Increasing lithium concentration despite extracorporeal treatment: a case report

Abstract

Lithium is used for the treatment of bipolar disorders; however, as lithium is renally excreted, it accumulates, with loss of renal function. We describe a patient with bipolar disorder, a long history of lithium use, and chronic kidney disease (CKD) who developed lithium intoxication following an intentional overdose with multiple drugs. The patient was taken by ambulance to the hospital emergency department and arrived there approximately 4 h after assumed ingestion. When toxicology screening was performed, the patient was found to have a lithium concentration of 2.7 mmol/L. Continuous venovenous hemofiltration (CVVH) was started, but lithium concentrations continued to rise. Intermittent hemodialysis (iHD) was therefore introduced and continued until lithium concentrations dropped below 2.0 mmol/L. Lithium intoxication was not the initial focus of treatment, but, in retrospect, was the primary cause for admission. This case report shows that CVVH is an insufficient technique to remove lithium as concentrations continued to increase during its use. iHD should be used instead of CVVH and, especially in CKD patients, should be introduced immediately when lithium concentrations are > 2.5 mmol/L.