Acute kidney injury (AKI) presents significant challenges for healthcare providers, particularly in the intensive care unit (ICU). It is highly prevalent in patients who are admitted to the ICU for care, regardless of presenting diagnosis, and carries with it an increased risk of ICU readmission and poor outcomes.
In managing patients with AKI, it is crucial to address the critical interplay between fluid balance in AKI and poor outcomes including higher ICU readmission rates. By understanding strategies to reduce ICU readmissions related to fluid imbalances in patients with AKI, providers can improve outcomes, avoid regulatory penalties and decrease costs.
The Link Between Fluid Imbalance and AKI Outcomes
AKI occurs commonly in patients admitted to the ICU, with a rate as high as 57%. Outcomes in this patient population remain a focus of quality improvement efforts, with high rates of morbidity and mortality observed.
One important contributing factor to complications in AKI is fluid imbalance. Preventing AKI progression and improving outcomes in AKI patients requires proactive intervention, especially in Stage 1 AKI, where the opportunity exists to avoid ongoing—and sometimes chronic—renal damage.
In the ICU, positive fluid balance has been associated with worse renal outcomes including increased mortality in some subsets of AKI patients. Aggressive fluid resuscitation is not uncommon in patients admitted to the ICU, but the intersection of AKI with fluid overload creates special challenges.
Recognizing and correcting positive fluid imbalances early can halt the progression of the cycle that drives renal deterioration and subsequent readmissions.
Fluid Imbalance and ICU Readmission in AKI
Increased mortality rates are not the only serious concern for AKI patients. Not only does research show that patients with AKI have a higher fluid balance than those without, but also that fluid overload is an independent risk factor for AKI incidence itself and, importantly, severity. Specifically, a high fluid balance has been directly correlated to an increase in AKI stage. This has both short and long-term implications; patients whose AKI progresses experience increased hospital length of stay (LOS), are at risk of requiring renal replacement therapy (RRT) and, at Stage 3 AKI, have significantly higher risk of developing chronic kidney disease.
Additionally, when AKI progresses to Stage 3 and persists for 72 hours or more, it has been associated with a higher risk of hospital readmission. This includes both short and long-term readmissions, with research showing higher rates of rehospitalization at both 90 days and 1 year for these patients.
Cost and Compliance Risks for Hospitals Under CMS
With the Centers for Medicare and Medicaid Services (CMS) intensifying scrutiny on readmission rates and financial penalties, optimizing fluid management in AKI patients is not just a clinical priority but a regulatory imperative.
There are two ways in which fluid mismanagement and worsening AKI can cause negative impacts in connection with CMS measures:
- The CMS Hospital Readmissions Reduction Program (HRRP)— Under this program, CMS levies financial penalties for institutions who have excessive readmissions. Any unplanned admissions within 30 days count against participating hospitals.
- The CMS AKI eCQM— As part of value-based care delivery, this quality measure rates the development of Stage 2 AKI and above as a hospital harm and affects reimbursement levels. With new changes proposed for CY2027, reporting on this metric will be mandatory.
While regulatory burden is one financial consideration, AKI management by itself is costly. The estimated financial impact of both severe AKI and associated readmissions is considerable: these patients have 58% higher ICU costs and 22% higher readmission costs.
Strategies to Reduce ICU Readmissions Due to Fluid Imbalance
Management of fluid balance is a complex challenge in hospital settings and require proactive strategies in evaluating both administration (input) and outcomes (including output).
Appropriate, evidence-based fluid stewardship has been advanced as one strategy to reduce complications, and consistent fluid administration guidelines, clinical education and oversight has been shown to improve outcomes.
Along with this approach, it is crucial to evaluate fluid balance on an individual basis, and research has shown that dedication to accurate urine output monitoring reduces the incidence of AKI — in one study by 33%.
Manual monitoring of urine output is prone to error and delays, and dependent on consistent workflows in a busy ICU environment where clinical staff must juggle multiple priorities. In contrast, leveraging automated, electronic urine monitoring demonstrates significant benefits in reducing fluid volume and detecting AKI in the earliest stages, allowing proactive intervention before it can progress to more severe stages and poor outcomes.
Better Outcomes with Proactive Management
Preventing AKI progression in the ICU patient population, improving outcomes and reducing readmission risk requires a proactive approach to optimizing fluid balance. Recognizing the impact of fluid balance on AKI and providing clinical education on this topic are essential. By combining evidence-based fluid stewardship with technologies that ensure data integrity and promote early detection, hospitals can simultaneously improve patient outcomes, reduce readmission risk, and meet CMS quality standards
References
- https://www.nature.com/articles/s41598-024-79533-6
- https://pmc.ncbi.nlm.nih.gov/articles/PMC3213281
- https://link.springer.com/article/10.1007/s40620-023-01829-z
- https://ccforum.biomedcentral.com/articles/10.1186/s13054-015-1085-4
- https://karger.com/kdd/article-pdf/8/1/82/3751756/000515533.pdf
- https://link.springer.com/article/10.1007/s00134-025-07821-4
- https://www.ajkd.org/article/S0272-6386(23)00067-7/abstract
- https://www.cms.gov/medicare/quality/value-based-programs/hospital-readmissions
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10103312/
- https://bmjopenquality.bmj.com/content/11/1/e001636
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5717957/
- https://www.nature.com/articles/s41598-021-97026-8
