Effect of positive fluid balance on acute kidney injury and in-hospital mortality in patients admitted to ICU after major surgery or trauma

Abstract

Objective: To evaluate whether or not positive fluid balance is associated with the development and severity of acute kidney injury in intensive care patients admitted after major surgery or trauma, and to examine its relationship with in-hospital mortality.

Method: The retrospective, analytical, cross-sectional study was conducted at the General Surgery Department of Shifa International Hospital, Islamabad, Pakistan, and comprised data from April 2021 to May 2021 of patients aged >16 years admitted to intensive care unit after major trauma.  Demographic and clinical data was noted, and serum creatinine levels and fluid balance were recorded. Mortality rate and incidence of acute kidney injury were the two outcomes of interest. Data was analysed using SPSS 20.

Results: Of the 132 patients with mean age 36.77±17.69 years, 84(63.64%) were males and 48(36.36%) were females. Positive fluid balance was noted in 26(19.7%) patients and negative fluid balance in 29(21.9%). In terms of acute kidney injury, stage 1 was noted in 103(78%) patients, stage 2 in 12(9.1%) and staged 3 in 11(8.3%). Fluid overload was significantly associated with stage 3 acute kidney injury (p<0.05). Overall fluid overload-related mortality was 2(1.5%).

Conclusion: Positive fluid balance was significantly associated with stage 3 acute kidney injury. Intravenous fluids in post-traumatic or post-surgical intensive care patients should be carefully handled to avoid overloading.

Key Words: Fluid resuscitation, Acute kidney injury, Positive fluid balance, Intravenous fluids, Major trauma.