Cardiorenal Syndrome

Defined as a pathophysiologic disorder of the heart and kidneys wherein the acute or chronic deterioration of one organ results in the acute or chronic deterioration of the other

Classified into five types

• Type 1 consists of acute kidney injury (AKI) stemming from acute cardiac disease

• Type 2 is chronic kidney disease (CKD) due to chronic cardiac disease

• Type 3 is acute cardiac disease as a result of AKI

• Type 4 is chronic cardiac decompensation from CKD

• Type 5 consists of heart and kidney dysfunction due to other acute or chronic systemic disorders (such as sepsis)

Cardiac dysfunction: acute or chronic heart failure, ischemic injury, or arrhythmias

Kidney disease: acute or chronic, depending on the type of cardiorenal syndrome

Evaluate cardiac status with applicable studies, such as BNP, ECG, and echocardiogram

Evaluate kidney status with applicable studies, such as

• BUN; serum creatinine, serum electrolytes, serum bicarbonate

• Complete blood count

• Urine microscopy

• Fractional excretion of sodium or FE_Na = (urine_Na/serum_Na)/(urine_Cr/serum_Cr) × 100%

• FE_Na is high (> 1%) in acute tubular necrosis

• Renal ultrasound

Treat primary underlying cardiac or renal dysfunction