Figure 1. Current understanding of the pathophysiology of ARC in which critical illness triggers the systemic inflammatory response syndrome (SIRS) or mobilizes renal functional reserve (RFR) to eventually increase renal blood flow and glomerular filtration rate (GFR). Intravenous fluids and drugs administered to critically ill patients may increase cardiac output and contribute to the increase in renal blood flow. Atrial natriuretic peptide (ANP) plasma concentrations are also elevated in patients with ARC and may play a role in increasing renal blood flow. (Modified from Sime FB, Udy AA, Roberts JA. Curr Opin Pharmacol 2015;24:1-6.).