Contrast-induced nephropathy: attributable incidence and potential harm

Contrast-induced nephropathy is a common form of hospital-acquired acute kidney injury. Incidence is low in patients with normal renal function but increases in high-risk patients. Patients with contrast-induced nephropathy have higher in-hospital complication rates and mortality. Critically ill patients have been assumed to be a high-risk group for contrast-induced nephropathy. In the previous issue of Critical Care, Cely and colleagues showed an unexpectedly low incidence of contrast-induced nephropathy in critically ill patients receiving radiographic contrast material for computerized tomography. We should note that it is difficult to establish the true frequency and impact of the contrast nephrotoxicity because of many other causes for acute kidney injury in this population. Moreover, the impact on long-term kidney function and the possible effect of this insult on the recovery of renal function when associated with other causes of acute kidney injury are unknown.