The American Thoracic Society Committee Task Force on Standards for Pulmonary Function had recommended a standardized reporting format for pulmonary function tests due to considerable variability in pulmonary function reports presented to end users, which might lead to potential confusion and miscommunication. This recommendation includes seven parts: overview, introduction, methods, report format, selecting and reporting reference values, grading the quality of pulmonary function tests and conclusions. This document presents a reporting format in test-specific units for spirometry, lung volumes, and diffusing capacity that can be assembled into a report appropriate for a laboratory’s practice. Recommended reference sources are updated, with especially emphasizing to adapt lower limit of normal (LLN) or z score instead of percent of prediction to estimate the abnormal results. This document provides detail and clear explanation on the recommendations, which might improve the interpretation, communication, and understanding of test results. However, parts of recommendation might not be used directly in our clinical practice owing to some specific conditions in China. We suggest to use appropriate normal predictions from Chinese population, to include small airway parameters such as mid-maximal expiratory flow for early detection of pulmonary function deterioration, and to include inspiratory flow volume curve, as well as strengthen the quality control data and figures in the report format.
Respiratory oscillometry is a lung function test that measures the mechanical properties of respiratory system by the forced oscillation technique. Oscillometry can be used in those who cannot perform traditional lung function tests, including young children. It is also an important tool to assess small airways function in clinical and research fields. In 2020, the European Respiratory Society published a new technical standard for respiratory oscillometry, which offered updated technical recommendations on the hardware, software, testing protocols and quality control of oscillometry measurements. This paper interpreted the new technical standard, for providing technical suggestions regarding oscillometry measurements in clinical and research settings, and as a reference for developing technical statements and recommendations for oscillometry in China.
ObjectiveTo investigate the static pulmonary function and cardiopulmonary exercise function of convalescent patients with coronavirus disease 2019 (COVID-19) after discharge.MethodsPulmonary function and cardiopulmonary exercise capacity of COVID-19 patients who admitted to our hospital from January to March 2020 were analyzed. The patients were divided into a non-critical group (3 cases of moderate illness, 2 cases of severe illness) and a critical group (5 cases of critical illness). Five of the 10 patients completed spirometry on day 14 after discharge. All patients performed spirometry, diffusion capacity and cardiopulmonary exercise test around 28 days post-discharge. Ten healthy subjects were used as a control group.ResultsForced expiratory volume in one second of percent predicted (FEV1%pred), forced vital capacity of percent predicted (FVC%pred), the FEV1/FVC ratio (FEV1/FVC), peak expiratory flow of percent predicted (PEF%pred) and mean forced expiratory flow between 25% and 75% of percent predicted (FEF25%-75%%pred) of COVID-19 group were all within normal ranges, and there were no significant difference between COVID-19 group and the healthy group (P>0.05). Diffusion capacity (the carbon monoxide diffusion capacity of percent predicted, DLCO%pred) decreased in 3 patients. The peak oxygen uptake of percent predicted (PeakVO2%pred), oxygen uptake efficiency slope (OUES), Oxygen pulse of percent predicted (VO2/HR%pred) in COVID-19 group decreased and were statistically significantly lower than the control group (P<0.05), but there was no significant difference in ventilatory equivalents for carbon dioxide at anaerobic threshold (VE/VCO2@AT) and the slope of ventilatory equivalent for carbon dioxide (VE/VCO2 slope) between the two groups (P>0.05). Compared to the non-critical group, the critical group displayed significantly lower FVC%pred and VO2/HR%pred (P<0.05). A decrease in PeakVO2%pred was observed in critical group, but the difference did not reach statistical significance (P>0.05). The FVC%pred and PEF%pred were significantly improved in 5 COVID-19 convalescents on Day 28 after discharge when comparing with day 14 (P<0.05).ConclusionsIn the first month after discharge, recovered COVID-19 patients mainly presented decreased exercise endurance in cardiopulmonary function tests.There are also some survivors with reduced diffusion function, but the impaired lung function of COVID-19 patients might return over time.