.1%), EFL was positive with NEP. When pulmonary function tests of EFL positive and EFL negative patients were compared, significant differences were found only in obstruction parameters such as FEV1 and forced expiratory flow 25-75, but no difference was found with lung volumes and diffusion test. However, there was a statistically significant correlation between IC and FVC (mL and % predicted), FEV1 (% predicted) and lung volumes (mL and % predicted) and FRC (mL) (p<0.05). There was a negative but statistically insignificant correlation between IC and presence of flow limitation (p>0.05).

Conclusion: We think that NEP application in COPD patients does not provide additional information about DH and that IC is the best predictor of DH.