The Particulars: Research shows that tuberculosis can cause frequent pulmonary impairment. However, pulmonary function testing had not been included in tuberculosis treatment guidelines until recently. Few studies have explored the usefulness of peak expiratory flow (PEF) in predicting pulmonary impairment in this patient population.
Data Breakdown: In a study, 317 patients with pulmonary tuberculosis underwent spirometry and bodyplethysmography to test pulmonary function. Of these patients, 55.8% had some level of pulmonary impairment, including 16.1% with airflow restriction, 43.8% with airflow obstruction, and 37.2% with low lung function. When a predicted value of PEF less than 70% was used as the cut-off for low lung function, PEF had a sensitivity of 80.5%, specificity of 88.4%, positive predictive value of 80.5%, and negative predictive value of 88.4%.
Take Home Pearl: Mechanical PEF appears to be a reliable measure for detecting pulmonary impairment in patients with pulmonary tuberculosis.