DOCSLIB.ORG

Lung Volume Indices Predict Morbidity in Smokers with Preserved Spirometry

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lung Volume Indices Predict Morbidity in Smokers with Preserved Spirometry Chronic obstructive pulmonary disease ORIGINAL ARTICLE Thorax: first published as 10.1136/thoraxjnl-2018-211881 on 20 July 2018. Downloaded from Lung volume indices predict morbidity in smokers with preserved spirometry Siyang Zeng,1,2 Andrea Tham,1,3 Bruce Bos,1,4 Joan Jin,1,5 Brian Giang,1,2 Mehrdad Arjomandi1,2 ► Additional material is ABSTRact published online only. To view Background Abnormal lung volumes that reflect Key messages please visit the journal online (http:// dx. doi. org/ 10. 1136/ air trapping are common in COPD. However, their thoraxjnl- 2018- 211881). significance in smokers with preserved spirometry What is the key question? ► Could lung volumes predict progression to overt (normal FEV1 to FVC ratio) is unclear. 1Medical Section, San Francisco Methods Using the Veterans Administration Informatics COPD in smokers without airflow obstruction? Veterans Affairs Medical Center, and Computing Infrastructure database, we identified San Francisco, California, USA What is the bottom line? 2 7479 patients at risk for COPD (ever smokers >40 Department of Medicine, ► This retrospective analysis of the US Veterans years of age without restrictive lung disease) who had University of California, San Affairs electronic health records showed Francisco, California, USA preserved spirometry and concomitant lung volume 3 that abnormal lung volumes representing air School of Medicine, University measurements, and examined their subsequent health of Southern California, Los trapping are common in smokers without COPD records for clinical diagnoses of COPD, healthcare Angeles, USA and are associated with higher healthcare 4 utilisation, follow-up spirometry and mortality. School of Medicine, Radboud utilisation, death and decline in lung function. University Medical Center, Results Air trapping was prevalent, with 31% of Nijmegen, Gelderland, The patients having residual volume to total lung capacity Why read on? Netherlands ratio (RV:TLC) greater than the upper limit of normal 5School of Pharmacy, University ► Understanding the predictors of morbidity and of Illinois at Chicago, Chicago, (ULN). RV:TLC varied widely from 14% to 77% (51% disease progression in smokers without COPD Illinois, USA to 204% of predicted) across the normal ranges of is extremely important for prognostication and FEV1:FVC and FEV1. Patients with RV:TLC greater early intervention. Correspondence to than the ULN were more likely to receive subsequent Dr Mehrdad Arjomandi, Division clinical diagnoses of COPD (HR (95% CI)=1.55 (1.42 of Pulmonary, Critical Care, to 1.70), p<0.001) and had higher all-cause mortality to develop overt disease.4–7 Thus, the ability to Allergy and Immunology, and Sleep Medicine, University (HR (95% CI)=1.41 (1.29 to 1.54), p<0.001). They had identify the smokers with preserved spirometry of California, San Francisco higher rates of respiratory medication prescriptions (GOLD-defined or LLN-defined) who are at risk http://thorax.bmj.com/ Veterans Affairs Medical Center, and hospital and intensive care unit admissions. Other for the development of respiratory problems and San Francisco, CA 94121, USA; air trapping and static hyperinflation indices showed disease progression is of great interest for prognos- mehrdad. arjomandi@ ucsf. edu similar associations with health outcomes. Additionally, tication and intervention purposes. high-normal RV:TLC was associated with intermediate Air trapping, defined as abnormal increase in SZ and AT contributed equally. adverse health outcomes compared with low-normal volume of air remaining in the lungs at the end of Received 30 March 2018 and abnormal RV:TLC. Abnormal RV:TLC predicted exhalation, is a manifestation of obstructive lung Revised 19 June 2018 higher likelihood of progression to spirometric COPD (OR diseases including COPD. Air trapping in people Accepted 25 June 2018 (95% CI)=1.30 (1.03 to 1.65), p=0.027). with COPD is associated with increased dyspnoea, on September 23, 2021 by guest. Protected copyright. Conclusion In this study of the Veterans Affairs reduced functional capacity and higher mortality.8 9 electronic health records, air trapping was common in However, its clinical significance in smokers without smokers with preserved spirometry and predicted adverse COPD (normal FEV1:FVC and FEV1) is unknown. respiratory outcomes and progression to overt COPD. In fact, abnormal lung volumes suggestive of air trapping are routinely ignored in the interpretation of lung function when spirometry is preserved. In this study, we hypothesised that in patients at INTRODUCTION risk for COPD due to smoking but with preserved The Global Initiative on Obstructive Lung Disease spirometry, those with air trapping (and static © Article author(s) (or their (GOLD) defines COPD by an absolute reduction hyperinflation) as measured by residual volume employer(s) unless otherwise in FEV1 to FVC ratio of <0.70 after albuterol (RV), functional residual capacity (FRC), inspiratory stated in the text of thearticle) administration (stage 1), with higher stages of capacity (IC) and their ratios to total lung capacity 2018. All rights reserved. No COPD defined by a concomitant reduction in FEV1 (TLC) have increased respiratory morbidity and commercial use is permitted 1 unless otherwiseexpressly as a per cent predicted. Other criteria empha- mortality. To test this, we identified 7479 patients granted. sise a lower-limit-of-predicted normal (LLN) from the Veterans Administration Informatics and approach rather than a standard fixed cut-point in Computing Infrastructure (VINCI) database at risk To cite: Zeng S, Tham A, FEV1:FVC, but nonetheless rely on the same basic for COPD due to smoking who ever had a pulmonary Bos B, et al. Thorax Epub 2 3 ahead of print: [please metrics of spirometry. Many current and former function test (PFT) with concomitant lung volume include Day Month Year]. smokers without GOLD-defined (or LLN-defined) measurements that showed preserved spirometry doi:10.1136/ COPD have similar acute and chronic respiratory (defined by FEV1:FVC and FEV1≥LLN). We then thoraxjnl-2018-211881 symptoms as those with COPD and may proceed reviewed their subsequent electronic health records Zeng S, et al. Thorax 2018;0:1–11. doi:10.1136/thoraxjnl-2018-211881 1 Chronic obstructive pulmonary disease (EHR) and determined whether patients with air trapping were defined by those who were >40 years of age and had diagnosis Thorax: first published as 10.1136/thoraxjnl-2018-211881 on 20 July 2018. Downloaded from more likely to have adverse health outcomes compared with of tobacco use at the time of their full PFT. Smoking status was those without air trapping. assigned by documented diagnosis of ICD-9 or ICD-10 codes or diagnosis of smoking on PFT report. Accordingly, 52 668 METHODS patients who were not considered to be at risk for COPD were Study design excluded. Patients were further excluded if they had evidence of This was a retrospective study of EHR available from the nation- restrictive lung disease on PFT as determined by TLC ≤80% or wide Veterans Health Administration (VHA) VINCI database <LLN, diagnoses of interstitial lung diseases, or allergic lung with patients at risk for COPD (current or former smokers >40 diseases (except for asthma). Patients with a diagnosis of asthma years of age) who ever had a full PFT between 1985 and 2017. who were considered to be at risk for COPD were not excluded Medical records of eligible patients were interrogated to quan- to avoid exclusion of those with overlap disease. A further tify the frequency of acute and chronic respiratory outcomes 35 286 patients were excluded who had abnormal spirometry and mortality subsequent to their very first PFT that included (FEV1:FVC or FEV1<LLN). Overall, data were available from prealbuterol and postalbuterol administration spirometry and 7479 patients at risk for COPD but with preserved spirom- lung volume measurement by plethysmography. The latest etry from 37 Veterans Affairs Medical Centers across the USA postbronchodilator spirometry that was available in their EHR (figure 1). Data from other Veterans Affairs Medical Centers was also examined. Mortality data were extracted from docu- were not used due to lack of availability of coded PFT data that mented death notes, and patients were considered to be alive would be obtainable through VINCI. up to the date of their last medical encounter, after which they were considered as lost to follow-up. The utility of lung volume Statistical analysis indices from the first PFT to predict the subsequent occurrence Data management of the above outcomes was assessed in those with preserved Predicted values and ranges for PFT measurements were calcu- spirometry. lated using Crapo predicted formulas,10–12 except for FRC:TLC, The University of California San Francisco Institutional IC and IC:TLC for which data from Quanjer et al and Francisco Review Board and the Veterans Health Administration Research et al were used.2 13 Patients were categorised to have air trapping and Development Committee approved this study. Detailed if they had abnormal RV:TLC (greater than the upper limit of inclusion and exclusion algorithm and the International Classifi- normal (ULN)). Those with normal RV:TLC were further cate- cation of Diseases (ICD)-9 and ICD-10 diagnosis codes used are gorised into low-normal and high-normal groups relative to the available in the online supplementary appendix. median value of the distribution of normal RV:TLC. Study population Outcomes From 1985 to 2017, 127 940 patients from the VHA were docu- Healthcare outcomes including clinical diagnoses, respiratory mented to have received full PFT including postbronchodilator medication prescribed, outpatient office visits, emergency room spirometry and lung volume measurements by plethysmog- (ER) visits, hospital admissions and intensive care unit (ICU) http://thorax.bmj.com/ raphy. Our study aimed to focus on patients at risk for COPD as admissions with a COPD diagnosis and all-cause mortality on September 23, 2021 by guest. Protected copyright. Figure 1 Subject flow. LLN, lower limit of normal; PFT, pulmonary function test; TLC, total lung capacity.
Load more

Recommended publications
  • Air Trapping on Computed Tomography: Regional Versus Diffuse
    EDITORIAL | SMOKING Air trapping on computed tomography: regional versus diffuse Firdaus A. Mohamed Hoesein and Pim A. de Jong Affiliation: Dept of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands. Correspondence: Firdaus A. Mohamed Hoesein, University Medical Center Utrecht, Department of Radiology, Heidelberglaan 100, PO box 855000, 3508 GA, Utrecht, The Netherlands. E-mail: [email protected] @ERSpublications Future studies on the distribution of air trapping in the lungs of COPD patients are needed http://ow.ly/86hc304JiIK Cite this article as: Mohamed Hoesein FA, de Jong PA. Air trapping on computed tomography: regional versus diffuse. Eur Respir J 2017; 49: 1601791 [https://doi.org/10.1183/13993003.01791-2016]. Chronic obstructive pulmonary disease (COPD) is diagnosed and classified by spirometry, assessing the presence of airflow obstruction and extent of forced expiratory flow deterioration. Spirometry, however, is unsuitable for characterising and quantifying the underlying pulmonary pathology of COPD, including alveolar destruction (emphysema) and airway remodelling (large- and small-airway disease). Accurate diagnosis of the pulmonary pathologies underlying COPD is seen as an important step towards better understanding its biology and “personalised” treatment. Computed tomography (CT) of the lungs provides an excellent opportunity to assess COPD in vivo and quantify its macroscopic pathology [1–3]. Emphysema and airway remodelling can be visually assessed and automatically quantified, and several studies have shown associations with morbidity and mortality [4–7]. In addition, CT can provide information on the spatial distribution of disease. In this issue of the European Respiratory Journal,KARIMI et al. [8] hypothesise that regional air trapping maybe a new imaging marker, in addition to emphysema, large-airway remodelling and diffuse air trapping.
    [Show full text]
  • Imaging of Small Airways Disease
    SYMPOSIA Imaging of Small Airways Disease Gerald F. Abbott, MD,* Melissa L. Rosado-de-Christenson, MD,w zy Santiago E. Rossi, MD,J and Saul Suster, MDz SECONDARY PULMONARY LOBULE Abstract: Small airways disease includes a spectrum of inflammatory The secondary pulmonary lobule (SPL) is a key and fibrotic pulmonary diseases centered on the small conducting structure in the lung anatomy and is distinguished as the airways. High-resolution computed tomography plays a key role in the detection and classification of small airways disease and, when smallest functioning subunit of lung that is bound by combined with relevant clinical and pathologic findings, leads to a connective tissue septa, supplied by a lobular bronchiole more accurate diagnosis. The imaging manifestations of small airways and arteriole, and drained by veins and lymphatics in the disease on high-resolution computed tomography may be direct or interlobular septa. Each SPL measures 1 to 2.5 cm and indirect signs of small airway involvement and include centrilobular contains 3 to 12 acini. The SPL are better formed and more nodules and branching nodular (tree-in-bud) opacities, or the easily recognized in the peripheral subpleural lung and demonstration of mosaic attenuation that is typically exaggerated on are smaller and less regular in the central lung. The SPL are expiratory computed tomography. This article reviews the normal not normally visible on radiography or computed tomo- anatomy and histology of bronchioles and the clinical, pathologic, and graphy (CT)/HRCT (Fig. 1).
    [Show full text]
  • Residual Volume and Total Lung Capacity to Assess Reversibility in Obstructive Lung Disease
    Residual Volume and Total Lung Capacity to Assess Reversibility in Obstructive Lung Disease Conor T McCartney MD, Melissa N Weis MD, Gregg L Ruppel MEd RRT RPFT FAARC, and Ravi P Nayak MD BACKGROUND: Reversibility of obstructive lung disease is traditionally defined by changes in FEV1 or FVC in response to bronchodilators. These may not fully reflect changes due to a reduction in hyperinflation or air-trapping, which have important clinical implications. To date, only a handful of studies have examined bronchodilators’ effect on lung volumes. The authors sought to better characterize the response of residual volume and total lung capacity to bronchodilators. METHODS: Responsiveness of residual volume and total lung capacity to bronchodilators was assessed with a retrospective analysis of pulmonary function tests of 965 subjects with obstructive lung disease as defined by the lower limit of normal based on National Health and Nutritional Examination Survey III prediction equations. RESULTS: A statistically significant number of subjects demonstrated response to bronchodilators in their residual volume independent of re- sponse defined by FEV1 or FVC, the American Thoracic Society and European Respiratory Society criteria. Reduced residual volume weakly correlated with response to FEV1 and to FVC. No statistically significant correlation was found between total lung capacity and either FEV1 or FVC. CONCLUSIONS: A significant number of subjects classified as being nonresponsive based on spirometry have reversible residual volumes. Subjects whose residual volumes improve in response to bronchodilators represent an important subgroup of those with obstructive lung disease. The identification of this subgroup better characterizes the heterogeneity of obstructive lung disease. The clinical importance of these findings is unclear but warrants further study.
    [Show full text]
  • PFT Interpretation
    PFT Interpretation Presented by: Shazhad Manawar, MD Medical Director Respiratory Care & Pulmonary Rehab McLaren Bay Region Introduction History or symptoms suggestive of lung disease. Risk factors for lung disease are present. Pulmonary Function Tests Spirometry Spirometry before and after bronchodilator Lung volumes Diffusing capacity for carbon monoxide Maximal respiratory pressures Flow volume loops Spirometry Volume of air exhaled at specific time points during forceful and complete exhalation. Total exhaled volume, know as the FVC (forced vital capacity). Volume exhaled in the first second, know as the forced expiratory volume in one second (FEV1) Spirometry - continued Ratio (FEV1/FVC) are the most important variables Minimal risk Key diagnostic test Asthma Chronic Obstructive Pulmonary Disease (COPD) Chronic cough Spirometry - continued Monitor a broad spectrum of respiratory diseases. Asthma COPD Interstitial Lung Disease Neuromuscular diseases affecting respiratory muscles Spirometry - continued Slow vital capacity (SVC) Useful measurement when FVC is reduced and airway obstruction is present Post-bronchodilator Determine the degree of reversibility Administration of albuterol Technique is important Increase in the FEV1 of more than 12% or greater than 0.2 L suggests acute bronchodilator responsiveness. Subjective improvements Post-bronchodilator - continued Thus, the lack of an acute bronchodilator response on spirometry should not preclude a one to eight week therapeutic trial of bronchodilators
    [Show full text]
  • Demystifying Fibrotic Hypersensitivity Pneumonitis Diagnosis: It’S All About Shades of Grey
    EDITORIAL | INTERSTITIAL LUNG DISEASE Demystifying fibrotic hypersensitivity pneumonitis diagnosis: it’s all about shades of grey Simon L.F. Walsh1 and Luca Richeldi2 Affiliations: 1National Heart and Lung Institute, Imperial College, London, UK. 2Fondazione Policlinico A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy. Correspondence: Simon L.F. Walsh, National Heart and Lung Institute, Imperial College, London SW3 6LY, UK. E-mail: [email protected] @ERSpublications The headcheese pattern which describes a form of mosaic attenuation which combines areas of ground-glass opacification, lobular areas of low attenuation and normal lung is highly specific for a diagnosis of fibrotic hypersensitivity pneumonitis http://bit.ly/2WO2mn7 Cite this article as: Walsh SLF, Richeldi L. Demystifying fibrotic hypersensitivity pneumonitis diagnosis: it’s all about shades of grey. Eur Respir J 2019; 54: 1900906 [https://doi.org/10.1183/13993003.00906-2019]. The spotlight on diagnosis in hypersensitivity pneumonitis (HP) intensifies. Over the past 18 months we have seen two pulmonary perspectives proposing diagnostic approaches to HP; an international Delphi survey and several imaging studies focused on clinical and imaging features predictive of HP; and clinical practice guideline initiatives for HP, sponsored by the American Thoracic Society and American College of Chest Physicians, are underway [1–5]. Despite this growing literature, HP continues to resist our best attempts to develop an accurate, reproducible case definition for this disorder. Making a diagnosis of HP is challenging because it is often shadowed by marginal exposure histories, borderline antigen positivity or discordant imaging patterns, and treatment decisions are often based on diagnostic probability rather than certainty [4, 5].
    [Show full text]
  • Small Airways Dysfunction in Asthma: Evaluation and Management to Improve Asthma Control Omar S Usmani*
    Review Allergy Asthma Immunol Res. 2014 September;6(5):376-388. http://dx.doi.org/10.4168/aair.2014.6.5.376 pISSN 2092-7355 • eISSN 2092-7363 Small Airways Dysfunction in Asthma: Evaluation and Management to Improve Asthma Control Omar S Usmani* Airway Disease Section, National Heart and Lung Institute, Imperial College London & Royal Brompton Hospital, London, UK This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The small airways have been neglected for many years, but interest in the topic has been rekindled with recent advances in measurement tech- niques to assess this region and also the ability to deliver therapeutics to the distal airways. Current levels of disease control in asthmatic patients remain poor and there are several contributory factors including; poor treatment compliance, heterogeneity of asthma phenotypes and associated comorbidities. However, the proposition that we may not be targeting all the inflammation that is present throughout the whole respiratory tree may also be an important factor. Indeed decades ago, pathologists and physiologists clearly identified the importance of small airways dysfunction in asthmatic patients. With improved inhaler technology to deliver drug to target the whole respiratory tree and more sensitive measures to assess the distal airways, we should certainly give greater consideration to treating the small airway region when seeing our asthmatic patients in clinic. The aim of this review is to address the relevance of small airways dysfunction in the daily clinical management of patients with asthma.
    [Show full text]
  • Differences in Regional Air Trapping in Current Smokers with Normal Spirometry
    ORIGINAL ARTICLE SMOKING Differences in regional air trapping in current smokers with normal spirometry Reza Karimi1,3, Göran Tornling 1, Helena Forsslund1, Mikael Mikko1, Åsa M. Wheelock1, Sven Nyrén2,3 and C. Magnus Sköld1,3 Affiliations: 1Dept of Medicine and Centre for Molecular Medicine (CMM) Respiratory Medicine Unit, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden. 2Dept of Molecular Medicine and Surgery, Division of Radiology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden. 3These authors contributed equally. Correspondence: Reza Karimi, Dept of Medicine Solna, Karolinska Institutet, Lung-Allergy Clinic N2:02, Karolinska University Hospital Solna, SE 171 76 Stockholm, Sweden. E-mail: [email protected] @ERSpublications Smokers with regional air trapping on expiratory CT scan are less obstructive/have less emphysema than those without http://ow.ly/96lV305tgtZ Cite this article as: Karimi R, Tornling G, Forsslund H, et al. Differences in regional air trapping in current smokers with normal spirometry. Eur Respir J 2017; 49: 1600345 [https://doi.org/10.1183/13993003.00345- 2016]. ABSTRACT We investigated regional air trapping on computed tomography in current smokers with normal spirometry. It was hypothesised that presence of regional air trapping may indicate a specific manifestation of smoking-related changes. 40 current smokers, 40 patients with chronic obstructive pulmonary disease (COPD), and 40 healthy never- smokers underwent computed tomography scans. Regional air trapping was assessed on end- expiratory scans and emphysema, micronodules and bronchial wall thickening on inspiratory scans. The ratio of expiratory and inspiratory mean lung attenuation (E/I) was calculated as a measure of static (fixed) air trapping. Regional air trapping was present in 63% of current smokers, in 45% of never smokers and in 8% of COPD patients (p<0.001).
    [Show full text]
  • Obliterative Bronchiolitis
    13 Obliterative Bronchiolitis C. Isabela S. Silva and Nestor L. Müller Summary Obliterative bronchiolitis (OB) is a condition characterized by inflammation and fibrosis of the bronchiolar walls resulting in narrowing or obliteration of the bronchiolar lumen. The most common causes are childhood lower respiratory tract infection, hematopoietic stem cell or lung and heart-lung transplantation, and toxic fume inhalation. The most frequent clinical manifestations are progressive dyspnea and dry cough. Pulmonary function tests demonstrate airflow obstruction and air trapping. Radiographic manifestations include reduction of the peripheral vascular markings, increased lung lucency, and overinflation. The chest radiograph, however, is often normal. High-resolution CT is currently the imaging modality of choice in the assessment of patients with suspected or proven OB. The characteristic findings on high-resolution CT consist of areas of decreased attenuation and vascularity (mosaic perfusion pattern) on inspiratory scans and air trapping on expiratory scans. Other CT findings of OB include bronchiectasis and bronchiolectasis, bronchial wall thickening, small centrilobular nodules, and three-in-bud opacities. Recent studies suggest that hyperpolarized 3He-enhanced magnetic resonance imaging may allow earlier recognition of obstructive airway disease and therefore may be useful in the diagnosis and follow-up of patients with OB. Key Words: Bronchiolitis; bronchiolitis obliterans; bronchiolitis obliterans syndrome; constrictive bronchiolitis; computed tomography; obliterative bronchiolitis; small airways disease. 1. INTRODUCTION Bronchiolitis is a generic term applied to various inflammatory and fibrosing diseases that affect the small airways, which by definition are airways that measure less than 2 mm in diameter (i.e., primarily membranous and respiratory bronchioles) (1,2). Bronchiolitis is common and occurs in various clinical settings (1–5).
    [Show full text]
  • Pulmonary Function Tests – a Refresher
    PULMONARY FUNCTION TESTS – A REFRESHER Khizer Hayat Khan M Rahim Khan York Teaching Hospital INTRODUCTION • Pulmonary function tests (PFTs) are non-invasive tests that show how well the lungs are working. • The tests measure lung volume, capacity, rates of flow, and gas exchange PURPOSE OF PFTs • Diagnosis of symptomatic disease • Screening of early asymptomatic disease • Monitoring response to treatment • Prognostication of known disease TYPES OF PFTs Spirometry STANDARD PFTs Lung volumes Gas transfer Exercise oximetry SPECIALIZED PFTs 6 minute walk test Peak flow CATEGORIES OF LUNG DISEASES • PFTs help classify disease in following categories: • OBSTRUCITVE | This is when air has trouble flowing out of the lungs due to airway resistance. This causes a decreased flow of air • RESTRICTIVE | This is when the lung tissue and/or chest muscles can’t expand enough • PULMONARY VASCULAR DISEASES | SPIROMETRY VALIDITY OF PFTs • Evaluate acceptability & reproducibility • Acceptability • Good effort – a rapid increase in airflow at the start of exhalation • Complete maneuver – at least 6s of exhalation ending up in plateau in flow • Reproducibility • All 3 FEV1 within 200ml of each other • All 3 FVC within 200ml of each other LUNG VOLUMES LUNG VOLUMES VOLUME AGAINST TIME FLOW VOLUME LOOP SPIROMETRY PATTERNS • Normal • Obstructive • Restrictive • Mixed • Fixed upper airway obstruction • Variable intra thoracic upper airway obstruction • Variable extra thoracic upper airway obstruction OBSTRUCTIVE SPIROMETRY • FEV1:FVC ratio <70% • FEV1 falls disproportionately
    [Show full text]
  • Recognizing Interstitial Lung Disease
    Recognizing Interstitial Lung DIsease Douglas Arenberg, M.D. University of Michigan Health System Division of Pulmonary/Critical Care Medicine No relevant disclosures Session Objectives By the end of this session, participants will be able to… • Recognize clinical scenarios where interstitial lung disease is to be suspected and the key clinical/radiographic findings in patients with the most common form(s) of interstitial lung disease • Understand the general diagnostic pathway patients with suspected interstitial lung disease • Discuss the potential benefits and adverse reactions of approved therapies for IPF • Outline – When to suspect interstitial lung disease – Tools for diagnosis (History, Spirometry, HRCT, Biopsy) IPF Prevalence among those with dyspnea COPD: chronic obstructive pulmonary disease; IPF: idiopathic pulmonary fibrosis. 1. Raghu G et al. Resp Crit Care Med. 2006;174:810-816. 2. Go AS et al. Circulation. 2013;127:e6-e245. 3. Wheaton AG et al. MMWR Morb Mortal Wkly Rep. 2015;64:289-295. Interstitial Lung Diseases - Difficulties • Diverse group of disorders (130+) • Similar symptoms, physiology, radiology • Difficult nomenclature • Limited, often toxic, treatments Diffuse Parenchymal Lung Disease (DPLD) DPLD of known cause, eg, Idiopathic Granulomatous Other forms of drugs or association, eg, Interstitial DPLD, eg, DPLD, eg, LAM, HX, collagen vascular disease Pneumonias sarcoidosis etc Major Rare Unclassifiable Idiopathic Pulmonary Fibrosis Lymphoid Interstitial Pneumonia Nonspecific interstitial pneumonia (idiopathic)
    [Show full text]
  • Interpretation of Pulmonary Function Tests (Pfts)
    INTERPRETATION OF PULMONARY FUNCTION TESTS (PFTS) Anna Neumeier, MD Assistant Professor, Department of Pulmonary Sciences and Critical Care Medicine ACP February 2020 LEARNING OBJECTIVES 1. Describe the clinical indications for pulmonary function testing 2. Understand the physiology of the core pulmonary function tests: spirometry, lung volumes and DLCO 3. Apply an organized approach to interpreting pulmonary function tests 4. Identify obstructive, restrictive, mixed obstructive-restrictive and pulmonary vascular patterns of abnormalities on pulmonary function testing. INDICATIONS FOR PFTS • Evaluation of patients presenting with dyspnea • Evaluating disease severity and monitoring response to treatment • Determine fitness for surgery • *thoracic surgery/lung resection PFTS: AVAILABLE MEASURES • Spirometry • Airflow (how much air, how fast) • (Static) Lung volumes • Volume (how much air) • Diffusing Capacity/DLCO • Gas exchange (how effective) • Other testing: • Airway responsiveness • Respiratory muscle strength testing • Compliance of the lungs A PHYSIOLOGY REFRESHER: LUNG VOLUMES AND CAPACITIES Al-Askhar. Cleveland Clinic Journal of Medicine. 2003 Al-Askhar. Cleveland Clinic Journal of Medicine. 2003 AN APPROACH TO PFT INTERPRETATION STEP 1: CONFIRM PATIENT DEMOGRAPHIC DATA DEFINING NORMAL AND ABNORMAL VALUES • Interpretation involves comparison of the patient’s values with reference values (Crapo Hsu, NHANES III, GLI) • Dependent on age, sex, race and ethnicity, height • African Americans have values that are 12% lower than Caucasians
    [Show full text]
  • What Is the Clinical Value of Lung Volumes?
    What Is the Clinical Value of Lung Volumes? Gregg L Ruppel MEd RRT RPFT FAARC Introduction Is a Low TLC (ie, Restriction) a Useful Measurement? Do Lung Volumes Tell Us Anything Meaningful About Obstruction? Does It Make Any Difference How You Measure Lung Volumes? Summary Lung volumes are considered part of a complete pulmonary function test, but their value for enhancing clinical decision making is unknown. Unlike spirometry and diffusing capacity of the lung for carbon monoxide (DLCO), which do contribute to confirming or excluding a diagnosis, there are few clear indications when lung volumes are discriminatory. Confirming “restriction” when vital capacity (VC) or FVC is reduced is perhaps the most important. A restrictive pattern can have many etiologies, and clinicians often use VC or FVC as a primary index of lung volume. This makes “physiologic” sense because, in healthy subjects, and in patients with true restriction, VC comprises most of the total lung capacity (TLC). Mixed obstruction-restriction and the nonspecific pattern (ie, reduced FVC and FEV1, normal FEV1/FVC and TLC) require measuring TLC to confirm the underlying physiology. In obesity, VC and TLC may remain within normal limits, but functional residual capacity (FRC) can exponentially decrease. Increased lung volumes, particularly residual volume (RV), are commonly observed in airway obstruction. TLC may be normal, but is frequently increased in the late stages of COPD. Hyperinflation and air-trapping are terms commonly used to reflect these changes, but are not well standardized. The variability of lung volumes related to degree of obstruction suggests that measuring gas-trapping may be needed to monitor therapy.
    [Show full text]