What is the main focus of treatment for severe lithium toxicity with renal failure?

In cases of severe lithium toxicity, especially when accompanied by renal failure, the primary focus of treatment is hemodialysis. Lithium is primarily excreted by the kidneys, and in the setting of renal failure, the elimination of lithium from the body is significantly impaired. Consequently, lithium levels can rise to dangerous levels, leading to toxicity.

Hemodialysis is effective in rapidly removing lithium from the bloodstream, particularly because lithium does not have significant protein binding and is small enough to be filtered during dialysis. This treatment not only helps in removing excess lithium but also addresses the metabolic derangements that can occur as a result of lithium toxicity.

Increasing hydration or utilizing diuretics may seem like reasonable approaches; however, they are often ineffective for lithium clearance in severe toxicity. Diuretics can actually exacerbate renal failure or lead to volume depletion, which is not desirable in this scenario. Sedatives would not address the underlying issue of lithium accumulation and toxicity, and they might even complicate the patient's condition due to potential respiratory depression and altered mental status from lithium's central nervous system effects. Thus, hemodialysis stands out as the most definitive and effective treatment in such cases.