Intravenous fluid resuscitation therapy is one of the pillars of critical care. However, fluid overload increases the risk of cardiorespiratory impairment and can severely affect kidney function.
The type and amount of fluid administered is known to influence renal outcomes. Whereas isotonic crystalloid solutions are largely preferred over colloid substances for critically ill patients, albumin solutions may be indicated in specific cases where there is high fluid demand.
By contrast, artificial colloid formulations have been associated with kidney-related mortality.
Capacity of urine output and serum creatinine levels are commonly used to measure renal function, but they vary according to type of fluid and need to be used with caution when assessing the effectiveness of fluid therapy for an individual patient.
This article discusses the usefulness of these measures of renal dysfunction as well as the requirement of fluid therapy in renal resuscitation and reviews the currently available data from studies examining the relationship of fluid therapy and acute kidney injury and mortality.
The authors also cover the underlying mechanisms of kidney injury for each type of fluid, emphasising that the administration of fluids should not constitute an automatic response to oliguria and increased creatinine levels in critically ill patients.