Hyperammonemia hemodialysis

Dialysis, including hemodialysis and peritoneal dialysis, relieves acute toxicity during fulminant hyperammonemia. Exchange transfusions also have been performed, but this technique has not been equally useful in removing ammonia. 

Acute neonatal hyperammonemia, irrespective of cause, is a medical emergency and requires immediate and rapid lowering of ammonia levels to prevent serious effects on the brain. Useful measures include hemodialysis, exchange transfusion, peritoneal dialysis, and administration of arginine hydrochloride. The general goals of management are to... 

In the case of rapidly increasing hyperammonemia, with anunonia values exceeding 400-500 pmol/L or if there is no significant decreasing of ammonia values (after 4 h of treatinent or, if after 12-24 h of treatment, the ammonia concentration still exceeds 200 pmol/L), a swift decision should be made to eliminate ammonia with extracorporeal methods. The limitation of peritoneal dialysis or blood transfusion is that these procedures are not so effective and induce catabolism. Hemofiltration or hemodialysis should be started, and the best method to use depends upon the patient s body mass and experience of the medical staff. If there is no possibility of performing hemodialysis, the patient should be immediately transferred to another center. If a transfer is not possible, peritoneal dialysis can be considered as a relatively simple method of extracorporeal filtration [8,14, 17]. 

In a systematic literature search, 31 reports have been identified of the use of extracorporeal elimination in acute valproate poisoning [415 j. Even though there have been no controlled comparisons of the clinical outcomes with or without extracorporeal elimination in valproate poisoning, extracorporeal methods of elimination should be considered in patients with features of severe valproate poisoning (coma or hemodynamic compromise) and plasma valproate concentrations over 850 mg/1, particularly if severe hyperammonemia and electrolyte and acid-base disturbances are present. Hemodialysis appears to be the extracorporeal method of choice to enhance valproate elimination in acute poisoning, and several case reports have consistently shown that during hemodialysis the half-life of valproate can be reduced to around 2 hours and that enhanced clearance is often associated with clinical improvement. 

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