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.

PURPOSE The objectives of this study were to analyze the high resolution computed tomography (HRCT) findings in rheumatoid arthritis (RA) patients with respiratory symptoms and to evaluate the relation between the extent of HRCT findings and functional impairment as assessed by spirometry. MATERIALS AND METHODS HRCT examination of the thorax and pulmonary function tests (PFTs) were performed in 34 RA patients with respiratory symptoms. Patients with smoking history or with emphysema evident on HRCT were excluded from the study. CT findings were assessed for the presence and pattern of abnormalities. Extent was scored based on the number of pulmonary segments involved. PFTs included forced expiratory flows (FEFs) and forced vital capacity (FVC). RESULTS Bronchial wall thickening was detected in 29 of 34 RA patients (85%), small nodules in 24 patients (71%), and bronchial dilatation in 21 patients (62%). The extent of bronchial wall thickening correlated with FEF25-75, FEF75, and FEF50 (p<0.0001, respectively) (Spearman's rank correlation). Extent of small nodules correlated with FEF25-75, FEF50, and FEF25 (p<0.01, respectively). Stepwise regression analysis showed independent correlations of bronchial wall thickening with decreases in FEF25-75 and FEF75 (p<0.0001, both). Bronchial dilatation was also independently associated with a decrease in FVC (p<0.05). CONCLUSION The most common HRCT findings in RA patients with respiratory symptoms are bronchial wall thickening and small nodules, and the extent of these findings correlates significantly with functional impairment.

Respiratory symptoms in rheumatoid arthritis: relation between high resolution CT findings and functional impairment.

Imaging of acute pulmonary thromboembolism: should spiral computed tomography replace the ventilation-perfusion scan?

PURPOSE: To evaluate the relationship between abnormalities at thin-section computed tomography (CT) and indexes of pulmonary gas exchange impairment at rest and during moderate exercise in workers exposed to asbestos. MATERIALS AND METHODS: Eighty-two workers with long-term exposure to asbestos and abnormal thin-section CT findings underwent respiratory physiologic measurements at rest (lung diffusing capacity, Dlco) and during exercise (oxygen uptake–corrected alveolar-arterial pressure difference for oxygen, ΔP[A-a]O2/VO2). CT results were compared with physiologic measurements of impairment in gas exchange (Dlco 20 mm Hg · L · min−1). The CT findings were divided into five categories by using a previously described method. Odds ratios and 95% CIs for gas exchange defects were calculated for patients grouped according to CT findings. Logistic regression analysis was performed with gas exchange as the dependent response and CT abnormalities as independent var...

Thin-section CT abnormalities and pulmonary gas exchange impairment in workers exposed to asbestos.

To investigate the usefulness of bronchoscopic examination, computerized tomography (CT), and radio-nuclide quantitative ventilation-perfusion lung scan to determine the response of patients with obstructive endobronchial tumors to photodynamic therapy (PDT), the findings in 24 patients treated with PDT were analyzed. PDT was found to be most effective when the tumor was bronchoscopically polypoid in appearance, with little or no submucosal invasion or peribronchial extension seen on CT scans. With increasing submucosal and/or peribronchial extension, the immediate response to treatment was poorer. Patients who had 50% or more of the airway obstruction due to mucosal tumor had no evidence of local tumor recurrence for a median interval of 22 weeks after treatment. In patients with predominant submucosal and/or peribronchial tumor, the duration of response was 7 weeks. Response to treatment did not correlate with the degree of airway obstruction. CT provided valuable information regarding the extent of the peribronchial involvement and airway distortion, which was often underestimated by bronchoscopy alone. Absent perfusion or reduction of regional perfusion out of proportion to ventilation on scintigraphy in the involved lung zone was found to be associated with extensive peribronchial involvement and a poor outcome. The authors conclude that the addition of CT and radionuclide quantitative ventilation-perfusion lung scan to bronchoscopic examination is useful in predicting the response of patients with obstructive endobronchial tumors to PDT.

Nestor L. Müller

Papers

Respiratory symptoms in rheumatoid arthritis: relation between high resolution CT findings and functional impairment.

Imaging of acute pulmonary thromboembolism: should spiral computed tomography replace the ventilation-perfusion scan?

Thin-section CT abnormalities and pulmonary gas exchange impairment in workers exposed to asbestos.

Predicting the response of obstructive endobronchial tumors to photodynamic therapy.

Pulmonary complications following lung transplantation.