Prerenal oliguria of cardiogenic cause

Specialty: Cardiovascular.

• oliguria due to low cardiac output
• decrease in urinary volume of cardiac origin
• cardiorenal syndrome type 1

Why it occurs

• Cardiogenic shock secondary to acute myocardial infarction
• Decompensated congestive heart failure with "cold" hemodynamic profile (systemic tissue hypoperfusion)
• Cardiac tamponade with severe limitation of ventricular filling
• Acute fulminant myocarditis
• Massive pulmonary thromboembolism with hemodynamic collapse

Initial workup

Determination of blood urea nitrogen/creatinine ratio (typically increased >20:1 in prerenal oliguria); Determination of sodium ejection fraction (FeNa, which is usually <1% in pure prerenal origin); Urinalysis with high urine density (>1,020) and high urine osmolarity (>500 mOsm/kg); Emergency transthoracic echocardiogram to measure LVEF, stroke volume, estimate cardiac output and left ventricular filling pressure (E/e'); Invasive monitoring using an arterial catheter for continuous blood pressure reading.

Standard management

• Dobutamine — beta-adrenergic inotrope indicated to increase ejection volume and improve renal perfusion in heart failure with low output and borderline blood pressure; intravenous infusion of 2.5 to 10 mcg/kg/min
• Furosemide — loop diuretic indicated with caution to force diuresis only if the patient is euvolemic or hypervolemic without refractory hypotension; 40 to 80 mg intravenous bolus, discontinuing if renal function worsens without diuretic response
• Norepinephrine — vasopressor indicated in deep cardiogenic shock with severe hypotension to maintain adequate coronary and renal perfusion MAP; infusion of 0.05 to 0.5 mcg/kg/min
• Milrinone (inodilator indicated if there is failure of contractility without severe hypotension; intravenous infusion of 0.375 to 0.75 mcg/kg/min).