IN THE NEWS: Contrast Nephropathy

Preventing contrast nephropathy has always been a research topic. From anti oxidants to hydration to dialysis all have been suggested. Hydration likely to be the only winner thus far.
Two recent studies need to be highlighted that have come out in the cardiology literature.

1.  Tamai et al from Japan studied a moderate size subgroup of patients with significantly high doses of bircarbonate infusion( close to 800meq/L) compared to standard bicarbonate infusions(160meq/L) pre cardiac cath at a rate of 3ml/kg/h for one hour. As expected urine pH was higher in the first group but statistical significant rate of decline of contrast induced nephrolopathy as well in that group. Potassium values didn't change much. 48 Hour GFR change was much more in the standard bicarbonate group. Interestingly, baseline renal function was around 1.3-1.4mg/dl with some difference in both groups making this study weaker. Also, while initial Na concentrations were similar, wonder what 24 hour Na levels were in these cases. Interesting study to bring back alkalization as a potential prevention for contrast nephropathy.

2. Marenzi et al show that fluids with match diuresis might prevent contrast induced nephropathy compared to standard fluid therapy The MYTHOS study looked at 250ml Normal Saline bolus followed by furosemide to keep urine output >300cc/h and then do the cardiac procedure versus a standard fluid infusion model. Contrast induced nephropathy rates were much lower in the case where urine output was high. Another interesting concept and study to look at this problem

Both studies: single centers, small studies, many limitations. Have a look but they might catch on in the cardiology world and we might be seeing some of this happening at our centers.