Continuous Monitoring of Pulse Oximetry During the 6-Minute Walk Test Improves Clinical Outcomes Prediction in COPD.

BACKGROUND: Continuous monitoring of SpO2 throughout the 6-min walk test (6MWT) unveiled that some patients with respiratory diseases may present values across the test lower than SpO2 measured at the end of the test. Nevertheless, it remains unclear whether this approach improves the yield of walk-induced desaturation detection in predicting mortality and hospitalizations in patients with COPD. METHODS: Four hundred twenty-one subjects (51% males) with mild-very severe COPD underwent a 6MWT with continuous measurement of SpO2 . Exercise desaturation was defined as a fall in SpO2 ≥ 4%. All-cause mortality was assessed up to 6 y of follow-up and the rate of hospitalizations in the year succeeding the 6MWT. RESULTS: One hundred forty-nine subjects (35.4%) died during a mean (interquartile) follow-up of 55.5 (30.2-64.1) months. Desaturation was observed in 299/421 (71.0%). SpO2 along the test was < end SpO2 (88 [82-92]% vs 90 [84-93]%, P < .001). Desaturation detected only during (but not at the end of) the test was found in 81/421 (19.2%) participants. Multivariate Cox regression model adjusted for sex, body composition, FEV1, residual volume/total lung capacity ratio, walk distance, O2 supplementation during the test, and comorbidities retained the presence of desaturation either at the end (1.85 [95% CI 1.02-3.36]) or only along the test (2.08 [95% CI 1.09-4.01]) as significant predictors of mortality. The rate of hospitalizations was higher in those presenting with any kind of desaturation compared to those without exercise desaturation. Logistic regression analysis revealed that walking interruption and diffusing capacity of the lung for carbon monoxide predicted desaturation observed only during the test. CONCLUSIONS: O2 desaturation missed by end-exercise SpO2 but exposed by measurements during the test was independently associated with all-cause mortality and hospitalizations in subjects with COPD.

2022 Brazilian Thoracic Association recommendations for long-term home oxygen therapy.

Some chronic respiratory diseases can cause hypoxemia and, in such cases, long-term home oxygen therapy (LTOT) is indicated as a treatment option primarily to improve patient quality of life and life expectancy. Home oxygen has been used for more than 70 years, and support for LTOT is based on two studies from the 1980s that demonstrated that oxygen use improves survival in patients with COPD. There is evidence that LTOT has other beneficial effects such as improved cognitive function, improved exercise capacity, and reduced hospitalizations. LTOT is indicated in other respiratory diseases that cause hypoxemia, on the basis of the same criteria as those used for COPD. There has been an increase in the use of LTOT, probably because of increased life expectancy and a higher prevalence of chronic respiratory diseases, as well as greater availability of LTOT in the health care system. The first Brazilian Thoracic Association consensus statement on LTOT was published in 2000. Twenty-two years later, we present this updated version. This document is a nonsystematic review of the literature, conducted by pulmonologists who evaluated scientific evidence and international guidelines on LTOT in the various diseases that cause hypoxemia and in specific situations (i.e., exercise, sleep, and air travel). These recommendations, produced with a view to clinical practice, contain several charts with information on indications for LTOT, oxygen sources, accessories, strategies for improved efficiency and effectiveness, and recommendations for the safe use of LTOT, as well as a LTOT prescribing model.

Occupational exposure to crystalline silica and peripheral biomarkers: An update.

Peripheral biomarkers are important tools for detecting occupational exposures to prevent the onset and/or progression of diseases. Studies that reveal early peripheral biomarkers are highly important to preserve the health of workers and can potentially contribute to diagnosing and/or prognosing occupational pathologies. Exposure to crystalline silica is a problem in several workplaces because it increases the risk of chronic obstructive pulmonary disease (COPD), tuberculosis, cancer, and pulmonary fibrosis, clinically defined as silicosis. Silicosis is diagnosed by chest radiography and/or lung tomography in advanced stages when there is a severe loss of lung function. Peripheral biomarkers can help in diagnosing early changes prior to silicosis and represent a highly important technical-scientific advance that is minimally invasive. This review aimed to investigate the biomarkers studied for evaluating occupational exposure to crystalline silica and to understand the recent advances in this area. Potential oxidative, inflammatory, and immunological biomarkers were reviewed, as well as routine biomarkers such as biochemical parameters. It was found that biomarkers of effect such as serum CC16 and l-selectin levels could represent promising alternatives. Additionally, studies have shown that neopterin levels in urine and serum can be used to monitor worker exposure. However, further studies are needed that include a greater number of participants, different times of exposure to crystalline silica, and a combination of silicosis patients and healthy volunteers. Evaluating the concentration of crystalline silica in occupational environments, its impact on biomarkers of effect, and alterations in lung function could contribute to revealing early health alterations in workers in a more robust manner.

Aerobic Exercise Increases Vascular Diameter of Arteriovenous Fistula in Hemodialysis Patients.

INTRODUCTION: A healthy arteriovenous fistula (AVF) depends on adequate vessel diameter which can be maintained through aerobic exercises. A randomized crossover study was conducted to evaluate the acute effects of aerobic exercise on a cycle ergometer on AVF vascular diameter, through ultrasound, and on blood pressure (BP). METHODS: Eight hemodialysis (HD) patients completed 2 different occasions in random order with a 7-day washout: (a) exercising moment, in which 30-min aerobic exercise was performed on a cycle ergometer; and (b) resting moment, which was performed 30-min with the patient sitting in a chair. Both occasions were evaluated 1-h before the second weekly HD day. RESULTS: A significant increase in AVF vascular diameter induced by 30-min aerobic exercise was found (1.15 ± 0.56 to 1.47 ± 0.66 cm; p = 0.042), whereas systolic (p = 0.105) and diastolic BP (p = 0.366) did not change. CONCLUSIONS: We can conclude that acute aerobic exercise was shown to be effective in improving the AVF vascular diameter in HD patients. The aerobic exercise benefits in endothelium-dependent vasodilation which may be an effective, practical, and economic strategy to maintain AVF patency.

2022 Brazilian Thoracic Association recommendations for long-term home oxygen therapy / Recomendações para oxigenoterapia domiciliar prolongada da Sociedade Brasileira de Pneumologia e Tisiologia (2022)

ABSTRACT Some chronic respiratory diseases can cause hypoxemia and, in such cases, long-term home oxygen therapy (LTOT) is indicated as a treatment option primarily to improve patient quality of life and life expectancy. Home oxygen has been used for more than 70 years, and support for LTOT is based on two studies from the 1980s that demonstrated that oxygen use improves survival in patients with COPD. There is evidence that LTOT has other beneficial effects such as improved cognitive function, improved exercise capacity, and reduced hospitalizations. LTOT is indicated in other respiratory diseases that cause hypoxemia, on the basis of the same criteria as those used for COPD. There has been an increase in the use of LTOT, probably because of increased life expectancy and a higher prevalence of chronic respiratory diseases, as well as greater availability of LTOT in the health care system. The first Brazilian Thoracic Association consensus statement on LTOT was published in 2000. Twenty-two years later, we present this updated version. This document is a nonsystematic review of the literature, conducted by pulmonologists who evaluated scientific evidence and international guidelines on LTOT in the various diseases that cause hypoxemia and in specific situations (i.e., exercise, sleep, and air travel). These recommendations, produced with a view to clinical practice, contain several charts with information on indications for LTOT, oxygen sources, accessories, strategies for improved efficiency and effectiveness, and recommendations for the safe use of LTOT, as well as a LTOT prescribing model.

RESUMO Algumas doenças respiratórias crônicas podem evoluir com hipoxemia e, nessas situações, a oxigenoterapia domiciliar prolongada (ODP) está indicada como opção terapêutica com o objetivo principal de melhorar a qualidade e a expectativa de vida desses pacientes. O oxigênio domiciliar é usado há mais de 70 anos, e a ODP tem como base dois estudos da década de oitenta que demonstraram que o uso de oxigênio melhora a sobrevida de pacientes com DPOC. Existem evidências de que a ODP tem outros efeitos benéficos como melhora da função cognitiva e da capacidade de exercício e redução de hospitalizações. A ODP está indicada para outras doenças respiratórias que cursam com hipoxemia, segundo os mesmos critérios estabelecidos para a DPOC. Tem sido observado aumento no uso da ODP provavelmente pela maior expectativa de vida, maior prevalência de doenças respiratórias crônicas e maior disponibilidade de ODP no sistema de saúde. O primeiro consenso sobre ODP da Sociedade Brasileira de Pneumologia e Tisiologia foi publicado em 2000; após 22 anos, apresentamos esta versão atualizada. Este documento é uma revisão não sistemática da literatura, realizada por pneumologistas que avaliaram evidências científicas e diretrizes internacionais sobre ODP nas diversas doenças que cursam com hipoxemia e em situações específicas (exercício, sono e viagens aéreas). Estas recomendações, tendo em vista a prática clínica, oferecem diversos quadros com informações sobre indicações, fontes de oxigênio, acessórios e estratégias para melhor eficiência, efetividade e uso seguro da ODP, assim como um modelo para sua prescrição.

The relationship between height of vertical jumps, functionality and fall episodes in patients with chronic obstructive pulmonary disease: A case-control study.

This study aimed to compare the height of jumps and functional parameters in patients with chronic obstructive pulmonary disease (COPD) to those in healthy people, in addition to assessing the relationship among variables in patients with COPD. Twenty patients with COPD (forced expiratory volume [FEV1] % of predicted: 39.98 ± 11.69%; age: 62.95 ± 8.06 years) and 16 healthy people (FEV1% of predicted: 97.44 ± 14.45%; age: 59.94 ± 6.43 years) were evaluated, and all participants performed the Squat Jump (SJ) and Counter Movement Jump (CMJ) tests to assess rapid force considering the jumping height. Functional capacity was assessed using the self-selected walking speed tests, walking speed in 10 m, walking test in 6 min, balance on one leg, sitting and standing, timed up and go, and a stair-climbing test. In addition, the questionnaires on recall of falls, Falls Efficacy Scale-International (concern with falling), International Physical Activity Questionnaires, and Saint George Respiratory Questionnaire were administered. The height of the jumps showed no difference between the groups, but the COPD group performed worse in most functional tests and was more afraid of falling. The number of falls was correlated with height in the SJ (r = -0.51) and CMJ (r = -0.62) jumps (p < 0.05), and with the performance in different functional tests. We suggest that interventions targeting rapid force may bring improvements in functional mobility and physical fitness as well as reducing fall episodes in patients with COPD.

Predictors of health-related quality of life among semi-precious stone mineworkers exposed to silica dust.

OBJECTIVE: The study aimed to comparatively evaluate HRQOL in miners of semi-precious stones with and without silicosis, and determine the associated factors, as well as the performance of two different questionnaires in measuring HRQOL. METHODS: In a cross-sectional study of 348 male miners (129 with silicosis) who underwent an interview and spirometry, HRQOL was assessed using the World Health Organization Quality of Life (WHOQOL-BREF) questionnaire and the Saint George's Respiratory Questionnaire (SGRQ). RESULTS: Miners with silicosis were older, had less schooling, worked more hours daily, and had longer exposure to silica. They also had worse scores of QoL in both questionnaires. Respiratory symptoms and %FEV1 were contributing factors for the models of total health and all the domains of the SGRQ, and 40% of the variability of the general health domain of WHOQOL-BREF was due to dyspnea, wheezing, %FEV1, and pack-years of cigarette smoking. Respiratory symptoms, lung function, pack-years of cigarette smoking, years of education, and average monthly income were contributing factors for the models of the different domains of the WHOQOL-BREF. CONCLUSIONS: Our study revealed impaired HRQOL in semi-precious stone miners evaluated using both questionnaire tools of SGRQ and WHOQOL-BREF, of which SGRQ had superior performance. Respiratory symptoms, functional impairment, and pack-years of cigarette smoking were the most important determinants of the workers' general HRQOL.

Phase Angle Evaluation of Lung Disease Patients and Its Relationship with Nutritional and Functional Parameters.

BACKGROUND: This study aimed to determine the value of phase angle (PhA) in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH) and its association with nutritional and functional parameters. METHODS: A cross-sectional study of 77 patients under follow-up at the pulmonary outpatient clinic of a public hospital. Anthropometric measurements and functional assessments of physical and pulmonary capacity were performed, and a regular physical activity questionnaire was administered. RESULTS: The sample consisted of 38 patients with COPD (mean age, 63.8 ± 9.9 years; 68.4% female) and 39 patients with PH (mean age, 46.6 ± 14.4 years; 79.5% female). There was no difference in anthropometric measurements between patients with COPD and PH. Patients with COPD had mild to moderate limitations of pulmonary function, while patients with PH had only mild limitations (p < 0.01). Although the median distance covered in the 6-minute walk test (6MWT) was different between the COPD and PH groups (p < 0.05), it was considered adequate for these populations. Mean PhA was within the range considered adequate in patients with COPD (6.3°±1°) and PH (6.2°±0.8°) (p > 0.05). In the statistical analyses, although the correlations were weak, adequate PhA correlated with fat free mass index, 6MWT, disease staging, forced vital capacity, and forced expiratory volume in the first second. CONCLUSION: The anthropometric profile of both patient groups was very similar, and PhA values were within the expected range. Despite weak correlations, PhA is a clinical component to be followed and investigated in patients with lung disease.

Effect of the expiratory positive airway pressure on dynamic hyperinflation and exercise capacity in patients with COPD: a meta-analysis.

Expiratory positive airway pressure (EPAP) is widely applicable, either as a strategy for pulmonary reexpansion, elimination of pulmonary secretion or to reduce hyperinflation. However, there is no consensus in the literature about the real benefits of EPAP in reducing dynamic hyperinflation (DH) and increasing exercise tolerance in subjects with chronic obstructive pulmonary disease (COPD). To systematically review the effects of EPAP application during the submaximal stress test on DH and exercise capacity in patients with COPD. This meta-analysis was performed from a systematic search in the PubMed, EMBASE, PeDRO, and Cochrane databases, as well as a manual search. Studies that evaluated the effect of positive expiratory pressure on DH, exercise capacity, sensation of dyspnea, respiratory rate, peripheral oxygen saturation, sense of effort in lower limbs, and heart rate were included. GRADE was used to determine the quality of evidence for each outcome. Of the 2,227 localized studies, seven studies were included. The results show that EPAP did not change DH and reduced exercise tolerance in the constant load test. EPAP caused a reduction in respiratory rate after exercise (- 2.33 bpm; 95% CI: - 4.56 to - 0.10) (very low evidence) when using a pressure level of 5 cmH2O. The other outcomes analyzed were not significantly altered by the use of EPAP. Our study demonstrates that the use of EPAP does not prevent the onset of DH and may reduce lower limb exercise capacity in patients with COPD. However, larger and higher-quality studies are needed to clarify the potential benefit of EPAP in this population.

Lung function and functional exercise capacity in underground semi-precious stone mineworkers.

BACKGROUND: Semi-precious stone mining may cause occupational lung disease. The impact of inhaling silica on workers' exercise capacity has only been partially studied. OBJECTIVES: To study lung function, exercise capacity, and identify factors associated with functional impairment. METHODS: In a cross-sectional study of 193 current miners from Ametista do Sul, Rio Grande do Sul, Brazil, medical and occupational data were collected. The diagnosis of silicosis was established by the history of dust exposure and chest radiographic findings. All workers performed a spirometry and a 6-minute walk test (6MWT). RESULTS: Of the sample 51 (26.4%) had silicosis. Time working in mine was 14.7±8.7 years. Spirometry showed a normal, restrictive or obstructive ventilatory pattern in 75.1 %, 13 % and 9.3 % of the workers, respectively. The diagnosis of silicosis and length of time working in mining negatively affected lung function, although exercise capacity was preserved. In the multivariate analysis, time working in mining, diagnosis of silicosis and education remained significant for forced expiratory volume in one second (FEV1; r = 0.60; r2 = 0.36; p < 0.001) and age and height for distance in 6MWT (r = 0.66; r2 = 0.43; p < 0.001). CONCLUSIONS: Our results show impaired lung function and preserved exercise capacity in current mineworkers exposed to silica. Length of time working in mining, presence of silicosis and lower education were factors associated with reduced lung function.

Altered Gut Microbiome Profile in Patients With Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is considered a disease of the pulmonary vasculature. Limited progress has been made in preventing or arresting progression of PAH despite extensive efforts. Our previous studies indicated that PAH could be considered a systemic disease since its pathology involves interplay of multiple organs. This, coupled with increasing implication of the gut and its microbiome in chronic diseases, led us to hypothesize that patients with PAH exhibit a distinct gut microbiome that contributes to, and predicts, the disease. Fecal microbiome of 18 type 1 PAH patients (mean pulmonary arterial pressure, 57.4, SD 16.7 mm Hg) and 13 reference subjects were compared by shotgun metagenomics to evaluate this hypothesis. Significant taxonomic and functional changes in microbial communities in the PAH cohort were observed. Pathways for the synthesis of arginine, proline, and ornithine were increased in PAH cohort compared with reference cohort. Additionally, groups of bacterial communities associated with trimethylamine/ trimethylamine N-oxide and purine metabolism were increased in PAH cohort. In contrast, butyrate-and propionate-producing bacteria such as Coprococcus, Butyrivibrio, Lachnospiraceae, Eubacterium, Akkermansia, and Bacteroides were increased in reference cohort. A random forest model predicted PAH from the composition of the gut microbiome with 83% accuracy. Finally, virome analysis showed enrichment of Enterococcal and relative depletion of Lactococcal phages in the PAH cohort. In conclusion, patients with PAH exhibit a unique microbiome profile that has the high predictive potential for PAH. This highlights previously unknown roles of gut bacteria in this disease and could lead to new therapeutic, diagnostic, or management paradigms for PAH.

Hepatopulmonary syndrome has low prevalence of pulmonary vascular abnormalities on chest computed tomography.

PURPOSE: Hepatopulmonary syndrome (HPS) is defined as an arterial oxygenation defect induced by intrapulmonary vascular dilatations associated with hepatic disease. This study aimed to assess the prevalence of type 1 and 2 pulmonary vascular abnormalities on chest computed tomography (CT) in patients with cirrhosis and HPS and to characterize intra- and interobserver reliability. MATERIALS AND METHODS: Two thoracic radiologists retrospectively evaluated chest CT scans from 38 cirrhosis patients with HPS. They classified the pulmonary vascular abnormalities as type 1 (multiple dilated distal pulmonary arteries), type 2(nodular dilatation or individual pulmonary arterial malformation), or absence of abnormality. Furthermore, they measured the diameters of the central pulmonary arteries and subsegmental pulmonary arteries and bronchi. We analyzed the prevalence, intraobserver reliability, and interobserver reliability of abnormal CT findings related to HPS, and the correlation of these findings with partial arterial oxygen pressure (PaO2). RESULTS: The overall prevalence of pulmonary vascular abnormalities was 28.9% (95% confidence intervals: 15.4%, 45.9%). Moreover, 26.3% of patients had type 1 abnormality (13.4%, 43.1%) and 2.6% of patients had type 2 abnormality (0.0%, 13.8%). The intraobserver reliability kappa value was 0.666 (0.40, 0.91) and the interobserver kappa value was 0.443 (0.12, 0.77). There was no correlation between pulmonary vascular abnormalities on CT and PaO2 values. CONCLUSIONS: The prevalence of pulmonary vascular abnormalities on chest CT of patients with cirrhosis and HPS is low and not correlated with PaO2. These findings question the usefulness of chest CT for the evaluation of patients with cirrhosis and HPS.

Tidal Flow-Volume Loop Enveloping at Rest in Advanced COPD.

BACKGROUND: Expiratory flow limitation (EFL) is a key physiological abnormality in COPD. Comparing tidal-to-maximum flow-volume (F-V) loops is a simple and widely available method to assess EFL in patients with COPD. We aimed to investigate whether subjects with COPD showing significant resting tidal F-V enveloping (ie, > 50% tidal volume) would present with higher exertional operating lung volumes, which would lead to greater burden of dyspnea and poorer exercise tolerance compared to their counterparts. METHODS: 37 subjects with COPD (21 males; 63.1 ± 9.2 years old; FEV1 = 37 ± 12% predicted) and 9 paired controls (3 males; 55.9 ± 11.7 y old) performed an incremental cardiopulmonary exercise testing on a cycle ergometer. Dyspnea perception, inspiratory capacity maneuvers after 3-4 sequential tidal F-V loops, and esophageal and gastric pressures were measured during exercise. RESULTS: Most subjects (31 of 37, 84%) presented with significant tidal F-V enveloping. Critical inspiratory constraints and upward dyspnea inflection points (as a function of both work rate and ventilation) were reached earlier in these subjects, thereby leading to poorer exercise tolerance compared to their counterparts (P = .01). Abdominal muscle recruitment (ie, increase in gastric pressure ≥ 15%) during tidal expiration was significantly higher in the EFL+ group. However, this did not bear an influence on the operating lung volumes, inspiratory constraints, dyspnea, cardiocirculatory responses, or exercise tolerance (P > .05). CONCLUSIONS: Tidal F-V loop enveloping at rest should be valued as it is related to relevant clinical outcomes, such as dyspnea burden and exercise tolerance in subjects with COPD.

Lung Ultrasound Prior to Spontaneous Breathing Trial Is Not Helpful in the Decision to Wean.

BACKGROUND: Lung ultrasound is increasingly becoming a diagnostic tool in the critical care setting. B-pattern on a lung ultrasound is an artifact composed of multiple B-lines and correlates with interstitial edema. A randomized controlled trial concluded that bedside thoracic ultrasound could predict postextubation distress through changes in lung aeration during a weaning procedure; however, it could not screen patients before performance of a spontaneous breathing trial (SBT). METHODS: We conducted a 2-year, prospective, multicenter, observational study in 2 adult medical-surgical ICUs in southern Brazil. All enrolled subjects met eligibility criteria for ventilation liberation. Patients with tracheostomy were excluded. Lung ultrasound was performed immediately before SBT. B-predominance was defined as any profile with anterior bilateral B-pattern. The primary outcome was SBT failure, defined as the inability to tolerate a T-piece trial of 30-120 min, in which case subjects were not extubated. RESULTS: From 2011 to 2013, 250 subjects undergoing weaning procedures were evaluated. SBT failure occurred in 51 (20.4%) subjects. Subjects with a successful SBT were extubated on the first attempt in 75.6% of cases. B-predominance was a very weak predictor for SBT outcome, showing 47% sensitivity, 64% specificity, 25% positive predictive value, and 82% negative predictive value. CONCLUSION: B-pattern detected by a simplified lung ultrasound protocol should not preclude hemodynamically stable, sufficiently oxygenated patients from performing an SBT.

Characteristics associated with mortality in patients with chronic obstructive pulmonary disease (COPD)-heart failure coexistence.

AimTo investigate if cardiac/pulmonary functional tests and variables obtained from clinical practice (body mass index, dyspnea, functional class, clinical judgment of disability to perform an exercise test and previous hospitalization rate) are related to mortality in patients with overlap chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF). BACKGROUND: Although the coexistence of COPD and CHF has been growingly reported, description of survival predictors considering the presence of both conditions is still scarce. METHODS: Using a cohort design, outpatients with the previous diagnosis of COPD and/or CHF that performed both spirometry and echocardiography in the same year were followed-up during a mean of 20.9±8.5 months.FindingsOf the 550 patients initially evaluated, 301 had both spirometry and echocardiography: 160 (53%) with COPD on isolation; 100 (33%) with CHF on isolation; and 41 (14%) with overlap. All groups presented similar mortality: COPD 17/160 (11%); CHF 12/100 (12%); and overlap 7/41 (17%) (P=0.73). In the overlap group (n=41), inability to exercise and hospitalization rate were the unique parameters associated with higher mortality (seven events) in univariate analyses. In conclusion, inability to exercise and hospitalization rate emerged as the unique parameters associated with mortality in our sample.

Comportamento dos achados de ultrassonografia pulmonar durante tentativa de respiração espontânea / Behavior of lung ultrasound findings during spontaneous breathing trial

RESUMO Objetivo: Investigar potencial associação entre a presença de linhas B e a falha do desmame. Métodos: Foram inscritos 57 pacientes elegíveis para liberação da ventilação. Excluíram-se pacientes com traqueostomia. Realizou-se avaliação ultrassonográfica pulmonar de seis zonas torácicas imediatamente antes e após o final da tentativa de respiração espontânea. Definiu-se a predominância de linhas B como qualquer perfil com padrão B bilateral anterior. Os pacientes foram seguidos por 48 horas após a extubação. Resultados: Foram extubados com sucesso 38 pacientes; 11 tiveram falha da tentativa de respiração espontânea; e 8 necessitaram de reintubação dentro de 48 horas após extubados. No início da tentativa com peça T, já se observava padrão B ou consolidação nas regiões posterior e inferior dos pulmões em mais de metade dos indivíduos, que permaneceram não aeradas ao final da tentativa. Observou-se certa tendência à perda da aeração pulmonar durante a tentativa de respiração espontânea apenas no grupo com falha da tentativa de respiração espontânea (p = 0,07), assim como maior predominância de padrão B ao final da tentativa (p = 0,01). Conclusão: A perda de aeração pulmonar durante a tentativa de respiração espontânea em áreas pulmonares não dependentes foi demonstrada em pacientes que tiveram falha do desmame.

ABSTRACT Objective: We aimed to investigate a potential association between B-lines and weaning failure. Methods: Fifty-seven subjects eligible for ventilation liberation were enrolled. Patients with tracheostomy were excluded. Lung ultrasound assessments of six thoracic zones were performed immediately before and at the exnd of the spontaneous breathing trial. B-predominance was defined as any profile with anterior bilateral B-pattern. Patients were followed up to 48 hours after extubation. Results: Thirty-eight individuals were successfully extubated; 11 failed the spontaneous breathing trial and 8 needed reintubation within 48 hours of extubation. At the beginning of the T-piece trial, B-pattern or consolidation was already found at the lower and posterior lung regions in more than half of the individuals and remained non-aerated at the end of the trial. A trend toward loss of lung aeration during spontaneous breathing trials was observed only in the spontaneous breathing trial-failure group (p = 0.07), and there was higher B-predominance at the end of the trial (p = 0.01). Conclusion: A loss of lung aeration during the spontaneous breathing trial in non-dependent lung zones was demonstrated in subjects who failed to wean.

Behavior of lung ultrasound findings during spontaneous breathing trial. / Comportamento dos achados de ultrassonografia pulmonar durante tentativa de respiração espontânea.

OBJECTIVE: We aimed to investigate a potential association between B-lines and weaning failure. METHODS: Fifty-seven subjects eligible for ventilation liberation were enrolled. Patients with tracheostomy were excluded. Lung ultrasound assessments of six thoracic zones were performed immediately before and at the exnd of the spontaneous breathing trial. B-predominance was defined as any profile with anterior bilateral B-pattern. Patients were followed up to 48 hours after extubation. RESULTS: Thirty-eight individuals were successfully extubated; 11 failed the spontaneous breathing trial and 8 needed reintubation within 48 hours of extubation. At the beginning of the T-piece trial, B-pattern or consolidation was already found at the lower and posterior lung regions in more than half of the individuals and remained non-aerated at the end of the trial. A trend toward loss of lung aeration during spontaneous breathing trials was observed only in the spontaneous breathing trial-failure group (p = 0.07), and there was higher B-predominance at the end of the trial (p = 0.01). CONCLUSION: A loss of lung aeration during the spontaneous breathing trial in non-dependent lung zones was demonstrated in subjects who failed to wean.

OBJETIVO: Investigar potencial associação entre a presença de linhas B e a falha do desmame. MÉTODOS: Foram inscritos 57 pacientes elegíveis para liberação da ventilação. Excluíram-se pacientes com traqueostomia. Realizou-se avaliação ultrassonográfica pulmonar de seis zonas torácicas imediatamente antes e após o final da tentativa de respiração espontânea. Definiu-se a predominância de linhas B como qualquer perfil com padrão B bilateral anterior. Os pacientes foram seguidos por 48 horas após a extubação. RESULTADOS: Foram extubados com sucesso 38 pacientes; 11 tiveram falha da tentativa de respiração espontânea; e 8 necessitaram de reintubação dentro de 48 horas após extubados. No início da tentativa com peça T, já se observava padrão B ou consolidação nas regiões posterior e inferior dos pulmões em mais de metade dos indivíduos, que permaneceram não aeradas ao final da tentativa. Observou-se certa tendência à perda da aeração pulmonar durante a tentativa de respiração espontânea apenas no grupo com falha da tentativa de respiração espontânea (p = 0,07), assim como maior predominância de padrão B ao final da tentativa (p = 0,01). CONCLUSÃO: A perda de aeração pulmonar durante a tentativa de respiração espontânea em áreas pulmonares não dependentes foi demonstrada em pacientes que tiveram falha do desmame.

Effects of Expiratory Positive Airway Pressure on Exercise Tolerance, Dynamic Hyperinflation, and Dyspnea in COPD.

INTRODUCTION: The application of expiratory positive airway pressure (EPAP) in patients with COPD during exercise may reduce dynamic hyperinflation, while, on the other hand, it can increase the resistive work of breathing. Therefore, we evaluated the effects of 2 intensities of EPAP during exercise on tolerance, dynamic hyperinflation, and dyspnea in subjects with moderate to very severe COPD. METHODS: We performed a cross-sectional, experimental, 4-visit study. In visit 1, subjects performed symptom-limited cycling incremental cardiopulmonary exercise test (CPET). In visits 2-4, at least 48 h apart, in a randomized order, subjects performed constant CPET without EPAP, EPAP with 5 cm H2O (EPAP5), or EPAP with 10 cm H2O (EPAP10). RESULTS: The study included 15 non-hypoxemic subjects ranging from moderate to very severe COPD (mean FEV1 = 35 ± 11% predicted). Increasing intensities of EPAP during constant CPET tended to cause progressive reduction in exercise tolerance (P = .11). Of note, 10 of 15 subjects demonstrated significantly shorter average exercise duration with EPAP10 compared to the test without EPAP (-151 ± 105 s, P = .03 or -41 ± 26%). Minute ventilation increment was constrained by EPAP, secondary to a limited increase in tidal volume (P = .01). Finally, dyspnea sensation and serial measurements of inspiratory capacity during exercise were similar when comparing the three interventions at isotime and at end-constant CPETs. CONCLUSIONS: The application of EPAP5 or EPAP10 during exercise tended to cause a progressive reduction in exercise tolerance in subjects with COPD without improvement in dyspnea or dynamic hyperinflation at equivalent exercise duration.