Does a lithium level of 3.5 mmol/L require dialysis?

From the Guidelines

Yes, a lithium level of 3.5 mmol/L typically requires dialysis as an emergency intervention. This level is considered severely toxic, well above the therapeutic range of 0.6-1.2 mmol/L, and represents a potentially life-threatening situation 1. Initial management should include discontinuation of lithium, hospital admission for intensive monitoring, and urgent nephrology consultation for hemodialysis.

Key Considerations

• Intravenous fluids with normal saline should be started immediately to promote lithium excretion while awaiting dialysis.
• Hemodialysis is particularly effective for lithium removal because lithium is a small molecule with minimal protein binding and distributes primarily in the extracellular fluid.
• Patients with this level may experience severe neurological symptoms including seizures, coma, or cardiac arrhythmias.
• Even after dialysis is initiated, multiple sessions may be required due to redistribution of lithium from tissues back into the bloodstream.
• Close monitoring of lithium levels, electrolytes, renal function, and neurological status is essential throughout treatment.

Decision for Dialysis

The decision for dialysis is based not only on the absolute lithium level but also on the patient's clinical condition and kidney function, as outlined in the KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease 1.

Clinical Guidelines

• Practice Point 5.4.1: Initiate dialysis based on a composite assessment of a person’s symptoms, signs, QoL, preferences, level of GFR, and laboratory abnormalities 1.
• Practice Point 5.4.2: Initiate dialysis if the presence of one or more of the following situations is evident, often but not invariably occurring in the GFR range between 5 and 10 ml/min per 1.73 m2 1.

From the FDA Drug Label

In severe cases of lithium poisoning, the first and foremost goal of treatment consists of elimination of this ion from the patient ... Hemodialysis is an effective and rapid means of removing the ion from the severely toxic patient Serum lithium levels above 3 mEq/l may produce a complex clinical picture involving multiple organs and organ systems

A lithium level of 3.5 mmol/L is considered severely toxic and may require hemodialysis to remove the ion from the patient.

• The decision to initiate dialysis should be based on the patient's overall clinical condition and the presence of severe symptoms.
• Hemodialysis is an effective treatment for severe lithium poisoning, and its use should be considered in patients with levels above 3 mEq/L 2.

From the Research

Lithium Level and Dialysis

• A lithium level of 3.5 mmol/L is considered severe intoxication, and hemodialysis therapy is recommended 3, 4.
• However, patients with acute lithium toxicity may not require hemodialysis therapy, even with potentially lethal levels, if they have mild symptoms 3.
• The decision to initiate dialysis should be based on the patient's clinical presentation, including the presence of severe symptoms, such as neurologic or cardiovascular symptoms 3.
• Lithium clearance occurs quickly with hemodialysis, but a rebound effect can occur as lithium in intracellular water equilibrates with extracellular fluid, requiring prolonged dialysis to reduce the blood lithium level to the therapeutic range 5.

Clinical Considerations

• Patients with chronic lithium intoxication are more likely to have severe symptoms and may require hemodialysis therapy 3.
• The duration of exposure to lithium is a major risk factor for renal toxicity, including decreased renal concentrating ability and chronic renal failure 6.
• Lithium-induced nephrogenic diabetes insipidus (NDI) is a common adverse effect of lithium, occurring in up to 40% of patients, and can be treated with the epithelial sodium channel (ENaC) inhibitor amiloride 7.

Treatment Guidelines

• Hemodialysis therapy is recommended for patients with severe lithium intoxication, defined as a serum lithium level greater than or equal to 3.5 mEq/L 3, 4.
• Patients with mild symptoms and a serum lithium level below 3.5 mEq/L may not require hemodialysis therapy, but should be closely monitored for signs of toxicity 3.