Concurrent validity between field tests and cardiopulmonary exercise testing in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Maximal treadmill cardiopulmonary exercise testing is the gold standard for assessing functional capacity in patients with idiopathic pulmonary fibrosis (IPF). PURPOSE: Primarily to investigate the concurrent validity between three field tests and cardiopulmonary exercise testing in these patients. METHODS: Patients performed the cardiopulmonary exercise testing, a six-minute walk test, an incremental shuttle walk test, and, the Glittre-ADL test. For cardiopulmonary exercise testing, the ten seconds with the higher average of the peak oxygen uptake obtained within the last 30 seconds were considered; for six-minute walk test and incremental shuttle walk test, the longer distance; and for the Glittre-ADL test, the shorter time spent. Concurrent validity was assessed using different regression models based on the best adjustment of the data. RESULTS: Twenty-two patients with IPF were assessed, aged: 68 ± 8.1 years, 13 male. Patients presented a peak oxygen uptake of 16.5 ± 3.6 mL.kg-1.min1, achieving a distance of 512.6 ± 102.8 meters in the six-minute walk test and 415.7 ± 125.1 meters in incremental shuttle walk test. The walking distance in the six-minute walk test and the incremental shuttle walk test explained, respectively, 64% and 56% peak oxygen uptake variance observed in the cardiopulmonary exercise testing (R2 = 0.64,p < .001; R2 = 0.56,p < .001). The time spent in the Glittre-ADL test was 233.4 ± 88.7 seconds and explained 47% of the peak oxygen uptake variance observed in cardiopulmonary exercise testing (R2 = 0.47,p = .001). CONCLUSION: The six-minute walk test, incremental shuttle walk test, and Glittre-ADL test were considered valid tests to explain the peak oxygen uptake variance obtained by the cardiopulmonary exercise testing in patients with IPF.

Relative incidence of interstitial lung diseases in Brazil.

OBJECTIVE: To assess the relative frequency of incident cases of interstitial lung diseases (ILDs) in Brazil. METHODS: This was a retrospective survey of new cases of ILD in six referral centers between January of 2013 and January of 2020. The diagnosis of ILD followed the criteria suggested by international bodies or was made through multidisciplinary discussion (MDD). The condition was characterized as unclassifiable ILD when there was no specific final diagnosis following MDD or when there was disagreement between clinical, radiological, or histological data. RESULTS: The sample comprised 1,406 patients (mean age = 61 ± 14 years), and 764 (54%) were female. Of the 747 cases exposed to hypersensitivity pneumonitis (HP)-related antigens, 327 (44%) had a final diagnosis of HP. A family history of ILD was reported in 8% of cases. HRCT findings were indicative of fibrosis in 74% of cases, including honeycombing, in 21%. Relevant autoantibodies were detected in 33% of cases. Transbronchial biopsy was performed in 23% of patients, and surgical lung biopsy, in 17%. The final diagnoses were: connective tissue disease-associated ILD (in 27%), HP (in 23%), idiopathic pulmonary fibrosis (in 14%), unclassifiable ILD (in 10%), and sarcoidosis (in 6%). Diagnoses varied significantly among centers (c2 = 312.4; p < 0.001). CONCLUSIONS: Our findings show that connective tissue disease-associated ILD is the most common ILD in Brazil, followed by HP. These results highlight the need for close collaboration between pulmonologists and rheumatologists, the importance of detailed questioning of patients in regard with potential exposure to antigens, and the need for public health campaigns to stress the importance of avoiding such exposure.

Relative incidence of interstitial lung diseases in Brazil / Incidência relativa de doenças pulmonares intersticiais no Brasil

ABSTRACT Objective: To assess the relative frequency of incident cases of interstitial lung diseases (ILDs) in Brazil. Methods: This was a retrospective survey of new cases of ILD in six referral centers between January of 2013 and January of 2020. The diagnosis of ILD followed the criteria suggested by international bodies or was made through multidisciplinary discussion (MDD). The condition was characterized as unclassifiable ILD when there was no specific final diagnosis following MDD or when there was disagreement between clinical, radiological, or histological data. Results: The sample comprised 1,406 patients (mean age = 61 ± 14 years), and 764 (54%) were female. Of the 747 cases exposed to hypersensitivity pneumonitis (HP)-related antigens, 327 (44%) had a final diagnosis of HP. A family history of ILD was reported in 8% of cases. HRCT findings were indicative of fibrosis in 74% of cases, including honeycombing, in 21%. Relevant autoantibodies were detected in 33% of cases. Transbronchial biopsy was performed in 23% of patients, and surgical lung biopsy, in 17%. The final diagnoses were: connective tissue disease-associated ILD (in 27%), HP (in 23%), idiopathic pulmonary fibrosis (in 14%), unclassifiable ILD (in 10%), and sarcoidosis (in 6%). Diagnoses varied significantly among centers (c2 = 312.4; p < 0.001). Conclusions: Our findings show that connective tissue disease-associated ILD is the most common ILD in Brazil, followed by HP. These results highlight the need for close collaboration between pulmonologists and rheumatologists, the importance of detailed questioning of patients in regard with potential exposure to antigens, and the need for public health campaigns to stress the importance of avoiding such exposure.

RESUMO Objetivo: Avaliar a frequência relativa de casos incidentes de doenças pulmonares intersticiais (DPI) no Brasil. Métodos: Levantamento retrospectivo de casos novos de DPI em seis centros de referência entre janeiro de 2013 e janeiro de 2020. O diagnóstico de DPI seguiu os critérios sugeridos por órgãos internacionais ou foi feito por meio de discussão multidisciplinar (DMD). A condição foi caracterizada como DPI não classificável quando não houve um diagnóstico final específico após a DMD ou houve discordância entre dados clínicos, radiológicos ou histológicos. Resultados: A amostra foi composta por 1.406 pacientes (média de idade = 61 ± 14 anos), sendo 764 (54%) do sexo feminino. Dos 747 casos expostos a antígenos para pneumonite de hipersensibilidade (PH), 327 (44%) tiveram diagnóstico final de PH. Houve relato de história familiar de DPI em 8% dos casos. Os achados de TCAR foram indicativos de fibrose em 74% dos casos, incluindo faveolamento, em 21%. Autoanticorpos relevantes foram detectados em 33% dos casos. Biópsia transbrônquica foi realizada em 23% dos pacientes, e biópsia pulmonar cirúrgica, em 17%. Os diagnósticos finais foram: DPI associada à doença do tecido conjuntivo (em 27%), PH (em 23%), fibrose pulmonar idiopática (em 14%), DPI não classificável (em 10%) e sarcoidose (em 6%). Os diagnósticos variaram significativamente entre os centros (c2 = 312,4; p < 0,001). Conclusões: Nossos achados mostram que DPI associada à doença do tecido conjuntivo é a DPI mais comum no Brasil, seguida pela PH. Esses resultados destacam a necessidade de uma estreita colaboração entre pneumologistas e reumatologistas, a importância de fazer perguntas detalhadas aos pacientes a respeito da potencial exposição a antígenos e a necessidade de campanhas de saúde pública destinadas a enfatizar a importância de evitar essa exposição.

Maximal respiratory pressures: Measurements at functional residual capacity in individuals with different health conditions using a digital manometer.

BACKGROUND: Measuring maximal respiratory pressure is a widely used method of investigating the strength of inspiratory and expiratory muscles. OBJECTIVES: To compare inspiratory pressures obtained at functional residual capacity (FRC) with measures at residual volume (RV), and expiratory pressures obtained at FRC with measures at total lung capacity (TLC) in individuals with different health conditions: post-COVID-19, COPD, idiopathic pulmonary fibrosis (IPF), heart failure (CHF), and stroke; and to compare the mean differences between measurements at FRC and RV/TLC among the groups. METHODS: Inspiratory and expiratory pressures were obtained randomly at different lung volumes. Mixed factorial analysis of covariance with repeated measures was used to compare measurements at different lung volumes within and among groups. RESULTS: Seventy-five individuals were included in the final analyses (15 individuals with each health condition). Maximal inspiratory pressures at FRC were lower than RV [mean difference (95% CI): 11.3 (5.8, 16.8); 8.4 (2.3, 14.5); 11.1 (5.5, 16.7); 12.8 (7.1, 18.4); 8.0 (2.6, 13.4) for COVID-19, COPD, IPF, CHF, and stroke, respectively] and maximal expiratory pressures at FRC were lower than TLC [mean difference (95% CI): 51.9 (37.4, 55.5); 60.9 (44.2, 77.7); 62.9 (48.1, 77.8); 58.0 (43.9, 73.8); 57.2 (42.9, 71.6) for COVID-19, COPD, IPF, CHF, and stroke, respectively]. All mean differences were similar among groups. CONCLUSION: Although inspiratory and expiratory pressures at FRC were lower than measures obtained at RV/TLC for the five groups of health conditions, the mean differences between measurements at different lung volumes were similar among groups, which raises the discussion about the influence of the viscoelastic properties of the lungs on maximal respiratory pressure.

Accuracy of Transthoracic Echocardiogram as a Screening Method in the Clinical Practice of Pulmonary Hypertension Investigation. / Acurácia do Ecocardiograma Transtorácico como Método de Triagem na Prática Clínica da Investigação da Hipertensão Pulmonar.

BACKGROUND: The transthoracic echocardiogram (TTE) plays a screening role in the diagnostic algorithm of pulmonary hypertension (PH). Studies have shown a significant disagreement between TTE measurements of the systolic pulmonary artery pressure (sPAP) and right atrial pressure (RAP) and those obtained by right heart catheterization (RHC). OBJECTIVE: To compare TTE measurements of sPAP and RAP with those obtained by RHC in patients being investigated for PH. METHODS: Patients referred to a PH reference center with a high or intermediate TTE probability of PH upon admission were submitted to RHC. The agreement between sPAP and RAP from both procedures was assessed through the Bland-Altman test. Differences of up to 10 mmHg for sPAP and 5 mmHg for RAP were considered within the variability of the test. Receiver Operating Characteristic (ROC) curve was constructed to determine the most accurate sPAP and Tricuspid regurgitation maximal velocity (TRV)values associated with the diagnosis of PH by RHC. The adopted level of statistical significance was 5%. RESULTS: Ninety-five patients were included. The Bland-Altman analysis showed a bias of 8.03 mmHg (95% CI:-34.9-50.9) for sPAP and -3.30 mmHg (95% CI:-15.9-9.3) for RAP. AUC for sPAP and TRV measured by TTE for discrimination of probable PH were 0.936 (95% CI: 0.836-1.0) and 0.919 (95% CI: 0.837-1.0), respectively. However, only 33.4% of the echocardiographic estimate of sPAP and 55.1% of RAP were accurate, as compared to the measurements obtained by RHC. CONCLUSION: TTE has a high discriminatory power as a screening diagnostic method for PH despite presenting disagreements between sPAP and RAP absolute values when compared to RHC measurements.

FUNDAMENTO: O ecocardiograma transtorácico (ETT) tem um papel de triagem no algoritmo diagnóstico da hipertensão pulmonar (HP). Estudos demonstraram uma discordância significativa entre as medições do ETT da pressão arterial pulmonar sistólica (PAPs) e da pressão atrial direita (PAD) e as obtidas pelo cateterismo do coração direito (CCD). OBJETIVO: Comparar as medições do ETT da PAPs e da PAD com as obtidas pelo CCD em pacientes com suspeita de HP. MÉTODOS: Pacientes encaminhados a um centro de referência com probabilidade alta ou intermediária de PH ao ETT na admissão hospitalar passaram por CCD. A concordância entre a PAPs e a PAD em ambos os procedimentos foi avaliada pelo teste de Bland-Altman. Diferenças de até 10 mmHg na PAPs e de até 5 mmHg na PAD foram consideradas dentro da variabilidade do teste. A curva de característica de operação do receptor (ROC) foi construída para determinar os valores mais precisos de PAPs e VRT associados ao diagnóstico de HP pelo CCD. O nível de significância estatística adotado foi 5%. RESULTADOS: Foram incluídos noventa e cinco pacientes. A análise de Bland-Altman análise revelou um viés de 8,03 mmHg (IC 95%: -34,9 a 50,9) na PAPs e -3,30 mmHg (IC 95%: -15,9 a 9,3) na PAD. AUC da PAPs e VRT medidas pelo ETT para a discriminação de provável HP foram de 0,936 (IC 95%: 0,836 a 1,0) e 0,919 (IC 95%: 0,837 a 1,0), respectivamente. Entretanto, apenas 33,4% da estimativa ecocardiográfica da PAPs e 55,1% da PAD foram precisas, em comparação às medições obtidas pelo CCD. CONCLUSÃO: O ETT tem um alto poder discriminatório como método diagnóstico de triagem para HP, apesar de apresentar discordâncias entre os valores absolutos de PAPs e PAD, em comparação às medições por CCD.

Poor cardiorespiratory fitness may be an indicator of more severe liver inflammation in non-alcoholic fatty liver disease patients.

INTRODUCTION: Non-alcoholic fatty liver disease (NAFLD) is related to cardiovascular disease. Cardiorespiratory fitness (CRF) is an important indicator of cardiovascular health. Therefore, we aimed to evaluate the CRF of NAFLD patients. METHODS: Cross-sectional study, including 32 patients with biopsy-proved NAFLD. The patients underwent ergometric test (ET) and six-minute walk test (6MWT) to determine CRF. The test results were compared to disease parameters and with each other. RESULTS: Considering the ET, 20 (62.5%) patients had very poor or poor CRF, and in 12 (37.5%), it was regular or good. In the 6MWT, 13 (40.6%) individuals had poor CRF, in 12 (37.5%), it was very poor, and in seven (21.9%), regular. NAFLD activity score (NAS) ≥5 was observed in 12 (37.5%) individuals. Twelve (37.5%) patients were sedentary, 11 (34.4%), insufficiently active, and nine (28.1%), active. Obesity and liver inflammation on biopsy were associated with very poor/poor CRF. NAS ≥5 and sedentary lifestyle were independently associated with very poor/poor CRF by ET. Although mean VO2max values determined by both tests were similar, no correlation of VO2max determined by ET and 6MWT was observed, as occurred for the distance walked in 6MWT and values of metabolic equivalent (MET) determined by ET. There was no reproducibility between CRF determined by ET and 6MWT. CONCLUSION: Most NAFLD patients had very poor or poor CRF. Severe liver injury (NAS ≥5) and sedentary lifestyle were independently associated with very poor/poor fitness, according to ET. No reproducibility was observed between the CRF defined by ET and 6MWT.

Acurácia do Ecocardiograma Transtorácico como Método de Triagem na Prática Clínica da Investigação da Hipertensão Pulmonar / Accuracy of Transthoracic Echocardiogram as a Screening Method in the Clinical Practice of Pulmonary Hypertension Investigation

Resumo Fundamento O ecocardiograma transtorácico (ETT) tem um papel de triagem no algoritmo diagnóstico da hipertensão pulmonar (HP). Estudos demonstraram uma discordância significativa entre as medições do ETT da pressão arterial pulmonar sistólica (PAPs) e da pressão atrial direita (PAD) e as obtidas pelo cateterismo do coração direito (CCD). Objetivo Comparar as medições do ETT da PAPs e da PAD com as obtidas pelo CCD em pacientes com suspeita de HP. Métodos Pacientes encaminhados a um centro de referência com probabilidade alta ou intermediária de PH ao ETT na admissão hospitalar passaram por CCD. A concordância entre a PAPs e a PAD em ambos os procedimentos foi avaliada pelo teste de Bland-Altman. Diferenças de até 10 mmHg na PAPs e de até 5 mmHg na PAD foram consideradas dentro da variabilidade do teste. A curva de característica de operação do receptor (ROC) foi construída para determinar os valores mais precisos de PAPs e VRT associados ao diagnóstico de HP pelo CCD. O nível de significância estatística adotado foi 5%. Resultados Foram incluídos noventa e cinco pacientes. A análise de Bland-Altman análise revelou um viés de 8,03 mmHg (IC 95%: -34,9 a 50,9) na PAPs e -3,30 mmHg (IC 95%: -15,9 a 9,3) na PAD. AUC da PAPs e VRT medidas pelo ETT para a discriminação de provável HP foram de 0,936 (IC 95%: 0,836 a 1,0) e 0,919 (IC 95%: 0,837 a 1,0), respectivamente. Entretanto, apenas 33,4% da estimativa ecocardiográfica da PAPs e 55,1% da PAD foram precisas, em comparação às medições obtidas pelo CCD. Conclusão O ETT tem um alto poder discriminatório como método diagnóstico de triagem para HP, apesar de apresentar discordâncias entre os valores absolutos de PAPs e PAD, em comparação às medições por CCD.

Abstract Background The transthoracic echocardiogram (TTE) plays a screening role in the diagnostic algorithm of pulmonary hypertension (PH). Studies have shown a significant disagreement between TTE measurements of the systolic pulmonary artery pressure (sPAP) and right atrial pressure (RAP) and those obtained by right heart catheterization (RHC). Objective To compare TTE measurements of sPAP and RAP with those obtained by RHC in patients being investigated for PH. Methods Patients referred to a PH reference center with a high or intermediate TTE probability of PH upon admission were submitted to RHC. The agreement between sPAP and RAP from both procedures was assessed through the Bland-Altman test. Differences of up to 10 mmHg for sPAP and 5 mmHg for RAP were considered within the variability of the test. Receiver Operating Characteristic (ROC) curve was constructed to determine the most accurate sPAP and Tricuspid regurgitation maximal velocity (TRV)values associated with the diagnosis of PH by RHC. The adopted level of statistical significance was 5%. Results Ninety-five patients were included. The Bland-Altman analysis showed a bias of 8.03 mmHg (95% CI:-34.9-50.9) for sPAP and -3.30 mmHg (95% CI:-15.9-9.3) for RAP. AUC for sPAP and TRV measured by TTE for discrimination of probable PH were 0.936 (95% CI: 0.836-1.0) and 0.919 (95% CI: 0.837-1.0), respectively. However, only 33.4% of the echocardiographic estimate of sPAP and 55.1% of RAP were accurate, as compared to the measurements obtained by RHC. Conclusion TTE has a high discriminatory power as a screening diagnostic method for PH despite presenting disagreements between sPAP and RAP absolute values when compared to RHC measurements.

Perception of patients with interstitial lung diseases submitted to inspiratory muscle training.

BACKGROUND: Although inspiratory muscle training reduces dyspnea in patients with chronic respiratory diseases, it was not yet evaluated in a sample composed exclusively of patients with interstitial lung diseases. OBJECTIVE: To discuss the perception of patients with interstitial lung diseases about inspiratory muscle training intervention. METHODS: This is a qualitative study. Data were collected using semi-structured interviews, transcribed, and analyzed by thematic analysis. RESULTS: Fourteen patients (64 ± 7 years) with interstitial lung disease were interviewed. Average participation in the inspiratory muscle training program was 90% (range, 66-100%). Three themes were elaborated: 1) dyspnea and other symptoms in daily life (e.g. "I could not carry out a bag; I was very uncomfortable"); 2) less symptom and greater performance (e.g. "I wash and change my clothes, house cleaning, do everything without feeling anything"); and 3) IMT: a time dedicated to my health (e.g. "For me it was great because I saw my evolution every day"). CONCLUSION: Patients noticed improvements in symptoms and performance related to daily activities. Despite initial difficulties, patients continued training as planned.

Practical approach lung health-global alliance against chronic respiratory diseases (PAL-GARD) initiative in Brazil.

Background: To evaluate the impact of training primary care physicians (PCPs) in the use of the practical approach lung health-global alliance against chronic respiratory diseases (PAL-GARD) upon their diagnostic skills. Methods: In this real-life three-phase study, PCPs were allocated to a PAL-GARD training or control group. Patients who sought a primary care health facility due to cough, dyspnea and/or wheezing were eligible. The clinical diagnoses made by PCPs during the baseline and post-intervention phase were audited by a panel of pulmonologists. Kappa inter-rater statistics was used to compare agreement between PCPs and pulmonologists. Results: Thirty PCPs evaluated 536 patients, 358 in the intervention and 178 in the control group. According to Kappa, there was an increase in the agreement in the diagnosis of asthma (from 0.546 to 0.638), tuberculosis (from 0.393 to 0.655) and acute respiratory infections (ARI) (from 0.577 to 0.584) was observed in the PAL-GARD group, but there was a reduction in chronic obstructive pulmonary disease (COPD) (from 0.430 to 0.284). Conclusions: In this setting, PAL-GARD-based guide and training improved the clinical diagnosis of common respiratory diseases with the exception of COPD.

PET/CT and inflammatory mediators in systemic sclerosis-associated interstitial lung disease.

OBJECTIVE: To investigate the correlation of HRCT findings with pulmonary metabolic activity in the corresponding regions using 18F-FDG PET/CT and inflammatory markers in patients with systemic sclerosis (SSc)-associated interstitial lung disease (ILD). METHODS: This was a cross-sectional study involving 23 adult patients with SSc-associated ILD without other connective tissue diseases. The study also involved 18F-FDG PET/CT, HRCT, determination of serum chemokine levels, clinical data, and pulmonary function testing. RESULTS: In this cohort of patients with long-term disease (disease duration, 11.8 ± 8.7 years), a nonspecific interstitial pneumonia pattern was found in 19 (82.6%). Honeycombing areas had higher median standardized uptake values (1.95; p = 0.85). Serum levels of soluble tumor necrosis factor receptor 1, soluble tumor necrosis factor receptor 2, C-C motif chemokine ligand 2 (CCL2), and C-X-C motif chemokine ligand 10 were higher in SSc patients than in controls. Serum levels of CCL2-a marker of fibroblast activity-were correlated with pure ground-glass opacity (GGO) areas on HRCT scans (p = 0.007). 18F-FDG PET/CT showed significant metabolic activity for all HRCT patterns. The correlation between serum CCL2 levels and GGO on HRCT scans suggests a central role of fibroblasts in these areas, adding new information towards the understanding of the mechanisms surrounding cellular and molecular elements and their expression on HRCT scans in patients with SSc-associated ILD. CONCLUSIONS: 18F-FDG PET/CT appears to be unable to differentiate the intensity of metabolic activity across HRCT patterns in chronic SSc patients. The association between CCL2 and GGO might be related to fibroblast activity in these areas; however, upregulated CCL2 expression in the lung tissue of SSc patients should be investigated in order to gain a better understanding of this association.

Heart rate recovery in 1 minute after the 6-minute walk test predicts adverse outcomes in pulmonary arterial hypertension.

Heart rate recovery in 1 minute (HRR1) after the end of the 6-minute walk test (6MWT) is a non-invasive method of determining autonomic dysfunction. This parameter remains largely unexplored in pulmonary arterial hypertension (PAH) registries. We aimed to define the cut-off value and accuracy for abnormal HRR1 after the 6MWT and to investigate the association between HRR1 and clinical worsening in patients with PAH. This composite outcome was defined as first occurrence of all-cause death OR hospitalization from any cause OR disease progression characterized by decreased ≥ 15% in six-minute walking distance from baseline AND start of new specific PAH treatment or persistent worsening of World Health Organization functional class (WHO-FC). We performed a prospective cohort study that included 102 consecutive patients with PAH confirmed by right heart catheterization that underwent an 6MWT upon the diagnosis, recruited from September 2004 to April 2020 and followed up until April 2021 or death. The median HRR1 was 18 beats (IQR: 10-22), 50 and 52 PAH patients with <18 beats and ≥18 beats, respectively. The best cut-off for HRR1 to discriminate clinical worsening was 17 beats, with area under the curve (AUC) of 0.704 (95%CI: 0.584-0.824). The internal validation model by bootstrap showed an AUC of 0.676 (95%CI: 0.566-0.786) and the most accurate value was obtained in the seventh year of follow-up (AUC = 0.711; 95%CI: 0.596-0.844). Patients with an HRR1 <18 beats at baseline had a median event-free time of 2.17 years (95%CI: 1.82 to 2.52) versus 4.75 years (95%CI: 1.43 to 8.07) from those with ≥18 beats. In conclusion, a HRR1 value of less than 18 beats may be a reliable indicator of poor prognosis in patients with PAH.

Lung function six months after severe COVID-19: Does time, in fact, heal all wounds?

BACKGROUND: COVID-19 has been associated with persistent symptoms and functional changes, especially in those surviving severe disease. METHODS: We conducted a prospective multicenter study in patients with severe COVID-19 to determine respiratory sequelae. Patients were stratified into two groups: ward admission (WA) and intensive care unit (ICU) admission. In each follow-up visit, the patients where inquired about cough and dyspnea, and performed spirometry, lung volumes, carbon monoxide diffusion capacity (DLCO), 6-minute walk test (6MWT), and respiratory muscle strength (MIP and MEP). Results of pulmonary function tests at 45 days and 6 months after hospital admission were compared using paired analysis. RESULTS: 211 patients were included, 112 in WA and 99 in ICU. Dyspnea persisted in 64.7% in the WA and 66.7% in the ICU group after 6 months. Lung function measures showed significant improvement between 45 days and 6 months, both in WA and ICU groups in VC, FVC, FEV1, total lung capacity, and 6MW distance measures. The improvement in the proportions of the altered functional parameters was significant in the ICU group for VC (44.2% 45 d; 20.8% 6 m; p = 0,014), FVC (47.6% 45 d; 28% 6 m; p = 0,003), FEV1 (45.1% 45 d; 28% 6 m; p = 0,044), DLCO (33.8% 45 d; 7.7% 6 m; p < 0,0001). CONCLUSION: Six months follow-up of patients with the severe forms of COVID-19 showed significant improvement in the lung function measures compared to 45 days post hospital discharge. The difference was more evident in those requiring ICU admission.

Predicting Pulmonary Function From the Analysis of Voice: A Machine Learning Approach.

INTRODUCTION: To self-monitor asthma symptoms, existing methods (e.g. peak flow metre, smart spirometer) require special equipment and are not always used by the patients. Voice recording has the potential to generate surrogate measures of lung function and this study aims to apply machine learning approaches to predict lung function and severity of abnormal lung function from recorded voice for asthma patients. METHODS: A threshold-based mechanism was designed to separate speech and breathing from 323 recordings. Features extracted from these were combined with biological factors to predict lung function. Three predictive models were developed using Random Forest (RF), Support Vector Machine (SVM), and linear regression algorithms: (a) regression models to predict lung function, (b) multi-class classification models to predict severity of lung function abnormality, and (c) binary classification models to predict lung function abnormality. Training and test samples were separated (70%:30%, using balanced portioning), features were normalised, 10-fold cross-validation was used and model performances were evaluated on the test samples. RESULTS: The RF-based regression model performed better with the lowest root mean square error of 10·86. To predict severity of lung function impairment, the SVM-based model performed best in multi-class classification (accuracy = 73.20%), whereas the RF-based model performed best in binary classification models for predicting abnormal lung function (accuracy = 85%). CONCLUSION: Our machine learning approaches can predict lung function, from recorded voice files, better than published approaches. This technique could be used to develop future telehealth solutions including smartphone-based applications which have potential to aid decision making and self-monitoring in asthma.

Lung function six months after severe COVID-19: Does time, in fact, heal all wounds?

ABSTRACT Background: COVID-19 has been associated with persistent symptoms and functional changes, especially in those surviving severe disease. Methods: We conducted a prospective multicenter study in patients with severe COVID-19 to determine respiratory sequelae. Patients were stratified into two groups: ward admission (WA) and intensive care unit (ICU) admission. In each follow-up visit, the patients where inquired about cough and dyspnea, and performed spirometry, lung volumes, carbon monoxide diffusion capacity (DLCO), 6-minute walk test (6MWT), and respiratory muscle strength (MIP and MEP). Results of pulmonary function tests at 45 days and 6 months after hospital admission were compared using paired analysis. Results: 211 patients were included, 112 in WA and 99 in ICU. Dyspnea persisted in 64.7% in the WA and 66.7% in the ICU group after 6 months. Lung function measures showed significant improvement between 45 days and 6 months, both in WA and ICU groups in VC, FVC, FEV1, total lung capacity, and 6MW distance measures. The improvement in the proportions of the altered functional parameters was significant in the ICU group for VC (44.2% 45 d; 20.8% 6 m; p = 0,014), FVC (47.6% 45 d; 28% 6 m; p = 0,003), FEV1 (45.1% 45 d; 28% 6 m; p = 0,044), DLCO (33.8% 45 d; 7.7% 6 m; p < 0,0001). Conclusion: Six months follow-up of patients with the severe forms of COVID-19 showed significant improvement in the lung function measures compared to 45 days post hospital discharge. The difference was more evident in those requiring ICU admission.

PET/CT and inflammatory mediators in systemic sclerosis-associated interstitial lung disease / PET/TC e mediadores inflamatórios na doença pulmonar intersticial associada à esclerose sistêmica

ABSTRACT Objective: To investigate the correlation of HRCT findings with pulmonary metabolic activity in the corresponding regions using 18F-FDG PET/CT and inflammatory markers in patients with systemic sclerosis (SSc)-associated interstitial lung disease (ILD). Methods: This was a cross-sectional study involving 23 adult patients with SSc-associated ILD without other connective tissue diseases. The study also involved 18F-FDG PET/CT, HRCT, determination of serum chemokine levels, clinical data, and pulmonary function testing. Results: In this cohort of patients with long-term disease (disease duration, 11.8 ± 8.7 years), a nonspecific interstitial pneumonia pattern was found in 19 (82.6%). Honeycombing areas had higher median standardized uptake values (1.95; p = 0.85). Serum levels of soluble tumor necrosis factor receptor 1, soluble tumor necrosis factor receptor 2, C-C motif chemokine ligand 2 (CCL2), and C-X-C motif chemokine ligand 10 were higher in SSc patients than in controls. Serum levels of CCL2-a marker of fibroblast activity-were correlated with pure ground-glass opacity (GGO) areas on HRCT scans (p = 0.007). 18F-FDG PET/CT showed significant metabolic activity for all HRCT patterns. The correlation between serum CCL2 levels and GGO on HRCT scans suggests a central role of fibroblasts in these areas, adding new information towards the understanding of the mechanisms surrounding cellular and molecular elements and their expression on HRCT scans in patients with SSc-associated ILD. Conclusions: 18F-FDG PET/CT appears to be unable to differentiate the intensity of metabolic activity across HRCT patterns in chronic SSc patients. The association between CCL2 and GGO might be related to fibroblast activity in these areas; however, upregulated CCL2 expression in the lung tissue of SSc patients should be investigated in order to gain a better understanding of this association.

RESUMO Objetivo: Investigar a correlação entre achados de TCAR e a atividade metabólica pulmonar nas regiões correspondentes por meio de PET/TC com 18F-FDG e marcadores inflamatórios em pacientes com doença pulmonar intersticial (DPI) associada à esclerose sistêmica (ES). Métodos: Estudo transversal envolvendo 23 pacientes adultos com DPI associada à ES sem outras doenças do tecido conjuntivo. O estudo também envolveu PET/TC com 18F-FDG, TCAR, dosagem sérica de quimiocinas, dados clínicos e testes de função pulmonar. Resultados: Nessa coorte de pacientes com doença de longa duração (11,8 ± 8,7 anos), 19 (82,6%) apresentaram o padrão de pneumonia intersticial não específica. A mediana dos valores padronizados de captação foi maior nas áreas de faveolamento (1,95; p = 0,85). Os níveis séricos de soluble tumor necrosis factor receptor 1, soluble tumor necrosis factor receptor 2, C-C motif chemokine ligand 2 (CCL2) e C-X-C motif chemokine ligand 10 foram maiores nos pacientes com ES que nos controles. Os níveis séricos de CCL2 - um marcador de atividade fibroblástica - correlacionaram-se com áreas de opacidade em vidro fosco (OVF) pura na TCAR (p = 0,007). A PET/TC com 18F-FDG mostrou atividade metabólica significativa para todos os padrões de TCAR. A correlação entre níveis séricos de CCL2 e OVF na TCAR sugere que os fibroblastos desempenham um papel fundamental nessas áreas, acrescentando novas informações para a compreensão dos mecanismos que envolvem elementos celulares e moleculares e sua expressão na TCAR em pacientes com DPI associada à ES. Conclusões: A PET/TC com 18F-FDG aparentemente não consegue diferenciar a intensidade da atividade metabólica nos diferentes padrões de TCAR em pacientes com ES crônica. A associação entre CCL2 e OVF pode estar relacionada à atividade fibroblástica nessas áreas; entretanto, a expressão suprarregulada de CCL2 no tecido pulmonar de pacientes com ES deve ser investigada para que se compreenda melhor essa associação.

Lung function of patients hospitalized with COVID-19 at 45 days after hospital discharge: first report of a prospective multicenter study in Brazil.

OBJECTIVE: Because SARS-CoV-2 infection can severely affect the lungs and persistent functional changes can occur after severe disease, we aimed to determine lung function parameters of COVID-19 patients at 45 days after hospital discharge and compare changes according to the severity of the disease. METHODS: This was a prospective descriptive analytical multicenter study. The participants were allocated into three groups: ward admission (WA) group; ICU admission not on mechanical ventilation (ICU/MV-) group; and ICU admission on MV (ICU/MV+) group. Lung volumes, DLco, MIP, MEP, and six-minute walk distance (6MWD) were measured 45 days after discharge. RESULTS: The sample comprised 242 patients (mean age = 59.4 ± 14.8 years; 52.1% of males), and 232 (96%) had altered lung function. In the total cohort, restrictive disorder was observed in 96%, as well as reductions in DLco (in 21.2% of the patients), FEV1/FVC (in 39.7%), and PEmax (in 95.8%), with no differences between the groups. Comparing the groups, the ICU/MV+ group had reduced DLco in 50% of the patients (p < 0.001) and a lower mean 6MWD % of the predicted value (p = 0.013). Oxygen desaturation in the six-minute walk test was observed in 32.3% of the cohort and was less frequent in the IE group. CONCLUSIONS: This is the first South American study involving severe COVID-19 survivors whose lung function was assessed 45 days after hospital discharge. Changes were frequent, especially in those on MV, which highlights the importance of lung function evaluation after severe COVID-19.

Occupational exposure to pesticides and chronic hypersensitivity pneumonia: a case report.

Hypersensitivity pneumonia is an immune-mediated inflammation of the lung parenchyma that occurs in previously susceptible individuals, after inhalation of antigens, usually organic. In recent years, various chemical agents have been described as inducers of hypersensitivity pneumonia, including exposure to high concentrations of pesticides. The objective of the present case report was to describe a possible association of hypersensitivity pneumonia with pesticide chronic inhalation and to draw attention to the importance of early diagnosis. The patient was 72-year-old man who worked for over 30 years as a health agent fumigating pesticides in rural and urban areas. He had progressive dyspnea and cough for the past 3 years. Chest tomography demonstrated parenchymal bands, honeycombing, and diffuse air trapping. Spirometry showed a severe restrictive pattern. Surgical lung biopsy was indicated, which confirmed the diagnosis of hypersensitivity pneumonia. Due to the wide use of pesticides in Brazil, the knowledge of their association with hypersensitivity pneumonia is of great importance in warning the teams involved in health care and surveillance of these workers, providing earlier diagnoses, with better prognosis. On the contrary, late diagnoses, such as that of the case reported, have important health impacts. As a priority, preventive measures must be taken to protect exposed individuals.