Exertional dyspnea-related acidotic and sympathetic responses in patients with sequelae of pulmonary tuberculosis

Abstract

The objective of this study was to investigate whether exertional dyspnea correlates with exercise responses, especially arterial blood pH and plasma norepinephrine (NE) changes, in patients with sequelae of tuberculosis TBsq). Cardiopulmonary exercise testings were performed in 49 TBsq patients and 9 controls. Each group had a break point in the dyspnea, plasma lactate, and plasma NE changes during exercise, all of which occurred at a similar exercise point. In TBsq patients in both exercise phases before and after the dyspnea break point, the dyspnea-slope (ΔBorg scale/Δminute ventilation) correlated with the pH-slope (ΔpH/Δoxygen uptake) (r = -0.616, p<0.0001; r = -0.629, p<0.0001, respectively, before and after the break point) and with the NE-slope (ΔNE/Δoxygen uptake)(r = 0.443, p = 0.0012; r = 0.643, p< 0.0001, respectively, before and after the break point). In TBsq patients during exercise, increases in circulating NE levels and exertional acidosis were correlated with exertional dyspnea. © The Physiological Society of Japan and Springer 2010.