1. Pediatric Emergency Medicine Clinical Case Presentation
Rudi-Ann Graham, PGY-1, Pediatrics

2. Case Scenario 1
A 16 year old female with known history of major depression, is brought to the emergency room by her parents, after having sudden onset of abdominal pain and vomiting. She admits to intentional ingestion of approximately 50 Pre-natal vitamin tablets, 3 hours prior to presentation. On arrival, her vital signs are BP 102/66, P 105, RR 24, Oxygen Saturations 99%, and T 38. 3˚. Weight 55kg. She is awake and alert, but diaphoretic, with moderate epigastric tenderness on palpation. Heart sounds are normal, and lungs are clear to auscultation. Which of the following are the most important initial investigations to obtain for this patient:

3. Case Scenario 1 CBC, urinalysis, blood and urine cultures
CBC, Serum Iron Level, TIBC, BMP
CBC, CMP, serum amylase and lipase levels
VBG, Serum iron levels, PT/INR, PTT and Liver Enzymes, and abdominal XR

4. Case Scenario 1 CBC, urinalysis, blood and urine cultures
CBC, Serum Iron Level, TIBC, BMP
CBC, CMP, serum amylase and lipase levels
VBG, Serum iron levels, PT/INR, PTT and Liver Enzymes, and abdominal XR

5. Acute Iron Poisoning
Iron toxicity is the leading cause of poisoning deaths in children.
Over cases of iron exposure reported to poison control centers annually
Most ingestion occurs unintentionally
Pre-natal vitamins or Ferrous sulphate pills
Excess intake of children's chewable vitamins unlikely to cause death
Intentional ingestion also occurs
Higher mortality rates than accidental exposure
The most serious exposures involve pre-natal vitamins and pure iron preparations that contain ferrous sulphate, which typically have significant levels of elemental iron.
Epidemiology of intentional overdose differs from unintentional: female, mean age 19 years.
Mortality rates increased among children with interntional ingestions (10 percent vs 1 percent)

6. Acute Iron Poisoning
Toxicity depend on amount of elemental iron ingested
Most common preparations are iron salts
Ferrous Gluconate (12 percent)
Ferrous Sulphate (20 percent)
Ferrous Chloride (28 percent)
Ferrous Fumarate (33 percent)
Pre-natal vitamins generally contain 65 mg elemental iron
MVT typically contain 15-18mg of elemental iron
Placebo pills in 28 day OCP packages contain iron
Iron also found in plant fertilisers, and snail baits

7. Iron Toxicity
Minimal toxic dose and lethal dose not firmly established:
Ingestion greater than 20mg/kg will often produce GI upset
Exposures above 60mg/kg are potentially fatal
Iron ingestions between 20-60mg/kg may or may not lead to toxicity

8. Iron Toxicity Ferric iron is toxic to cellular processes:
Free radical production
Lipid peroxidation
Toxic effects seen when TIBC becomes overwhelmed
Local Toxicity: Iron is corrosive to GI mucosa
Abdominal pain, vomiting, diarrhea, GI hemorrhage
Hypovolemia
GI perforation
Systemic Toxicity: Injury to cardiovascular system and liver
Major cause of death is shock or liver failure

9. Stages of Iron Poisoning
Time Post-Ingestion
Description 1
< 6 hours
Vomiting, hematemesis, explosive diarrhea, melena, abdominal pain, lethargy;
Tachypnea, tachycardia, hypotension, coma 2
6-36 hours
Resolution of GI symptoms (latent period) 3
2-5 days
Shock, metabolic acidosis, liver failure, coagulopathy, hypoglycemia 4
2-5 weeks
Gastric outlet or duodenal obstruction secondary to scarring
Symptoms of iron poisoning occur in 4 stages:
The progression of these phases may occur rapidly depending on the severity of the ingestion. The clinical phase should therefore be determines by the patients clinical and laboratory manifestations, not by the time since ingetion.
Vomiting is the most serious indicator of serious ingestion in the early phase. Hypovolemic shock is most common cause of death.
Quiesent phase: period of apparent recovery. Important to distinguish patients who are in this phase from patients with low-dose ingestion whos toxicity is actually resolved.
Stage 3: Cardiogenic, hypovolemic and distributive shock. Metabolic acidosis is often profound and is an indicator of iron induced toxicity.

10. Acute Iron Poisoning
Thorough history of amount of elemental iron and timing of ingestion
What type and how much?
When did ingestion occur?
Intentional or accidental exposure?
Other toxic substances?
Patients asymptomatic 6 hours after ingestion unlikely to become symptomatic, unless enteric-coated tablets
Evaluate serum iron concentrations after 8 hours

11. Acute Iron Poisoning Asymptomatic Patients: If tablet ingestion
Abd Xray. If Abd Xray negative, no further investigation or observation
If unknown amount or >40mg/kg ingested, measure serum iron concentration q4h until falling

12. Acute Iron Poisoning All symptomatic patients:
Abdominal XR if tablet ingestion
Venous blood gas (anion gap metabolic acidosis)
Serum glucose (hyperglycemia)
Serum Iron
Usually peaks at 4-6 hours after ingestion
Enteric-coated tablets, absorption may be erratic and delayed
Serum electrolytes and creatinine
PT/INR, PTT, liver enzymes (reversible early coagulopathy and late coagulopathy secondary to hepatic injury)
Type and Screen

13. Acute Iron Poisoning Additional tests: EKG Urine Toxicology
Serum Drug levels

14. Serum Iron Concentration
Peak serum iron concentrations correlate with levels of toxicity
Less than 350 mcg/dl: Minimal toxicity
Between mcg/dl: Mild to moderate GI symptoms
Greater than 500 mcg./dl: Serious systemic toxicity
Greater than 1000 mcg/dl: Significant morbidity and mortality

15. Radiographic Evaluation
Indication:
Ingestion more than 40mg/kg
Significant symptoms
Depends on type of formulation and content of elemental iron

16. Index Case
Patient is symptomatic, and has potentially ingested 59mg/kg of elemental iron!!!
Although patient has a low-grade fever, there is no history suggestive of infectious exposure. Iron toxicity, which is more likely, may also present with pyrexia. Urinalysis, blood and urine cultures are not the most appropriate initial investigations in this case.
CBC may show leucocytosis; BMP may show hyperglycemia. But absence does not exclude iron toxicity.
Acute pancreatitis is a likely differential for epigastric abdominal pain with vomiting. But given history, this is much less likely, and amylase and lipase would not be initially ordered.

17. Case Scenario 2
A 3 year old boy is brought to the emergency room, after being found with an open container of Pre- natal vitamins. His weight is 15kg. His parents estimate that 20 pills are missing from bottle. He has had 5 episodes of large hematemesis prior to arrival. On presentation, his vital signs are
BP 66/45, P 125, RR 26, Oxygen Saturation 98%, T 37.9 ˚. POC glucose is 102 mg/dl.
He is lethargic and pale, with a tender, distended abdomen.
His airways are patent, and chest is clear to auscultation
Which of the following is the best initial management for this patient.

18. Case Scenario 2
Treat with activated charcoal immediately for gastric decontamination
Whole bowel irrigation (WBI) with nasogastric colonic lavage solution at 30 cc/kg/hr until rectal effluent is clear
Establish IV access, fluid resuscitation with Normal Saline bolus at 20cc/kg, and prepare for chelation therapy
Administer of 125mg/5ml syrup of ipecac to induce gastric emptying

19. Case Scenario 2
Treat with activated charcoal immediately for gastric decontamination
Whole bowel irrigation (WBI) with nasogastric colonic lavage solution at 30 cc/kg/hr until rectal effluent is clear
Establish IV access, fluid resuscitation with Normal Saline bolus at 20cc/kg, and prepare for chelation therapy
Administer of 125mg/5ml syrup of ipecac to induce gastric emptying
Airway protection and respiratory support should be provided as needed.
Volume resuscitation to maintain euvolemia.

21. Treatment of Iron Poisoning
Decontamination:
Activated charcoal does not bind iron and is of no use in a pure ingestion!!!

22. Treatment of Iron Poisoning
Whole bowel irrigation has been shown to be effective in reducing toxicity, especially of tablets on plain radiograph
Awake and alert
No evidence of GI dysfunction
Intractable vomiting
Ileus
Significant bleeding
Bowel obstruction or perforation
Administer cc/kg/hour of polyethylene glycol by NGT until effluent clear and radiograph no longer shows iron tablets

23. Treatment of Iron Poisoning
Antidote:
Deferoxamine is chelating agent; forms water-soluble deferoxamine-iron complex
Consider deferoxamine if:
Serum iron concentration > 500 mcg/dl
Estimated dose > 60mg/kg elemental iron
Patient has significant symptoms (altered conscious state, hypotension, tachycardia, tachypnea) irrespective of ingested dose, or serum iron concentrations
Significant pills seen on xray
Do not wait for iron concentrations if severe symptoms

24. Treatment of Iron Poisoning
Dose 15mg/kg/hr IV Deferoxamine. Total dose should not exceed 80mg/kg/24 hours.
Deferoxamine iron complex excreted renally.
Patient’s urine will turn pink ‘vin rose’
If oliguria or anuria, may need peritoneal or hemodialysis
End-point for chelation therapy:
Patient is asymptomatic
Decontamination complete (urine no longer pink)
Anion gap acidosis resolved
Serum iron concentration < 335 mcg/dl

25. Treatment of Iron Poisoning
Chelation therapy side-effects
Hypotension
ARDS

26. References
Erica L Liebelt, MD; Rana Kronfol, MD; Acute Iron Poisoning Gerald F O’Malley, DO; Rika O’Malley, MD Merck Manual: Iron Poisoning

27. QSL!