Breathing Reserve Index at Anaerobic Threshold of Cardiopulmonary Exercise Test in Chronic Obstructive Pulmonary Disease.

Lee, Byoung Hoon; Kang, Soon Bock; Park, Sung Jin; Jee, Hyun Suk; Choi, Jae Chol; Park, Yong Bum; Ahn, Chang Hyuk; Kim, Jae Yeol; Park, In Won; Choi, Byung Whui; Hue, Sung Ho

doi:1999.46.6.795

Tuberc Respir Dis > Volume 46(6); 1999 > Article

Original Article

Tuberculosis and Respiratory Diseases 1999;46(6):795-802.
DOI: https://doi.org/10.4046/trd.1999.46.6.795 Published online June 1, 1999.

Breathing Reserve Index at Anaerobic Threshold of Cardiopulmonary Exercise Test in Chronic Obstructive Pulmonary Disease.

Byoung Hoon Lee, Soon Bock Kang, Sung Jin Park, Hyun Suk Jee, Jae Chol Choi, Yong Bum Park, Chang Hyuk Ahn, Jae Yeol Kim, In Won Park, Byung Whui Choi, Sung Ho Hue

Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.

Abstract

OBJECTIVE: Cardiopulmonary exercise test is a useful tool to evaluate the operative risk and to plan exercise treatment for the patients with chronic obstructive pulmonary disease(COPD). In cardiopulmonary exercise test, most of the measured parameters are recorded at the time of peak exercise, which are hard to attain in COPD patients. So we evaluated the usefulness of the parameter, breathing reserve index(BRI=minute ventilation [VE]/maximal voluntary ventilation[MVV]) at the time of anaerobic threshold(BRIAT) for the differentiation of COPD patients with normal controls. METHODS: Thirty-six COPD patients and forty-two healthy subjects underwent progressive, incremental exercise test with bicycle ergometer upto possible maximal exercise. All the parameters was measured by breath by breath method. RESULTS: The maximal oxygen uptake in COPD patients (mean+/-SE) was 1061.2+/-65.6ml/min which was significantly lower than 2137.6+/-1.4ml/min of normal subjects(p<0.01). Percent predicted maximal oxygen uptake was 54.3% in COPD patients and 86.0% in normal subjects(p<0.01). Maximal exercise(respiratory quotient; VCO2/VO2 > or =1.09) was accomplished in 7 of 36 COPD patients(19.4%) and in 18 of 42 normal subjects(42.9%). The BRIAT of COPD patients was higher(0.50+/-0.03) than that of control subject(0.28+/-0.02, p<0.01), reflecting early hyperventilation in COPD patient during exercise. The correlation between BRIAT and BRI at maximal exercise in COPD patients was good(r=0.9687, p<0.01). CONCLUSION: The BRIAT could be a useful parameter for the differentiation of COPD patients with normal controls in the submaximal cardiopulmonary exercise test.

Key Words: Cardiopulmonary exercise test, Submaximal exercise, COPD, Breathing reserve index