الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 109 |  |  |
| | | from | 109 | | |
Abstract
CIN is defined as an increase in baseline serum creatinine by 0.5 mg/dl or a rise of 25% from the baseline level prior to contrast administration and the nephropathy cannot be attributed to any other known cause of deranged kidney function, and it usually occurs within 48-72 hours after IV contrast administration1. It is a well-known complication of CA and PCI due to the use of iodinated contrast media4.
CIN is most commonly associated with identifiable risk factors, such as advanced age, DM, HTN, and underlying CKD which is considered the most important risk factor. Physical properties of the contrast agent such as osmolarity, ionicity, molecular structure and viscousity determine the level of nephrotoxicity. Higher doses, intra-arterial compared with IV administration, high-osmolar contrast media, and administration of multiple doses of contrast within 72 hours all increase the risk for development of CIN in at-risk populations7. Although there are many complex pathways involved in the development of CIN, the end result is thought to be ischemic injury to the renal medulla. After administration of contrast, renal blood flood temporarily increases, then decreases over a prolonged period. These changes are mediated by a complex interplay of many factors. Renal vasoconstriction plays a major role and is mediated by vasoactive substances5, 7.
Randomized trials have found IV hydration with normal saline to be consistently effective in the prevention of CIN in patients of all risk categories10. The efficacy of oral hydration for the prevention of CIN in patients who receive contrast as outpatients or elective radiological procedures is still conflicting. A randomized controlled trial study found a higher rate of CIN in patients undergoing elective cardiac catheterization who received oral fluid regimen than those who received IV normal saline. Conversely, a few studies demonstrated no difference in the incidence of CIN between oral fluid hydration group and IV fluid regimen group13-17.
Because providing water alone does not increase the sodium content of body fluids, increasing the water intake of patients does not expand the intravascular volume or promote renal blood flow. In contrast, supplementation with an ORS might be effective as a CIN prophylactic. Low-osmolar ORS formula is 2.6 grams sodium chloride (NaCl),