Acute Kidney Injury (AKI) is a frequent and important complication to cardiac surgery. The pathophysiology is multifactorial, but renal functions in this setting is determined by a complex interplay between renal perfusion, fluid status, cardiac output, mean arterial pressure and back pressure to venous outflow.~Renal perfusion may be quantified with novel ultrasound techniques. Ultrasonography of the kidney and renal vasculature allows for assessment of renal afferent flow and renal venous flow and, together with venous flow patterns of the portal vein and liver veins, may identify patients in risk of AKI.~The study is observational and will describe the diagnostic accuracy of the ultrasound measures in predicting postoperative AKI. Patients will be examined with ultrasound of kidney and liver flow along with echocardiography on on the day before surgery and on the 1st and 4th. In addition, patients are followed with markers of kidney function, fluid balance and invasive measures of mean arterial pressure and central venous pressure.
Acute Kidney Injury (AKI) is a frequent and important complication to cardiac surgery. This study will evaluate the diagnostic ability of ultrasonographic measures of blood flow in kidneys and liver in predicting AKI after cardiac surgery.