Is Chloride Really Nephrotoxic?

International guidelines recommend the early first-line use of crystalloids for fluid loading in the management of sepsis and septic shock. However, this recommendation is accompanied by a warning regarding the need to monitor blood chloride levels due to the possible involvement of chloride in the occurrence of metabolic acidosis and acute kidney injury by mechanism of vasoconstriction of the afferent arterioles. In the literature, numerous observational studies comparing sodium chloride (NaCl 0.9%) and so-called ``balanced'' solutions have yielded conflict results as regards with the possible causal relationship between hyperchloremia and occurrence of acute kidney injury or death. Only two large randomized, controlled studies in critically ill patients comparing NaCl 0.9% and a ``balanced'' solution (Ringer Lactate (R) and/or Plasma-Lyte (R)) failed to find any significant difference between the two groups in terms of frequency of acute kidney injury, need for renal replacement therapy or death. Future research should probably focus on identifying situations at risk, or on determining the quantities of crystalloids that it is appropriate to administer.