Diaphragm thickness and ICU admission risk in elderly COVID-19 patients: a CT-based analysis

The objective of this study was to examine the impact of diaphragm thickness (DT) on the prognosis of elderly patients infected with COVID-19, particularly with regard to the necessity of intensive care unit (ICU) admission.

Between August 2020 and January 2021, 188 patients aged ≥ 65 years who were admitted to the internal medicine department of our hospital with a diagnosis of COVID-19 infection, were included in this study. The patients' DTs of the patients were measured by a radiologist using computed tomography (CT) scans from the right and left diaphragm dome level. DT was compared with the progression of respiratory distress and the necessity of intensive care. In statistical analysis, p < 0.05 was considered significant.

Right DT was higher in the group of patients with admission to the ICU (p = 0.11). According to multivariate logistic regression analysis, ferritin level (OR = 1; 95% CI = 1-1; p = 0.014), IL-6 level (OR = 1.004; 95% CI = 1-1.007; p = 0.045) and higher right DT (OR = 11.015; 95% CI = 3.739-32.447; p = 0.035) were found to be independent risk factors predicting the ICU admission in COVID-19 patients. There was no significant association with left DT. The predictive value of right DT for ICU requirement in COVID-19 patients was evaluated by ROC analysis. The ROC analysis showed a cut-off value > 1.8, AUC = 0.632, p = 0.009, 95% Cl (0.558-0.701). In correlation analysis, a positive correlation was found between right DT and ICU admission (r = 0.331, p < 0.001).

Our study is the first to evaluate dome-level DT with CT in elderly patients with COVID-19. In the elderly population, higher right DT levels have been observed to enhance the probability of ICU admission. This may be due to the fact that our sample group consists only of elderly people and the effects of COVID-19. We believe that further validation with more comprehensive studies is needed for DT assessment for clinical treatment decisions, particularly in COVID-19 patients. In addition, we think that the proposal for a standardized measurement site and method for DT measurement will be a guide for future studies.

Not applicable.