Positive fluid balance is associated with earlier acute kidney injury in COVID-19 patients
Abstract
Introduction
Managing fluid balance in COVID-19 patients can be challenging, particularly if acute kidney injury (AKI) develops.
Aim of the study
We study the relationship between fluid net input and output (FNIO) in COVID-19 patients with development of AKI, time to development of AKI, in-hospital length of stay (LOS), and in-hospital mortality.
Material and Methods
Retrospective study of 403 patients with COVID-19. Data for FNIO were from day 1 through day 10 or earlier if AKI occurred.
Results
AKI occurred in 22.8%, in-hospital mortality occurred in 26.3%, mean days to AKI were 7.7 (SD=6.3), and mean LOS was 11.5 (SD=13.2) days. In the multivariate logistic regression analyses, increased FNIO mean was significantly associated with slightly increased odds for mortality (OR=1.001, 95% CI:1.0001, 1.0011, p=0.02) but was not significantly associated with AKI. In the multivariate linear regression analyses, increased FNIO mean was significantly associated with lesser days to AKI (B=−6.63*10−5, SE=<0.001, p=0.003) in the whole sample, greater days to AKI in the subset of those with ICU treatment (B=<0.001, SE=<0.001, p<0.001), while FNIO mean was not significantly associated with LOS.
Conclusions
Positive fluid balance was associated with faster onset of AKI and increased mortality. Fluid administration in patients with COVID-19 should be guided by routinely measuring FNIO. A restrictive fluid management regimen rather than usual care should be practiced.
© 2026 Rezwan Munshi, Sandra Gomez-Paz, Salman Bhutta, Joshua Fogel, James Pellegrini, Narois Nehru, Eric Lam, Sofia Rubinstein, published by University of Medicine, Pharmacy, Science and Technology of Targu Mures
This work is licensed under the Creative Commons Attribution 4.0 License.