Objective: To determine the accuracy of the variables related to the fixed-height stair climbing test (SCT) using maximal oxygen uptake (VO2 max) as the gold standard. Methods: The SCT was performed on a staircase consisting of 6 flights (72 steps; 12.16 m total height), with verbal encouragement, in 51 patients. Stair-climbing 'time' was measured, and the variables 'work' and 'power' also being calculated. The VO2 max was measured using ergospirometry according to the Balke protocol. We calculated the Pearson linear correlation (r), as well as the values of p, between the SCT variables and VO2 max. To determine accuracy, the VO2 max cut-off point was set at 25 mL/kg/min, and individuals were classified as normal or altered. The cut-off points for the SCT variables were determined using the receiver operating characteristic curve. The Kappa statistic (k) was used in order to assess concordance. Results: The following values were obtained for the variable 'time': cut-off point = 40 s; x_ = 41 ± 15.5 s; r = −0.707; p < 0.005; specificity = 89%; sensibility = 83%; accuracy = 86%; and k = 0.724. For 'power', the values obtained were as follows: cut-off point = 200 w; x_ = 222.3 ± 95.2 w; r = 0.515; p < 0.005; specificity = 67%; sensibility = 75%; accuracy = 71%; and k = 0.414. Since the correlation between 'work' and VO2 max was not significant, that variable was discarded. Conclusion: Of the SCT variables tested, using VO2 max as the gold standard, the variable 'time' was the most accurate.

Keywords: Exercise test; Respiratory function tests; Heart function tests; Spirometry; Ergometry

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.

Objective: To evaluate the behavior of oxygen saturation curves throughout the six-minute walk test (6MWT) in patients with COPD. Methods: We included 85 patients, all of whom underwent spirometry and were classified as having moderate COPD (modCOPD, n = 30) or severe COPD (sevCOPD, n = 55). All of the patients performed a 6MWT, in a 27-m corridor with continuous SpO2 and HR monitoring by telemetry. We studied the SpO2 curves in order to determine the time to a 4% decrease in SpO2, the time to the minimum SpO2 (Tmin), and the post-6MWT time to return to the initial SpO2, the last designated recovery time (RT). For each of those curves, we calculated the slope. Results: The mean age in the modCOPD and sevCOPD groups was 66  10 years and 62  11 years, respectively. At baseline, SpO2 was > 94% in all of the patients; none received supplemental oxygen during the 6MWT; and none of the tests were interrupted. The six-minute walk distance did not differ significantly between the groups. The SpO2 values were lowest in the sevCOPD group. There was no difference between the groups regarding RT. In 71% and 63% of the sevCOPD and modCOPD group patients, respectively, a ≥ 4% decrease in SpO2 occurred within the first minute. We found that FEV1% correlated significantly with the SpO2 (r = −0.398; p < 0.001), Tmin (r = −0.449; p < 0.001), and minimum SpO2 (r = 0.356; p < 0.005). Conclusions: In the sevCOPD group, in comparison with the modCOPD group, SpO2 was lower and the Tmin was greater, suggesting a worse prognosis in the former.

Keywords: Pulmonary disease, chronic obstructive; Exercise test; Blood gas monitoring, transcutaneous.

Objective: To assess the frequency and severity of 24-hour respiratory symptoms according to COPD GOLD-ABCD classification (2017-version), the distribution of the patients with COPD into GOLD categories using mMRC (=2) or CAT (=10) scores, and agreement between these cut-off points. Methods: In this cross-sectional study (LASSYC study), 24-hour day respiratory symptoms were assessed by the Evaluating Respiratory Symptoms in COPD (E-RS) questionnaire, Nighttime Symptoms of COPD Instrument (NiSCI), Early Morning Symptoms of COPD Instrument (EMSCI), CAT and mMRC scores. Results: Among the 734 patients with COPD, 61% were male, age 69.6±8.7 years, FEV1% post-BD 49.1±17.5%, mMRC 1.8±1.0 and CAT 15.3±.8.1. By mMRC 33.7% were group-A, 29.2% group-B, 10.2% group-C and 26.9% group-D. By CAT 22.3% were group-A, 41% group-B, 4.8% group-C and 31.9% group-D. Using the mMRC the severity of E-RS, NiSCI and EMSCI scores increased from group A to D. Using the CAT, the groups B and D had the higher scores. Agreement between mMRC and CAT was 89.5% (Kappa statistics=75.7%). For mMRC score of 2, CAT score of =11 showed the maximum Youden's index (1.34). For mMRC score of 1, CAT score of =9 and =10 showed the maximum Youden's index (1.48). Conclusion: GOLD COPD classification by CAT seems to better discriminate 24-hour symptoms. Results do not support the equivalent use of CAT=10 and mMRC=2 for assessing symptoms.

Keywords: Chronic obstructive pulmonary disease; Symptoms and COPD.

Objective: To determine the probability of oxygen desaturation in healthy individuals undergoing the incremental shuttle walk test (ISWT). Methods: We enrolled 83 healthy subjects: 55 males (including 1 smoker) and 28 females. We determined pre-ISWT FEV1, FEV6, HR and SpO2, as well as post-ISWT HR and SpO2. Results: Mean values overall were as follows: age, 35.05 ± 12.53 years; body mass index, 24.30 ± 3.47 kg/m2; resting HR, 75.12 ± 12.48 bpm; resting SpO2, 97.96 ± 1.02%; FEV1, 3.75 ± 0.81 L; FEV6, 4.45 ± 0.87 L; FEV1/FEV6 ratio, 0.83 ± 0.08 (no restriction or obstruction); incremental shuttle walk distance, 958.30 ± 146.32 m; post-ISWT HR, 162.41 ± 18.24 bpm; and post-ISWT SpO2, 96.27 ± 2.21%. In 11 subjects, post-ISWT SpO2 was higher than was pre-ISWT SpO2. In 17 subjects, there was a 4% decrease in SpO2 after the ISWT. There were no statistically significant differences between the groups with and without post-ISWT oxygen desaturation in terms of age, gender, FEV1, FEV6, FEV1/FEV6, pre-ISWT SpO2, incremental shuttle walk distance, HR, or percentage of maximal HR. In the individuals with post-ISWT oxygen desaturation, the body mass index was higher (p = 0.01) and post-ISWT SpO2 was lower (p = 0.0001). Conclusions: Healthy individuals can present oxygen desaturation after the ISWT. Using the ISWT to predict subtle respiratory abnormalities can be misleading. In healthy subjects, oxygen desaturation is common after the ISWT, as it is during any intense physical activity.

Keywords: Heart function tests; Respiratory function tests; Body mass index; Oximetry

Objective: Levels of procalcitonin, midregional pro-atrial natriuretic peptide (MR-proANP), C-terminal provasopressin (copeptin), and C-reactive protein (CRP), as well as Sequential Organ Failure Assessment (SOFA) scores, are associated with severity and described as predictors of outcome in ventilator-associated pneumonia (VAP). This study sought to compare the predictive value of these biomarkers for mortality in VAP. Methods: An observational study of 71 patients with VAP. Levels of procalcitonin, MR-proANP, copeptin, and CRP, together with SOFA scores, were determined at VAP onset, designated day 0 (D0), and on day 4 of treatment (D4). Patients received empirical antimicrobial therapy, with modifications based on culture results. Patients who died before D28 were classified as nonsurvivors. Results: Of the 71 patients evaluated, 45 were classified as survivors. Of the 45 survivors, 35 (77.8%) received appropriate antimicrobial therapy, compared with 18 (69.2%) of the 26 nonsurvivors (p = 0.57). On D0 and D4, the levels of all biomarkers (except CRP), as well as SOFA scores, were lower in eventual survivors than in eventual nonsurvivors. For D0 and D4, the area under the ROC curve was largest for procalcitonin. On D0, MR-proANP had the highest positive likelihood ratio (2.71) and positive predictive value (0.60), but procalcitonin had the highest negative predictive value (0.87). On D4, procalcitonin had the highest positive likelihood ratio (3.46), the highest positive predictive value (0.66), and the highest negative predictive value (0.93). Conclusions: The biomarkers procalcitonin, MR-proANP, and copeptin can predict mortality in VAP, as can the SOFA score. Procalcitonin alone has the greatest predictive power for such mortality.

Keywords: Pneumonia, ventilator-associated/mortality; Biological markers/analysis; Health Status Indicators.

Objective: Simple diagnostic methods can facilitate the diagnosis of COPD, which is a major public health problem. The objective of this study was to investigate the accuracy of clinical variables in the diagnosis of COPD. Methods: Patients with COPD and control subjects were prospectively evaluated by two investigators regarding nine clinical variables. The likelihood ratio for the diagnosis of COPD was determined using a logistic regression model. Results: The study comprised 98 patients with COPD (mean age, 62.3 ± 12.3 years; mean FEV1, 48.3 ± 21.6%) and 102 controls. The likelihood ratios (95% CIs) for the diagnosis of COPD were as follows: 4.75 (2.29-9.82; p < 0.0001) for accessory muscle recruitment; 5.05 (2.72-9.39; p < 0.0001) for pursed-lip breathing; 2.58 (1.45‑4.57; p < 0.001) for barrel chest; 3.65 (2.01-6.62; p < 0.0001) for decreased chest expansion; 7.17 (3.75-13.73; p < 0.0001) for reduced breath sounds; 2.17 (1.01-4.67; p < 0.05) for a thoracic index ≥ 0.9; 2.36 (1.22-4.58; p < 0.05) for laryngeal height ≤ 5.5 cm; 3.44 (1.92-6.16; p < 0.0001) for forced expiratory time ≥ 4 s; and 4.78 (2.13-10.70; p < 0.0001) for lower liver edge ≥ 4 cm from lower costal edge. Inter-rater reliability for those same variables was, respectively, 0.57, 0.45, 0.62, 0.32, 0.53, 0.32, 0.59, 0.52 and 0.44 (p < 0.0001 for all). Conclusions: Various clinical examination findings could be used as diagnostic tests for COPD.

Keywords: Physical examination; Diagnosis; Pulmonary disease, chronic obstructive.

Objective: To compare the behavior of the oxygen uptake efficiency slope (OUES) with that of oxygen uptake at peak exertion (VO2peak). Methods: This was a prospective cross-sectional study involving 21 patients (15 men) with mild-to-moderate COPD undergoing spirometry, handgrip strength (HGS) testing, cardiopulmonary exercise testing, and determination of lactate at peak exertion (LACpeak). Results: Mean weight was 66.7 ± 13.6 kg, and mean age was 60.7 ± 7.8 years. With the exception of FEV1 and FEV1/FVC ratio (75.8 ± 18.6% of predicted and 56.6 ± 8.8%, respectively), all spirometric variables were normal, as was HGS. The patients exhibited significant metabolic and hemodynamic stress, as evidenced by the means (% of predicted) for VO2peak (93.1 ± 15.4), maximum HR (92.5 ± 10.4), and OUES (99.4 ± 24.4), as well as for the gas exchange rate (1.2 ± 0.1). The correlation between VO2peak and OUES was significant (r = 0.747; p < 0.0001). The correlation between HGS and VO2peak (r = 0.734; pX< 0.0001) was more significant than was that between HGS and OUES (r = 0.453; p < 0.05). Similar results were found regarding the correlations of VO2peak and OUES with MIP. Although LACpeak correlated significantly with VO2peak (r = −0.731; p < 0.0001), only LACpeak/maximum power correlated significantly with OUES (r = −0.605; p = 0.004). Conclusions: Our findings suggest that, in mild-to-moderate COPD, VO2 determinants other than overall muscle strength have a greater impact on OUES than on VO2peak.

Keywords: Respiratory function tests; Pulmonary disease, chronic obstructive; Muscle strength; Oxygen consumption.

Objective: To compare gastric lavage (GL) performed in inpatients with GL performed in outpatients in terms of its accuracy in diagnosing pulmonary tuberculosis (TB) in children. Methods: A prospective study was carried out in the state of Espírito Santo, Brazil, from 1999 to 2003. A total of 230 children suspected of having TB (103 inpatients and 127 outpatients) were selected to undergo GL. Those thus diagnosed with TB (n = 53) were divided into two groups: inpatient GL (n = 30) and outpatient GL (n = 23). All 53 children were monitored for 6 months in order to evaluate the accuracy of the diagnosis. Accuracy was determined based on any change in diagnosis, cure rate, and the percentage of positive cultures in the two groups studied. Results: The cure rate was 100% in both groups, and there was no change in diagnosis in the 53 children studied. No significant difference was found between the two groups studied in terms of detection of Mycobacterium tuberculosis (RR = 1.47; 95% CI: 0.95-2.27; p = 0.095), although the outpatient group presented a greater rate of positive cultures. Conclusions: Our results show that the accuracy of GL performed in an inpatient setting is similar to that of GL performed in an outpatient setting. This indicates that hospitalization is required only in more severe cases in which GL cannot be performed as an outpatient procedure.

Keywords: Gastric lavage; Tuberculosis; Diagnosis.

Objective: Previous studies have demonstrated that closed pleural biopsy (CPB) has a sensitivity of less than 60% for diagnosing malignancy. Therefore, controversy has recently emerged regarding the value of CPB as a diagnostic test. Our objective was to assess the accuracy of CPB in diagnosing malignancy in patients with pleural effusion. Methods: This was a prospective 8-year study of individuals who underwent CPB to establish the etiology of pleural effusion. Information on each patient was obtained from anatomopathological reports and medical records. When CPB findings showed malignancy or tuberculosis, the biopsy was considered diagnostic, and that was the definitive diagnosis. In cases in which biopsy histopathological findings were nonspecific, a definitive diagnosis was established on the basis of other diagnostic procedures, such as thoracoscopy, thoracotomy, fiberoptic bronchoscopy, biochemical and cellular measurements in pleural fluid, and/or microbiological tests. The accuracy of CPB was determined with 2 × 2 contingency tables. Results: A total of 1034 biopsies from patients with pleural effusion were studied. Of those, 171 (16.54%) were excluded from the accuracy analysis either because of inadequate samples or insufficient information. The results of the accuracy analysis were as follows: sensitivity, 77%; specificity, 98%; positive predictive value, 99%; negative predictive value, 66%; positive likelihood ratio, 38.5; negative likelihood ratio, 0.23; pre-test probability, 2.13; and post-test probability, 82. Conclusions: CPB is useful in clinical practice as a diagnostic test, because there is an important change from pre-test to post-test probability.

Keywords: Biopsy; Pleural effusion, malignant/diagnosis; Pleural effusion, malignant/epidemiology.

Objective: To evaluate the quality of ChatGPT answers to asthma-related questions, as assessed from the perspectives of asthma specialists and laypersons. Methods: Seven asthma-related questions were asked to ChatGPT (version 4) between May 3, 2024 and May 4, 2024. The questions were standardized with no memory of previous conversations to avoid bias. Six pulmonologists with extensive expertise in asthma acted as judges, independently assessing the quality and reproducibility of the answers from the perspectives of asthma specialists and laypersons. A Likert scale ranging from 1 to 4 was used, and the content validity coefficient was calculated to assess the level of agreement among the judges. Results: The evaluations showed variability in the quality of the answers provided by ChatGPT. From the perspective of asthma specialists, the scores ranged from 2 to 3, with greater divergence in questions 2, 3, and 5. From the perspective of laypersons, the content validity coefficient exceeded 0.80 for four of the seven questions, with most answers being correct despite a lack of significant depth. Conclusions: Although ChatGPT performed well in providing answers to laypersons, the answers that it provided to specialists were less accurate and superficial. Although AI has the potential to provide useful information to the public, it should not replace medical guidance. Critical analysis of AI-generated information remains essential for health care professionals and laypersons alike, especially for complex conditions such as asthma.

Keywords: Asthma; Artificial intelligence; Pulmonologists

Objective: To evaluate the health-related quality of life of patients with chronic obstructive pulmonary disease receiving long-term oxygen therapy (LTOT) at home through oxygen cylinders and compare these results with those obtained six months after the transition from oxygen cylinders to oxygen concentrators. Methods: A total of 45 patients were evaluated. Of those, 24 had chronic hypoxemia and 21 presented no evidence of hypoxemia. The patients with chronic hypoxemia had been regularly receiving LTOT for at least the last six months and were evaluated at baseline, while using cylinders, and six months after the transition from cylinders to concentrators. The non-hypoxemic patients were evaluated at the same time points as were the hypoxemic patients. In order to evaluate quality of life, a version of the Saint George's Respiratory Questionnaire (SGRQ), translated and validated for use in Brazil, was administered. Results: At baseline, quality of life, as evaluated using the total score and the symptom and impact domain scores of the SGRQ, was more impaired in the hypoxemic patients than in the non-hypoxemic patients. After six months of using the concentrators, the hypoxemic patients presented a significant improvement in the quality of life, and, at that time, no difference was found between the patients with and without hypoxemia. Conclusion: Our findings show that quality of life is impaired in patients with chronic obstructive pulmonary disease and chronic hypoxemia, that their quality of life can be improved through regular use of LTOT, and that the oxygen delivery system has an influence on this improvement.

Keywords: Pulmonary disease, Chronic obstructive; Anoxemia; Oxygen inhalation therapy; Quality of life.

Objective: To assess predictive factors for improved diagnostic accuracy with the use of radial-probe EBUS (RP-EBUS). Methods: This was a retrospective review of consecutive patients undergoing RP-EBUS between February of 2012 and January of 2020. Parameters including the presence of a bronchus sign on CT scans, the position of the radial EBUS probe, lesion size, lesion location, and lesion type were analyzed in relation to two defined outcomes (final diagnosis or no diagnosis). Univariate analysis was used in order to explore the individual effects of each parameter on diagnostic accuracy. Multivariate logistic regression was performed to identify significant predictors of diagnostic accuracy. Results: RP-EBUS was used for diagnostic purposes in 101 patients. The lesion was < 3 cm in size in 59 patients (58.4%) and predominantly solid in 60.3%. There was a positive correlation between radial EBUS probe position and diagnostic accuracy (p = 0.036), with 80.9% of the patients showing a bronchus sign on CT scans. Furthermore, 89% of the patients showed a bronchus sign on CT scans and a correlation with diagnostic accuracy (p = 0.030), with 65.8% of the lesions being located in the left/right upper lobe (p = 0.046). When the radial EBUS probe was within the target lesion, the diagnostic yield was = 80.8%. When the probe was adjacent to the lesion, the diagnostic yield was = 19.2%. A bronchus sign on CT scans was the only parameter that independently influenced diagnostic accuracy (adjusted OR, 3.20; 95% CI, 1.081-9.770; p = 0.036). Conclusions: A bronchus sign on CT scans is a powerful predictor of successful diagnosis by RP-EBUS.

Keywords: Diagnostic techniques, respiratory system; Ultrasonography; Bronchoscopy.

Objective: The identification of persistent airway obstruction is key to making a diagnosis of COPD. The GOLD guidelines suggest a fixed criterion-a post-bronchodilator FEV1/FVC ratio < 70%-to define obstruction, although other guidelines suggest that a post-bronchodilator FEV1/FVC ratio < the lower limit of normal (LLN) is the most accurate criterion. Methods: This was an observational study of individuals = 40 years of age with risk factors for COPD who were referred to our pulmonary function laboratory for spirometry. Respiratory symptoms were also recorded. We calculated the prevalence of airway obstruction and of no airway obstruction, according to the GOLD criterion (GOLD+ and GOLD-, respectively) and according to the LLN criterion (LLN+ and LLN-, respectively). We also evaluated the level of agreement between the two criteria. Results: A total of 241 individuals were included. Airway obstruction was identified according to the GOLD criterion in 42 individuals (17.4%) and according to the LLN criterion in 23 (9.5%). The overall level of agreement between the two criteria was good (? = 0.67; 95% CI: 0.52-0.81), although it was lower among the individuals = 70 years of age (? = 0.42; 95% CI: 0.12-0.72). The proportion of obese individuals was lower in the GOLD+/LLN+ category than in the GOLD+/LLN- category (p = 0.03), as was the median DLCO (p = 0.04). Conclusions: The use of the GOLD criterion appears to be associated with a higher prevalence of COPD. The agreement between the GOLD and LLN criteria also appears to be good, albeit weaker in older individuals. The use of different criteria to define airway obstruction seems to identify individuals with different characteristics. It is essential to understand the clinical meaning of discordance between such criteria. Until more data are available, we recommend a holistic, individualized approach to, as well as close follow-up of, patients with discordant results for airway obstruction.

Keywords: Pulmonary disease, chronic obstructive; Airway obstruction; Spirometry.

Objective: To evaluate the effect of adenotonsillectomy on oxygen saturation measured through nocturnal pulse oximetry in children with sleep disordered breathing. Methods: A pre- and post-intervention study was carried out using nocturnal pulse oximetry. The study involved 31 children who were suspected of having sleep disordered breathing and had been referred for adenotonsillectomy. Results: A total of 27 children completed the study. The mean age was 5.2 ± 1.8 years, and 18 (66.7%) of them were male. Upon physical examination, 23 (85.2%) of the children presented class III or class IV hyperplasia of the palatine tonsils. There was significant improvement in the post-operative period over the pre-operative period in terms of the oxygen desaturation rate (OR = 0.65; 95% CI: 0.5-1.3 vs. OR = 1.63; 95% CI: 1.1-2.4; p < 0.001). Conclusion: Adenotonsillectomy significantly improved oxygen saturation, as measured through nocturnal pulse oximetry, in children with sleep disordered breathing.

Keywords: Sleep apnea obstructive; Tonsillectomy; Oximetry; Child