Dialysis disequilibrium syndrome in neurointensive care unit: the benefit of intracranial pressure monitoring
© BioMed Central Ltd 2012
Published: 31 December 2012
Dialysis disequilibrium syndrome (DDS) is a brain disease characterized by neurological symptoms due to cerebral edema after hemodialysis (HD). However, a direct measurement of intracranial pressure (ICP) rarely objectified this edema . We report the case of a patient whose DDS was diagnosed by an increase of ICP.
DDS was first described in 1962 . Symptoms due to cerebral edema vary from headache, nausea, and convulsion to coma. In our case, we detect DDS by ICP monitoring. Risk factors are first HD, severe uremia, age, pre-existing neurological disorders, and metabolic acidosis. A rapid clearing of small-sized molecules (such as urea) generated the symptoms. The main theory is the 'reverse urea effect', in which the shift of urea between brain intracellular space and plasma is not immediate but causes a brain intracellular space to interstitial osmotic gradient and leads to cerebral edema .
This case is didactic because, as we monitored the ICP, we saw the consequences of DDS on the brain. Treatments consist of a slow gentle start of HD, increasing dialysate sodium levels, and administration of osmotically active substances. We think that CVVH should be used to treat patients with risk factors, especially in the neurointensive care unit . This technique allows gradual osmotic movement and minimizes the gradient between blood and cerebrospinal fluid.
In conclusion, in the intensive care unit, DDS should be considered at each alteration of consciousness during an HD. We suggest that CVVH be used in predisposed patients to minimize the risk of DDS.
continuous veno-venous hemofiltration
dialysis disequilibrium syndrome
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