ICU · toxicology

Acute Lithium Toxicity — Comprehensive ICU Management

Also known as Lithium poisoning · Lithium toxicity · Lithium intoxication · SILENT · Syndrome of irreversible lithium-effectuated neurotoxicity · Narrow therapeutic index · Whole bowel irrigation lithium · Lithium haemodialysis

Acute and chronic lithium toxicity — a narrow therapeutic-index drug excreted almost exclusively by the kidney as the free ion (maintenance targets 0.6-0.8 mmol/L, some authorities 0.8-1.2; clearance falls with ageing, renal insufficiency and interacting drugs — diuretics, ACE inhibitors, NSAIDs). THREE patterns — acute, acute-on-chronic and chronic; chronic is the commonest, usually unintentional, driven by impaired kidney function from volume depletion (including lithium-induced nephrogenic diabetes insipidus) or drug interactions. The CNS is the primary site of toxicity (confusion, ataxia, seizures); persistent, particularly cerebellar, neurological deficits are described after chronic poisoning. Management: STOP lithium and interacting drugs, correct volume depletion (routine sodium chloride infusion to force lithium excretion is NOT recommended — no specific effect on excretion, caused hypernatraemia), consider whole-bowel irrigation for substantial sustained-release ingestions, and apply EXTRIP extracorporeal criteria — recommended in severe poisoning, with impaired kidney function and level over 4.0 mEq/L, or with decreased consciousness, seizures or life-threatening dysrhythmias at any level; suggested for level over 5.0 mEq/L, significant confusion, or expected time to under 1.0 over 36 h; haemodialysis preferred (lithium is readily dialyzable), continuous RRT an acceptable alternative; continue until clinical improvement or level under 1.0 mEq/L — intracellular lithium redistributes, so EXPECT REBOUND.