There had been many studies demonstrated that the phosphodiesterase inhibitor pentoxifylline (PTX) is a potent anti-inflammatory, anti-proliferative, and anti-fibrotic agent capable of attenuating experimental renal disease such as drugs, ischemic and sepsis induced AKI. We thereby design this controlled, non-randomized clinical trial, aiming at investigating the potential renoprotective efficacy of PTX, as compared to placebo, in 200 patients with AKI.