How a positive fluid balance develops in acute kidney injury: A binational, observational study

Area of Science:

• Critical Care Medicine
• Nephrology
• Fluid Management

Background:

• Positive fluid balance (FB) is linked to adverse outcomes in intensive care unit (ICU) patients diagnosed with acute kidney injury (AKI).
• Understanding the development of positive FB in this vulnerable patient population is crucial for improving clinical management and patient outcomes.

Purpose of the Study:

• To investigate the mechanisms and contributing factors behind the development of a positive fluid balance in critically ill patients with AKI.
• To identify key elements in patient management that lead to fluid accumulation after AKI diagnosis.

Main Methods:

• A multinational, retrospective cohort study was conducted.
• The study included critically ill patients diagnosed with AKI who did not require renal replacement therapy.

Main Results:

• Acute kidney injury (AKI) occurred in 17.3% of patients, typically two days post-admission.
• Cumulative FB progressively increased after AKI diagnosis, driven by persistent crystalloid administration, nutritional intake, and limited urine output.
• A positive FB four days post-AKI diagnosis was significantly associated with an increased risk of hospital mortality (OR 1.12).

Conclusions:

• Positive fluid balance in ICU patients with AKI is a common occurrence post-diagnosis.
• Fluid accumulation results from a combination of ongoing crystalloid administration, nutritional fluid intake, insufficient urine output, and minimal diuretic use.
• Current management strategies contribute to fluid overload, highlighting a need for revised fluid management protocols in AKI patients.