Prophylaxis of Contrast-induced nephropathy

Prophylaxis of Contrast-induced Nephropathy (CIN)

Contrast-induced nephropathy (CIN) is a well-known potential complication of contrast-enhanced radiographic or ultrasound studies. CIN is an impairment of renal function occurring after the administration of iodinated contrast media and is defined as an absolute rise in serum creatinine of 0.5 mg/dL or 25% from baseline, within the first 48 to 72 hours. CIN is associated with increased morbidity, mortality, and higher costs.

There are a number of pharmacologic and non-pharmacologic interventions that have been studied to evaluate the effectiveness of their potential in preventing CIN. These include pharmacologic interventions such as saline hydration, loop diuretics, N-acetylcysteine, ascorbic acid, and statins, as well as non-pharmacologic interventions, such as volume expansion, reflex late nephron blockade, and temporary dialysis.

Hydration is one of the most studied and most beneficial interventions for CIN prevention. The volume of fluids administered varies according to patient characteristics, but the goal is to ensure adequate urine output and a urine osmolality that is lower than that of serum. For patients with normal kidney function, 1 to 1.5 L of isotonic saline should be administered the day before the scheduled procedure, followed by 0.5 to 1 L/h for 6 to 12 hours before the procedure.

Ascorbic acid, oral administration of which has been studied in adult patients and children, has been suggested to be beneficial for CIN prevention. N-acetylcysteine has been considered an effective prophylactic agent for its ability to reduce serum creatinine levels in patients at risk for CIN. Loop diuretics, such as furosemide, have also been studied and found to be effective for the prevention of CIN.

Non-pharmacological interventions

Volume expansion, by far the most studied non-pharmacological intervention to prevent CIN, entails the administration of 0.45% or 0.9% sodium chloride solution as an isotonic infusion solution. The goal is to achieve an adequate urine output with urine osmolality lower than that of serum. Temporary dialysis, i.e., hemodialysis or peritoneal dialysis, is another potential strategy for preventing CIN, however, it has not been universally accepted since it requires highly specialized medical expertise and equipment. Recently, suggested in the literature is a reflex late nephron blockade that involves the continuous infusion of modified isotonic solutions to achieve a relative hypoosmolar state with sustained total osmolality.

Conclusion

Several strategies, such as pharmacological, non-pharmacological, and temporary dialysis interventions have been studied as potential methods for prophylaxis against CIN. Hydration, ascorbic acid, N-acetylcysteine, and loop diuretics have been identified as effective pharmacological prophylactic agents. Non-pharmacological interventions, such as volume expansion and reflex late nephron blockade, have been studied and found to be beneficial for preventing CIN. In addition, temporary dialysis has been suggested, although it has not been universally accepted due to the necessity of specialized medical expertise and equipment.