P1113TREATMENT OF ACUTE LITHIUM INTOXICATION WITH SUSTAINED LOW-EFFICIENCY DIALYSIS (SLED)
Authors: Di motta Tommaso , Di Mario Francesca , Giunta Rosa , Zambrano Cristina , Maccari Caterina , Parenti Elisabetta , Regolisti Giuseppe , Fiaccadori Enrico , Greco Paolo 
Published: June 2020

Abstract

Background and Aims
Lithium salts are widely used in psychiatry for prophylaxis and treatment of bipolar affective disorders. Given its narrow therapeutic range, drug overdosage is not infrequent, and lithium intoxication has potentially fatal neurologic and cardiac side effects. Owing to its low molecular weight (7 Da), relatively small volume of distribution, and its negligible protein binding, lithium can be efficiently removed by any extracorporeal modality of renal replacement therapy (RRT). Although conventional intermittent haemodialysis (IHD) is effective in promptly cleating lithium, postdialysis rebound is common. The use of sustained low-efficiency dialysis (SLED) in lithium intoxication seems to be a valid therapeutic strategy, but strong evidence is still lacking in the literature. We present here two cases of lithium intoxication, in one case acute (naïve patient) and in the other case acute-on-chronic (a deliberate overdose in a patient previously on lithium therapy), successfully treated with SLED.
Method: Patient A - A 47 years-old woman without history of lithium consumption was admitted to the ER. after a voluntary acute lithium ingestion of 40 tablets of lithium carbonate (8.12 mEq lithium each). Notwithstanding treatment with intravenous crystalloids and gastric lavage, lithium concentration increased up to 4.18 mEq/l at about 24 h after admission. She developed mental status changes, oliguria, hypotension and bradycardia.
Patient B – A 58 years-old man on lithium therapy for bipolar syndrome was admitted to ER after a voluntary acute lithium ingestion of an unknown quantity of lithium carbonate tablets. Lithium concentration, after an initial level of 0.4 mEq/L, increased up to 4.35 mEq/l about 15 h from admission, despite irst-line therapies with intravenous crystalloids and gastric lavage were promptly started. His mental status worsened, together with oliguria, bradycardia and hypotension.
Results: Patient A - A 8-hour SLED session with regional citrate anticoagulation (RCA) was planned [blood flow rate (Qb) 200 mL/min; dialysis fluid rate (Qd) 300 mL/min; countercurrent flow direction]. Lithium serum levels decreased by 87% during treatment (0.55 mEq/L), and the patient fully awoke recovering a normal mental status within the first 4 h of treatment. SLED was completed safely within the prescribed time. After the end of treatment, lithium rebound was unremarkable and renal function completely recovered and the patients was discharged after 3 days.
Patient B - A 12-hour SLED session with RCA was planned (Qb 200 mL/min; Qd 500 mL/min; countercurrent flow direction). Serum lithium levels decreased by 55% (2.10 mEq/L) during treatment, and the patient awoke, recovering a normal mental status. At the end of treatment, rebound of lithium concentration was observed at 4 hours from SLED end detected (from 2.1 to 2.5 mEq/L), with initial signs of mental deterioration. A second SLED (12 h) was performed, with the same operative parameters and, by the end of the second treatment, lithium concentration was 0.49 mEq/L. Afterward, mental status and renal function fully recovered and no rebound rebound was observed. The patient was discharged after 6 days.

Conclusion
SLED could represent a good therapeutic strategy to treat acute lithium intoxication, providing an initial rapid clearance with resolution of symptoms, and limiting major rebound.