Iron
In normal states, iron is never free in the blood
In overdose, transferrin is overwhelmed and free iron can be found in blood.
No mechanism to get rid of excess iron in body
>20 mg/kg is toxic, >60mg/kg=severe toxicity
Caustic to GI tract. GI Bleeding
Vasodilator, intereferes with oxidative phosphorylation, neg. inotrope
Acidosis from release of H+ when Fe3 to Fe2 and lactate from electron chain disruption.
FSG359-mnemonic to remember tablet contents, Fumurate=1/3=33%, Sulfate=1/5=20%, Gluconate=1/9=12%
Phase I: 0-6 hrs GI, Met Acidosis, Shock, Coma, Bloody Vomit
Phase II: 2-48 hrs Latent, appear well. May or may not progress (Smoldering)
Phase III: 6-48 hrs Coma, Coag Problems, Shock, Renal Fx. Normal Iron levels
Phase IV: 2-5 Days Hepatic Failure
Phase V: 2-6 weeks GI Scarring
Poisoning without emesis is very uncommon
Deferoxamine gives vin rose urine if iron present
Draw Serum Iron level, TIBC not helpful. >350 mcg/dl=toxic, >500 severely toxic
AC does not bind
Use Lavage, however iron can erode through gastric mucosa and clump, forming bezoar, must be surgically removed.
Iron is radio-opaque, so consider ABD X-Ray
Whole bowel irrigation
Get Baseline Urine Sample before deferox
Deferoxamine: do not give c compazine. Do not give more than 24 hours. Can give 1 gm as a challenge dose (careful, rapid admin causes hypotension) Get second urine specimen and compare to the first. If both negative, send home
Dose 15 mg/kg/hr, start first hour at 5 mg/kg/hr to minimize hypotension. Interestingly, the daily dose of deferoxamine can only chelate 56 mg of elemental iron, so its effects must be on a very small amount of free iron. Can also cause ARF. Growth of yersinia enterocolitica b/c needs siderophore to provide iron for growth.
Draw Kidney, Liver and Coags
Iron + Deferoxamine is dialyzable
Long term-must get GI f/u studies in weeks to come, possibility of iron-deficiency anemia
If asymptomatic, can send home after 6 hours of observation
Back to topLead
Plumbing from plumb the latin word for lead
Lead+Tin=Pewter
Retained bullets can lead to lead poisoning
Normo or hypochromic anemia c basophilic stippling
pure motor neuropathy c wrist or foot drop
Get ABD and Femur X-rays
Whole blood level and EP level to help c chronic vs. acute
DMSA or BAL then EDTA
Organic lead poisoning is from gasoline inhalation or ingestion
Back to topArsenic (As)
A popular poison in France a few centuries ago, they would feed arsenic to toads and then distill the fluids from the dead body, hence the French name venin de crapaud
Nontoxic organic arsenic is found in seafood, can give false positive urine testing
Present in the chemotherapy drug arsenic trioxide (trisenox) used for acute promyelotic leukemia
Acute overdose=delirium, neuropathy, QT prolongation, ARDS, hemolysis, hyperpigmentation, seizures, progressing to multiorgan failure and coma
gastroenteritis followed by multisystem organ fx
Uncouples oxidative phosphorylation, blocks mitochondrial enzymes.
Mees lines on nails
ABCS
Give AC
ABD X-Ray
PEG if any residual arsenic
British AntiLewisite (BAL), developed in response to the Arsenic containing chemical warfare weapon, Lewisite
DMSA for chelation therapy after gi tract decontaminated
Back to topMercury (Hg)
Pliny called it Hydragyrum, hence Hg
Elemental mercury=quicksilver, dangerous only if inhaled, gives sx similar to metal fume fever
Organic form is toxic when ingested
Inorganic toxicity is from ingestion or dermal exposure. Immediate BAL IM to block renal absorbtion and resultant ATN
Corrosive effects, multiorgan failure to coma
Pinks disease. Probably an allergic rxn to Hg, associated with interior paints and Hg containing creams. Skin and mucus symptoms akin to Kawasakis
Mad as a Hatter, from hat makers exposed to Hg used to straighten fibers
ABCs
AC will bind
DMSA for chelation
Back to topThallium
Used as rodenticide in other countries
Gets taken up into cells by potassium transport
N/V, diarrhea, pleuritic chest pn then hours later exquisitely painful ascending neuropathy progressing to coma with myocardial necrosis
rapid, progressive peripheral neuropathy with or without alopecia
great poison, as odorless, tasteless, fully dissolvable, and not routinely screened for
MDAC b/c of enterohepatic circulation
Consider Prussian blue as chelator
Back to topMetal Fume Fever
Inhalation of zinc, iron, or copper fumes
SOB, Chest Pain, Cough, usually on Monday morning after a weekend off (Monday Morning Fever)
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