Prevention of contrast-induced nephropathy with volume expansion.

Contrast-induced nephropathy is one of the few preventable forms of acute kidney injury. Several pharmacologic agents have been evaluated for the prevention of contrast-induced nephropathy, yet disappointingly, few have been shown conclusively to reduce the risk for this condition. A series of studies have demonstrated that volume expansion, particularly with intravenous fluids, is an effective intervention to reduce the risk for contrast-induced nephropathy. This article reviews the clinical trials that have assessed the role of volume expansion for the prevention of contrast-induced nephropathy. The administration of isotonic sodium chloride before and after radiocontrast injection seems to be more protective than equivalent volumes of hypotonic saline and, when feasible, should be administered over a sustained period of time. Recent clinical trials suggested that an abbreviated regimen of intravenous sodium bicarbonate may be superior to a comparable protocol of sodium chloride. Although a small number of studies have found that volume supplementation by mouth may be effective in preventing contrast-induced nephropathy, the routine use of enteral fluids or solute in lieu of intravenous fluids in high-risk patients cannot be recommended at this time. Rather, liberal oral fluid and solute intake should complement intravenous fluid administration to minimize risk. Future studies will be required to define clearly the optimal prophylactic intravenous fluid regimen for contrast-induced nephropathy and further delineate the independent role of oral volume expansion for the prevention of this condition.