Assessment of respiratory muscle strength and inspiratory drive in patients with pulmonary tuberculosis

Abstract

Respiratory muscles (RM) are a part of the respiratory system that enables ventilation. RM dysfunction exacer-bates breathing insufficiency. The aim: to study the RM strength and inspiratory drive in pulmonary tuberculo-sis (PT). Materials and methods. In 247 patients with verified PT we measured the maximal occlusion inspira-tory (PImax), expiratory (PEmax) pressures and shut off airways during the first 100 ms of inspiration (P0.1). Cli-nical manifestations of tuberculosis, computed tomog-raphy and perfusion scintigraphy data were evaluated. Results. The decrease of PImax was in 49.6%, PEmax — in 17.8%, both — in 32.6%. PEmax had weak negative dependence on the disease duration, contralateral lung blood flow, and a weak direct dependence with BMI. Statistically significant dependence was not found be-tween PImax and the clinical and instrumental charac-teristics of PT. A moderate dependence of P0.1 was with the PT clinical form, its duration, total volume of foci, blood flow disorders in the lung, the weak dependence of P0.1 was with BMI and the contralateral lung blood flow. The frequency of RM dysfunction in different PT forms did not differ. An increase of P0.1 in patients with fibrosis and cavities was 3–3.5 times more frequent than in the others patients. There were no statistically signifi-cant differences in PImax, PEmax, P0.1 in the group of fi-brosis and cavities and group of infiltrative foci with the same total lesion volume. Conclusion. The RM strength and inspiratory drive were significantly dependent on the duration of the disease, the extent of the lesion and the state of the pulmonary blood flow