[Recommendations on interpretive strategies for routine lung function tests].

During the annual conference of the German Respiratory Society (DGP = Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin) in 2024, updated recommendations for lung function testing have been published. The original full-length version can be downloaded free of charge as pfd-paper from the journal entitled "Atemwegs- und Lungenkrankheiten, Jahrgang 50 (2024) März (111-184)". In the current recommendations new approaches have been embedded that focus on modern interpretations of lung function results, as has been proposed by the ERS (European Respiratory Society) in collaboration with the ATS (American Thoracic Society).

Capnovolumetry in combination with clinical history for the diagnosis of asthma and COPD.

Capnovolumetry performed during resting ventilation is an easily applicable diagnostic tool sensitive to airway obstruction. In the present analysis, we investigated in which way capnovolumetric parameters can be combined with basic anamnestic information to support the diagnosis of asthma and COPD. Among 1400 patients of a previous diagnostic study, we selected 1057 patients with a diagnosis of asthma (n = 433), COPD (n = 260), or without respiratory disease (n = 364).

Correspondence between Capnovolumetric and Conventional Lung Function Parameters in the Diagnosis of Obstructive Airway Diseases.

Background: Capnovolumetry is of interest as a method for the diagnosis of obstructive airway diseases, requiring little cooperation from the patient.

Objective: To help in the interpretation of capnovolumetric parameters, we aimed to identify their correspondence to conventional lung function indices.

Methods: We studied 978 patients from a diagnostic study with complete functional data and the clinical diagnosis of asthma, chronic obstructive pulmonary disease (COPD), or no respiratory disease.

A simple method to reconstruct the molar mass signal of respiratory gas to assess small airways with a double-tracer gas single-breath washout.

For the assessment of small airway diseases, a noninvasive double-tracer gas single-breath washout (DTG-SBW) with sulfur hexafluoride (SF) and helium (He) as tracer components has been proposed. It is assumed that small airway diseases may produce typical ventilation inhomogeneities which can be detected within one single tidal breath, when using two tracer components. Characteristic parameters calculated from a relative molar mass (MM) signal of the airflow during the washout expiration phase are analyzed.

[Standardization of spirometry: 2015 update. Published by German Atemwegsliga, German Respiratory Society and German Society of Occupational and Environmental Medicine].

Spirometry is a simple test and considered the gold standard in lung function. An obstructive ventilatory defect is a disproportionate reduction of maximal airflow from the lung in relation to the maximal volume that can be displaced from the lung. It implies airway narrowing and is defined by a reduced FEV1/FVC ratio below the 5th percentile of the predicted value (lower limit of normal, LLN).