ARC--augmented renal clearance

In-hospital and intensive care unit mortality rates for sepsis remain un-acceptably high, and have prompted the publication of international guidelines on best practice. Crucial to this is the application of early appropriate antibacterial therapy, in the correct dose. However, antibacterial regimes in this setting have largely been extrapolated from those in healthy volunteers, and fail to consider the unique pathophysiology and treatment provided to this population. As such, augmented renal clearance (ARC) - the enhanced renal elimination of circulating solute - is likely to be one of the more common physiological changes encountered in this setting, although to date remains largely under-appreciated. Significantly this may alter the pharmacokinetics of many routinely prescribed agents in this setting, pre-disposing to subtherapeutic levels or treatment failure. This review paper examines this phenomenon in detail, providing a summary of the likely underlying mechanisms, those patients at greatest risk, and the implications for antibacterial dosing in the critically ill.