Presentations

Abstract

Introduction:

Lithium has long been used as a mood stabilizer for patients with bipolar disorder and major depressive disorder. While effective, it can lead to various side effects, ranging from mild to severe. We present a case of lithium toxicity with significant hyperthermia, highlighting the challenges in diagnosis and management.

Case Description:

A 27-year-old female with a history of bipolar disorder, prediabetes, and traumatic brain injury presented with altered mental state progressing from combativeness to lethargy and obtundation over two days. Due to concerns of airway protection, she was intubated immediately. Physical examination revealed rigidity of the extremities, hyperreflexia, and a fever of 102.5 °F. Initial treatment with dantrolene was initiated for suspected neuroleptic malignant syndrome (NMS), but subsequent lab results revealed lithium toxicity, hypernatremia, and impaired renal function. Hemodialysis and continuous renal replacement therapy were initiated, leading to improvement in renal function and lithium levels. However, hypernatremia persisted, necessitating treatment with hypotonic fluids, free water, amiloride, and desmopressin therapy. After resolution of metabolic abnormalities, the patient was successfully extubated with restored mental function and no neurological deficits.

Discussion:

Lithium toxicity is a well-documented condition, with an estimated 6000 cases reported annually in the U.S. The majority of cases are chronic, with acute intoxications occurring in individuals at high risk for overdose. Acute toxicity presents initially with gastrointestinal symptoms, followed by neurological manifestations at higher lithium levels. Our case exhibited symptoms similar to other psychiatric medication overdoses, such as muscle rigidity and tremors. The presence of hyperthermia further complicated the diagnosis, as it can be seen in syndromes like NMS or serotonin syndrome. Empiric dantrolene use in our case had uncertain utility. Additionally, delayed recognition of lithium-induced diabetes insipidus resulted in hypernatremia, which was managed through hydration and fluid removal via hemodialysis. This case underscores the importance of considering lithium toxicity in patients with psychiatric history and suspected overdose, as it can mimic other associated conditions. Prompt identification and initiation of appropriate treatment, including emergent hemodialysis, are crucial in optimizing patient outcomes.