Dialysis in patients with TBI is made more complicated by their propensity to develop pulmonary oedema, and by their sensitivity to fluctuations of blood pressure, all of which can exacerbate secondary brain injury. The normal pre-packaged dialysate fluids have the wrong electrolytes for a TBI patient, and the normal dialysis prescription (designed to maximise the efficiency of the circuit) can lead to unacceptable episodes of ICP elevation. Apart from that, circuit anticoagulation and vas cath position can play a role in promoting new complications. Having said that, it is usually impossible to completely avoid dialysis in these people. Both chronic renal failure and acute renal failure are associated with a worse outcome in TBI.