Objective: To evaluate the association between extubation failure and outcomes (clinical and functional) in patients with traumatic brain injury (TBI). Methods: A prospective cohort study involving 311 consecutive patients with TBI. The patients were divided into two groups according to extubation outcome: extubation success; and extubation failure (defined as reintubation within 48 h after extubation). A multivariate model was developed in order to determine whether extubation failure was an independent predictor of in-hospital mortality. Results: The mean age was 35.7 ± 13.8 years. Males accounted for 92.3%. The incidence of extubation failure was 13.8%. In-hospital mortality was 4.5% and 20.9% in successfully extubated patients and in those with extubation failure, respectively (p = 0.001). Tracheostomy was more common in the extubation failure group (55.8% vs. 1.9%; p < 0.001). The median length of hospital stay was significantly greater in the extubation failure group than in the extubation success group (44 days vs. 27 days; p = 0.002). Functional status at discharge was worse among the patients in the extubation failure group. The multivariate analysis showed that extubation failure was an independent predictor of in-hospital mortality (OR = 4.96; 95% CI, 1.86-13.22). Conclusions: In patients with TBI, extubation failure appears to lengthen hospital stays; to increase the frequency of tracheostomy and of pulmonary complications; to worsen functional outcomes; and to increase mortality.

Keywords: Brain injuries; Ventilator weaning; Intensive care units; Glasgow outcome scale.

Objective: To compare the effects of early tracheostomy and of late tracheostomy in patients with acute severe brain injury. Methods: A retrospective study involving 28 patients admitted to the ICU of the Federal University of Juiz de Fora University Hospital in Juiz de Fora, Brazil, diagnosed with acute severe brain injury and presenting with a Glasgow coma scale (GCS) score < 8 within the first 48 h of hospitalization. The patients were divided into two groups: early tracheostomy (ET), performed within the first 8 days after admission; and late tracheostomy (LT), performed after postadmission day 8. At admission, we collected demographic data and determined the following scores: Acute Physiology and Chronic Health Evaluation (APACHE) II, GCS and Sequential Organ Failure Assessment (SOFA). Results: There were no significant differences between the groups (ET vs. LT) regarding the demographic data or the scores: APACHE II (26 ± 6 vs. 28 ± 8; p = 0.37), SOFA (6.3 ± 2.7 vs. 7.2 ± 3.0; p = 0.43) and GCS (5.4 ± 1.7 vs. 5.5 ± 1.7; p = 0.87). The 28-day mortality rate was lower in the ET group (9% vs. 47%; p = 0.04). Nosocomial pneumonia occurring within the first 7 days was less common in the ET group, although the difference was not significant (0% vs. 23%; p = 0.13). There were no differences regarding the occurrence of late pneumonia or in the duration of mechanical ventilation between the groups. Conclusions: On the basis of these findings, early tracheostomy should be considered in patients with acute severe brain injury.

Keywords: Tracheostomy; Pulmonary ventilation; Coma.

Objective: To determine whether the predictive accuracy of clinical judgment alone can be improved by supplementing it with an objective weaning protocol as a decision support tool. Methods: This was a multicenter prospective cohort study carried out at three medical/surgical ICUs. The study involved all consecutive difficult-to-wean ICU patients (failure in the first spontaneous breathing trial [SBT]), on mechanical ventilation (MV) for more than 48 h, admitted between January of 2002 and December of 2005. The patients in the protocol group (PG) were extubated after a T-piece weaning trial and were compared with patients who were otherwise extubated (non-protocol group, NPG). The primary outcome measure was reintubation within 48 h after extubation. Results: We included 731 patients-533 (72.9%) and 198 (27.1%) in the PG and NPG, respectively. The overall reintubation rate was 17.9%. The extubation success rates in the PG and NPG were 86.7% and 69.6%, respectively (p < 0.001). There were no significant differences between the groups in terms of age, gender, severity score, or pre-inclusion time on MV. However, COPD was more common in the NPG than in the PG (44.4% vs. 17.6%; p < 0.001), whereas sepsis and being a post-operative patient were more common in the PG (23.8% vs. 11.6% and 42.4% vs. 26.4%, respectively; p < 0.001 for both). The time on MV after the failure in the first SBT was higher in the PG than in the NPG (9 ± 5 days vs. 7 ± 2 days; p < 0.001). Conclusions: In this sample of difficult-to-wean patients, the use of a weaning protocol improved the decision-making process, decreasing the possibility of extubation failure.

Keywords: Ventilator weaning; Ventilation; Ventilators, mechanical.

Objective: To evaluate the usefulness of simple motor tasks such as hand grasping and tongue protrusion as predictors of extubation failure in critically ill neurological patients. Methods: This was a prospective cohort study conducted in the neurological ICU of a tertiary care hospital in the city of Porto Alegre, Brazil. Adult patients who had been intubated for neurological reasons and were eligible for weaning were included in the study. The ability of patients to perform simple motor tasks such as hand grasping and tongue protrusion was evaluated as a predictor of extubation failure. Data regarding duration of mechanical ventilation, length of ICU stay, length of hospital stay, mortality, and incidence of ventilator-associated pneumonia were collected. Results: A total of 132 intubated patients who had been receiving mechanical ventilation for at least 24 h and who passed a spontaneous breathing trial were included in the analysis. Logistic regression showed that patient inability to grasp the hand of the examiner (relative risk = 1.57; 95% CI: 1.01-2.44; p < 0.045) and protrude the tongue (relative risk = 6.84; 95% CI: 2.49-18.8; p < 0.001) were independent risk factors for extubation failure. Acute Physiology and Chronic Health Evaluation II scores (p = 0.02), Glasgow Coma Scale scores at extubation (p < 0.001), eye opening response (p = 0.001), MIP (p < 0.001), MEP (p = 0.006), and the rapid shallow breathing index (p = 0.03) were significantly different between the failed extubation and successful extubation groups. Conclusions: The inability to follow simple motor commands is predictive of extubation failure in critically ill neurological patients. Hand grasping and tongue protrusion on command might be quick and easy bedside tests to identify neurocritical care patients who are candidates for extubation.

Keywords: Ventilator weaning; Airway extubation/adverse effects; Critical care; Neurosurgery.

Objective: To characterize a population of patients with bronchiectasis, correlating clinical, radiological, and functional aspects with the severity of dyspnea. Methods: This was a cross-sectional study involving adult patients with HRCT-confirmed bronchiectasis, categorized according to the severity of dyspnea (as being mildly or severely symptomatic, on the basis of the modified Medical Research Council scale). We correlated the severity of dyspnea with clinical parameters, functional parameters (spirometry values, lung volumes, and DLCO), and CT parameters. Results: We evaluated 114 patients, 47 (41%) of whom were men. The median age (interquartile range) was 42 years (30-55 years). The most common form was idiopathic bronchiectasis. Of the 114 patients, 20 (17.5%) were colonized with Pseudomonas aeruginosa and 59 (51.8%) were under continuous treatment with macrolides. When we applied the Exacerbation in the previous year, FEV1, Age, Colonization, Extension, and Dyspnea score, the severity of dyspnea was categorized as moderate in 54 patients (47.4%), whereas it was categorized as mild in 50 (43.9%) when we applied the Bronchiectasis Severity Index. The most common lung function pattern was one of obstruction, seen in 95 patients (83.3%), and air trapping was seen in 77 patients (68.7%). The prevalence of an obstructive pattern on spirometry was higher among the patients with dyspnea that was more severe, and most functional parameters showed reasonable accuracy in discriminating between levels of dyspnea severity. Conclusions: Patients with bronchiectasis and dyspnea that was more severe had greater functional impairment. The measurement of lung volumes complemented the spirometry data. Because bronchiectasis is a complex, heterogeneous condition, a single variable does not seem to be sufficient to provide an overall characterization of the clinical condition.

Keywords: Bronchiectasis; Dyspnea; Respiratory function tests; Multidetector computed tomography; Plethysmography.

Objective: To evaluate the frequency of asthma-COPD overlap (ACO) in patients with COPD and to compare, from a clinical, laboratory, and functional point of view, patients with and without ACO, according to different diagnostic criteria. Methods: The participants underwent evaluation by a pulmonologist, together with spirometry and blood tests. All of the patients were instructed to record their PEF twice a day. The diagnosis of ACO was based on the Proyecto Latinoamericano de Investigación en Obstrucción Pulmonar (PLATINO, Latin American Project for the Investigation of Obstructive Lung Disease) criteria, the American Thoracic Society (ATS) Roundtable criteria, and the Spanish criteria. We investigated patient histories of exacerbations and hospitalizations, after which we applied the COPD Assessment Test and the modified Medical Research Council scale, to classify risk and symptoms in accordance with the GOLD criteria. Results: Of the 51 COPD patients, 14 (27.5%), 8 (12.2%), and 18 (40.0) were diagnosed with ACO on the basis of the PLATINO, ATS Roundtable, and Spanish criteria, respectively. The values for pre-bronchodilator FVC, post-bronchodilator FVC, and pre-bronchodilator FEV1 were significantly lower among the patients with ACO than among those with COPD only (1.9 ± 0.4 L vs. 2.4 ± 0.7 L, 2.1 ± 0.5 L vs. 2.5 ± 0.8 L, and 1.0 ± 0.3 L vs. 1.3 ± 0.5 L, respectively). When the Spanish criteria were applied, IgE levels were significantly higher among the patients with ACO than among those with COPD only (363.7 ± 525.9 kU/L vs. 58.2 ± 81.6 kU/L). A history of asthma was more common among the patients with ACO (p < 0.001 for all criteria). Conclusions: In our sample, patients with ACO were more likely to report previous episodes of asthma and had worse lung function than did those with COPD only. The ATS Roundtable criteria appear to be the most judicious, although concordance was greatest between the PLATINO and the Spanish criteria.

Keywords: Asthma/diagnosis; Pulmonary disease, chronic obstructive/diagnosis; Asthma-chronic obstructive pulmonary disease overlap syndrome/diagnosis.

Objective: To analyze the association of dysglycemia with clinical, laboratory, and radiographic characteristics of patients with pulmonary tuberculosis (PTB), as well as with their tuberculo-sis treatment outcomes. Methods: This was a longitudinal study involving 140 patients diag-nosed with PTB (positive cultures for Mycobacterium tuberculosis or positive Xpert MTB/RIF results from sputum samples). Patients were evaluated at diagnosis (M0), after completing the second month of treatment (M2), and at the end of treatment (MEND). At M0, the pati-ents were classified into three groups: normoglycemia+PTB (NGTB); pre-diabetes melli-tus+PTB (PDMTB), and diabetes mellitus+PTB (DMTB), in accordance with glycated hemoglo-bin levels (< 5.7%, 5.7%-6.4%, and = 6.5%, respectively). Treatment outcomes were classified as favorable (cure or treatment completion) and unfavorable (death, loss to follow-up, or treatment failure). Results: In our sample, 76 patients (61.4%) had dysglycemia, 20 of whom (14.3%) had DM at M0. The patients with dysglycemia, in comparison with those in the NGTB group, more frequently presented with positive sputum smear microscopy (94.2% vs. 75.9%; p = 0.003); cavities (80.2% vs. 63.0%; p = 0.03); bilateral lesions (67.4% vs. 46.0%; p = 0.02); and higher median of affected thirds of the lungs (3.0 vs. 2.0; p = 0.03) on chest radiography. No significant differences regarding outcomes were found among the groups, but tuberculosis lethality was higher in the DMTB group than in the PDMTB and NGTB groups (20% vs. 2.2%). Conclusions: PTB patients with dysglycemia had laboratory and radiographic manifestations indicative of more advanced disease, and the risk of death was higher in the DMTB group. These findings reinforce the recommendation for early screening for DM in patients with newly diagnosed tuberculosis in order to reduce the risk of death during treatment.

Keywords: Tuberculosis/diagnosis; Tuberculosis/diagnostic imaging; Tuberculosis/therapy; Diabetes mellitus; Treatment outcome.

Objective: To evaluate the diagnostic performance of the rapid shallow breathing index (RSBI) in predicting extubation failure among adult patients in the intensive care unit and to determine the appropriateness of the classical RSBI cut-off value. Methods: This was a prospective study conducted in the adult intensive care unit of the Botucatu School of Medicine Hospital das Clínicas. The RSBI was evaluated in 73 consecutive patients considered clinically ready for extubation. Results: The classical RSBI cut-off value (105 breaths/min/L) presented a sensitivity of 20% and a specificity of 95% (sum = 115%). Analysis of the receiver operator characteristic (ROC) curve revealed a better cut-off value (76.5 breaths/min/L), which presented a sensitivity of 66% and a specificity of 74% (sum = 140%). The area under the ROC curve for the RSBI was 0.78. Conclusions: The classical RSBI cut-off value proved inappropriate, predicting only 20% of the cases of extubation failure in our sample. The new cut-off value provided substantial improvement in sensitivity, with an acceptable loss of specificity. The area under the ROC curve indicated that the discriminative power of the RSBI is satisfactory, which justifies the validation of this index for use.

Keywords: Adult; Intensive care; ROC curve; Ventilator weaning; Diagnosis; Respiration, artificial.

Neuromuscular diseases affect alveolar air exchange and therefore cause chronic respiratory failure. The onset of respiratory failure can be acute, as in traumas, or progressive (slow or rapid), as in amyotrophic lateral sclerosis, muscular dystrophies, diseases of the myoneural junction, etc. Respiratory muscle impairment also affects cough efficiency and, according to the current knowledge regarding the type of treatment available in Brazil to these patients, it can be said that the high rates of morbidity and mortality in these individuals are more often related to the fact that they cough inefficiently rather than to the fact that they ventilate poorly. In this review, with the objective of presenting the options of devices available to support and substitute for natural ventilation in patients with neuromuscular diseases, we have compiled a brief history of the evolution of orthopedic braces and prostheses used to aid respiration since the end of the 19th century. In addition, we highlight the elements that are fundamental to the diagnosis of alveolar hypoventilation and of failure of the protective cough mechanism: taking of a clinical history; determination of peak cough flow; measurement of maximal inspiratory and expiratory pressures; spirometry in two positions (sitting and supine); pulse oximetry; capnography; and polysomnography. Furthermore, the threshold values available in the literature for the use of nocturnal ventilatory support and for the extension of this support through the daytime period are presented. Moreover, the maneuvers used to increase cough efficiency, as well as the proper timing of their introduction, are discussed.

Keywords: Respiratory insufficiency/diagnosis; Chronic disease; Respiratory insufficiency/therapy;

Objective: To evaluate the effects of non-invasive positive pressure ventilation (NIPPV) on acute respiratory failure and to identify the factors associated with its failure or success. Patients and methods: This open and prospective study analyzed 60 episodes of NIPPV use in 53 patients with respiratory failure. Results: In 37 occasions (62%), the patients were successfully ventilated with NIPPV (Success Group, SG) whereas in 23 episodes (38%) intubation was necessary (Failure Group, FG). FG patients showed a higher Apache II score (30.4 ± 9 versus 22.2 ± 8, p = 0.001). The use of NIPPV reduced respiratory rate after 2 hs. This reduction was less evident in FG (from 33 ± 9 to 30 ± 8 bpm, p = 0.094) than in SG (from 39 ± 11 to 28 ± 9 bpm, p < 0.001). PaO2 increased from 62 ± 22 to 101 ± 65 mmHg, (p < 0.001) with no differences between groups. Among patients with hypercapnia, PaCO2 level decreased in SG (from 76 ± 20 to 68 ± 21mmHg, p = 0.032) but not in FG (from 89 ± 23 to 93 ± 40mmHg, p = 0.54). Arterial pH increased in SG (from 7.25 ± 0.10 to 7.34 ± 0.11, p = 0.007) and not in FG (from 7.24 ± 0.07 to 7.21 ± 0.12, p = 0.48). NIPPV was used for longer in SG (3.4 ± 2.5 versus 2.3 ± 2 days, p = 0.003). Higher IPAP levels were used in SG (13.2 ± 3 versus 11 ± 4cmH2O, p = 0.02). The 10 patients (17%) who died, all belonged to FG. Skin lesions at the site of mask contact was the most common complication of NIPPV (5, 8%). NIPPV was efficient in treating acute respiratory failure in 2/3 of patients. The factors associated with failure were: greater severity of the illness, smaller reduction in the respiratory rate, no improvement of respiratory acidosis in 2 h and use of lower IPAP levels. The high mortality rate observed in FG (10, 43%) justifies efforts to optimize NIPPV implementation and to recognize its failure, as early as possible, in order to avoid delays in endotracheal intubation.

Keywords: Non-invasive positive pressure ventilation. Respiratory failure. Apache II. Hypercapnia.

Background: Cystic fibrosis (CF) is a disease marked by airway inflammation and airflow obstruction, resulting in air trapping in the lungs. Objective: To assess the associations between airflow limitation, pulmonary volume and X-ray findings in patients with cystic fibrosis. Method: A cross-sectional retrospective study. Review of spirometric, plethysmographic, and chest X-ray findings of outpatients (age ³ 16 years). The airflow findings were classified as within normal limits or as airflow obstruction: mild, moderate or severe obstructive alteration. Results: A total of 23 patients (15 male and eight female; mean age, 21 ± 5.9 years) were studied. Six of them were within normal limits, four had a mild, five had a moderate, and eight had a severe obstructive alteration. There was an association between airflow limitation and the increase of residual volume (p = 0.006) and also with the Brasfield score (p = 0.001), but not with the total lung capacity (p = 0.33). There was a correlation between residual volume and Brasfield score (r = 0,73, p = 0,002), but not with the total pulmonary capacity. Moreover, according to X-ray criteria, the air trapping was correlated only with the residual volume (p = 0.006). Conclusion: In patients with cystic fibrosis (age ³ 16 years), the progressive airflow limitation is accompanied by an increase in residual volume, while the total pulmonary capacity remains normal or tends to decrease. The X-ray score was associated with airflow limitation and residual volume, but not with total lung capacity.

Keywords: Cystic fibrosis. Pulmonary disease. Lung volume measurements. Radiography, thoracic.

Recent studies suggest that non-invasive positive pressure ventilation (NPPV) improves clinical signs and gas exchange, apart from avoiding the need for endotracheal intubation in selected patients with acute respiratory failure. In this prospective, open trial in the Intensive Care Unit (Hospital Universitário da Universidade Federal de Juiz de Fora), the authors evaluated the efficacy and security of using NPPV in patients with acute respiratory failure. Twenty-five patients with clinical or gasometric diagnosis of acute respiratory failure (respiratory rate > 25 breaths/min, accessory muscle use, PaO2 < 60 mmHg, PaCO2 > 50 mmHg after supplemental oxygen) received NPPV. Fifteen patients (60%) were successfully ventilated with NPPV, avoiding the tracheal intubation. After two hours with NPPV, the respiratory rate was reduced (from 36 ± 2 breaths/min to 26 ± 1 breaths/min, p < 0.01) and the PaO2 increased (from 76 ± 6 mmHg to 100 ± 12 mmHg, p < 0.05). Among the patients with hypercapnia, after two hours, the PaCO2 decreased (from 60 ± 2 mmHg to 49 ± 3 mmHg, p < 0.05). Four patients (16%) presented complications with facial skin necrosis, but only one had the NPPV stopped. Among the patients who did not respond to the method, three did not adapt to the NPPV and seven had it interrupted because of clinical deterioration. The authors conclude that NPPV is a safe option that can be used to treat selected patients with acute respiratory failure.

Objective: Massive hemoptysis is one of the most serious complications in patients with cystic fibrosis (CF). This study aimed to evaluate the hemoptysis-free period following bronchial and non-bronchial artery embolization (BAE/non-BAE) in CF patients and to investigate predictors of recurrent bleeding and mortality by any cause. Methods: This was a retrospective cohort study of CF patients = 16 years of age undergoing BAE/non-BAE for hemoptysis between 2000 and 2017. Results: We analyzed 39 hemoptysis episodes treated with BAE/non-BAE in 17 CF patients. Hemoptysis recurrence rate was 56.4%. Of the sample as a whole, 3 (17.6%) were hemoptysis-free during the study period, 2 (11.8%) underwent lung transplantation, and 3 (17.6%) died. The median hemoptysis-free period was 17 months. The median hemoptysis-free period was longer in patients with chronic infection with Pseudomonas aeruginosa (31 months; 95% CI: 0.00-68.5) than in those without that type of infection (4 months; 95% CI: 1.8-6.2; p = 0.017). However, this association was considered weak, and its clinical significance was uncertain due to the small number of patients without that infection. Conclusions: BAE appears to be effective in the treatment of hemoptysis in patients with CF.

Keywords: Cystic fibrosis; Hemoptysis; Bronchial arteries; Embolization, therapeutic.

Objective: Barriers to physical activity can affect the functional capacity and quality of life of patients with pulmonary hypertension (PH). This study aimed to identify the main barriers to physical activity in patients with PH and to examine whether those barriers are related to functional capacity, echocardiographic variables, or quality of life. Methods: This was a cross-sectional observational study involving 70 patients. Participants scored seven potential barriers to their activities, with a score = 5 indicating a significant barrier. Participants completed the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) and Manchester Respiratory Activity of Daily Living questionnaire, as well as the six-minute walk test. Correlation analysis, univariate analysis and multiple logistic regression were performed. Results: As a perceived barrier to physical activity, 'lack of will' or 'lack of energy' was cited by 67% of the patients. The 'lack of will' barrier was found to correlate with all SF-36 domains except bodily pain. We also identified a correlation between the SF-36 vitality domain and the barriers 'lack of energy', 'lack of will' and 'lack of structure'. The logistic regression analysis indicated that the vitality domain correlated significantly with the barriers 'social influence', 'lack of energy', 'lack of will', and 'lack of structure'. For each unit decrease in the vitality score, there was a 10% increase in the probability of citing the barrier 'lack of will'. No significant correlations were identified between any of the perceived barriers and echocardiographic parameters. Conclusions: The perceived barrier most commonly reported was 'lack of will/energy', which correlated with almost all SF-36 domains, especially vitality. The 'lack of will' barrier also correlated with functional capacity.

Keywords: Pulmonary arterial hypertension; Exercise; Motivation; Quality of life; Surveys and questionnaires; Walk test.

Objective: To establish a cut-off point for clinical and functional variables to determinate sarcopenia and dynapenia in COPD patients, and to analyze the impact of skeletal muscle dysfunction (SMD) on these variables. Methods: Cross-sectional study, screened COPD patients for sarcopenia or dynapenia through low muscle mass and hand grip strength (HGS). Clinical variables: pulmonary function, respiratory muscle strength and functional capacity (FC). The precision of the variables in determining points of predictive cut-off for sarcopenia or dynapenia were performed using the Receiver Operating Characteristic curve and two-way analysis of variance. Results: 20 COPD patients stratified for sarcopenia (n = 11) and dynapenia (n = 07). Sarcopenia group presented lower lean mass and lower maximal inspiratory pressure (MIP), decreased HGS, reduced FC (p<0.050). Dynapenia group presented reduced MIP, lower HGS and walked a shorter distance at Incremental shuttle walk test (ISWT) (p<0.050). We found cut-off points of forced expiratory volume in one second (FEV1), MIP and maximal expiratory pressure (MEP) and ISWT. It is possible to identify sarcopenia or dynapenia in these patients. We found the coexistence of the conditions (SMD effect) in COPD - reduction in the distance in the ISWT (p = 0.002) and %ISWT (p = 0.017). Conclusion: In moderate to very severe COPD patients the sarcopenia could be predicted by FEV1 (%predicted) < 52, MIP < 73 cmH2O, MEP < 126 cmH2O and distance traveled of < 295 m in ISWT. Whereas dynapenia could be predicted by FEV1 < 40%, MIP < 71 cmH2O, MEP < 110 cmH2O and distance of < 230 m traveled in ISWT.

Keywords: Sarcopenia; Chronc obstructive pulmonary disease; Musculoskeletal system.

Objective: To determine whether the variation in lung function over one year is associated with worse clinical outcomes, as well as with a decline in lung function in the following years, in patients with cystic fibrosis (CF). Methods: This was a retrospective study involving CF patients (4-19 years of age), evaluated over a three-year period. We evaluated demographic characteristics, chronic Pseudomonas aeruginosa infection, antibiotic use, hospitalization, six-minute walk distance (6MWD), and lung function. The inclusion criterion was having undergone pulmonary function testing at least three times in the first year and at least once in each of the next two years. Results: We evaluated 35 CF patients. The variation in FEV1 in the first year (ΔFEV1) was greater among those who, in the third year, showed reduced FEV1, had a below-average 6MWD, or were hospitalized than among those with normal FEV1, normal 6MWD, or no hospital admissions, in that same year (p < 0.05), although no such difference was found for antibiotic use in the third year. Subjects showing a ΔFEV1 ≥ 10% also showed a greater decline in FEV1 over the two subsequent years (p = 0.04). The ΔFEV1 also showed an inverse correlation with absolute FEV1 in the third year (r = −0.340, p = 0.04) and with the rate of FEV1 decline (r = −0.52, p = 0.001). Linear regression identified ΔFEV1 as a predictor of FEV1 decline (coefficient of determination, 0.27). Conclusions: Significant variation in lung function over one year seems to be associated with a higher subsequent rate of FEV1 decline and worse clinical outcomes in CF patients. Short-term ΔFEV1 might prove useful as a predictor of CF progression in clinical practice.

Keywords: Cystic fibrosis; Respiratory function tests; Disease progression; Hospitalization; Forced expiratory volume.

Introduction: Spirometry and analysis of blood gases data have been extensively used to assess ventilatory limitation and prognosis of COPD patients. However, functional physical tests, such as the six-minute walk test (6wt) have been used for the dynamic assessment of COPD patients. Objective: To determine correlations between respiratory function test data and the six-minute walk test in COPD patients. Patients and methods: 45 patients were submitted to clinical history survey and complete physical examination performed by the medical staff of the Pneumology Department of the Brasilia University Hospital, followed by spirometry, analysis of arterial blood gases, maximal respiratory pressures data, and the six-minute walk test. Results: Concerning the spirometric, analysis of blood gases and maximal respiratory pressures data, statistically significant positive correlations (p < 0.05) between FEV1, PaO2, SpO2, MEP and the six-minute walk test were obtained. Conclusions: For the studied group, the six minute walk test has significant correlation with FEV1, PaO2, SpO2 and MEP, and can be used as an alternative functional assessment of COPD patients.