Objective: To compare TLC and RV values obtained by the single-breath helium dilution (SBHD) method with those obtained by whole-body plethysmography (WBP) in patients with normal lung function, patients with obstructive lung disease (OLD), and patients with restrictive lung disease (RLD), varying in severity, and to devise equations to estimate the SBHD results. Methods: This was a retrospective cross-sectional study involving 169 individuals, of whom 93 and 49 presented with OLD and RLD, respectively, the remaining 27 having normal lung function. All patients underwent spirometry and lung volume measurement by both methods. Results: TLC and RV were higher by WBP than by SBHD. The discrepancy between the methods was more pronounced in the OLD group, correlating with the severity of airflow obstruction. In the OLD group, the correlation coefficient of the comparison between the two methods was 0.57 and 0.56 for TLC and RV, respectively (p < 0.001 for both). We used regression equations, adjusted for the groups studied, in order to predict the WBP values of TLC and RV, using the corresponding SBHD values. It was possible to create regression equations to predict differences in TLC and RV between the two methods only for the OLD group. The TLC and RV equations were, respectively, ∆TLCWBP-SBHD in L = 5.264 − 0.060 × FEV1/FVC (r2 = 0.33; adjusted r2 = 0.32) and ∆RVWBP-SBHD in L = 4.862 − 0.055 × FEV1/FVC (r2 = 0.31; adjusted r2 = 0.30). Conclusions: The correction of TLC and RV results obtained by SBHD can improve the accuracy of this method for assessing lung volumes in patients with OLD. However, additional studies are needed in order to validate these equations.

Keywords: Plethysmography, whole body; Total lung capacity; Residual volume.

Objective: To derive reference values for healthy white Brazilian adults who have never smoked and to compare the obtained values with reference values derived by Crapo and by Neder. Methods: Reference equations by quantile regressions were derived in 122 men and 122 women, non-obese, living in seven cities in Brazil. Age ranged from 21 to 92 years in women and from 25 to 88 years in men. Lung function tests were performed using SensorMedics automated body plethysmographies according ATS/ERS recommendations. Lower and upper limits were derived by specific equations for 5 and 95 percentiles. The results were compared to those suggested by Crapo in 1982, and Neder in 1999. Results: Median values for total lung capacity (TLC) were influenced only by stature in men, and by stature and age in women. Residual volume was influenced by age and stature in both genders. Weight was directly related to inspiratory capacity and inversely with functional residual capacity and expiratory reserve volume in both genders. A comparison of observed TLC data with values predicted by Neder equations showed significant lower values by the present data. Mean values were similar between data from present study and those derived by Crapo. Conclusion: New predicted values for lung volumes were obtained in a sample of white Brazilians. The values differ from those derived by Neder, but are similar to those derived by Crapo.

Keywords: Pulmonary volumes; Pulmonary function tests; Reference values; Pulmonary plethysmography

Objective: To evaluate whether a six-minute walk distance (6MWD) of < 80% of the predicted value can predict the occurrence of acute exacerbations of COPD in patients in Brazil over a 2-year period. Methods: This was a retrospective cross-sectional study involving 50 COPD patients in Brazil. At enrollment, anthropometric data were collected and patients were assessed for pulmonary function (by spirometry) and functional exercise capacity (by the 6MWD). The patients were subsequently divided into two groups: 6MWD ≤ 80% of predicted and 6MWD > 80% of predicted. The occurrence of acute exacerbations of COPD over 2 years was identified by analyzing medical records and contacting patients by telephone. Results: In the sample as a whole, there was moderate-to-severe airflow obstruction (mean FEV1 = 41 ± 12% of predicted) and the mean 6MWD was 469 ± 60 m (86 ± 10% of predicted). Over the 2-year follow-up period, 25 patients (50%) experienced acute exacerbations of COPD. The Kaplan-Meier method showed that the patients in whom the 6MWD was ≤ 80% of predicted were more likely to have exacerbations than were those in whom the 6MWD was > 80% of predicted (p = 0.01), whereas the Cox regression model showed that the former were 2.6 times as likely to have an exacerbation over a 2-year period as were the latter (p = 0.02). Conclusions: In Brazil, the 6MWD can predict acute exacerbations of COPD over a 2-year period. The risk of experiencing an acute exacerbation of COPD within 2 years is more than twice as high in patients in whom the 6MWD is ≤ 80% of predicted.

Keywords: Pulmonary disease, chronic obstructive; Risk groups; Exercise.

Objective: To determine whether abnormal continuous glucose monitoring (CGM) readings (hypoglycemia/hyperglycemia) can predict the onset of cystic fibrosis-related diabetes (CFRD) and/or clinical impairment (decline in BMI and/or FEV1) in pediatric patients with cystic fibrosis (CF). Methods: This was a longitudinal prospective cohort study involving CF patients without diabetes at baseline. The mean follow-up period was 3.1 years. The patients underwent 3-day CGM, performed oral glucose tolerance test (OGTT), and had FEV1 and BMI determined at baseline. OGTT, FEV1, and BMI were reassessed at the end of the follow-up period. Results: Thirty-nine CF patients (10-19 years of age) had valid CGM readings at baseline, and 34 completed the follow-up period (mean = 3.1 ± 0.5 years). None of the study variables predicted progression to CFRD or were associated with hypoglycemic events. CGM could detect glucose abnormalities not revealed by OGTT. Patients with glucose levels = 140 mg/dL, as compared with those with lower levels, on CGM showed lower BMI values and z-scores at baseline-17.30 ± 3.91 kg/m2 vs. 19.42 ± 2.07 kg/m2; p = 0.043; and -1.55 ± 1.68 vs. -0.17 ± 0.88; p = 0.02, respectively-and at the end of follow-up-17.88 ± 3.63 kg/m2 vs. 19.95 ± 2.56 kg/m2; p = 0.039; and -1.65 ± 1.55 vs. -0.42 ± 1.08; p = 0.039. When comparing patients with and without CFRD, the former were found to have worse FEV1 (in % of predicted)-22.67 ± 5.03 vs. 59.58 ± 28.92; p = 0.041-and a greater decline in FEV1 (-36.00 ± 23.52 vs. -8.13 ± 17.18; p = 0.041) at the end of follow-up. Conclusions: CGM was able to identify glucose abnormalities not detected by OGTT that were related to early-stage decreases in BMI. CGM was ineffective in predicting the onset of diabetes in this CF population. Different diagnostic criteria for diabetes may be required for individuals with CF.

Keywords: Cystic fibrosis; Glucose intolerance; Glucose tolerance test; Diabetes mellitus.

Background: Gastroplasty has been increasingly used in the treatment of morbidly obese patients, who typically present pronounced alterations in lung volume and capacity. Objective: To evaluate post-gastroplasty lung volume, lung capacity, respiratory muscle strength and respiratory pattern, as well as any postoperative pulmonary complications. Method: 21 patients (3 of them men), with an average age of 39 ± 9.7 years and an average body mass index of 50.4 kg/m2, all candidates for gastroplasty, were evaluated during the preoperative period and again on the first, third and fifth postoperative days. Tidal volume, vital capacity, minute volume, maximal expiratory pressure and maximal inspiratory pressure, as well as chest and waist circumferences, were measured. Postoperative pulmonary complications and mortality were assessed. Results: On the first and third postoperative days, respectively, there were drops of 47% and 30.5% in vital capacity, 18% and 12.5% in minute volume, 28% and 21% in tidal volume, 47% and 32% in the diaphragmatic index, 51% and 26% in maximal inspiratory pressure, and 39.5% and 26% in maximal expiratory pressure (p < 0.05). On the fifth postoperative day, all variables analyzed were higher than on the first postoperative day, indicating a linear increase, with only tidal volume, minute volume diaphragmatic index returning to preoperative values. The incidence of postoperative pulmonary complications was 4.7%, and there were no deaths. Conclusion: Patients submitted to gastroplasty present reduced pulmonary function, following a pattern quite similar to that previously observed following other types of upper abdominal surgery.

Keywords: Key words: Gastroplasty. Obesity. Respiratory function tests. Postoperative care.

Objective: The interrupter technique is used for determining interrupter resistance (Rint) during quiet breathing. This noninvasive method requires minimal cooperation and can therefore be useful in evaluating airway obstruction in uncooperative children. To date, no reference values have been determined for Rint in a Brazilian population. The objective of this study was to define a prediction equation for airway resistance using the interrupter technique for healthy children aged 3-13 years. Methods: This was a prospective, cross-sectional study involving preschool and school children in Porto Alegre, Brazil, in whom Rint was measured during peak expiratory flow. Results: ­One-hundred and ninety-three children were evaluated. Univariate analysis using linear regression showed that height, weight and age correlated significantly and independently with Rint. Multiple regression with height, weight, age and gender as variables resulted in a model in which only height and weight were significant, independent predictors of Rint. Collinearity was identified among height, weight and age. ­Conclusions: Reference values and an equation for calculating Rint in healthy children were obtained and are adjusted for height.

Keywords: Respiratory function tests; Airway resistance; Diagnostic techniques, respiratory system; Airway obstruction/diagnosis; Reference values.

Objective: To determine the agreement between interrupter resistance (Rint) and airway resistance (Raw) by plethysmography in order to verify the clinical applicability of the interrupter technique. Methods: The Rint technique was performed with the patients in a sitting position, during exhalation, with a nose clip and cheek support. Plethysmography was carried out in accordance with standard protocols. All measurements were taken prior to and after the administration of an inhaled bronchodilator via a metered dose inhaler with a spacer. Results: The study comprised 99 consecutive patients referred to the Porto Alegre Hospital de Clínicas, located in the city of Porto Alegre, Brazil, for pulmonary function testing. Patient ages ranged from 18 to 82 years, and 52 of the patients were women. In the patients with FEV1 ≥ 60% of predicted, there was good agreement between the methods (r = 0.8; intraclass correlation coefficient = 0.8). The Rint values were lower than were those of Raw by plethysmography in the patients with more severe disease. However, there was good agreement between Rint ≥ 4 cmH2O  L−1  s−1 and Raw by plethysmography > 2.5 cmH2O  L−1  s−1 (likelihood ratio > 8; kappa coefficient = 0.73). Conclusions: In the patients with less severe disease, there was good agreement between Rint and Raw by plethysmography. The agreement between the two methods was also strong regarding the detection of an increase in Raw. The Rint technique is a potentially useful method for the evaluation of adult patients.

Keywords: Plethysmography; Airway resistance; Diagnostic techniques, respiratory system; Respiratory function tests; Airway obstruction/diagnosis.

Objective: To evaluate the influence of chronic heart failure (CHF) on resting lung volumes in patients with COPD, i.e., inspiratory fraction-inspiratory capacity (IC)/TLC-and relative inspiratory reserve-[1 − (end-inspiratory lung volume/TLC)]. Methods: This was a prospective study involving 56 patients with COPD-24 (23 males/1 female) with COPD+CHF and 32 (28 males/4 females) with COPD only-who, after careful clinical stabilization, underwent spirometry (with forced and slow maneuvers) and whole-body plethysmography. Results: Although FEV1, as well as the FEV1/FVC and FEV1/slow vital capacity ratios, were higher in the COPD+CHF group than in the COPD group, all major "static" volumes-RV, functional residual capacity (FRC), and TLC-were lower in the former group (p < 0.05). There was a greater reduction in FRC than in RV, resulting in the expiratory reserve volume being lower in the COPD+CHF group than in the COPD group. There were relatively proportional reductions in FRC and TLC in the two groups; therefore, IC was also comparable. Consequently, the inspiratory fraction was higher in the COPD+CHF group than in the COPD group (0.42 ± 0.10 vs. 0.36 ± 0.10; p < 0.05). Although the tidal volume/IC ratio was higher in the COPD+CHF group, the relative inspiratory reserve was remarkably similar between the two groups (0.35 ± 0.09 vs. 0.44 ± 0.14; p < 0.05). Conclusions: Despite the restrictive effects of CHF, patients with COPD+CHF have relatively higher inspiratory limits (a greater inspiratory fraction). However, those patients use only a part of those limits, probably in order to avoid critical reductions in inspiratory reserve and increases in elastic recoil.

Keywords: Respiratory function tests; Pulmonary disease, chronic obstructive; Heart failure; Spirometry.

Objective: Many patients with proportional reductions in FVC and FEV1 on spirometry show no reduction in TLC. The aim of this study was to evaluate the role that measuring lung volumes and airway resistance plays in the correct classification of patients with a possible restrictive pattern on spirometry. Methods: This was a prospective study involving adults with reduced FVC and FEV1, as well as an FEV1/FV(C) ratio within the predicted range. Restrictive lung disease (RLD) was characterized by TLC below the 5th percentile, as determined by plethysmography. Obstructive lung disease (OLD) was characterized by high specific airway resistance, significant changes in post-bronchodilator FEV1, or an FEF25-75% < 50% of predicted, together with a high RV/TLC ratio. Nonspecific lung disease (NLD) was characterized by TLC within the predicted range and no obstruction. Combined lung disease (CLD) was characterized by reduced TLC and findings indicative of airflow obstruction. Clinical diagnoses were based on clinical suspicion, a respiratory questionnaire, and the review of tests of interest. Results: We included 300 patients in the study, of whom 108 (36%) were diagnosed with RLD. In addition, 120 (40%) and 72 (24%) were diagnosed with OLD/CLD and NLD, respectively. Among the latter, 24 (33%) were clinically diagnosed with OLD. In this sample, 151 patients (50.3%) were obese, and obesity was associated with all patterns of lung disease. Conclusions: Measuring lung volumes and airway resistance is often necessary in order to provide an appropriate characterization of the pattern of lung disease in patients presenting with a spirometry pattern suggestive of restriction. Airflow obstruction is common in such cases.

Keywords: Spirometry; Airway resistance; Lung volume measurements.

Objective: To investigate the diagnostic accuracy of a chest X-ray (CXR) score and of clinical and laboratory data in predicting the clinical course of patients with SARS coronavirus 2 (SARS-CoV-2) infection. Methods: This is a pilot multicenter retrospective study including patients with SARS-CoV-2 infection admitted to the ERs in three hospitals in Italy between February and March of 2020. Two radiologists independently evaluated the baseline CXR of the patients using a semi-quantitative score to determine the severity of lung involvement: a score of 0 represented no lung involvement, whereas scores of 1 to 4 represented the first (less severe) to the fourth (more severe) quartiles regarding the severity of lung involvement. Relevant clinical and laboratory data were collected. The outcome of patients was defined as severe if noninvasive ventilation (NIV) or intubation was necessary, or if the patient died. Results: Our sample comprised 140 patients. Most of the patients were symptomatic (132/138; 95.7%), and 133/140 patients (95.0%) presented with opacities on CXR at admission. Of the 140 patients, 7 (5.0%) showed no lung involvement, whereas 58 (41.4%), 31 (22.1%), 26 (18.6%), and 18 (12.9%), respectively, scored 1, 2, 3, and 4. In our sample, 66 patients underwent NIV or intubation, 37 of whom scored 1 or 2 on baseline CXR, and 28 patients died. Conclusions: The severity score based on CXR seems to be able to predict the clinical progression in cases that scored 0, 3, or 4. However, the score alone cannot predict the clinical progression in patients with mild-to-moderate parenchymal involvement (scores 1 and 2).

Keywords: Coronavirus infections; Radiography, thoracic; Pneumonia; Respiratory insufficiency; Severe acute respiratory syndrome.

Incidence of metastatic disease to the hypothalamic-pituitary area is low (1 to 6% in most studies), the lung and the prostate being the most common primary sites in men. Clinical presentation as panhypopituitarism is rare (0.2 to 0.8%) in patients with bronchogenic carcinoma. The authors describe a case of a man with diagnosis of squamous cell carcinoma of the lung that, during the clinical course of the disease, presented clinical and laboratorial evidence of panhypopituitarism, with an expansive sellar and supra-sellar lesion image in the CT scan of the brain.

Keywords: Panhypopituitarism. Bronchogenic carcinoma. Hypothalamic-pituitary metastases.

Objetivo: Investigar os efeitos agudos da administração endovenosa de extrato da fumaça do cigarro (EFC) em parâmetros funcionais respiratórios, inflamatórios e histológicos em ratos e comparar esse potencial modelo de lesão pulmonar aguda (LPA) com aquele com o uso de ácido oleico (AO). Métodos: Foram estudados 72 ratos Wistar machos divididos em quatro grupos: tratados somente com soro fisiológico (SF; grupo controle); tratados com EFC e SF (grupo EFC); tratados com SF e AO (grupo AO); e tratados com EFC e AO (grupo EFC/AO). Resultados: As médias de complacência foram significantemente menores nos grupos AO e EFC/AO (2,12 ± 1,13 mL/cmH2O e 1,82 ± 0,77 mL/cmH2O, respectivamente) do que no controle (3,67 ± 1,38 mL/cmH2O). A proporção de neutrófilos e a atividade das metaloproteinases 2 e 9 em lavado broncoalveolar foram significantemente maiores nos grupos AO e EFC/AO que no controle. O acometimento pulmonar avaliado por morfometria foi significantemente maior nos grupos AO e EFC/AO (72,9 ± 13,8% e 77,6 ± 18,0%, respectivamente) do que nos grupos controle e EFC (8,7 ± 4,1% e 32,7 ± 13,1%, respectivamente), e esse acometimento foi significantemente maior no grupo EFC que no grupo controle. Conclusões: A administração endovenosa de EFC, nas doses e tempos deste estudo, associou-se à LPA mínima. O EFC não potencializou a LPA induzida por AO. Estudos adicionais são necessários para esclarecer o papel potencial desse modelo como método de estudo dos mecanismos de agressão pulmonar pelo tabaco.

Keywords: Tabagismo; Lesão pulmonar aguda; Modelos animais.

Objective: Thoracentesis is one of the bedside procedures most commonly associated with iatrogenic complications, particularly pneumothorax. Various risk factors for complications associated with thoracentesis have recently been identified, including an inexperienced operator; an inadequate or inexperienced support team; the lack of a standardized protocol; and the lack of ultrasound guidance. We sought to determine whether ultrasound-guided thoracentesis can reduce the risk of pneumothorax and improve outcomes (fewer procedures without fluid removal and greater volumes of fluid removed during the procedures). In our comparison of thoracentesis with and without ultrasound guidance, all procedures were performed by a team of expert pulmonologists, using the same standardized protocol in both conditions. Methods: A total of 160 participants were randomly allocated to undergo thoracentesis with or without ultrasound guidance (n = 80 per group). The primary outcome was pneumothorax following thoracentesis. Secondary outcomes included the number of procedures without fluid removal and the volume of fluid drained during the procedure. Results: Pneumothorax occurred in 1 of the 80 patients who underwent ultrasound-guided thoracentesis and in 10 of the 80 patients who underwent thoracentesis without ultrasound guidance, the difference being statistically significant (p = 0.009). Fluid was removed in 79 of the 80 procedures performed with ultrasound guidance and in 72 of the 80 procedures performed without it. The mean volume of fluid drained was larger during the former than during the latter (960  500 mL vs. 770  480 mL), the difference being statistically significant (p = 0.03). Conclusions: Ultrasound guidance increases the yield of thoracentesis and reduces the risk of post-procedure pneumothorax. (Chinese Clinical Trial Registry identifier: ChiCTR-TRC-12002174 [http://www.chictr.org/en/])

Keywords: Pneumothorax; Ultrasonography; Thoracic surgical procedures.

Objective: To determine the success rate of flexible bronchoscopy as the first-choice method of removing foreign bodies from the airways of adults. Methods: This was a retrospective study of all adult patients (over 18 years of age) with foreign body aspiration submitted to bronchoscopy between January of 2009 and January of 2011 at the University of São Paulo School of Medicine Hospital das Clínicas, located in São Paulo, Brazil. Results: The study sample comprised 40 adult patients, with a mean age of 52 years (range, 18-88 years). The median time of permanence of the foreign body in the airway was 15 days (range, 12 h to 10 years). All of the patients first underwent diagnostic flexible bronchoscopy. Foreign bodies were successfully removed with flexible bronchoscopy in 33 (82.5%) of the patients. In 1 patient, a metal object lodged in the distal bronchial tree required the use of fluoroscopy. Six patients (15%) required rigid bronchoscopy due to tracheal foreign body-induced dyspnea, in 2, and because the foreign body was too large for the flexible forceps, in 4. Bronchoscopy failed in 1 patient, who therefore required surgical bronchotomy. Conclusions: Although rigid bronchoscopy is considered the gold standard for the removal of foreign bodies from the airways, our experience showed that flexible bronchoscopy can be safely and effectively used in the diagnosis and treatment of stable adult patients.

Keywords: Bronchoscopy; Foreign bodies; Airway obstruction; Airway management.