L4: Iron

Question 1

Manner of Poisoning by Iron Toxicity

Answer 1

• Iron toxicity typically occur in children, 3-5 tablets may induce significant toxicity according to amount of elemental iron contained in ingested preparation.

Question 2

Toxic Action of Iron Toxicity

Answer 2

Question 2

Distribution of Iron

Answer 2

Transferrin Carier

• Iron is transported in the blood by transferrin.
• When binding sites on transferrin are saturated, Unbound iron reacts with blood vessels and platelets.

Question 2

Absorbtion of Iron

Answer 2

Question 2

Elimination of Iron

Answer 2

• There is no significant natural route of elimination other than by Gastrointestinal cell loss & blood loss.

Question 2

1st GI Phase of Iron Toxicity

Answer 2

Question 2

CP of Iron Toxicity

Answer 2

Severe iron poisoning may proceed in four phases

• 1st Gastrointestinal phase (Gastrointestinal effects)
• 2nd Window phase
• 3rd Multi-organ failure phase
• Late complications phase

Question 3

2nd window Phase of Iron Toxicity

Answer 3

Question 3

3rd Multi-Organ Failure phase of Iron Toxicity

Answer 3

Question 3

Late Complications phase of Iron Toxicity

Answer 3

Question 3

Investigations in Iron Toxicity

Answer 3

• Blood Iron Level
• Abdominal X-ray
• Electrolytes, Arterial blood gases & Blood glucose level & Full blood count
• Renal and Liver functions & Coagulation studies.

Question 4

Blood Iron level investigations

Answer 4

Question 5

What Might Abdominal X-Ray show in cases of Iron Toxicity?

Answer 5

• To identify radio-opaque tablets
• however their absence does not exclude iron overdose.

Question 6

Determination of severity of Iron Toxicity

Answer 6

• Clinical Evaluation.
• Blood Iron Level.
• Dose of Ingested Elemental Iron

Question 6

Dose of Ingested elemental Iron

Answer 6

Question 6

TTT aspects of Iron Toxicity

Answer 6

• Emergency and supporlive
• Decontamination
• Antidote: (Desferrioxamine)

Question 7

Emergency & Supportive TTT of Iron Toxicity

Answer 7

• Severe poisoning requires close monitoring (ABC, CVP line, regular electrolytes, blood gases and blood sugar monitoring)
• Volume replacement may be required (blood, fresh frozen plasma or crystalloids)
• Correction of acidosis.

Question 7

Decontamination options in Iron Toxicity

Answer 7

• Activated Charcoal
• Gastric Lavage
• Whole bowel irrigation

Question 7

Is Activated Charcoal effective in Iron Toxicity?

Answer 7

• Not effective.
• Iron is not adsorbed to charcoal.

Question 8

Gastric Lavage in Iron Toxicity

Answer 8

• Limited value
• Intact tablets may not pass via lavage tube

Question 8

What is the Method of choice of decontamination in Iron Toxicity?

Answer 8

Whole bowel irrigation

Question 9

Indications for WBI

Answer 9

• Ingestions >60 mg/kg confirmed on X-ray.
• Un-dissolved tablets were detected on abdominal x-ray.
• Sustained release or enteric coated iron tablets were reported.

Question 10

Antidote in Iron Toxicity

Answer 10

(Desferrioxamine)

Question 11

Dose & Route of Desferrioxamine

Answer 11

• Desferrioxamine is given intravenously at a rate of 15 mg/kg body. weight/hour.
• Reduce dose by 50% in severe renal impairment.
• The urine will often (but not always) change to vin rose color.

Question 11

MOA of Desferrioxamine

Answer 11

• It chelates ferric iron and causes redistribution of iron from tissue sites back into plasma.
• The iron- desferrioxamine complex is renally eliminated.

Question 12

SE of Desferrioxamine

Answer 12

• Desferrioxamine infusion for greater than 24 hours may result in Non-cardiogenic pulmonary edema.

Question 12

End point of therapy by Desferrioxamine

Answer 12

• Treatment should be continued until serum iron concentrations fall below 60 micromol/ L
• The urine (if it changed color) has returned to normal.
• This normally takes 6-8 hours of treatment but may be longer in severe poisoning.

Question 13

Indications of Desferrioxamine

Answer 13

Question 14

When to Cease Desferrioxamine?

Answer 14