Lithium toxicity: Difference between revisions
m (moved Lithium Overdose to Lithium Toxicity over redirect) |
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== | ==Background== | ||
*Toxicity most often involves a drug-drug interaction or decreased renal excretion | |||
*Lithium levels are only helpful for chronic toxicity | |||
*Pts die of respiratory failure or CV collapse | |||
==Precipitants== | |||
#Overdose | |||
#Renal failure | |||
#Volume depletion | |||
##Diuretic use, vomiting, diarrhea, diaphoresis, decreased oral intake | |||
#Hyperthermia | |||
#Infection | |||
#CHF | |||
#Surgery | |||
#Cirrhosis | |||
==Clinical Features== | |||
#GI | |||
##Usually first to develop | |||
##N/V | |||
##Diarrhea | |||
##Generalized abd pain | |||
#CNS | |||
##Usually develops as GI symptoms are abating | |||
##Tremor | |||
##Muscle weakness | |||
##Ataxia | |||
##Stupor | |||
##Seizure | |||
##Coma | |||
==Diagnosis== | |||
#Lithium level | |||
== | ##Correlates better with chronic than acute toxicity | ||
#Chemistry | |||
##Low or negative ion gap | |||
##Elevated osmolar gap | |||
#ECG | |||
##QT prolongation | |||
##Diffuse TWI | |||
==Treatment== | |||
#GI decontamination | |||
##Consider lavage for massive ingestions (>4gm) if can be performed w/in 1hr | |||
##Activated charcoal is ineffective | |||
#Fluid resuscitation | |||
##Average pt has Na/volume deficit; giving fluid helps reestablish normal Li excretion | |||
###Give 2L NS bolus; then give 200mL/hr | |||
#Seizure | |||
##Benzos are 1st line | |||
##Phenobarbital is 2nd line | |||
##Phenytoin is ineffective | |||
#Dialysis | |||
##Indications: | |||
###Li level >4 (acute overdose) | |||
###Li level >3.5 (chronic toxicity) | |||
###Little change in Li level after 6hr IVF | |||
###Sustained Li level >1.0 after 36hr | |||
###Baseline renal failure | |||
###Ingestion of sustained-release preparations | |||
##Goal: | |||
###Li level <1 | |||
####Must monitor for up to 8hr following dialysis to ensure levels stay <1 | |||
==Disposition== | |||
*Consider discharge for pts asymptomatic after 4-6hr obs | |||
*Admit all pts w/ Li level >1.5 | |||
*Admit all pts w/ ingestion of sustained-release preparation (regardless of Li level) | |||
==Source== | |||
*Tintinalli | |||
[[Category:Tox]] | [[Category:Tox]] |
Revision as of 23:01, 2 January 2012
Background
- Toxicity most often involves a drug-drug interaction or decreased renal excretion
- Lithium levels are only helpful for chronic toxicity
- Pts die of respiratory failure or CV collapse
Precipitants
- Overdose
- Renal failure
- Volume depletion
- Diuretic use, vomiting, diarrhea, diaphoresis, decreased oral intake
- Hyperthermia
- Infection
- CHF
- Surgery
- Cirrhosis
Clinical Features
- GI
- Usually first to develop
- N/V
- Diarrhea
- Generalized abd pain
- CNS
- Usually develops as GI symptoms are abating
- Tremor
- Muscle weakness
- Ataxia
- Stupor
- Seizure
- Coma
Diagnosis
- Lithium level
- Correlates better with chronic than acute toxicity
- Chemistry
- Low or negative ion gap
- Elevated osmolar gap
- ECG
- QT prolongation
- Diffuse TWI
Treatment
- GI decontamination
- Consider lavage for massive ingestions (>4gm) if can be performed w/in 1hr
- Activated charcoal is ineffective
- Fluid resuscitation
- Average pt has Na/volume deficit; giving fluid helps reestablish normal Li excretion
- Give 2L NS bolus; then give 200mL/hr
- Average pt has Na/volume deficit; giving fluid helps reestablish normal Li excretion
- Seizure
- Benzos are 1st line
- Phenobarbital is 2nd line
- Phenytoin is ineffective
- Dialysis
- Indications:
- Li level >4 (acute overdose)
- Li level >3.5 (chronic toxicity)
- Little change in Li level after 6hr IVF
- Sustained Li level >1.0 after 36hr
- Baseline renal failure
- Ingestion of sustained-release preparations
- Goal:
- Li level <1
- Must monitor for up to 8hr following dialysis to ensure levels stay <1
- Li level <1
- Indications:
Disposition
- Consider discharge for pts asymptomatic after 4-6hr obs
- Admit all pts w/ Li level >1.5
- Admit all pts w/ ingestion of sustained-release preparation (regardless of Li level)
Source
- Tintinalli