Chronic Obstructive Pulmonary Disease in Heart Failure: Challenges in Diagnosis and Treatment for HFpEF and HFrEF.

PURPOSE OF REVIEW: Chronic obstructive pulmonary disease (COPD) is common in heart failure (HF), and it has a significant impact on the prognosis and quality of life of patients. Additionally, COPD is independently associated with lower adherence to first-line HF therapies. In this review, we outline the challenges of identifying and managing HF with preserved (HFpEF) and reduced (HFrEF) ejection fraction with coexisting COPD. RECENT FINDINGS: Spirometry is necessary for COPD diagnosis and prognosis but is underused in HF. Therefore, misdiagnosis is a concern. Also, disease-modifying drugs for HF and COPD are usually safe but underprescribed when HF and COPD coexist. Patients with HF-COPD are poorly enrolled in clinical trials. Guidelines recommend that HF treatment should be offered regardless of COPD presence, but modern registries show that undertreatment persists. Treatment gaps could be attenuated by ensuring an accurate and earlier COPD diagnosis in patients with HF, clarifying the concerns related to pharmacotherapy safety, and increasing the use of non-pharmacologic treatments. Acknowledging the uncertainties, this review aims to provide key clinical resources to support better physician-patient co-decision-making and improve collaboration between health professionals.

Vocal Impact in Patients With Unilateral Diaphragmatic Paralysis.

OBJECTIVES: This study aimed to investigate the possible vocal impact confirmed by diagnostic tests, the degree of perception of possible vocal impairment by patients with Unilateral Diaphragmatic paralysis (UDP) and its correlation with ventilatory weakness. METHODS: The researchers conducted an analytical, observational and case-control study with 70 individuals, including 35 UDP patients and 35 healthy patients in a control group, who underwent the following assessments: 1) Self-assessment of voice handicap (VHI-10); 2) Self-Assessment of Quality of Life (SF-36); 3) Self-Assessment of Dyspnea (MRC); 4) Objective vocal measures (Maximum Phonation Time (MPT) in /a/, /s/, /z/ and glottal-to-noise excitation ratio); 5) Functional respiratory pressures (Spirometry and maximum ventilatory pressures); 6) General degree of dysphonia - G on the GRBAS Scale. The sex, age and body mass index (BMI) of the individuals were the variables used to match the sample of this study. RESULTS: When compared with controls, patients with UDP had a restrictive functional pattern and inspiratory weakness, with symptoms of dyspnea and worsening quality of life. When associated with a possible vocal impact, these patients had voice handicap and decreased MPT values for all phonemes, especially /a/. There was also a correlation between vocal performance and inspiratory weakness. However, it should be noted that, despite having vocal impairment, many patients did not report the perception of this fact, somehow neglecting such impairment. CONCLUSIONS: In addition to the expected weakness of the ventilatory muscles, patients with UDP had clinically verified vocal impact, and those who had greater inspiratory weakness also had greater voice impairment. Finally, it is relevant that not all patients perceived such vocal impact, which showed a very reduced perception of this impairment in patients with UDP.

Long-term respiratory follow-up of ICU hospitalized COVID-19 patients: Prospective cohort study.

BACKGROUND: Coronavirus disease (COVID-19) survivors exhibit multisystemic alterations after hospitalization. Little is known about long-term imaging and pulmonary function of hospitalized patients intensive care unit (ICU) who survive COVID-19. We aimed to investigate long-term consequences of COVID-19 on the respiratory system of patients discharged from hospital ICU and identify risk factors associated with chest computed tomography (CT) lesion severity. METHODS: A prospective cohort study of COVID-19 patients admitted to a tertiary hospital ICU in Brazil (March-August/2020), and followed-up six-twelve months after hospital admission. Initial assessment included: modified Medical Research Council dyspnea scale, SpO2 evaluation, forced vital capacity, and chest X-Ray. Patients with alterations in at least one of these examinations were eligible for CT and pulmonary function tests (PFTs) approximately 16 months after hospital admission. Primary outcome: CT lesion severity (fibrotic-like or non-fibrotic-like). Baseline clinical variables were used to build a machine learning model (ML) to predict the severity of CT lesion. RESULTS: In total, 326 patients (72%) were eligible for CT and PFTs. COVID-19 CT lesions were identified in 81.8% of patients, and half of them showed mild restrictive lung impairment and impaired lung diffusion capacity. Patients with COVID-19 CT findings were stratified into two categories of lesion severity: non-fibrotic-like (50.8%-ground-glass opacities/reticulations) and fibrotic-like (49.2%-traction bronchiectasis/architectural distortion). No association between CT feature severity and altered lung diffusion or functional restrictive/obstructive patterns was found. The ML detected that male sex, ICU and invasive mechanic ventilation (IMV) period, tracheostomy and vasoactive drug need during hospitalization were predictors of CT lesion severity(sensitivity,0.78±0.02;specificity,0.79±0.01;F1-score,0.78±0.02;positive predictive rate,0.78±0.02; accuracy,0.78±0.02; and area under the curve,0.83±0.01). CONCLUSION: ICU hospitalization due to COVID-19 led to respiratory system alterations six-twelve months after hospital admission. Male sex and critical disease acute phase, characterized by a longer ICU and IMV period, and need for tracheostomy and vasoactive drugs, were risk factors for severe CT lesions six-twelve months after hospital admission.

Evaluation of quality of online shopping services in times of COVID-19 based on E-S-QUAL model and Fuzzy TOPSIS method.

This paper aims to propose an approach to evaluate the quality of online shopping services in times of pandemic COVID-19, from the ordering of quality attributes taking into account customers' perception. The proposed approach was developed from a structured questionnaire containing 25 quality attributes adapted from the E-S-QUAL model and applied to consumers of online shopping services. Fuzzy set theory was used in the approach to simplify the subjectivity of human judgment, along with the extension of Technique for Order Performance by Similarity to Ideal Solution (TOPSIS). Therefore, this research was classified as applied, exploratory, quantitative and survey. To achieve the research objective, 819 questionnaires were collected. Among the main findings, it is highlighted that the attributes "product availability", "products with excellent quality", "confidence in online shopping processes" and "ease of buying online" were the ones that presented the best perceptions of quality by the respondents. At the other end, the attributes "opinion sharing on social networks", "buying online is a good option when you have little time", "distraction in online shopping searches" and "shopping online is a pleasure" showed the highest level of dissatisfaction with the service. Thus, this article highlights the importance of online shopping services in times of the pandemic caused by COVID-19, and its main contribution and originality is the development of an approach that aims to support the decision-making process, establishing strategic actions for the continuous improvement of online shopping services with the reduction of subjectivity in customer perception and with successive refinements.

Robotic Lung Volume Reduction Surgery With Extracorporeal Membrane Oxygenation.

Lobectomy for consolidation of failed endoscopic lung volume reduction for emphysema has been reported in selected patients with favorable results but with considerable morbidity. The challenging issues in such patients are frailty caused by severe emphysema itself, poor tolerance to single-lung ventilation, target lobe hyperinflation, and inability to use gas inflation for the minimally invasive resection. Careful planning, including use of a robotic platform and extracorporeal membrane oxygenation support, can circumvent such difficulties and ensure a safe, minimally invasive resection in the high-risk emphysematous patient.

Quantitative CT Analysis in Chronic Hypersensitivity Pneumonitis: A Convolutional Neural Network Approach.

RATIONALE AND OBJECTIVES: Chronic hypersensitivity pneumonitis (cHP) is a heterogeneous condition, where both small airway involvement and fibrosis may simultaneously occur. Computer-aided analysis of CT lung imaging is increasingly used to improve tissue characterization in interstitial lung diseases (ILD), quantifying disease extension, and progression. We aimed to quantify via a convolutional neural network (CNN) method the extent of different pathological classes in cHP, and to determine their correlation to pulmonary function tests (PFTs) and mosaic attenuation pattern. MATERIALS AND METHODS: The extension of six textural features, including consolidation (C), ground glass opacity (GGO), fibrosis (F), low attenuation areas (LAA), reticulation (R) and healthy regions (H), was quantified in 27 cHP patients (age: 56 ± 11.5 years, forced vital capacity [FVC]% = 57 ± 17) acquired at full-inspiration via HRCT. Each class extent was correlated to PFTs and to mosaic attenuation pattern. RESULTS: H showed a positive correlation with FVC%, FEV1% (forced expiratory volume), total lung capacity%, and diffusion of carbon monoxide (DLCO)% (r = 0.74, r = 0.78, r = 0.73, and r = 0.60, respectively, p < 0.001). GGO, R and C negatively correlated with FVC% and FEV1% with the highest correlations found for R (r = -0.44, and r = -0.46 respectively, p < 0.05); F negatively correlated with DLCO% (r = -0.42, p < 0.05). Patients with mosaic attenuation pattern had significantly more H (p = 0.04) and lower R (p = 0.02) and C (p = 0.0009) areas, and more preserved lung function indices (higher FVC%; p = 0.04 and DLCO%; p = 0.05), but did not show more air trapping in lung function tests. CONCLUSION: CNN quantification of pathological tissue extent in cHP improves its characterization and shows correlation with PFTs. LAA can be overestimated by visual, qualitative CT assessment and mosaic attenuation pattern areas in cHP represents patchy ILD rather than small-airways disease.

A Convolutional Neural Network Approach to Quantify Lung Disease Progression in Patients with Fibrotic Hypersensitivity Pneumonitis (HP).

Rationale and Objectives To evaluate associations between longitudinal changes of quantitative CT parameters and spirometry in patients with fibrotic hypersensitivity pneumonitis (HP). Materials and Methods Serial CT images and spirometric data were retrospectively collected in a group of 25 fibrotic HP patients. Quantitative CT analysis included histogram parameters (median, interquartile range, skewness, and kurtosis) and a pretrained convolutional neural network (CNN)-based textural analysis, aimed at quantifying the extent of consolidation (C), fibrosis (F), ground-glass opacity (GGO), low attenuation areas (LAA) and healthy tissue (H). Results At baseline, FVC was 61(44-70) %pred. The median follow-up period was 1.4(0.8-3.2) years, with 3(2-4) visits per patient. Over the study, 8 patients (32%) showed a FVC decline of more than 5%, a significant worsening of all histogram parameters (p≤0.015) and an increased extent of fibrosis via CNN (p=0.038). On histogram analysis, decreased skewness and kurtosis were the parameters most strongly associated with worsened FVC (respectively, r2=0.63 and r2=0.54, p<0.001). On CNN classification, increased extent of fibrosis and consolidation were the measures most strongly correlated with FVC decline (r2=0.54 and r2=0.44, p<0.001). Conclusion CT histogram and CNN measurements provide sensitive measures of functional changes in fibrotic HP patients over time. Increased fibrosis was associated with FVC decline, providing index of disease progression. CNN may help improve fibrotic HP follow-up, providing a sensitive tool for progressive interstitial changes, which can potentially contribute to clinical decisions for individualizing disease management.

Thoracoabdominal asynchrony associates with exercise intolerance in fibrotic interstitial lung diseases.

BACKGROUND AND OBJECTIVE: The precise coordination of respiratory muscles during exercise minimizes work of breathing and avoids exercise intolerance. Fibrotic interstitial lung disease (f-ILD) patients are exercise-intolerant. We assessed whether respiratory muscle incoordination and thoracoabdominal asynchrony (TAA) occur in f-ILD during exercise, and their relationship with pulmonary function and exercise performance. METHODS: We compared breathing pattern, respiratory mechanics, TAA and respiratory muscle recruitment in 31 f-ILD patients and 31 healthy subjects at rest and during incremental cycle exercise. TAA was defined as phase angle (PhAng) >20°. RESULTS: During exercise, when compared with controls, f-ILD patients presented increased and early recruitment of inspiratory rib cage muscle (p < 0.05), and an increase in PhAng, indicating TAA. TAA was more frequent in f-ILD patients than in controls, both at 50% of the maximum workload (42.3% vs. 10.7%, p = 0.01) and at the peak (53.8% vs. 23%, p = 0.02). Compared with f-ILD patients without TAA, f-ILD patients with TAA had lower lung volumes (forced vital capacity, p < 0.01), greater dyspnoea (Medical Research Council > 2 in 64.3%, p = 0.02), worse exercise performance (lower maximal work rate % predicted, p = 0.03; lower tidal volume, p = 0.03; greater desaturation and dyspnoea, p < 0.01) and presented higher oesophageal inspiratory pressures with lower gastric inspiratory pressures and higher recruitment of scalene (p < 0.05). CONCLUSION: Exercise induces TAA and higher recruitment of inspiratory accessory muscle in ILD patients. TAA during exercise occurred in more severely restricted ILD patients and was associated with exertional dyspnoea, desaturation and limited exercise performance.

Pulmonary fibrosis secondary to COVID-19: a narrative review.

Introduction: Coronavirus disease 2019 (COVID-19) is still increasing worldwide, and as a result, the number of patients with pulmonary fibrosis secondary to COVID-19 will expand over time. Risk factors, histopathological characterization, pathophysiology, prevalence, and management of post-COVID-19 pulmonary fibrosis are poorly understood, and few studies have addressed these issues.Areas covered:This article reviews the current evidence regarding post-COVID-19 pulmonary fibrosis, with an emphasis on the potential risk factors, histopathology, pathophysiology, functional and tomographic features, and potential therapeutic modalities. A search on the issue was performed in the MEDLINE, Embase, and SciELO databases and the Cochrane library between 1 December 2019, and 25 January 2021. Studies were reviewed and relevant topics were incorporated into this narrative review. Expert opinion: Pulmonary sequelae may occur secondary to COVID-19, which needs to be included as a potential etiology in the current differential diagnosis of pulmonary fibrosis. Therefore, serial clinical, tomographic, and functional screening for pulmonary fibrosis is recommended after COVID-19, mainly in patients with pulmonary involvement in the acute phase of the disease. Further studies are necessary to determine the risk factors, markers, pathophysiology, and appropriate management of post-COVID-19 pulmonary fibrosis.

Unilateral diaphragmatic paralysis: inspiratory muscles, breathlessness and exercise capacity.

BACKGROUND: Patients with unilateral diaphragmatic paralysis (UDP) may present with dyspnoea without specific cause and limited ability to exercise. We aimed to investigate the diaphragm contraction mechanisms and nondiaphragmatic inspiratory muscle activation during exercise in patients with UDP, compared with healthy individuals. METHODS: Pulmonary function, as well as volitional and nonvolitional inspiratory muscle strength were evaluated in 35 patients and in 20 healthy subjects. Respiratory pressures and electromyography of scalene and sternocleidomastoid muscles were continuously recorded during incremental maximal cardiopulmonary exercise testing until symptom limitation. Dyspnoea was assessed at rest, every 2 min during exercise and at the end of exercise with a modified Borg scale. MAIN RESULTS: Inspiratory muscle strength measurements were significantly lower for patients in comparison to controls (all p<0.05). Patients achieved lower peak of exercise (lower oxygen consumption) compared to controls, with both gastric (-9.8±4.6 cmH2O versus 8.9±6.0 cmH2O) and transdiaphragmatic (6.5±5.5 cmH2O versus 26.9±10.9 cmH2O) pressures significantly lower, along with larger activation of both scalene (40±22% EMGmax versus 18±14% EMGmax) and sternocleidomastoid (34±22% EMGmax versus 14±8% EMGmax). In addition, the paralysis group presented significant differences in breathing pattern during exercise (lower tidal volume and higher respiratory rate) with more dyspnoea symptoms compared to the control group. CONCLUSION: The paralysis group presented with exercise limitation accompanied by impairment in transdiaphragmatic pressure generation and larger accessory inspiratory muscles activation compared to controls, thereby contributing to a neuromechanical dissociation and increased dyspnoea perception.

Preoperative evaluation for lung resection in patients with bronchiectasis: should we rely on standard lung function evaluation?

OBJECTIVES: The scant data about non-cystic fibrosis bronchiectasis, including tuberculosis sequelae and impairment of lung function, can bias the preoperative physiological assessment. Our goal was to evaluate the changes in lung function and exercise capacity following pulmonary resection in these patients; we also looked for outcome predictors. METHODS: We performed a non-randomized prospective study evaluating lung function changes in patients with non-cystic fibrosis bronchiectasis treated with pulmonary resection. Patients performed lung function tests and cardiopulmonary exercise tests preoperatively and 3 and 9 months after the operation. Demographic data, comorbidities, surgical data and complications were collected. RESULTS: Forty-four patients were evaluated for lung function. After resection, the patients had slightly lower values for spirometry: forced expiratory volume in 1 s preoperatively: 2.21 l ± 0.8; at 3 months: 1.9 l ± 0.8 and at 9 months: 2.0 l ± 0.8, but the relationship between the forced expiratory volume in 1 s and the forced vital capacity remained. The gas diffusion measured by diffusing capacity for carbon monoxide did not change: preoperative value: 23.2 ml/min/mmHg ± 7.4; at 3 months: 21.5 ml/min/mmHg ± 5.6; and at 9 months: 21.7 ml/min/mmHg ± 8.2. The performance of general exercise did not change; peak oxygen consumption preoperatively was 20.9 ml/kg/min ± 7.4; at 3 months: 19.3 ml/kg/min ± 6.4; and at 9 months: 20.2 ml/kg/min ± 8.0. Forty-six patients were included for analysis of complications. We had 13 complications with 2 deaths. To test the capacity of the predicted postoperative (PPO) values to forecast complications, we performed several multivariate and univariate analyses; none of them was a significant predictor of complications. When we analysed other variables, only bronchoalveolar lavage with positive culture was significant for postoperative complications (P = 0.0023). Patients who had a pneumonectomy had a longer stay in the intensive care unit (P = 0.0348). CONCLUSIONS: The calculated PPO forced expiratory volume in 1 s had an excellent correlation with the measurements at 3 and 9 months; but the calculated PPO capacity for carbon monoxide and the PPO peak oxygen consumption slightly underestimated the 3- and 9-month values. However, none of them was a predictor for complications. Better tools to predict postoperative complications for patients with bronchiectasis who are candidates for lung resection are needed. CLINICAL TRIAL REGISTRATION NUMBER: Clinicaltrials.gov: NCT01268475.

Mechanisms of Exercise Limitation and Prevalence of Pulmonary Hypertension in Pulmonary Langerhans Cell Histiocytosis.

BACKGROUND: Pulmonary Langerhans cell histiocytosis (PLCH) determines reduced exercise capacity. The speculated mechanisms of exercise impairment in PLCH are ventilatory and cardiocirculatory limitations, including pulmonary hypertension (PH). RESEARCH QUESTION: What are the mechanisms of exercise limitation, the exercise capacity, and the prevalence of dynamic hyperinflation (DH) and PH in PLCH? STUDY DESIGN AND METHODS: In a cross-sectional study, patients with PLCH underwent an incremental treadmill cardiopulmonary exercise test with an evaluation of DH, pulmonary function tests, and transthoracic echocardiography. Those patients with lung diffusing capacity for carbon monoxide (Dlco) < 40% predicted and/or transthoracic echocardiogram with tricuspid regurgitation velocity > 2.5 m/s and/or with indirect PH signs underwent right heart catheterization. RESULTS: Thirty-five patients were included (68% women; mean age, 47 ± 11 years). Ventilatory and cardiocirculatory limitations, impairment suggestive of PH, and impaired gas exchange occurred in 88%, 67%, 29%, and 88% of patients, respectively. The limitation was multifactorial in 71%, exercise capacity was reduced in 71%, and DH occurred in 68% of patients. FEV1 and Dlco were 64 ± 22% predicted and 56 ± 21% predicted. Reduction in Dlco, an obstructive pattern, and air trapping occurred in 80%, 77%, and 37% of patients. FEV1 and Dlco were good predictors of exercise capacity. The prevalence of PH was 41%, predominantly with a precapillary pattern, and mean pulmonary artery pressure correlated best with FEV1 and tricuspid regurgitation velocity. INTERPRETATION: PH is frequent and exercise impairment is common and multifactorial in PLCH. The most prevalent mechanisms are ventilatory, cardiocirculatory, and suggestive of PH limitations. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT02665546; URL: www.clinicaltrials.gov.

Diaphragmatic ultrasound findings correlate with dyspnea, exercise tolerance, health-related quality of life and lung function in patients with fibrotic interstitial lung disease.

BACKGROUND: Fibrotic interstitial lung disease (FILD) patients are typically dyspneic and exercise-intolerant with consequent impairment of health-related quality of life (HRQoL). Respiratory muscle dysfunction is among the underlying mechanisms of dyspnea and exercise intolerance in FILD but may be difficult to diagnose. Using ultrasound, we compared diaphragmatic mobility and thickening in FILD cases and healthy controls and correlated these findings with dyspnea, exercise tolerance, HRQoL and lung function. METHODS: We measured diaphragmatic mobility and thickness during quiet (QB) and deep breathing (DB) and calculated thickening fraction (TF) in 30 FILD cases and 30 healthy controls. We correlated FILD cases' diaphragmatic findings with dyspnea, exercise tolerance (six-minute walk test), lung function and HRQoL (St. George's Respiratory Questionnaire). RESULTS: Diaphragmatic mobility was similar between groups during QB but was lower in FILD cases during DB when compared to healthy controls (3.99 cm vs 7.02 cm; p <  0.01). FILD cases showed higher diaphragm thickness during QB but TF was lower in FILD when compared to healthy controls (70% vs 188%, p <  0.01). During DB, diaphragmatic mobility and thickness correlated with lung function, exercise tolerance and HRQoL, but inversely correlated with dyspnea. Most FILD cases (70%) presented reduced TF, and these patients had higher dyspnea and exercise desaturation, lower HRQoL and lung function. CONCLUSION: Compared to healthy controls, FILD cases present with lower diaphragmatic mobility and thickening during DB that correlate to increased dyspnea, decreased exercise tolerance, worse HRQoL and worse lung function. FILD cases with reduced diaphragmatic thickening are more dyspneic and exercise-intolerant, have lower HRQoL and lung function.

Forced Oscillation Technique and Small Airway Involvement in Chronic Hypersensitivity Pneumonitis.

OBJECTIVE: Hypersensitivity pneumonitis (HP) is an interstitial lung disease caused by the inhalation of specific organic antigens or low-molecular weight substances in genetically susceptible individuals. Although small airway involvement is prominent in patients with chronic HP, conventional pulmonary function tests (PFTs) are relatively insensitive to identify it. Thus, the authors aimed to evaluate resistance (R5) and reactance (X5) values at 5Hz on inspiration, expiration, and whole breath, as well as small airway resistance (R5-19) values using a forced oscillation technique (FOT) in patients with chronic HP, and their responses after bronchodilator. In addition, R5 and X5 values according to the presence or absence of mosaic attenuation on computed tomography (CT) were compared. METHODS: PFTs with plethysmography, diffusing capacity of the lungs for carbon monoxide (DLCO) and FOT measurements were performed pre-bronchodilator and post-bronchodilator. High-resolution CT was performed at the same visit, and classified according to the presence or absence of mosaic attenuation. R5 and X5 values were then compared according to the presence or absence of mosaic attenuation on CT. RESULTS: Twenty-eight patients with chronic HP (57.1% female; mean age, 56±11.5 years; mean forced vital capacity 57±17% predicted) were evaluated. All patients had low X5 values, reflecting lower lung compliance, and only three (8%) demonstrated elevated R5 (whole-breath) values. No patients exhibited bronchodilator response in R5, X5 and R5-19 values. In patients who exhibited greater extension of mosaic attenuation (n=11), R5 and X5 values could not discriminate those with a greater presence of these areas on CT. CONCLUSIONS: The results suggest that FOT does not help to additionally characterise concomitant small airway involvement in patients with chronic fibrotic HP who demonstrate restrictive ventilatory pattern in conventional PFTs. Nevertheless, FOT appeared to better characterise decreased lung compliance due to fibrosis through X5. Bronchodilator therapy did not appear to induce an acute response in chronic HP patients with restrictive disease. The precise role of FOT in subacute HP and obstructive chronic HP, therefore, must be evaluated.

Mechanisms of exercise limitation in patients with chronic hypersensitivity pneumonitis.

Small airway and interstitial pulmonary involvements are prominent in chronic hypersensitivity pneumonitis (cHP). However, their roles on exercise limitation and the relationship with functional lung tests have not been studied in detail. Our aim was to evaluate exercise performance and its determinants in cHP. We evaluated maximal cardiopulmonary exercise testing performance in 28 cHP patients (forced vital capacity 57±17% pred) and 18 healthy controls during cycling. Patients had reduced exercise performance with lower peak oxygen production (16.6 (12.3-19.98) mL·kg-1·min-1versus 25.1 (16.9-32.0), p=0.003), diminished breathing reserve (% maximal voluntary ventilation) (12 (6.4-34.8)% versus 41 (32.7-50.8)%, p<0.001) and hyperventilation (minute ventilation/carbon dioxide production slope 37±5 versus 31±4, p<0.001). All patients presented oxygen desaturation and augmented Borg dyspnoea scores (8 (5-10) versus 4 (1-7), p=0.004). The prevalence of dynamic hyperinflation was found in only 18% of patients. When comparing cHP patients with normal and low peak oxygen production (<84% pred, lower limit of normal), the latter exhibited a higher minute ventilation/carbon dioxide production slope (39±5.0 versus 34±3.6, p=0.004), lower tidal volume (0.84 (0.78-0.90) L versus 1.15 (0.97-1.67) L, p=0.002), and poorer physical functioning score on the Short form-36 health survey. Receiver operating characteristic curve analysis showed that reduced lung volumes (forced vital capacity %, total lung capacity % and diffusing capacity of the lung for carbon dioxide %) were high predictors of poor exercise capacity. Reduced exercise capacity was prevalent in patients because of ventilatory limitation and not due to dynamic hyperinflation. Reduced lung volumes were reliable predictors of lower performance during exercise.

Is the 6-minute pegboard and ring test valid to evaluate upper limb function in hospitalized patients with acute exacerbation of COPD?

Background: The 6-minute pegboard and ring test (6-PBRT) is a useful test for assessing the functional capacity of upper limbs in patients with stable COPD. Although 6-PBRT has been validated in stable patients, the possibility of a high floor effect could compromise the validity of the test in the hospital setting. The aim of this study was to verify the convergent validity of 6-PBRT in hospitalized patients with acute exacerbation of COPD (AECOPD). Methods: A cross-sectional study was conducted in a tertiary hospital. Patients who were hospitalized due to AECOPD and healthy elderly participants, voluntarily recruited from the community, were considered for inclusion. All participants underwent a 6-PBRT. Isokinetic evaluation to measure the strength and endurance of elbow flexors and extensors, handgrip strength (HGS), spirometry testing, the modified Pulmonary Functional Status Dyspnea Questionnaire (PFSDQ-M), the COPD assessment test (CAT), and symptoms of dyspnea and fatigue were all measured as comparisons for convergent validity. Good convergent validity was considered if >75% of these hypotheses could be confirmed (correlation coefficient>0.50). Results: A total of 17 patients with AECOPD (70.9±5.1 years and forced expiratory volume in 1 second [FEV1] of 41.8%±17.9% of predicted) and 11 healthy elderly subjects were included. The HGS showed a significant strong correlation with 6-PBRT performance (r=0.70; p=0.002). The performance in 6-PBRT presented a significant moderate correlation with elbow flexor torque peak (r=0.52; p=0.03) and elbow extensor torque peak (r=0.61; p=0.01). The total muscular work of the 15 isokinetic contractions of the elbow flexor and extensor muscles showed a significant moderate correlation with the performance in 6-PBRT (r=0.59; p=0.01 and r=0.57; p=0.02, respectively). Concerning the endurance of elbow flexors and extensors, there was a significant moderate correlation with 6-PBRT performance (r=-0.50; p=0.04 and r=-0.51; p=0.03, respectively). In relation to the upper-extremity physical activities of daily living (ADLs) assessed by means of PFSDQ-M, there was a significant moderate correlation of 6-PBRT with three domains: influence of dyspnea on ADLs (r=-0.66; p<0.001), influence of fatigue on ADLs (r=-0.60; p=0.01), and change in ADLs in relation to the period before the disease onset (r=-0.51; p=0.03). The CAT was also correlated with 6-PBRT (r=-0.51; p=0.03). Finally, the performance in 6-PBRT showed a significant moderate correlation with the increase in dyspnea (r=-0.63; p=0.01) and a strong correlation with the increase in fatigue of upper limbs (r=-0.76; p<0.001) in patients with AECOPD. Convergent validity was considered adequate, since 81% from 16 predefined hypotheses were confirmed. There was no correlation between 6-PBRT and patients' height. The performance in 6-PBRT was worse in patients with AECOPD compared to healthy elderly individuals (248.7±63.0 vs 361.6±49.9 number of moved rings; p<0.001). Conclusion: The 6-PBRT is valid for the evaluation of functional capacity of upper limbs in hospitalized patients with AECOPD.

Diaphragmatic Ultrasound Correlates with Inspiratory Muscle Strength and Pulmonary Function in Healthy Subjects.

Diaphragm ultrasound (DUS) has been used to identify diaphragm dysfunction. However, its correlations with respiratory strength and lung function are unclear, even in healthy patients. A total of 64 healthy patients (30 males) had lung function and inspiratory strength (maximal inspiratory pressure and sniff nasal inspiratory pressure) measured. Gastric and oesophageal pressures were measured in a subgroup (n = 40). DUS was characterized by mobility (quiet breathing [QB] and deep breathing [DB]) and thickness (at functional residual capacity [ThFRC] and total lung capacity [ThTLC]). We calculated the thickening fraction (TF). During QB, DUS was similar between sexes. However, during DB, females had lower mobility, thickness and TF than males. Mobility at DB, ThTLC and TF significantly correlated with lung function and inspiratory strength. These correlations were affected by sex. DUS correlated with inspiratory gastric pressure. In healthy patients, DUS correlated with lung function and inspiratory strength during DB. Significant differences between genders were noticeable when DUS was performed during DB.

Accuracy of Invasive and Noninvasive Parameters for Diagnosing Ventilatory Overassistance During Pressure Support Ventilation.

OBJECTIVE: Evaluate the accuracy of criteria for diagnosing pressure overassistance during pressure support ventilation. DESIGN: Prospective clinical study. SETTING: Medical-surgical ICU. PATIENTS: Adults under mechanical ventilation for 48 hours or more using pressure support ventilation and without any sedative for 6 hours or more. Overassistance was defined as the occurrence of work of breathing less than 0.3 J/L or 10% or more of ineffective inspiratory effort. Two alternative overassistance definitions were based on the occurrence of inspiratory esophageal pressure-time product of less than 50 cm H2O s/min or esophageal occlusion pressure of less than 1.5 cm H2O. INTERVENTIONS: The pressure support was set to 20 cm H2O and decreased in 3-cm H2O steps down to 2 cm H2O. MEASUREMENTS AND MAIN RESULTS: The following parameters were evaluated to diagnose overassistance: respiratory rate, tidal volume, minute ventilation, peripheral arterial oxygen saturation, rapid shallow breathing index, heart rate, mean arterial pressure, change in esophageal pressure during inspiration, and esophageal and airway occlusion pressure. In all definitions, the respiratory rate had the greatest accuracy for diagnosing overassistance (receiver operating characteristic area = 0.92; 0.91 and 0.76 for work of breathing, pressure-time product and esophageal occlusion pressure in definition, respectively) and always with a cutoff of 17 incursions per minute. In all definitions, a respiratory rate of less than or equal to 12 confirmed overassistance (100% specificity), whereas a respiratory rate of greater than or equal to 30 excluded overassistance (100% sensitivity). CONCLUSION: A respiratory rate of 17 breaths/min is the parameter with the greatest accuracy for diagnosing overassistance. Respiratory rates of less than or equal to 12 or greater than or equal to 30 are useful clinical references to confirm or exclude pressure support overassistance.