Lithium Toxicity

CC: 66 yom + AMS + ~3 days HPI: 66 yom with PMH significant for HTN, CKD-IV, CHF, diabetes, hypothyroidism, HDL, gout, PTSD, and schizoaffective disorder presents with 3 days of altered mental status. Patient states that Vietnamese soldiers were chasing him to the foot of his bed and that he couldn’t walk. He complained of “shaking.” He also was experiencing memory lapses and was unable to recall his transfer from an outside hospital. 

ROS: Blurry Vision Dizziness Decreased energy Irritability Nausea/Vomiting Abdominal pain Shaking Polydipsia Polyurea Bowel incontinence Generalized pain

PMH: HTN, CKD-IV, CHF, diabetes, hypothyroidism, HDL, Gout, PTSD, schizoaffective disorder, various vitamin deficiencies Medications: Allopurinol, Amlodipine, ASA, Atorvastatin, Tylenol #3, Gabapentin, Insulin, Levothyroxine, Lisinopril, Lithium, Metoprolol tartrate, Mirtazapine, Omeprazole, Sertraline Allergies: Maxzide, Quetiapine, Risperidone Social history: Vietnam vet, 100% SC, lives at home with his wife. Remote smoking, heavy alcohol, and IV Drug use. Brother died in the past week, patient smoked marijuana at the funeral

Vitals: BP: 221/92 P: 61 T: 98.8 R: 18 Po2: 94% BMI: 39.5 Physical Exam Gen: Difficult to arouse, oriented to self, year is 2020, location is outside hospital, groaning HEENT: NC/AT, PERRL, sclera non-icteric, MMM CV: RRR, no M/R/G Resp: No respiratory distress, CTAB GI: +BS, obese, mild tenderness to palpation, no rigidity or guarding Extremities: No edema, clubbing, or cyanosis Skin: Warm, dry, no rashes Neuro: Some stuttering, repetitive speech, no involuntary movements or tremors, no facial drooping, moves extremities against gravity

PAUSE Differential diagnosis Audience requests labs/imaging 

Labs: Na: 145, Cr: 2.37 UDS: +MJ/opiates Ammonia: 18 Lithium: 0.82 CT Head @ OSH: no acute intercranial abnormality MRI Brain: unable to tolerate ECG: no changes

PAUSE Differential diagnosis part 3 Audience votes on diagnosis

Lithium Toxicity Presentation: Neurotoxicity: tremor, hyperreflexia, AMS (confusion to delirium) Nausea/vomiting/diarrhea  Hypernatremia Nephrogenic diabetes insipidus Endocrinopathies: Hypothyroidism/hyperparathyroidism

Diagnosis Lithium has a narrow therapeutic index Associated with polypharmacy and medical comorbidities Lithium levels, CBC, electrolytes, BUN and Cr Mild symptoms: nausea, vomiting, lethargy, tremor, and fatigue (Serum lithium concentration between 1.5-2.5 mEq/L). Moderate intoxication: confusion, agitation, delirium, tachycardia, and hypertonia (serum lithium concentration between 2.5-3.5 mEq/L). Severe intoxication: Coma, seizures, hyperthermia, and hypotension (serum lithium concentration (less than 3.5 mEq/L).

Treatment Discontinuation of drug IVF Hemodialysis

References Uptodate: Lithium poisoning Sun, M., Herrmann, N. & Shulman, K.I. Clin Drug Investig (2018) 38: 201. https://doi.org/10.1007/s40261-017-0598-9