It has been hypothesized that alkalinization of tubular fluid might be beneficial by reducing pH dependent free radical levels. A recent trial found a lower frequency of creatinine rise > 25% within two days of contrast with a 7 hour infusion of isotonic sodium bicarbonate than with saline infusion (Merten GJ, JAMA 2004). However, it remains to be proven that bicarbonate is superior as this trial has a number of methodological flaws.