Enhanced elimination

Baird-Gunning 2017Buckley 2020

Haemodialysis increases lithium clearance, but is not usually required to treat chronic lithium toxicity in patients with normal kidney function. Haemodialysis may be indicated if:

  • the serum lithium concentration is expected to still be elevated (ie more than 1 mmol/L) after 36 hours
  • the patient has clinical features of severe toxicity.
Use the nomogram in Nomogram to predict if serum lithium concentration will be more than 1 mmol/L after 36 hours to predict if the serum lithium concentration will be more than 1 mmol/L after 36 hours. If considering haemodialysis, discuss with a clinical toxicologist.
Figure 1. Nomogram to predict if serum lithium concentration will be more than 1 mmol/L after 36 hours.

[NB1]

Plot the patient’s eGFR (mL/min/1.73m2) against their lithium concentration (mmol/L) at presentation. If this point is above the line, the patient’s lithium concentration is expected to be more than 1 mmol/L after 36 hours—seek advice from a clinical toxicologist about using haemodialysis. If the patient has clinical features of severe toxicity, discuss with a clinical toxicologist whether haemodialysis would be beneficial.

Note:

eGFR = estimated glomerular filtration rate

NB1: The dotted line signifies that in patients with an eGFR above 90 mL/minute, the actual eGFR value is not often reported on a standard laboratory assay.

Adapted with permission from Buckley NA, Cheng S, Isoardi K, Chiew AL, Siu W, Vecellio E, et al. Haemodialysis for lithium poisoning: Translating EXTRIP recommendations into practical guidelines. Br J Clin Pharmacol 2020;86(5):999-1006. https://www.ncbi.nlm.nih.gov/pubmed/31912536. John Wiley and Sons, Inc. © 2020 The British Pharmacological Society.

Lithium clearance by haemodialysis is proportional to flow rate, but even low-intensity haemodialysis (eg continuous renal replacement therapy [CRRT]) will at least double the clearance of lithium. If using haemodialysis, continue until there is clinical improvement and the serum lithium concentration is below 1.0 mmol/L. Monitor serum lithium concentration after haemodialysis to detect any rebound.

For more information on haemodialysis, see here.