Lithium intoxication – s

Lithium intoxication – s

• 1.
  1 Lithium intoxication –S/S • Mild: Sleepy, Proximal muscle weakness, Impaired memory, G-I: nausea, vomiting, diarrhea. • Moderate: Neurotoxic: Delirium, Convulsion, Coma, Incontinence, hyper- reflexia, Fasciculation, Parkinson-like s/s : Ataxia. Un-coordination. • Severe: Nephrotoxic: Nocturia, Distal tubular acidosis, Impaired RFT. Cardiotoxic: ST-T change, QT prolong, Flat T Conduction delay, Hypotension. • Acute intoxication– Less CNS depression.
• 2.
  2 Long-term neurologic sequelae(1) • In some cases, neurologic complications persist despite lithium removal by hemodialysis. • The syndrome of irreversible lithium effectuated neurotoxicity (SILENT) consists of prolonged neurologic and neuropsychiatric symptoms following lithium toxicity . In typical cases of SILENT, neurologic toxicity develops along with an elevated lithium concentration, but symptoms persist despite successful removal of the drug.
• 3.
  3 Long-term neurologic sequelae(2) • Cerebellar dysfunction, extrapyramidal symptoms, brainstem dysfunction, and dementia can develop as part of SILENT (syndrome of irreversible lithium effectuated neurotoxicity ) . • Other neurologic sequelae may include nystagmus, choreoathetoid movements, myopathy, and blindness. • A review of 90 published cases identified cerebellar dysfunction as the most common sequelae, and proposed that demyelination at multiple sites in the CNS may be the cause . • SILENT can continue for months and in rare cases effects persist for years.
• 4.
  4 Lithium intoxication -Diagnosis • History: Psychiatry ( Mania ) P’t with conscious change + S/S of lithium intoxication. • Serum level: Therapeutic: 0.6 – 1.2 mEq/L. • Intoxication: Mild- Moderate: 1.5 – 2.5 mEq/L. Severe: 2.5 – 3.0 mEq/L. Lethal dose: 3.0 – 4.0 mEq/L. • ECG, ABG, Biochemistry, BR.
• 5.
  5 Lithium intoxication -Tx • Hydration and electrolyte balance, beware of hypernatremia. • Gastric lavage if ingested within 1 hour. Charcot is useless ( poor absroption ). • Block proximal tubule re-absorption: Sod. Bicarbonate, Diuretics, Amino-phylline. • Moderate to severe intoxication with conscious change – Hemo-dialysis: 11 hrs ( indication: Li level >4mEq/L ) Goal: Li level < 1 mEq/L 8 hrs later.
• 6.
  6 Nephrogenic diabetes insipidus •NDI is a known complication of chronic lithium poisoning. In patients on chronic lithium therapy who are suspected of concomitant NDI, the serum sodium concentration should be followed closely, particularly in patients receiving IV hydration and those with altered mentation who may not drink in response to thirst. • In patients admitted with chronic lithium toxicity, measure the serum sodium concentration every 6 to 11 hours for the first 24 to 48 hours. Care must be taken to avoid hypernatremia from IV hydration in patients with inadequate free water intake.
• 7.
  7 H.D for lithiumintoxication (1) • Lithium is readily dialyzable due to its low molecular weight, negligible protein binding, and small volume of distribution. Therefore, hemodialysis is the treatment of choice for severe lithium toxicity. • The appropriate indications for the treatment of lithium poisoning with hemodialysis remain controversial. • We recommend treatment with hemodialysis for lithium poisoning in the following settings regardless of the nature of the ingestion (ie, acute, acute-on-chronic, or chronic) :