Prolonged Oxygen Kinetics During Early Recovery From Maximal Exercise in Adult Patients With Cystic Fibrosis

• Published in: Chest Vol. 119; no. 4; pp. 1073 - 1078
• Main Authors: Pouliou, Eleni, Nanas, Serafim, Papamichalopoulos, Antonios, Kyprianou, Theodoros, Perpati, Georgia, Mavrou, Irini, Roussos, Charis
• Format: Journal Article
• Language: English
• Published: Northbrook, IL Elsevier Inc 01.04.2001; American College of Chest Physicians
• Subjects: Adolescent; Adult; Biological and medical sciences; Carbon Dioxide - physiology; cystic fibrosis; Cystic Fibrosis - metabolism; Cystic Fibrosis - physiopathology; exercise; Exercise Test; Female; Forced Expiratory Volume; Humans; Male; Medical sciences; Middle Aged; Oxygen Consumption; Pneumology; recovery; Respiratory Mechanics; Respiratory system : syndromes and miscellaneous diseases; Schwachman score; Severity of Illness Index; Vital Capacity; exercise; recovery; Schwachman score; cystic fibrosis; Human; Maximal physical exercise; Maximum oxygen consumption; Prognosis; Functional recovery; Respiratory disease; Digestive diseases; Metabolic diseases; Adult; Cystic fibrosis; Genetic disease; Pancreatic disease
• ISSN: 0012-3692; 1931-3543
• DOI: 10.1378/chest.119.4.1073

To explore the significance of oxygen kinetics during early recovery after maximal cardiopulmonary exercise testing (CPET) in the assessment of functional capacity and severity of the disease in cystic fibrosis (CF) patients. Eighteen patients with CF (9 male/9 female; mean ± SD age, 23 ± 13 years) and 11 healthy subjects (3 male/8 female; mean age, 29 ± 4 years) underwent maximum CPET on a treadmill. Breath-by-breath analysis was used for measuring oxygen consumption ( V˙o2), carbon dioxide production, and ventilation. Maximum V˙o2 ( V˙o2peak) and the first-degree slope of V˙o2 decline during early recovery ( V˙o2/t-slope) were calculated. To assess the severity of the disease, we used standard indexes like FEV1 (% predicted), V˙o2peak, and a widely accepted system of clinical evaluation, the Schwachman score (SS). V˙o2/t-slope was significantly lower in CF patients compared to healthy subjects (0.61 ± 0.31 L/min/min vs 1.1 ± 0.13 L/min/min; p < 0.01) and was closely correlated to FEV1(r = 0.90, p < 0.001), V˙o2peak (r = 0.81, p < 0.001), and the SS (r = 0.81, p < 0.001). The multivariate analysis showed that the only independent predictor of the SS is the V˙o2/t-slope. We conclude that in CF patients, the prolonged oxygen kinetics during early recovery from maximal exercise is related to the disease severity.