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.
Tag Archives: fluid balance
The Correspondence between Fluid Balance and Body Weight Change Measurements in Critically Ill Adult Patients
Introduction: Positive fluid status has been associated with a worse prognosis in intensive care unit (ICU) patients. Given the potential for errors in the calculation of fluid balance totals and the problem of accounting for indiscernible fluid losses, measurement of body weight change is an alternative non-invasive method commonly used for estimating body fluid status. The objective of the study is to compare the measurements of fluid balance and body weight changes over time and to assess their association with ICU mortality. Methods: This prospective observational study was conducted in the 34-bed multidisciplinary ICU of a tertiary teaching hospital in southern Brazil. Adult patients were eligible if their expected length of stay was more than 48 hours, and if they were not receiving an oral diet. Clinical demographic data, daily and cumulative fluid balance with and without indiscernible water loss, and daily and total body weight changes were recorded. Agreement between daily fluid balance and body weight change, and between cumulative fluid balance and total body weight change were calculated. Results: Cumulative fluid balance and total body weight change differed significantly among survivors and non survivors respectively, +2.53L versus +5.6L (p= 0.012) and -3.05kg vs -1.1kg (p= 0.008). The average daily difference between measured fluid balance and body weight was +0.864 L/kg with a wide interval: -3.156 to +4.885 L/kg, which remained so even after adjustment for indiscernible losses (mean bias: +0.288; limits of agreement between -3.876 and +4.452 L/kg). Areas under ROC curve for cumulative fluid balance, cumulative fluid balance with indiscernible losses and total body weight change were, respectively, 0.65, 0.56 and 0.65 (p= 0.14). Conclusion: The results indicated the absence of correspondence between fluid balance and body weight change, with a more significant discrepancy between cumulative fluid balance and total body weight change. Both fluid balance and body weight changes were significantly different among survivors and non-survivors, but neither measurement discriminated ICU mortality.










