European Respiratory Society/American Thoracic Society technical statement: standardisation of the measurement of lung volumes, 2023 update.

This document updates the 2005 European Respiratory Society (ERS) and American Thoracic Society (ATS) technical standard for the measurement of lung volumes. The 2005 document integrated the recommendations of an ATS/ERS task force with those from an earlier National Heart, Lung, and Blood Institute workshop that led to the publication of background papers between 1995 and 1999 and a consensus workshop report with more in-depth descriptions and discussion. Advancements in hardware and software, new research and emerging approaches have necessitated an update to the 2005 technical standard to guide laboratory directors, physiologists, operators, pulmonologists and manufacturers. Key updates include standardisation of linked spirometry, new equipment quality control and validation recommendations, generalisation of the multiple breath washout concept beyond nitrogen, a new acceptability and grading system with addition of example tracings, and a brief review of imaging and other new techniques to measure lung volumes. Future directions and key research questions are also noted.

Collaboration between explainable artificial intelligence and pulmonologists improves the accuracy of pulmonary function test interpretation.

BACKGROUND: Few studies have investigated the collaborative potential between artificial intelligence (AI) and pulmonologists for diagnosing pulmonary disease. We hypothesised that the collaboration between a pulmonologist and AI with explanations (explainable AI (XAI)) is superior in diagnostic interpretation of pulmonary function tests (PFTs) than the pulmonologist without support. METHODS: The study was conducted in two phases, a monocentre study (phase 1) and a multicentre intervention study (phase 2). Each phase utilised two different sets of 24 PFT reports of patients with a clinically validated gold standard diagnosis. Each PFT was interpreted without (control) and with XAI's suggestions (intervention). Pulmonologists provided a differential diagnosis consisting of a preferential diagnosis and optionally up to three additional diagnoses. The primary end-point compared accuracy of preferential and additional diagnoses between control and intervention. Secondary end-points were the number of diagnoses in differential diagnosis, diagnostic confidence and inter-rater agreement. We also analysed how XAI influenced pulmonologists' decisions. RESULTS: In phase 1 (n=16 pulmonologists), mean preferential and differential diagnostic accuracy significantly increased by 10.4% and 9.4%, respectively, between control and intervention (p<0.001). Improvements were somewhat lower but highly significant (p<0.0001) in phase 2 (5.4% and 8.7%, respectively; n=62 pulmonologists). In both phases, the number of diagnoses in the differential diagnosis did not reduce, but diagnostic confidence and inter-rater agreement significantly increased during intervention. Pulmonologists updated their decisions with XAI's feedback and consistently improved their baseline performance if AI provided correct predictions. CONCLUSION: A collaboration between a pulmonologist and XAI is better at interpreting PFTs than individual pulmonologists reading without XAI support or XAI alone.

Does arterial oxygenation during exercise add prognostic value in pulmonary arterial hypertension?

BACKGROUND: The 6-min walking distance (6MWD) is often used to assess prognosis in pulmonary arterial hypertension (PAH) patients. Whether or not changes in arterial oxygen saturation (SpO2) during exercise add prognostic value to the 6MWD in these patients is unclear. The objective of this study was to investigate if SpO2 changes during exercise adds prognostic value to the 6MWD in PAH patients. METHODS: Ambispective study that includes 137 patients with PAH: 38 idiopathic/heritable (i/h PAH), 42 with connective tissue disease (CTD-PAH), 34 with porto-pulmonary hypertension (PoPH), 21 with HIV-associated PAH and 2 with pulmonary venous occlusive disease (PVOD). Patients were characterized and, treated according to international recommendations, and were followed-up for 5 years. To integrate SpO2 changes during exercise, we calculated the desaturation distance ratio (DDR) either in its original form (from a maximal theoretical value of 100%) or the actual resting SpO2 value of the patient (new DDR) as well as the distance saturation product (DSP). RESULTS: (1) during follow-up, 40 patients died (29.2%); (2) results confirmed the prognostic value of the 6MWD (AUC 0.913 [IQR 0.868-0.958]; p < 0.0001), original DDR (AUC 0.923 [0.881-0.966]; p < 0.001), New DDR (AUC 0.917 [0.872-0.961], p < 0.001), and DSP (AUC 0.914 [0.869-0.959], p < 0.001); and, (3) neither the original or new DDR or DSP added significant prognostic value to 6MWD in these patients. CONCLUSIONS: Consideration of three different composite indices of arterial oxygenation changes during exercise does not add prognostic value to that of the 6MWD in patients with PAH.

Sex as a main determinant of bi-atrial acute and chronic adaptation to exercise.

PURPOSE: Athlete's heart encompasses multiple physiological cardiac adaptations, although less is known at atrial level. How sex may influence the type and extent of atrial adaptations to exercise stimuli is also unknown. Our objective was to compare gender differences of echocardiographic atrial function indices in response to exercise in endurance athletes (EAs). METHODS: Highly trained (> 10 h/week) endurance athletes performed a maximal cardiopulmonary exercise test (CPET). Echocardiographic evaluation was performed at rest and immediately after exercise. Atria analysis consisted of standard and speckle-tracking echocardiographic assessment of atrial dimensions and contractile, reservoir, and conduit functions with myocardial deformation. RESULTS: 80 EAs (55% women) were enrolled and performed excellent CPET (129.6% of predicted VO2 maximal consumption). At rest, left atrial (LA) volumes and strain were similar between men and women. Women had lower right atrial (RA) volumes (26.7 vs 32.9 ml/m2, p < 0.001) and higher reservoir and conduit strain absolute values. After exercise, women exhibited a larger improvement in reservoir and conduit LA strain, and the same trend was observed for the RA. In EAs with LA dilatation on baseline (~ 50%), women persistently showed higher increase in reservoir and conduit strain profile with exercise compared to men. CONCLUSION: In highly trained EAs, women have similar or even lower atrial dimensions remodelling compared to men, but better function based on reservoir and conduit strain values both at rest and in response to exercise. This phenomenon should be confirmed in larger studies and its potential role in the development of supraventricular arrhythmias, addressed in a specifically designed protocol.

International consensus on lung function testing during the COVID-19 pandemic and beyond.

Coronavirus disease 2019 (COVID-19) has negatively affected the delivery of respiratory diagnostic services across the world due to the potential risk of disease transmission during lung function testing. Community prevalence, reoccurrence of COVID-19 surges and the emergence of different variants of SARS-CoV-2 have impeded attempts to restore services. Finding consensus on how to deliver safe lung function services for both patients attending and for staff performing the tests are of paramount importance. This international statement presents the consensus opinion of 23 experts in the field of lung function and respiratory physiology balanced with evidence from the reviewed literature. It describes a robust roadmap for restoration and continuity of lung function testing services during the COVID-19 pandemic and beyond. Important strategies presented in this consensus statement relate to the patient journey when attending for lung function tests. We discuss appointment preparation, operational and environmental issues, testing room requirements including mitigation strategies for transmission risk, requirement for improved ventilation, maintaining physical distance and use of personal protection equipment. We also provide consensus opinion on precautions relating to specific tests, filters, management of special patient groups and alternative options to testing in hospitals. The pandemic has highlighted how vulnerable lung function services are and forces us to re-think how long-term mitigation strategies can protect our services during this and any possible future pandemic. This statement aspires to address the safety concerns that exist and provide strategies to make lung function tests and the testing environment safer when tests are required.

A New and More Sensitive Method to Integrate the Desaturation Distance Ratio During a 6-Minute Walking Test in Chronic Respiratory Diseases: Physiological Correlates / Un método nuevo y más sensible para integrar la relación entre distancia y desaturación durante la prueba de la marcha de seis minutos en las enfermedades respiratorias crónicas: correlaciones fisiológicas

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Exercise Capacity in Young Adults Born Small for Gestational Age.

Importance: Being born small for gestational age (SGA), approximately 10% of all births, is associated with increased risk of cardiovascular mortality in adulthood, but mechanistic pathways are unclear. Cardiac remodeling and dysfunction occur in fetuses SGA and children born SGA, but it is uncertain whether and how these changes persist into adulthood. Objective: To evaluate baseline cardiac function and structure and exercise capacity in young adults born SGA. Design, Setting, and Participants: This cohort study conducted from January 2015 to January 2018 assessed a perinatal cohort born at a tertiary university hospital in Spain between 1975 and 1995. Participants included 158 randomly selected young adults aged 20 to 40 years born SGA (birth weight below the 10th centile) or with intrauterine growth within standard reference ranges (controls). Participants provided their medical history, filled out questionnaires regarding smoking and physical activity habits, and underwent incremental cardiopulmonary exercise stress testing, cardiac magnetic resonance imaging, and a physical examination, with blood pressure, glucose level, and lipid profile data collected. Exposure: Being born SGA. Main Outcomes and Measures: Cardiac structure and function assessed by cardiac magnetic resonance imaging, including biventricular end-diastolic shape analysis. Exercise capacity assessed by incremental exercise stress testing. Results: This cohort study included 81 adults born SGA (median age at study, 34.4 years [IQR, 30.8-36.7 years]; 43 women [53%]) and 77 control participants (median age at study, 33.7 years [interquartile range (IQR), 31.0-37.1 years]; 33 women [43%]). All participants were of White race/ethnicity and underwent imaging, whereas 127 participants (80% of the cohort; 66 control participants and 61 adults born SGA) completed the exercise test. Cardiac shape analysis showed minor changes at rest in right ventricular geometry (DeLong test z, 2.2098; P = .02) with preserved cardiac function in individuals born SGA. However, compared with controls, adults born SGA had lower exercise capacity, with decreased maximal workload (mean [SD], 180 [62] W vs 214 [60] W; P = .006) and oxygen consumption (median, 26.0 mL/min/kg [IQR, 21.5-33.5 mL/min/kg vs 29.5 mL/min/kg [IQR, 24.0-36.0 mL/min/kg]; P = .02). Exercise capacity was significantly correlated with left ventricular mass (ρ = 0.7934; P < .001). Conclusions and Relevance: This cohort of young adults born SGA had markedly reduced exercise capacity. These results support further research to clarify the causes of impaired exercise capacity and the potential association with increased cardiovascular mortality among adults born SGA.

Prediction Equations for Maximal Aerobic Capacity on Cycle Ergometer for the Spanish Adult Population / Ecuaciones de referencia de la capacidad aeróbica máxima ciclo-ergoespirometría para la población española adulta

Background: Frequently used reference values for clinical exercise testing have been derived from non-random samples and some with poorly defined maximal criteria.Our objective was to obtain population based reference values for peak oxygen uptake (V?O2) and work rate (WR) for cardiopulmonary exercise testing in a representative sample of Caucasian Spanish men and women. Methods: 182 men and women, 20–85 years old, were included and exercised on cycle-ergometer to exhaustion. (V?O2) and WR were measured. The equations obtained from this sample were validated in an independent cohort of 69 individuals, randomly sampled form the same population. Then a final equation merging the two cohorts (=251) was produced. Results: Height, sex and age resulted predictive of both V?O2 peak and WR. Weight and physical activity added very little to the accuracy to the equations. The formulas V?O2peak=0.017·height?(cm)-0.023·age?(years)+0.864·sex?(female=0/male=1)±179?l?min-1, and peak WR=1.345 · height (cm) - 2.074 · age (years)+76.54 · sex (female=0/male=1)±21.2W were the best compromise between accuracy and parsimony. Conclusions: This study provides new and accurate V?O2 peak and WR rate reference values for individuals of European Spanish descent. (AU)

Antecedentes: Los valores de referencia utilizados con frecuencia para las pruebas de esfuerzo clínicas derivan de muestras no aleatorias y los criterios máximos para algunos de ellos están mal definidos. Nuestro objetivo fue obtener valores de referencia basados en la población general para el consumo máximo de oxígeno (VO2) y la carga de trabajo (CT) para las pruebas de ejercicio cardiopulmonar a partir de una muestra representativa de varones y mujeres caucásicos españoles. Métodos: Se incluyeron 182 varones y mujeres, de entre 20 y 85 años, que realizaron ejercicio en el cicloergómetro hasta el agotamiento. Se midieron el VO2 y la CT. Las ecuaciones obtenidas de esta muestra se validaron en una cohorte independiente de 69 individuos, seleccionados aleatoriamente de la misma población. A continuación, se creó una ecuación final que fusionó las dos cohortes (n=251). Resultados: La altura, el sexo y la edad resultaron predictivos tanto del V?O2 máximo como de la CT. El peso y la actividad física contribuyeron muy poco a la precisión de las ecuaciones. Las fórmulas V?O2 máximo=0,017×altura (cm)-0,023×edad (años)+0,864×sexo (mujer=0/varón=1)±179 L×min-1; y CT máxima=1,345×altura (cm)-2,074×edad (años)+76,54×sexo (mujer=0/varón=1)±21,2W fueron el mejor equilibrio entre precisión y parsimonia. Conclusiones: Este estudio proporciona valores de referencia del V?O2 máximo y la CT nuevos y precisos para personas de ascendencia española europea. (AU)

Validation of a Novel Compact System for the Measurement of Lung Volumes.

BACKGROUND: Current techniques for measuring absolute lung volumes rely on bulky and expensive equipment and are complicated to use for the operator and the patient. A novel method for measurement of absolute lung volumes, the MiniBox method, is presented. RESEARCH QUESTION: Across a population of patients and healthy participants, do values for total lung capacity (TLC) determined by the novel compact device (MiniBox, PulmOne Advanced Medical Devices, Ltd.) compare favorably with measurements determined by traditional whole body plethysmography? STUDY DESIGN AND METHODS: A total of 266 participants (130 men) and respiratory patients were recruited from five global centers (three in Europe and two in the United States). The study population comprised individuals with obstructive (n = 197) and restrictive (n = 33) disorders as well as healthy participants (n = 36). TLC measured by conventional plethysmography (TLCPleth) was compared with TLC measured by the MiniBox (TLCMB). RESULTS: TLC values ranged between 2.7 and 10.9 L. The normalized root mean square difference (NSD) between TLCPleth and TLCMB was 7.0% in healthy participants. In obstructed patients, the NSD was 7.9% in mild obstruction and 9.1% in severe obstruction. In restricted patients, the NSD was 7.8% in mild restriction and 13.9% in moderate and severe restriction. No significant differences were found between TLC values obtained by the two measurement techniques. Also no significant differences were found in results obtained among the five centers. INTERPRETATION: TLC as measured by the novel MiniBox system is not significantly different from TLC measured by conventional whole body plethysmography, thus validating the MiniBox method as a reliable method to measure absolute lung volumes.

Electronic Health Records and Pulmonary Function Data: Developing an Interoperability Roadmap. An Official American Thoracic Society Workshop Report.

A workshop "Electronic Health Records and Pulmonary Function Data: Developing an Interoperability Roadmap" was held at the American Thoracic Society 2019 International Conference. "Interoperability" is defined as is the ability of different information-technology systems and software applications to directly communicate, exchange data, and use the information that has been exchanged. At present, pulmonary function test (PFT) equipment is not required to be interoperable with other clinical data systems, including electronic health records (EHRs). For this workshop, we assembled a diverse group of experts and stakeholders, including representatives from patient-advocacy groups, adult and pediatric general and pulmonary medicine, informatics, government and healthcare organizations, pulmonary function laboratories, and EHR and PFT equipment and software companies. The participants were tasked with two overarching Aobjectives: 1) identifying the key obstacles to achieving interoperability of PFT systems and the EHR and 2) recommending solutions to the identified obstacles. Successful interoperability of PFT data with the EHR impacts the full scope of individual patient health and clinical care, population health, and research. The existing EHR-PFT device platforms lack sufficient data standardization to promote interoperability. Cost is a major obstacle to PFT-EHR interoperability, and incentives are insufficient to justify the needed investment. The current vendor-EHR system lacks sufficient flexibility, thereby impeding interoperability. To advance the goal of achieving interoperability, next steps include identifying and standardizing priority PFT data elements. To increase the motivation of stakeholders to invest in this effort, it is necessary to demonstrate the benefits of PFT interoperability across patient care and population health.

Prediction Equations for Maximal Aerobic Capacity on Cycle Ergometer for the Spanish Adult Population.

BACKGROUND: Frequently used reference values for clinical exercise testing have been derived from non-random samples and some with poorly defined maximal criteria. Our objective was to obtain population based reference values for peak oxygen uptake (V?O2) and work rate (WR) for cardiopulmonary exercise testing in a representative sample of Caucasian Spanish men and women. METHODS: 182 men and women, 20-85 years old, were included and exercised on cycle-ergometer to exhaustion. (V?O2) and WR were measured. The equations obtained from this sample were validated in an independent cohort of 69 individuals, randomly sampled form the same population. Then a final equation merging the two cohorts (=251) was produced. RESULTS: Height, sex and age resulted predictive of both V?O2 peak and WR. Weight and physical activity added very little to the accuracy to the equations. The formulas V?O2peak=0.017·height?(cm)-0.023·age?(years)+0.864·sex?(female=0/male=1)±179?l?min-1, and peak WR=1.345 · height (cm) - 2.074 · age (years)+76.54 · sex (female=0/male=1)±21.2W were the best compromise between accuracy and parsimony. CONCLUSIONS: This study provides new and accurate V?O2 peak and WR rate reference values for individuals of European Spanish descent.

Prediction Equations for Maximal Aerobic Capacity on Cycle Ergometer for the Spanish Adult Population.

BACKGROUND: Frequently used reference values for clinical exercise testing have been derived from non-random samples and some with poorly defined maximal criteria. Our objective was to obtain population based reference values for peak oxygen uptake (V˙O2) and work rate (WR) for cardiopulmonary exercise testing in a representative sample of Caucasian Spanish men and women. METHODS: 182 men and women, 20-85 years old, were included and exercised on cycle-ergometer to exhaustion. (V˙O2) and WR were measured. The equations obtained from this sample were validated in an independent cohort of 69 individuals, randomly sampled form the same population. Then a final equation merging the two cohorts (=251) was produced. RESULTS: Height, sex and age resulted predictive of both V˙O2 peak and WR. Weight and physical activity added very little to the accuracy to the equations. The formulas V˙O2peak=0.017⋅height(cm)-0.023⋅age(years)+0.864⋅sex(female=0/male=1)±179lmin-1, and peak WR=1.345 · height (cm) - 2.074 · age (years)+76.54 · sex (female=0/male=1)±21.2W were the best compromise between accuracy and parsimony. CONCLUSIONS: This study provides new and accurate V˙O2 peak and WR rate reference values for individuals of European Spanish descent.

La función pulmonar no está pasada de moda / Lung Function is Not Outdated

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Pulmonary transit of contrast during exercise is related to improved cardio-pulmonary performance in highly trained endurance athletes.

BACKGROUND: The mechanisms underlying the high interindividual variability demonstrated for right-ventricular (RV) adaptation to exercise have not yet been identified, but different pulmonary vascular adaptations among individuals could be involved. Pulmonary transit of agitated saline (PTAS) during exercise has been demonstrated to be a good estimator of vascular reserve. AIM: The aim of this study was to evaluate the presence of PTAS among endurance athletes (EAs) of both sexes and its influence on RV adaptation to exercise. METHODS: A total of 100 highly trained EAs performed a maximal cardiopulmonary exercise test. Bi-ventricular functional and structural characteristics as well as PTAS were evaluated at baseline and at peak exercise. Athletes were distributed between two groups based on the amount of PTAS during exercise as high (HTPAS; >12 bubbles) and low (LPTAS; ≤12 bubbles). RESULTS: Overall, 11 EAs exhibited an intra-cardiac shunt at rest and 1 met the criteria for chronic pulmonary disease and were excluded from the study. Among the remaining 88 EAs (51% women), 47 (53%) athletes were classified as HPTAS and 41 (47%) as LPTAS. HPTAS capability was associated with significantly larger RV contractile reserve, larger pulmonary vascular reserve and an enhanced maximal exercise capacity. On multivariate analysis, females were the only independent correlate of the HPTAS capability. CONCLUSION: In highly trained endurance athletes, a HPTAS capability during exercise corresponded to an increase in pulmonary vascular and RV contractile reserves as well as an enhanced maximal exercise capacity. The long-term clinical or performance implications of the absence or presence of pulmonary shunting, and the subsequent RV afterload increase while performing exercise, remains to be determined.

Evaluation of integrated care services in Catalonia: population-based and service-based real-life deployment protocols.

BACKGROUND: Comprehensive assessment of integrated care deployment constitutes a major challenge to ensure quality, sustainability and transferability of both healthcare policies and services in the transition toward a coordinated service delivery scenario. To this end, the manuscript articulates four different protocols aiming at assessing large-scale implementation of integrated care, which are being developed within the umbrella of the regional project Nextcare (2016-2019), undertaken to foster innovation in technologically-supported services for chronic multimorbid patients in Catalonia (ES) (7.5 M inhabitants). Whereas one of the assessment protocols is designed to evaluate population-based deployment of care coordination at regional level during the period 2011-2017, the other three are service-based protocols addressing: i) Home hospitalization; ii) Prehabilitation for major surgery; and, iii) Community-based interventions for frail elderly chronic patients. All three services have demonstrated efficacy and potential for health value generation. They reflect different implementation maturity levels. While full coverage of the entire urban health district of Barcelona-Esquerra (520 k inhabitants) is the main aim of home hospitalization, demonstration of sustainability at Hospital Clinic of Barcelona constitutes the core goal of the prehabilitation service. Likewise, full coverage of integrated care services addressed to frail chronic patients is aimed at the city of Badalona (216 k inhabitants). METHODS: The population-based analysis, as well as the three service-based protocols, follow observational and experimental study designs using a non-randomized intervention group (integrated care) compared with a control group (usual care) with a propensity score matching method. Evaluation of cost-effectiveness of the interventions using a Quadruple aim approach is a central outcome in all protocols. Moreover, multi-criteria decision analysis is explored as an innovative method for health delivery assessment. The following additional dimensions will also be addressed: i) Determinants of sustainability and scalability of the services; ii) Assessment of the technological support; iii) Enhanced health risk assessment; and, iv) Factors modulating service transferability. DISCUSSION: The current study offers a unique opportunity to undertake a comprehensive assessment of integrated care fostering deployment of services at regional level. The study outcomes will contribute refining service workflows, improving health risk assessment and generating recommendations for service selection. TRIALS REGISTRATION: NCT03130283 (date released 04/06/2018), NCT03768050 (date released 12/05/2018), NCT03767387 (date released 12/05/2018).

Training-induced changes on quadriceps muscle oxygenation measured by near-infrared spectroscopy in healthy subjects and in chronic obstructive pulmonary disease patients.

AIM: We hypothesize that training-induced changes in muscle oxygen saturation (StO2 ) assessed by near-infrared spectroscopy (NIRS) during constant work rate cycling exercise (CWRE) may be a useful marker of the effects of training at 'vastus medialis' of the quadriceps in patients with chronic obstructive pulmonary disease (COPD). METHODS: Incremental exercise [peak oxygen uptake (VO2 )] and CWRE at 70% pretraining peak VO2 , before and after 8-w training, were done in 10 healthy age-matched subjects (H) [80% men, 65(11) years, FEV1 105(14)%] and 16 COPD patients [94% men, 70(5) years, FEV1 46(11) %] encompassing the entire spectrum of disease severity, recruited in the outpatient clinics. NIRS was used to assess StO2 in the 'vastus medialis' of the left quadriceps. RESULTS: Pretraining CWRE decreased StO2 (P<0·05) and generated marked StO2 rebound (P<0·001) after unloading in the two groups. After training, VO2 peak increased in H [253(204) ml min-1 ] (P<0·01) and in COPD [180(183) ml·min-1 ] (P = 0·01) and blood lactate fell [-4·4 (2·7) and -1·6(2·3) mmol·m-1 ] (P<0·05 each). Training generated a further fall in StO2 during CWRE [-10(12)% and -10(10)%, P<0·05] and increased StO2 rebound after unloading [8(7)% and 5(9)%, P<0·05] in both groups. CONCLUSION: Endurance training further decreased StO2 during CWRE, similarly in both groups, likely due to training-induced enhancement of muscle O2 transfer and utilization. Training-induced StO2 fall during CWRE may be useful individual marker for non-invasive assessment of enhanced muscle aerobic post-training function.