Many studies have looked at this question but with no real answer that was put forth. In a recent 2013 AKI ( European best practice position statement) on KDIGO guidelines on RRT, they mention the following:
##Use of CRRT or IHD as complementary therapies in AKI( Grade 1A)
##Using CRRT or SLED than IHD for hemodynamically unstable patients( no grade given)
##Using CRRT rather than IHD for AKI associated with brain injury or increased intracranial pressure ( grade 2D). – This is based on limited evidence poor quality studies. Intermittent modes of renal replacement therapy have been shown to cause an increase in intracranial pressure in susceptible patients, including those with acute liver failure and cerebral edema from trauma or post neurosurgery. Such changes are due to the combination of adverse effects on cerebral oxygen delivery and/or cerebral perfusion pressure and the generation of an osmotic gradient between plasma and cerebral tissues. Compared with standard IHD, CRRT provides an effective therapy in terms of solute clearance, coupled with improved cardiovascular and intracranial stability. The disadvantage of CRRT is that anticoagulation may be required, and anticoagulants with systemic effects may provoke intracerebral hemorrhage. CRRT also has been shown to help in case reports to decrease intra cranial HTN.
##The dose of CRRT to be delivered an effluent volume of 20-25ml/kg/h for post dilution CRRT in AKI( Grade 1A)
##Medication adjustment based on clearance needs to be taken into account.