Intravascular volume depletion
Acute coronary syndrome within 4 weeks
Indication for hemodialysis
Creatinine >3.5 mg/dL at admission to the hospital
Systolic blood pressure <90 mm Hg at time of enrollment
Alternate explanation for worsening renal function, such as obstructive nephropathy, contrast induced nephropathy, acute tubular necrosis
Hematocrit >45%
Poor venous access
Clinical instability likely to require the addition of intravenous vasoactive drugs including vasodilators and/or inotropic agents
Allergy or contraindications to the use of heparin
The use of a iodinated radiocontrast material in the past 72 hours or anticipated use of intravenous contrast during the current hospitalization