Global strategy for asthma management and prevention

This document is an international evidence-based guideline on the diagnosis and management of idiopathic pulmonary fibrosis, and is a collaborative effort of the American Thoracic Society, the European Respiratory Society, the Japanese Respiratory Society, and the Latin American Thoracic Association. It represents the current state of knowledge regarding idiopathic pulmonary fibrosis (IPF), and contains sections on definition and epidemiology, risk factors, diagnosis, natural history, staging and prognosis, treatment, and monitoring disease course. For the diagnosis and treatment sections, pragmatic GRADE evidence-based methodology was applied in a question-based format. For each diagnosis and treatment question, the committee graded the quality of the evidence available (high, moderate, low, or very low), and made a recommendation (yes or no, strong or weak). Recommendations were based on majority vote. It is emphasized that clinicians must spend adequate time with patients to discuss patients' values and preferences and decide on the appropriate course of action.

An Official ATS/ERS/JRS/ALAT Statement: Idiopathic Pulmonary Fibrosis: Evidence-Based Guidelines for Diagnosis and Management

SERIES “ATS/ERS TASK FORCE: STANDARDISATION OF LUNG FUNCTION TESTING” 

Edited by V. Brusasco, R. Crapo and G. Viegi 

Number 5 in this Series 







This section is written to provide guidance in interpreting pulmonary function tests (PFTs) to medical directors of hospital-based laboratories that perform PFTs, and physicians who are responsible for interpreting the results of PFTs most commonly ordered for clinical purposes. Specifically, this section addresses the interpretation of spirometry, bronchodilator response, carbon monoxide diffusing capacity ( D L,CO) and lung volumes.

The sources of variation in lung function testing and technical aspects of spirometry, lung volume measurements and D L,CO measurement have been considered in other documents published in this series of Task Force reports 1–4 and in the American Thoracic Society (ATS) interpretative strategies document 5.

An interpretation begins with a review and comment on test quality. Tests that are less than optimal may still contain useful information, but interpreters should identify the problems and the direction and magnitude of the potential errors. Omitting the quality review and relying only on numerical results for clinical decision making is a common mistake, which is more easily made by those who are dependent upon computer interpretations.

Once quality has been assured, the next steps involve a series of comparisons 6 that include comparisons of test results with reference values based on healthy subjects 5, comparisons with known disease or abnormal physiological patterns ( i.e. obstruction and restriction), and comparisons with self, a rather formal term for evaluating change in an individual patient. A final step in the lung function report is to answer the clinical question that prompted the test.

Poor choices made during these preparatory steps increase the risk of misclassification, i.e. a falsely negative or falsely positive interpretation for a lung function abnormality or a change …

https://erj.ersjournals.com/content/erj/26/5/948.full.pdf

Interpretative strategies for lung function tests

Lung volumes are subdivided into static and dynamic lung volumes. Static lung volumes are measured by methods which are based on the completeness of respiratory manoeuvres, so that the velocity of the manoeuvres should be adjusted accordingly. The measurements taken during fast breathing movements are described as dynamic lung volumes and as forced inspiratory and expiratory flows.

### 1.1 Static lung volumes and capacities

The volume of gas in the lung and intrathoracic airways is determined by the properties of lung parenchyma and surrounding organs and tissues, surface tension, the force exerted by respiratory muscles, by lung reflexes and by the properties of airways. The gas volumes of thorax and lung are the same except in the case of a pneumothorax. If two or more subdivisions of the total lung capacity are taken together, the sum of the constituent volumes is described as a lung capacity. Lung volumes and capacities are described in more detail in § 2.

#### 1.1.1 Determinants

Factors which determine the size of the normal lung include stature, age, sex, body mass, posture, habitus, ethnic group, reflex factors and daily activity pattern. The level of maximal inspiration (total lung capacity, TLC) is influenced by the force developed by the inspiratory muscles (disorders include e.g. muscular dystrophy), the elastic recoil of the lung (disorders include e.g. pulmonary fibrosis and emphysema) and the elastic properties of the thorax and adjacent structures (disorders include e.g. ankylosis of joints). The level of maximal expiration (residual volume, RV) is determined by the force exerted by respiratory muscles (disorders include e.g. muscle paralysis), obstruction, occlusion and compression of small airways (disorders include e.g. emphysema) and by the mechanical properties of lung and thorax (disorders include diffuse fibrosis, kyphoscoliosis).

Assessing the total lung capacity is indispensable in establishing a restrictive ventilatory defect or in diagnosing abnormal lung distensibility, as may occur in patients …

Lung volumes and forced ventilatory flows

Diagnostic Criteria of Nontuberculous Mycobacterial Lung Disease Key Laboratory Features of NTM Health Careand Hygiene-associated Disease Prevention Prophylaxis and Treatment of NTM Disease Introduction Methods Taxonomy Epidemiology Pathogenesis Host Defense and Immune Defects Pulmonary Disease Body Morphotype Tumor Necrosis Factor Inhibition Laboratory Procedures Collection, Digestion, Decontamination, and Staining of Specimens Respiratory Specimens Body Fluids, Abscesses, and Tissues Blood Specimen Processing Smear Microscopy Culture Techniques Incubation of NTM Cultures NTM Identification Antimicrobial Susceptibility Testing for NTM Molecular Typing Methods of NTM Clinical Presentations and Diagnostic Criteria Pulmonary Disease Cystic Fibrosis Hypersensitivity-like Disease Transplant Recipients Disseminated Disease Lymphatic Disease Skin, Soft Tissue, and Bone Disease

/pdf/an-official-ats-idsa-statement-diagnosis-treatment-and-1jy41yfwpp.pdf

An official ATS/IDSA statement: diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases.

Magnetic resonance imaging (MRI) is considered inferior to computed tomography (CT) in the assessment of lung parenchyma, being hampered by low proton density, magnetic susceptibility effects, flow, and cardiac and respiratory motion. In this study the authors assessed the potential usefulness of MRI by comparing it with corresponding CT images of the lung in the absence of motion. They studied eight excised normal canine lung lobes inflated with oxygen before and after induction of pulmonary edema produced by intravascular infusion of saline at 30 cm H2O. T1, T2 and proton density weighted, 5-mm thick, gapped, multislice sequences were performed at 1.5 T. Magnetic resonance images were compared with corresponding 5-mm collimation CT scans at identical levels both before and after the induction of pulmonary edema. The MR and CT scans were assessed independently by two chest radiologists. In normal lung, there was equivalent visualization of vessels down to 1 mm and bronchi to 2 mm in diameter. T1 and proton density scans demonstrated lower spatial resolution but greater contrast than the corresponding CT images. In pulmonary edema both T1 and proton density sequences demonstrated peribronchial edema with greater contrast than CT. Air-space filling was equally well demonstrated by either technique. The authors conclude that, in motionless lung, MRI has lower spatial but greater contrast resolution than CT. It is potentially superior to CT in assessing focal and diffuse lung disease if cardiac and respiratory motion artifacts can be minimized or suppressed.

Magnetic resonance imaging of hydrostatic pulmonary edema in isolated dog lungs: comparison with computed tomography.

High-resolution computed tomography of chronic interstitial lung disease.

Rheumatoid arthritis (RA) is commonly associated with interstitial lung disease. Abnormalities consistent with interstitial lung disease are seen on the radiograph in approximately 6% of patients. The most common histologic pattern of interstitial lung disease seen in RA is usual interstitial pneumonia (UIP). The characteristic high-resolution CT findings of UIP consist of a reticular pattern and honeycombing involving mainly the subpleural lung regions and lung bases. The clinical course of UIP is characterized by gradual deterioration over several years. Occasionally patients may have a rapid decline due to development of diffuse alveolar damage (DAD). Such an accelerated phase has been described mainly in idiopathic pulmonary fibrosis but can also be seen in RA. Most cases of accelerated UIP have been reported by investigators from Japan. We report the high resolution CT and histologic findings of accelerated phase of UIP in a patient with RA who developed new honeycomb cysts within 9 days of onset of DAD. This is to our knowledge the first documented case of such rapid development of honeycombing. CASE REPORT A 72-year-old male with longstanding RA was admitted to the emergency department with complaints of severe dyspnea over 5 days. He described a mildly productive cough without hemoptysis. He was an ex-smoker with a 30-pack-year history and denied occupational exposures. There was no history of previous pulmonary interstitial disease and no previous chest imaging. The patient had positive rheumatoid factor but no acute musculoskeletal symptoms and was not receiving any medications that could account for the respiratory symptoms. Initial chest radiograph demonstrated diffuse bilateral reticular interstitial opacities and large hiatus hernia. High resolution CT performed on a multidetector scanner demonstrated bilateral reticular pattern, traction bronchiectasis, and mild honeycombing involving mainly the peripheral lung regions and lung bases (Figs. 1A and B). Also noted was diffuse bilateral ground glass attenuation. The CT findings were interpreted as consistent with UIP related to RA. The diffuse ground glass opacities raised concern for superimposed DAD (accelerated UIP) or infection. The patient’s condition progressively deteriorated. Repeat sputum cultures were negative. Serial chest radiographs demonstrated extensive reticulation and progressive increase in the bilateral ground glass opacification. Nine days after admission the patient underwent repeat high resolution CT on a multidetector scanner (Figs. 1C and D). The CT showed progression of fibrosis, with development of reticulation and traction bronchiectasis in areas that previously demonstrated ground glass opacities. Also noted was interval development of new areas of honeycombing. The development of new areas of fibrosis was most marked in the subpleural regions of the lower lung zones, including lower aspects of the lingula, middle lobe, and lower lobes. The patient died 10 days after admission to hospital. At autopsy, the right and left lungs weighed 835 and 615 g, respectively, and were firm to palpation. The pleura demonstrated a “cobblestone” appearance. On parasagittal (right lung) and transverse (left lung) sectioning, the cut surfaces showed patchy honeycomb cyst formation that was predominant in the lingula and present to a lesser extent in the subpleural regions of the upper and lower lobes bilaterally (Fig. 2A). Patchy areas consistent with organizing pneumonia were identified in all lobes. Ectatic airways, cut in both transverse and longitudinal section, were observed. Microscopically, there was evidence of temporally heterogeneous lung injury and remodeling (Figs. 2B and C). Acute DAD with hyaline membrane formation was present in areas with minimal alteration to the underlying lung architecture and adjacent to areas of interstitial and airspace organization. A notable feature in the areas of interstitial and airspace From the *Department of Pathology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, Canada; and the †Department of Radiology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, Canada. Reprints: Dr. Nestor L. Müller, Department of Radiology, Vancouver General Hospital, 899 W. 12th Ave, Vancouver, BC, Canada V5Z 1M9 (e-mail: nmuller@vanhosp.bc.ca). Copyright © 2004 by Lippincott Williams & Wilkins

Accelerated deterioration of usual interstitial pneumonia with acute development of honeycomb cysts in rheumatoid arthritis.

Juvenile xanthogranuloma with tracheal and bronchial involvement.

High-resolution computed tomography (HRCT) has an established role in the detection and differential diagnosis of chronic diffuse infiltrative lung disease. Available data suggest that, in certain cases, HRCT may also be used to determine the presence or absence of, and extent of, abnormalities that are likely to reflect potentially reversible (acute or active) lung disease, as compared with irreversible (fibrotic) lung disease. In doing so, HRCT permits an assessment of disease prognosis. Furthermore, because HRCT can accurately identify subtle active lung disease, it may be used to monitor the success or failure of treatment. This article reviews the HRCT features associated with potentially reversible, as compared with irreversible, lung disease, and the accuracy with which these features can be used to predict disease activity and prognosis in chronic diffuse infiltrative lung disease and therefore assist management.

Nestor L. Müller

Papers

Magnetic resonance imaging of hydrostatic pulmonary edema in isolated dog lungs: comparison with computed tomography.

High-resolution computed tomography of chronic interstitial lung disease.

Accelerated deterioration of usual interstitial pneumonia with acute development of honeycomb cysts in rheumatoid arthritis.

Juvenile xanthogranuloma with tracheal and bronchial involvement.

Insights from HRCT: how they affect the management of diffuse parenchymal lung disease.