HYPERLITHEMIA CORRECTION AND PERSISTENT DELIRIUM

Experience with three patients whose courses are described suggested t hat delirium and persistent neurologic dysfunction follow rapid correc tion of hyperlithemia, which develops after regular lithium doses. Fro m all retrievable published reports of adult hospitalization for hyper lithemia, all cases that described cognitive dysfunction after lithium administration for at least 10 days with insubstantial neuroleptic ex posure were selected. Lithium was universally discontinued before or o n admission. Of the 65 such cases, 50 were at least somewhat responsiv e on admission; of these, substantial deterioration during hospitaliza tion occurred in 56%. Dialysis was associated with greater incidence o f persistent neurologic sequelae (62% vs. 22%, P = .012) and deteriora tion during hospitalization (85% vs. 46%, P = .016), although cognitiv e dysfunction on hospital admission was less (P < .001) for patients w ho were then dialyzed. The greater neurotoxicity after dialysis sugges ts that while hyperlithemia can be toxic, its rapid correction can be more toxic. Parallels with hyponatremia, including a potential mechani sm, suggest that gradual rather than abrupt correction of hyperlithemi a might decrease the risk of neurotoxicity.