A symptom-limited incremental step test determines maximum physiological responses in patients with chronic obstructive pulmonary disease

Autor(es)

Dal Corso, Simone ^[1] ; de Camargo, Anderson Alves ^[1] ; Izbicki, Meyer ^[2] ; Malaguti, Carla ^{[2, 3]} ; Nery, Luiz Eduardo ^[2]

Afiliação do(s) autor(es)

^[1] Univ Nove Julho UNINOVE, Postgrad Program Rehabil Sci, BR-01504001 Sao Paulo - Brazil

^[2] Fed Univ Sao Paulo UNIFESP, Dept Med, Div Resp Dis, Sao Paulo - Brazil

^[3] Univ Fed Juiz de Fora, Human Physiol Dept, Juiz De Fora, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: RESPIRATORY MEDICINE; v. 107, n. 12, p. 1993-1999, DEC 2013.
• Citações Web of Science: 16

Resumo

Background: Step tests have been used to evaluate exercise tolerance and effort-related hypoxemia in different diseases. A symptom-limited incremental step test (IST) has never been tested in COPD patients. Aim: To compare maximal physiological responses between an IST and cardiopulmonary exercise testing (CPET), to test the reproducibility of the IST on different days, and to provide a predict equation to estimate VO2 from the IST in patients with COPD. Material and methods: At the same day, thirty-four patients (VEF1 46 +/- 14% of pred) underwent a CPET on cycle ergometer and the first 151 (IST-1) (1 h apart). After 2-5 days, patients repeated the IST (IST-2). Pulmonary gas exchange was measured during all tests. Results: Peak VO2 was significantly higher in IST-1 and IST-2 than in CEPT (Mean +/- SD: 1.19 +/- 0.39 L, 1.20 +/- 0.40 L, 1.07 +/- 0.35 L) with no difference for ventilation (VE), heart rate (HR), and perception of effort. ISTs were highly reproducible, with significant intraclass correlation coefficient (CCI {[}95% confidence interval]) for number of steps (0.98{[}0.95-0.99]), VO2 (0.99 {[}0.98-0.99]), VE (0.97{[}0.93-0.99]), HR (0.92{[}0.81-0.97]), and SpO(2) (0.96{[}0.90-0.98]). Desaturation was significantly higher for IST-1 and IST-2 compared with cycling (Mean +/- SD: -6 +/- 5%, -6 +/- 4%, - 3 +/- 3%). Number of steps and patient weight explained 81% of the variance in peak VO2 (p < 0.001). Conclusion: A symptom-limited incremental step test, externally paced, elicits maximal cardiopulmonary and metabolic responses, and is well tolerated and reproducible in patients with COPD. (C) 2013 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 10/09732-6 - Validade e reprodutibilidade de um teste do degrau incremental em pacientes com doença pulmonar obstrutiva crônica
• Beneficiário: Simone Dal Corso
• Modalidade de apoio: Auxílio à Pesquisa - Regular