From a recent review:
Augmented renal clearance (ARC) is a prevalent condition in the critically ill.
ARC may result in sub-therapeutic exposure of renally eliminated antibiotics.
Beta-lactams are particularly affected due to their pharmacokinetic and pharmacodynamic characteristics.
Dose optimization is necessary to circumvent the influence of ARC.
Therapeutic drug monitoring may be necessary to guide dose optimization.
Dose optimization might consist, in the case of beta lactam antibiotics and their congeners, of extended or continuous infusion dosing. Although ARC is defined by a creatinine clearance of greater than 130 mL/min/173 m2 routine clinical estimates may not be reliable. Moreover, enhanced tubular secretion or diminished reabsorption may account for ARC of some antibiotics. Less severely ill patients tend to be at greater risk for ARC.