Steady-state diffusing capacity determined by a simplified method

2017 ERS/ATS standards for single-breath carbon monoxide uptake in the lung

This document provides an update to the European Respiratory Society (ERS)/American Thoracic Society (ATS) technical standards for single-breath carbon monoxide uptake in the lung that was last updated in 2005. Although both D_LCO (diffusing capacity) and T_LCO (transfer factor) are valid terms to describe the uptake of carbon monoxide in the lung, the term D_LCO is used in this document. A joint taskforce appointed by the ERS and ATS reviewed the recent literature on the measurement of D_LCO and surveyed the current technical capabilities of instrumentation being manufactured around the world. The recommendations in this document represent the consensus of the taskforce members in regard to the evidence available for various aspects of D_LCO measurement. Furthermore, it reflects the expert opinion of the taskforce members on areas in which peer-reviewed evidence was either not available or was incomplete. The major changes in these technical standards relate to D_LCO measurement with systems using rapidly responding gas analysers for carbon monoxide and the tracer gas, which are now the most common type of D_LCO instrumentation being manufactured. Technical improvements and the increased capability afforded by these new systems permit enhanced measurement of D_LCO and the opportunity to include other optional measures of lung function.

Clinical applications of lung function tests: a revisit

The development and clinical application of lung function tests have a long history, and the various components of lung function tests provide very important tools for the clinical evaluation of respiratory health and disease. Spirometry, measurement of the diffusion factor, bronchial provocation tests and forced oscillation techniques have found diverse clinical applications in the diagnosis and monitoring of respiratory diseases, such as chronic obstructive pulmonary disease, interstitial lung diseases and asthma. However, there are some practical issues to be resolved, including the establishment of reference values for individual test parameters and the roles of these tests in preoperative risk assessment and pulmonary rehabilitation. Novel measurements, including negative expiratory pressure, the fraction of exhaled nitric oxide and analysis of exhaled breath condensate, may provide new insights into physiological abnormalities or airway inflammation in respiratory diseases, but their clinical applications need to be further evaluated. The clinical application of lung function tests continues to face challenges, which may be overcome by further improvement of conventional techniques for lung function testing and further specification of new testing techniques.