Hypervolemia and acute renal damage in intensive care unit patients

INTRODUCTION: Avoiding hypervolemia is an important factor in survival for patients in critical intensive care. In these patients, hypervolemia may be originated from a specific cause such as excessive fluid administration, congestive heart failure, and oliguria. Our study aims to investigate the effects of acute kidney injury on a degree of fluid overload, determining the link between acute kidney injury and the development of hypervolemia, and whether the acute kidney injury stage contributes to hypervolemia. METHOD: The clinical and laboratory records of severely ill patients who were hospitalized in the intensive care units of the TOGU Faculty of Medicine between August 2021 and October 2022 are examined retrospectively and a total of 70 patients were included in the study. Patient records were obtained and analyzed during their stay in the intensive care unit, limited to a maximum of 28 days. AKI diagnosis and staging were made according to the "Kidney Disease: Improving Global Outcomes guidelines". All vital signs of the patients, physical examination findings of hypervolemia, fluid intake and output during hospitalization, fluid balances, imaging methods, nephrotoxic drugs and agents used by the patients, diuretic and dialysis treatments applied during their hospitalization were recorded. Presence, causes and frequency of hypervolemia in patients without acute kidney injury (AKI) were compared with suitable statistical methods. RESULTS: Hypervolemia was detected in 52 (74.2%) of the 70 patients included in the study, and acute kidney injury was not found in 20 of the patients with hypervolemia. Thirty-eight patients with AKI were identified, of which 9 were mild (stage 1), 7 had stage 2 and 22 had stage 3 AKI. While 84.2% of patients with AKI were hypervolemic, this rate was 62.5% in patients without AKI (p>0.05). No significant correlation was demonstrated between the AKI stage and the prospect of hypervolemia in patients. The most significant indicator was the daily urine output in determining the risk of hypervolemia in both patient groups with and without kidney damage (with or without oliguria). CONCLUSION: In the development of hypervolemia, acute kidney injury takes part as much as other factors such as heart failure, sepsis, and excessive fluid administration. Either forced diuresis is applied or not, having a daily fluid output greater than 1.9 L prevents the development of hypervolemia to a great extent. KEYWORDS: Acute kidney injury, hypervolemia, fluid replacement, hypovolemia