Objective: To identify the predictive factors of oxygen desaturation during the six-minute walk test (6MWT) in patients with cystic fibrosis (CF). Methods: Prospective cross-sectional study involving clinically stable patients with CF aged ≥ 10 years. The patients were submitted to nutritional evaluations, oral glucose tolerance tests, pulmonary function tests, chest X-rays and 6MWTs. Results: The study included 88 patients (43 females and 45 males; mean age, 19.9 ± 7.2 years; mean FEV1, 65.4 ± 28.4%). We observed oxygen desaturation in 13 patients (OD+ group) and no oxygen desaturation in 75 (OD− group). In comparison with OD− group patients, OD+ group patients presented higher mean age (p = 0.004), worse clinical score (p < 0.001), worse radiological score (p < 0.001), higher incidence of glucose intolerance (p = 0.004), lower incidence of methicillin-sensitive Staphylococcus aureus infection (p < 0.001), higher incidence of methicillin-resistant S. aureus infection (p = 0.016), higher incidence of Pseudomonas aeruginosa infection (p = 0.008), lower mean resting SpO2 (p < 0.001) and lower mean FEV1 (p < 0.001). In the logistic regression analysis, oxygen desaturation during the 6MWT correlated with resting SpO2 (OR = 0.305, p < 0.001) and FEV1 (OR = 0.882, p = 0.025). The parameters maximizing the predictive value for oxygen desaturation were resting SpO2 < 96% and FEV1 < 40%. In this sample, 15% of the patients with CF aged ≥ 10 years presented oxygen desaturation during the 6MWT. Conclusions: Resting SpO2 < 96% and FEV1 < 40% can predict oxygen desaturation during the 6MWT.

Keywords: Cystic fibrosis; Respiratory function tests; Exercise tolerance.

Once considered a childhood disease, cystic fibrosis is now also a disease of adults. Increased longevity has resulted in the aging of the cystic fibrosis population. The consequent age-related medical problems among adults with cystic fibrosis have increased medical care needs. These needs are being met by a growing number of non-pediatric pulmonologists and other non-pediatric specialists. The objective of this review was to summarize the current knowledge about diagnosis and treatment in adult cystic fibrosis. In most cases, the diagnosis is suggested by manifestations of chronic sinopulmonary disease and exocrine pancreatic insufficiency. The diagnosis is confirmed by a positive sweat test result. Adult patients may, however, present pancreatic sufficiency and atypical clinical features, sometimes in combination with normal or borderline sweat test results. In such cases, identifying cystic fibrosis mutations and measuring nasal potential difference can have diagnostic utility. The standard therapeutic approach to pulmonary disease includes the use of antibiotics, airway clearance, exercise, mucolytics, bronchodilators, oxygen therapy, anti-inflammatory agents and nutritional support. Appropriate application of these therapies results in most cystic fibrosis patients surviving into adulthood with an acceptable quality of life.

Keywords: Cystic fibrosis; Diagnosis; Therapeutics; Mucoviscidosis.