Nearly one-third of patients with mild COVID-19 have impaired DLCO 34 days post-diagnosis, and one-fifth of patients have lung restriction. The odds of having an impaired DLCO at follow-up increased by 10% for every one-year increase in age (from 25 to 83) and increased 12-fold if a restrictive spirometric pattern was evident. However, having excessive night sweats and a blocked/runny nose each reduced the probability of an impaired DLCO at follow-up by about 90%, demonstrating a protective effect against an impaired gas exchange. In a summary of 22 studies, having severe COVID-19 disease at diagnosis increased the percentage of those with impaired DLCO by 21%. And, if the study used < 80% of predicted to define DLCO impairment, then 13% more patients would be classified as having a poor gas exchange.
SARS-CoV2: Severe acute respiratory syndrome coronavirus 2; COVID-19: Coronavirus disease 2019; DLCO: Pulmonary diffusing capacity for carbon monoxide; LLN: Lower limit of normality; WHO: World Health Organization; BMI: Body mass index; FEV1: Forced expiratory volume in 1 s; FVC: Forced vital capacity; FEF25–75: Forced expiratory flow rate over the middle half of expiration; PEF: Peak expiratory flow; TLC: Total lung capacity; CVD: Cardiovascular disease.
Availability of data and materials
All data generated or analysed during this study are included in this article and/or its supplementary material files. The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.
Ethics approval and consent to participate
Ethics approval was obtained from the Ethics Committee of the High Specialty Regional Hospital in Yucatan, Mexico (No. CONBIOETICA- 31-CEI-002-20170731). The Ethics Committee assigned this study as protocol number 2020-024. All patients signed a written informed consent to participate in the scheduled visit in compliance with the Helsinki declaration.
Consent for publication
BMC Pulm Med. 2022;22(294) © 2022 BioMed Central, Ltd.