What is a common reason for patients with acute kidney injury (AKI) to have increased fluid retention?

Increased fluid retention in patients with acute kidney injury (AKI) is primarily due to decreased urine output. When the kidneys are impaired, their ability to filter blood and excrete waste products diminishes, resulting in reduced production of urine. This leads to the accumulation of fluids in the body, which can manifest as swelling (edema) in various tissues, increased blood volume, and potential complications such as hypertension and pulmonary congestion. The inability to adequately eliminate excess fluids is a hallmark of AKI, emphasizing the importance of monitoring fluid intake and output in these patients.