Dialysis and iodinated contrast media

Abstract

Contrast media are excreted mainly by glomerular filtration. There is thus, a significant correlation between both body and renal clearances of contrast media and glomerular filtration rate, and their renal excretion will be delayed in patients with renal insufficiency. Contrast media can be efficiently removed from blood by hemodialysis (HD). Since most contrast media are middle-sized molecules, the main factors potentially influencing their removal by HD are blood flow, membrane surface area, molecular size, transmembrane pressure, and dialysis time. Peritoneal dialysis is also effective in removing contrast agents from the body but takes longer than HD. Dialysis immediately after radiographic contrast studies has been suggested for two groups of patients. Those on chronic HD and those at very high risk for contrast nephropathy. Three studies have examined the necessity of immediate dialysis after intravascular injection of contrast media in chronic HD patients; the authors found no evidence that it is effective at preventing contrast nephropathy. The reasons why HD treatment was not beneficial in those three studies are not known. Perhaps, the rapid onset of renal injury after administration of contrast media is one answer. It is also possible that HD per se was nephrotoxic and might have offset the beneficial effect of the removal of contrast media. Marenzi et al. randomized 114 consecutive patients with chronic renal failure undergoing coronary interventions to either hemofiltration in an intensive care unit or isotonic saline hydration. The authors concluded that periprocedural hemofiltration given in an intensive care unit setting appears to be effective in preventing the deterioration of renal function due to contrast agent induced nephropathy and is associated with improved in-hospital and long term outcomes. The concentration of contrast media can effectively be reduced by HD and peritoneal dialysis. HD does not offer any protection against contrast media induced nephrotoxicity. Hemofiltration may decrease the risk of contrast induced nephropathy and have some long-term benefits, but additional studies are needed to better define the appropriate population for this treatment.

Risks and Complications of Coronary Angiography: Contrast Related Complications

“…Meanwhile, the rate of chronic dialysis at the time of discharge in salin group was 45% (Solomon etal., 2004). Nevertheless, other studies demonstrated that hemodialysis in patients with previous history of renal failure was not beneficial and the incidence of CIN will not be changed by this modality (Deray, 2006;Vogt, 2001).One meta-analysis has supported this result (Cruz etal., 2006). Patients on dialysis do not also need dialysis after contrast exposure (Hamani etal., 1998;Morcos etal., 2002).…”

“…Only few study reported the prophylactic usefulness of hemodialysis (Lee etal., 2007;McCullough & Soman, 2005). But repeatedly it has been shown that hemodialysis has no role in preventing CIN (Cruz etal., 2006;deray, 2006;Marenzi etal., 2006b). In contrast to positive studies one RCT showed that prophylactic dialysis caused more reduction of renal function and these patients need more dialysis after exposure to contrast (Vogt etal., 2001).…”

Renal Replacement Therapy for Prevention of Contrast-Induced Acute Kidney Injury: A Meta-Analysis of Randomized Controlled Trials

“…The first study was criticized for the methodological flaw using serum creatinine to evaluate the renal function and for the insufficient clearance of contrast with a low dosage of substitution solution [25]. Several potential reasons for the efficacy of CVVH, such as the use of heparin and biocarbonate-based solution, have been raised, but none of them seemed plausible.…”

Contrast-induced nephropathy: Update with special emphasis on patients with diabetes

“…There have a very high osmolality; however, because only small amounts (0.3 mL/kg of body weight) are injected for most studies compared with 1 to 2 mL/kg of body weight for iodinated contrast media, the systemic effect of osmolality is minimal. However, when these agents are used for radiograph attenuation rather than their magnetic properties (as in digital subtraction angiography), doses that are two to three times higher are required and nephrotoxicity (CIN) has been reported [22].…”