A number of individuals living with emphysema, small airways diseases, bronchial asthma, and some children with asthma exhibited disproportionately low forced expiratory volume in one second (FEV1) relative to the amount of air their lungs can hold. A new study published in BMC Pulmonary Medicine, “Non Specific Pattern of Lung Function in a Respiratory Physiology Unit: Causes and Prevalence: Results of an Observational Cross-sectional and Longitudinal Study,” investigated the contributors behind this observed phenomenon.
As suspected by the authors at Hôpital européen Georges-Pompidou in France, non specific pattern (NSP) of lung function, also known as small airway obstruction syndrome, was identified in patients with lung diseases. Cases of NSP were numbered at 841 of 12,775 patients studied. Seven lung diseases were the main players, including asthma, emphysema, chronic obstructive pulmonary disease (COPD), and sarcoidosis. Only 185 patients had NSP and indisputable nonoverlapping causes.
Other groups have published similar findings. The present study was motivated to validate a study that concluded 68% of patients with airway disease had NSP. Those data were obtained through a database of lung function test results and medical records.
Armed with this information, clinicians who treat patients with asthma, COPD, emphysema, bronchiectasis, sarcoidosis, pulmonary hypertension, or interstitial pneumonia after bilateral lung transplantation may want to measure static lung volume using a technique such as body plethysmography to determine if a patient has NSP. These diagnoses can be coupled with lung imaging and clinical judgment to postulate why patients see a reduction in FEV1 and forced vital capacity, both of which can cause symptoms in patients with abnormal lung volumes.