Diaphragmatic Dysfunction among Indians Recovered from Coronavirus Disease-19: A Cross-sectional Study from a Tertiary Care Center

Background: Diaphragm muscle invasion by severe acute respiratory syndrome coronavirus (SARS-CoV) may result in diaphragm dysfunction that may persist beyond recovery from acute infection.We used ultrasonography to evaluate the diaphragmatic function among patients with long coronavirus disease (COVID), irrespective of the severity of the acute illness.Methods: In this cross-sectional study conducted in the post-COVID clinic of a tertiary hospital, we performed diaphragm ultrasonography at least 4 weeks after the symptom onset of acute COVID-19.Preceding acute COVID-19 was classified as severe in the presence of hypoxemia (SpO 2 < 90% on room air), tachypnea (respiratory rate > 30 breaths per minute), or shock.We determined the prevalence of diaphragmatic dysfunction [diaphragm thickness fraction (DTF) < 20%, or diaphragm excursion on deep breathing below the lower limit of normal (LLN)].We evaluated the clinicodemographic variables associated with diaphragmatic dysfunction using logistic regression analysis.Results: We included 77 subjects (72.7% male) with a mean [standard deviation (SD)] age of 46.0 (13.3) years at a median [interquartile range (IQR)] duration of 8 (6-9) weeks after symptom onset.The preceding acute COVID-19 illness was severe in 37 (48.0%)subjects.We observed a very high prevalence of diaphragmatic dysfunction affecting 45.4% of post-COVID subjects.The proportion of subjects with diaphragmatic dysfunction following mild, moderate, and severe COVID-19 was 25, 30, and 64.9, respectively.On multivariate logistic regression analysis, preceding severe COVID-19 was significantly associated with diaphragmatic dysfunction [odds ratio (OR): 4.57; 95% confidence intervals (CI): 1.21-17.24;p = 0.02].Conclusion: Diaphragmatic dysfunction is common after recovery from COVID-19.Preceding severe COVID-19 may be associated with a higher prevalence of diaphragmatic dysfunction.