 Patients with Stage 3B, 4,or 5 Chronic Kidney Disease who are to undergo an angiography procedure with contrast agent will be asked if they are willing to join the trial. If so they will be screened and randomized to receive either sodium bicarbonate or saline before, during and after the contrast media is given. They will be asked for serum samples 1 to 3 days, 7, 30, 90 and 180 days after the procedure to evaluate whether the sodium bicarbonate has reduced the incidence of contrast induced chronic kidney disease by measuring their serum creatinine, as well as whether they have required renal dialysis or other renal replacement therapy. 