CHAPTER 449 HEAVY METAL POISONING Flashcards
LEAD METABOLISM
interferes with the mitochondrial oxidative phosphorylation and enhances the oxidation and cell apoptosi
HOW LEAD IS ABSORBED?
thru inhalation and ingestion
half life of lead in soft tissues and bone
soft tissue- 30 days
bone- >20 years
LEAD IS EXCRETED THRU?
URINE BUT SOME CAN BE FOUND IN THE BREASTMILK
ACUTE EXPOSURE OF LEAD
> 60 TO 80 mg
impair neurotransmission and neuronal cell death
impair hematopoiesis
renal tubular dysfunction
HIGHER LEAD EXPOSURE
> 80-120
Acute encephalopathy with convulsions
coma
death
SUBACUTE EXPOSURE IN CHILDREN OF LEAD
25-60 mg
anemia
mental retardation
deficits in language, motor function, language, hearing, balance, behavior and school performance
SUBACUTE EXPOSURE IN ADULTS OF LEAD
>40mg risk for anemia demyelinating peripheral neuropathy impairment of reaction time and hearing decline in recognition risk for cardiovascular disease death renal failure diminished sperm count spontaneous abortions
DIAGNOSIS OF LEAD EXPOSURE IN CHILDREN
abdominal pain irritability lethargy anorexia anemia fanconi syndrome pyuria azotemia epiphyseal plate lead lines in long bone xray
coma happens at what level of blood lead
> 120 mg
diagnosis of lead toxicity in adult
headaches myalgias depression memory loss loss of libido lead line at the gingiva pallor wrist drop
lab test in lead toxicity
normocytic normochromic anemia
basophilic strippling
elevated blood protoporphyrin level
motor delays in conduction
TREATMENT OF LEAD TOXICITY
chelation with oral DMSA (succimer)
acutely exposed treatment of lead
hospitalization with IM or IV chelation with CaEDTA addition with dimercaprol
what is the use of addition of dimercaprol in lead toxicity treatment
to avoid worsening of encephalopathy
weak but natural chelating agent of lead toxicity
vitamin c
shown to lower lead levels in pregnant woman
calcium supplementation (1200 mg at bedtime)
main source of mercury
dispersed in waste incineration, bacteria convert inorganic to organic build up in aquatic food chain contaminate fishes
metabolism of mercury
binds to sulfhydryl groups and interferes with enzymatic process
what type of mercury that is well absorbed and not well absorbed
elemental mercury not well absorbed but highly volatilize into highly absorbable vapor while inorganic mercury is absorbed thru gut and skin and organic mercury thru inhalation and ingestion
what type of mercury can cross blood brain barrier and placenta
elemental and organic
mercury is excreted in
urine and feces
half life of mercury
in blood- 60 days
but will remain in kidney and brain for years
acute inhalation of vapor mercury can cause
pneumonitis and noncardiogenic pulmonary edema leading to death
chronic high exposure of vapor mercury can lead to
CNS toxicity, impair renal function and memory and coordination
acute ingestion of inorganic mercury can lead to
gastroenteritis and nephritic syndrome and acute renal failure , hypertension and tacycardia
death can occur in how many ingestion of mercury
10-42 mg
ingestion of organic mercury can lead to
gastroenteritis, arrythmias and lesions in basal ganglia, gray matter and cerebellum doses of >1.7 mg
high exposure of mercury during pregnancy can lead to
derangement of fetal neuronal migration results to severe mental retardation
mild exposure (From fish) of mercury during pregnancy lead to
decline in neurobehavioural performance of the offspring
compound of mercury that is super toxic and one drop can lead to severe cerebellar degeneration and death via skin inhalation
dimethylmercury
diagnostic of metallic mercury ingestion via P.E
intention tremor and mercurial erethism, excitability and memory loss, insomia and timidity
children exposed to mercury results to
acrodynia (pink disease) flushing itching swelling tacycardia hypertension excessive salivation morbilidiform rashes desquamation of palms and soles
toxicity will happen if blood levels and urine levels of mercury is
> 180 mg - blood
>0.7 mg- urine
how do you measure organic mercury exposure
levels in the blood if acute
hair if chronic
Where do children get their CNS toxicity
fetal exposures with maternal hair mercury >30
how do you treat acute ingestion of mercury
induced vomitting and gastric lavage and polythiol residues to bind in the GI tract
chelating agents for mercury exposure
dimercaprol and DMSA
if there is renal failure during the treatment course of mercury exposure
treat with peritoneal dialysis, hemodialysis
best treatment for chronic inorganic mercury poisoning
n-acetyl penicillamine
where can you get arsenic exposure
shallow tube walls inserted for drinking water
aluminum exposure can lead to
encephalopathy in px with severe renal disease who are going dialysis
fatal cardiomyopathy in px with beer heavy consumer
cobalt chloride
it can cause parkinsonian syndrome within 1-2 years including gait disorders, postural stability and masked expressionless face with psychiatric symptoms
manganesse
