RESUMO
A 6-min step test (6MST) may constitute a practical method for routinely assessing effort tolerance and exercise-related oxyhaemoglobin desaturation (ERD) in the primary care of patients with interstitial lung disease. In total, 31 patients (19 males) with idiopathic pulmonary fibrosis (n = 25) and chronic hypersensitivity pneumonia were submitted, on different days, to two 6MSTs. Physiological responses were compared with those found on maximal and submaximal cycle ergometer tests at the same oxygen uptake (V'(O(2))). Chronic breathlessness was also determined, as measured by the baseline dyspnoea index (BDI). Responses to 6MST were highly reproducible: 1.3+/-2.0 steps x min(-1), +/-5 beats x min(-1) (cardiac frequency), +/-50 mL x min(-1) (V'(O(2))), +/-7 L x min(-1) (minute ventilation) and +/-2% (arterial oxygen saturation measured by pulse oximetry (S(p,O(2)))). The number of steps climbed in 6 min was correlated to peak V'(O(2)) and the BDI. There were significant associations among the tests in relation to presence (change in S(p,O(2)) between rest and exercise > or = 4%) and severity (S(p,O(2)) <88%) of ERD. Four patients, however, presented ERD only in response to 6MST. Resting diffusing capacity of the lung for carbon monoxide and alveolar-arterial oxygen tension difference were the independent predictors of the number of steps climbed. A single-stage, self-paced 6-min step test provided reliable and reproducible estimates of exercise capacity and exercise-related oxyhaemoglobin desaturation in interstitial lung disease patients.
Assuntos
Teste de Esforço , Oxiemoglobinas/análise , Fibrose Pulmonar/diagnóstico , Fibrose Pulmonar/fisiopatologia , Adulto , Idoso , Tolerância ao Exercício , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Chronic cough with established diagnostic protocols has been well described in secondary and tertiary centres. Little information is available about adult patients to a general respiratory clinic where no such protocols exist. The objective of this study is to determine clinical characteristics, laboratory findings, diagnostic spectrum and outcomes of specific therapy in adult patients with chronic cough in a general respiratory clinic. In this prospective, longitudinal, descriptive study for patients with chronic cough defined as more than 8 weeks, we studied, according to a questionnaire, chest radiography, spirometry and reversibility, methacholine challenge and other measures. Treatment was prescribed on the basis of diagnosis informed by investigation results.We evaluated 147 patients (102 females) of a mean age of 48 years and complaining of cough an average of 24 weeks. On the basis of a successful response to treatment, the causes of cough were determined in 92% and the frequencies were asthma in 39%, COPD in 11%, chronic upper airway cough syndrome (CUACS) in 9%, gastro-oesophageal reflux disease (GERD) in 9% and no diagnosis in 8%. Cough was due to one condition in 82%. Our treatment success rate was 92%. The most frequent causes of chronic cough (asthma, COPD, CUACS and GERD) could be determined in a general respiratory clinic with a sequential approach. The frequencies are different from those in a tertiary cough clinic, but outcome of specific therapy is successful in our patients.