Abstract
BackgroundFluid overload is associated with morbidity and mortality in patients receiving renal replacement therapy (RRT). We aimed to explore whether fluid overload at initiation of RRT was independently associated with mortality and whether changes in cumulative fluid balance during RRT were associated with outcome.MethodsWe retrospectively analysed the data of patients who were admitted to the multidisciplinary adult intensive care unit (ICU) in a tertiary care centre in the UK between 2012 and 2015 and received continuous RRT (CRRT) for acute kidney injury for at least 24 h. We collected baseline demographics, body mass index (BMI), comorbidities, severity of illness, laboratory parameters at CRRT initiation, daily cumulative fluid balance (FB), daily prescribed FB target, fluid bolus and diuretic administration and outcomes. The day of the lowest cumulative FB during CRRT was identified as nadir FB.ResultsEight hundred twenty patients were analysed (median age 65 years; 49% female). At CRRT initiation, the median cumulative FB was + 1772 ml; 89 patients (10.9%) had a cumulative FB > 10% body weight (BW). Hospital survivors had a significantly lower cumulative FB at CRRT initiation compared to patients who died (1495 versus 2184 ml; p < 0.001). In the 7 days after CRRT initiation, hospital survivors had a significant decline in cumulative FB (mean decrease 473 ml per day, p < 0.001) whilst there was no significant change in cumulative FB in non-survivors (mean decrease 112 ml per day, p = 0.188). Higher severity of illness at CRRT initiation, shorter duration of CRRT, the number of days without a prescribed FB target and need for higher doses of noradrenaline were independent risk factors for not reaching a FB nadir during CRRT. Multivariable analysis showed that older age, lower BMI, higher severity of illness, need for higher doses of noradrenaline and smaller reductions in cumulative FB during CRRT were independent risk factors for ICU and hospital mortality. Cumulative FB at CRRT initiation was not independently associated with mortality.ConclusionIn adult patients receiving CRRT, a decrease in cumulative FB was independently associated with lower mortality. Fluid overload and need for vasopressor support at CRRT initiation were not independently associated with mortality after correction for severity of illness.
Highlights
In critically ill patients, haemodynamic stabilisation often involves aggressive fluid resuscitation and vasopressor support
At continuous renal replacement therapy (RRT) (CRRT) initiation, the median cumulative fluid balance (FB) was + 1772 ml; 89 patients (10.9%) had a cumulative FB > 10% body weight (BW)
Patients with a cumulative FB above the median value (1772 ml) at CRRT initiation were older, had a significantly higher Sequential Organ Failure Assessment (SOFA) score and higher arterial lactate concentration and were more likely to be on vasopressors at CRRT initiation compared to those with a lower cumulative FB (Supplementary Table S1)
Summary
Haemodynamic stabilisation often involves aggressive fluid resuscitation and vasopressor support. Evidence is accumulating that fluid overload is associated with harm, including worsening organ dysfunction and mortality [1,2,3,4,5,6,7,8]. In patients with early AKI, fluid overload increases the risk of worsening AKI [9]. In patients treated with renal replacement therapy (RRT), fluid overload on the first day of RRT correlates with mortality, dialysis dependency and reduced renal recovery [2, 3]. Most studies which demonstrate a relationship between fluid accumulation and mortality are confounded by the fact that patients with fluid overload tend to be sicker and often need more organ support. Fluid overload is associated with morbidity and mortality in patients receiving renal replacement therapy (RRT). We aimed to explore whether fluid overload at initiation of RRT was independently associated with mortality and whether changes in cumulative fluid balance during RRT were associated with outcome
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
