Introduction There is relatively little published on the effects of COVID-19 on respiratory physiology, particularly breathing patterns. We sought to determine if there were lasting detrimental effect following hospital discharge and if these related to the severity of COVID-19. Methods We reviewed lung function and breathing patterns in COVID-19 survivors > 3 months after discharge, comparing patients who had been admitted to the intensive therapy unit (ITU) (n = 47) to those who just received ward treatments (n = 45). Lung function included spirometry and gas transfer and breathing patterns were measured with structured light plethysmography. Continuous data were compared with an independent t-test or Mann Whitney-U test (depending on distribution) and nominal data were compared using a Fisher’s exact test (for 2 categories in 2 groups) or a chi-squared test (for > 2 categories in 2 groups). A p-value of < 0.05 was taken to be statistically significant. Results We found evidence of pulmonary restriction (reduced vital capacity and/or alveolar volume) in 65.4% of all patients. 36.1% of all patients has a reduced transfer factor (TL CO ) but the majority of these (78.1%) had a preserved/increased transfer coefficient (K CO ), suggesting an extrapulmonary cause. There were no major differences between ITU and ward lung function, although K CO alone was higher in the ITU patients (p = 0.03). This could be explained partly by obesity, respiratory muscle fatigue, localised microvascular changes, or haemosiderosis from lung damage. Abnormal breathing patterns were observed in 18.8% of subjects, although no consistent pattern of breathing pattern abnormalities was evident. Conclusions An “extrapulmonary restrictive” like pattern appears to be a common phenomenon in previously admitted COVID-19 survivors. Whilst the cause of this is not clear, the effects seem to be similar on patients whether or not they received mechanical ventilation or had ward based respiratory support/supplemental oxygen.
【저자키워드】 Ventilation, Interstitial lung disease, Infectious disease, Respiratory Physiology, Critical Care and Emergency Medicine, 【초록키워드】 COVID-19, Treatment, therapy, mechanical ventilation, fatigue, obesity, spirometry, oxygen, discharge, Survivors, Respiratory Physiology, severity of COVID-19, Lung function, Patient, respiratory, distribution, Intensive, patients, Evidence, detrimental, lung damage, evidence of, vital capacity, respiratory muscle, changes, supplemental oxygen, reduced vital capacity, transfer factor, alveolar volume, P-value, hospital discharge, transfer, Continuous data, Fisher’s exact test, Chi-squared test, abnormality, independent t-test, Muscle fatigue, Effect, Result, reduced, appear, majority, determine, subjects, explained, category, groups, statistically significant, were measured, A p-value, Continuous, 【제목키워드】 COVID-19, hospitalised,