Management of Acute Lithium Toxicity in the Emergency Setting
Acute lithium toxicity requires immediate supportive care with intravenous isotonic saline resuscitation, and hemodialysis should be strongly considered for patients with severe symptoms (especially neurological), chronic or acute-on-chronic toxicity with levels >2.5 mEq/L, or renal impairment regardless of level. 1, 2
Initial Assessment and Stabilization
Distinguish the pattern of toxicity immediately, as this determines both prognosis and treatment intensity 3:
- Acute ingestion (lithium-naive patients): Often presents with mild symptoms despite high serum levels due to limited tissue distribution; may not require aggressive intervention 4, 5
- Chronic toxicity: Most common pattern, typically unintentional, results from impaired elimination (volume depletion, renal dysfunction, drug interactions); associated with severe neurological symptoms and prolonged recovery 3
- Acute-on-chronic: Combines features of both; treat as chronic toxicity 2, 3
Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 4-14 mL/kg/hour while simultaneously correcting electrolyte abnormalities 6, 7. Target urine output >1 mL/kg/hour as an indicator of adequate resuscitation 6, 7.
Gastric Decontamination
Perform gastric lavage only in acute ingestions presenting within 1-2 hours 1, 4. This intervention has minimal utility in chronic toxicity where lithium is already distributed throughout total body water 2.
Whole-bowel irrigation may be considered for acute ingestions of sustained-release formulations, though evidence is limited and this is not mentioned in the primary guidelines 1.
Fluid and Electrolyte Management
Administer isotonic saline aggressively to restore intravascular volume and enhance renal lithium elimination 6, 1. The FDA label specifically recommends correction of fluid and electrolyte imbalance as a cornerstone of treatment 1.
Maintain high-normal sodium levels (avoid hyponatremia), as sodium administration may reduce intracellular lithium accumulation in excitable cells 4. Never use hypotonic fluids (0.45% or 0.2% NaCl) as these worsen hyponatremia 6.
Monitor and correct electrolytes immediately, particularly potassium, as metabolic acidosis often coexists with dangerous electrolyte disturbances 6, 7. Check baseline sodium, potassium, chloride, and bicarbonate to guide therapy 6.
Loop Diuretics: NOT Recommended
Avoid loop diuretics in lithium toxicity. While the FDA label mentions that mannitol and aminophylline produce significant increases in lithium excretion 1, loop diuretics are not recommended and could worsen volume depletion, which is often the precipitating cause of chronic toxicity 3. Focus instead on volume repletion with isotonic saline 6, 1.
Hemodialysis Indications
Hemodialysis is the most effective method for rapidly removing lithium and should be initiated based on clinical presentation rather than serum level alone 1, 4, 2.
Strong Indications for Hemodialysis:
- Severe neurological symptoms (confusion, seizures, coma, ataxia) with any elevated lithium level 2, 5
- Chronic or acute-on-chronic toxicity with serum lithium >2.5 mEq/L 2
- Renal impairment (reduced ability to eliminate lithium naturally) 2, 5
- Persistent or worsening symptoms despite supportive care 5
Hemodialysis May NOT Be Required:
- Acute ingestion in lithium-naive patients with mild symptoms, even with levels >3.5 mEq/L, as these patients frequently have minimal tissue distribution and good outcomes with supportive care alone 5
- In one study, 10 patients with acute intoxication and levels ≥3.5 mEq/L (range 4.7-5.7 mEq/L) had no severe symptoms; 5 received hemodialysis and 5 did not, with no deaths or permanent sequelae in either group 5
Hemodialysis Technical Considerations:
Expect rebound in serum lithium concentrations after hemodialysis due to redistribution from tissues; repeated or prolonged treatment may be required 2. Continuous venovenous hemodiafiltration (CVVHD) sustained for >16 hours allows effective removal of total body lithium while avoiding rebound effects 2.
The choice between intermittent hemodialysis and continuous techniques depends on local accessibility and urgency: use intermittent hemodialysis for severe acute presentations requiring rapid removal, and consider continuous techniques for sustained elimination without rebound 2.
Monitoring Parameters
Check serum lithium levels every 4-6 hours initially during active treatment, then adjust frequency based on clinical response 8, 6.
Monitor continuously:
- Vital signs (blood pressure, heart rate) 6
- Urine output (target >1 mL/kg/hour) 6, 7
- Neurological status (level of consciousness, tremor, ataxia, seizures) 5, 3
- ECG for arrhythmias related to electrolyte disturbances 7
Laboratory monitoring every 1-2 hours during acute resuscitation 7:
- Serum sodium, potassium, chloride, bicarbonate 6, 7
- BUN and creatinine (assess renal function) 8, 1
- Arterial blood gas, pH, anion gap, lactate 6, 7
Medications That Enhance Lithium Excretion
Sodium administration (via isotonic saline) is the primary pharmacological intervention 1, 4. The FDA label notes that urea, mannitol, and aminophylline all produce significant increases in lithium excretion 1, though these are rarely used in modern practice compared to hemodialysis for severe cases 2.
Common Pitfalls to Avoid
Do not rely solely on serum lithium levels to guide treatment in chronic toxicity; clinical symptoms (especially neurological) are more important than absolute levels 5, 3. Patients with chronic toxicity can have severe symptoms at therapeutic or mildly elevated levels due to high tissue concentrations 2, 3.
Do not delay hemodialysis in symptomatic patients with chronic toxicity while waiting for levels to reach arbitrary thresholds like 4.0 mEq/L 2, 5.
Avoid nephrotoxic medications (NSAIDs, ACE inhibitors, ARBs) that precipitated the toxicity 9, 8.
Do not discharge patients prematurely; chronic lithium poisoning can require prolonged hospitalization due to impaired mobility, cognition, and nosocomial complications 3. Persistent neurological deficits, particularly cerebellar dysfunction, are described though uncommon in uncomplicated acute poisoning 3.
Maintain hydration during intercurrent illness and avoid volume depletion, which is the most common precipitant of chronic toxicity 9, 8, 3.
Prognosis
Acute lithium toxicity has a low mortality rate 3. Patients with acute ingestion typically recover fully with supportive care 5. Chronic toxicity carries higher risk of prolonged symptoms and potential permanent neurological sequelae, though the incidence is poorly understood 3.