P1113TREATMENT OF ACUTE LITHIUM INTOXICATION WITH SUSTAINED LOW-EFFICIENCY DIALYSIS (SLED)

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.

Is Capillary Electrophoresis a New Tool to Monitor Acute Lithium Poisoning in Human?†

A 38-year-old man was admitted in the intensive care unit (ICU) after supposed ingestion of 504 sustained-release tablets of Theralithe™ corresponding ~200 g of lithium carbonate. At the admission, ~19.5 h after ingestion, the patient was conscious with trembling limbs, intense thirst, profuse sweats and vomiting and lithium serum concentration was 14.2 mmol/L. Toxicological screenings performed in urine and serum, were negative. Patient was treated with continuous extrarenal epuration by continue veno-venous hemodiafiltration starting (CCVHDF) 24 h post-admission and was carried on until 64 h. After 11 days in ICU, the patient was dismissed to the service without sequelae, and transferred to a psychiatric unit. To follow lithium concentrations in serum, urines and dialysates, we developed a simple, rapid and reliable method by capillary zone electrophoresis (CZE). Separation was achieved in 7 min. The method was linear between 0.14 and 1.44 mmol/L for serum samples, and between 0.07 and to 1.44 mmol/L for urines and dialysates. Limits of quantification were 0.15 mmol/L and 0.07 mmol/L for serum and others fluids, respectively. Intra- and inter-day precisions expressed as CV were systematically inferior to 12.1% for serum and 8.2% for other fluids. Results obtained regarding precision, accuracy, recovery and stability were satisfying, with recoveries ranging from 91.0 to 102.0%. Serum, urine and dialysate samples were measured using CZE and flame photometry. We observed a strong correlation between both methods as assessed by linear regression and Bland–Altman analysis. For the intoxicated patient, the assay was successfully applied to serum, urine and dialysates to determine the amount of lithium present in circulation and excreted. Lithium amounts in dialysates were estimated to correspond to 89% of total lithium excreted during CCVHF session while urine excretion account only for 11%.

Polypharmacy May Be the Cause of Acute Lithium Intoxication at the Second Day of Treatment

Lithium is frequently used as a mood stabilizer in patients with mood disorders. Lithium has a narrow therapeutic index and high toxicity. Predisposing factors for intoxication are advanced age, diet disturbances, comorbid medical conditions affecting heart, kidneys or central nervous system and polypharmacy. CASE REPORT: Here we present a case of a 74-year-old woman with a history of Parkinson’s disease, hypertension and bipolar disorder. She was using quetiapine, valsartan with hydrochlorothiazide and levodopa with carbidopa. She presented with altered mental status and muscle rigidity. The patient was admitted with acute lithium intoxication after her second dose of treatment. Blood lithium level increased to 3.58 mEq/L. The woman was hospitalized in the Internal Medicine Intensive Care Unit. With hydration, her symptoms resolved and her lithium level returned to normal after 118 hours. CONCLUSIONS: Prescribing physicians and emergency room physicians should be aware of conditions which may cause a decreased threshold for intoxication.