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IRON and STINGS

IRON and STINGS. Rob Hall Dr. M. Yarema June 20th, 2002. IRON recognize dx explain pathophysiology know how, when and why to treat. STINGS know the basic management of bee/wasp/fire ant stings know the approach to management of marine bites, stings, and nematocysts envenomations. GOALS.

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IRON and STINGS

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  1. IRON and STINGS Rob Hall Dr. M. Yarema June 20th, 2002

  2. IRON recognize dx explain pathophysiology know how, when and why to treat STINGS know the basic management of bee/wasp/fire ant stings know the approach to management of marine bites, stings, and nematocysts envenomations GOALS

  3. She got into my pills…….. • 3yo female - 10 kg • 5 pills of Ferrrous sulphate 325 mg gone • Presents early vomiting blood • Are you worried? • What if it was 10 pills?

  4. Toxic Ingestions • Depends on ELEMENTAL IRON • Look up % elemental iron in ingested tab • Ferrous sulphate (20% elemental Fe + 10kg child) • 325 mg X 0.20 = 65 mg elemental Fe • 65 mg X 5 pills = 325 mg ----> 32 mg/kg • 65 mg X 10 pills = 650 mg ----> 65 mg/kg

  5. TOXICITY • Elemental Fe Peak [] Toxicity • < 20 mg/kg < 30 umol/L none • 20 - 40 mg/kg 30 - 60 mild • 40 - 60 mg/kg 60 - 90 mod • > 60 mg/kg > 90 umol/L severe

  6. LOCAL TOXICITY • Direct GI corrosive/irritant • Nausea, vomiting, abdominal pain, diarrhea, hematemasis, melena, hematochezia • Must consider on ddx of gastroenteritis, GI bleed in peds

  7. SYSTEMIC TOXICITY • Coagulopathy (inhibits thrombin formation) • Liver toxicity (periportal necrosis) • Increased Anion Gap Metabolic Acidosis • Inhibits oxidative phosphylation ---> lactate • Direct negative ionotropy ---> lactate • Direct vasodilation ---> lactate • MUST be on ddx of SHOCK and AGMA NYD

  8. What causes the increased AGMA in Fe overdose? • Fe 2+ ----------------> Fe 3+ and Hydrogen • Anerobic metabolism ---------> lactate • Hypovolemia from V/D --------> lactate • Hypovolemia from GIB ---------> lactate • -ve Ionotropy ---------------> lactate • Vasodilation ----------------> lactate

  9. FIVE STAGES • STAGE I (< 6hrs): GI signs symptoms • STAGE II (6 - 24hrs): Latent period • STAGE III (variable): Systemic toxicity • STAGE IV (2-3 days): Liver failure • STAGE V (weeks): Gastric outlet obstruction

  10. Complications • Yersinsia enterocolitica • Noted increased rates of infection • Iron as a growth factor • Increases with deferoxamine use • Abdo pain, fever, diarrhea, sepsis

  11. LABS • ? WBC > 15 and Glucose > 7.5 • may be a bad sign but not reliable • Increased AGMA • remember ddx: AMUDPILECAT • TIBC • theoretical reassurance if Fe level less than TIBC b/c enough transferrin around to bind • NOT reliable; DO NOT USE or MEASURE

  12. IRON LEVELS • Measure at 2 - 6 hrs (Peak 4hrs usually) • Repeat levels to catch peak (?) • Normal is 14 - 32 umol/L • Goes down town; turn around in 2hrs but must notify lab of STAT order • Levels used to help guide therapy • Falsely lowered in presence of deferoxamine thus must do before

  13. Radiopaque Liquids and chewables are NOT radiopaque Absence on AXR does NOT r/o ingestion Ddx of radiopaque ingestant C ca carbonate, chloral hydrate H heavy metals (iron, zinc, ba, Li, bisthmus) I iron P KCl, Play-doh P phenothiazines E enteric coated pills D dental amalgan AXR

  14. DECONTAMINATION • NO ipecac • Doesn’t bind charcoal • Gastric Lavage • Indicated if visible in stomach on AXR • Water or saline NOT bicarb, phosphosoda, Mg • Whole Bowel Irrigation • Indicated if visible past stomach on AXR

  15. DEFEROXAMINE • Specific iron chelator • Derived from Streptomyces pilosus • Ferric iron + deferoxamine -----------------> ferrioxamine (colors urine red/brown) • Chelates free iron in blood and intracellular

  16. DEFEROXAMINE • Administration • iv > im > po • iv indicated • goal is 15 mg/kg/hr • start at ? 5 mg/kg/hr and increase to target

  17. DEFEROXAMINE • Adverse Effects • Hypotension with rapid administration • ARDS (more common with higher doses, longer administrations > 24hrs) • Increased Yersinsia infections • Ocular and Ototoxicity have been reported with chronic administration • Deferoxamine is NOT contraindicated in pregnancy

  18. DEFEROXAMINE CHALLENGE • 90 mg/kg im and see if urine color changes • +ve = urine color change -----------> tx • -ve = no urine color change --------->no tx • Problems • shown to be UNRELIABLE • DO NOT use as sole determinant for basis of treatment

  19. Vin Rose’

  20. DEFEROXAMINE • Indications for use • Ingestion of > 60 mg/kg • Iron level > 90 umol/L • Systemic toxicity: hypotension, coma, AGMA, seizures • Discontinuation (generally at 24hrs) • Clinically well • AGMA resolved • No further urine color change

  21. OTHER Mx • Deferiprone • Oral active iron chelator • Used in chronic setting; being looked at with acute ingestions • CAVH • Infuse deferoxamine on arterial side; dog studies • Essentially experimental at this point

  22. DISPOSITION • Asymptomatic after 6 - 8 hrs rules out significant ingestion and d/c home • Management of moderate to severe ingestions depends on ……. • Clinical assessment: hx, physical, labs • Amount ingested: > 60 mg/kg is bad • Iron level: > 90 umol/L is bad

  23. APPROACH

  24. MILD • < 20 mg/kg and asymptomatic • Management • Observe 6-8 hrs • D/C if asymptomatic • No iron levels necessary

  25. MODERATE • 20 - 60 mg/kg or unknown + “mild”GI s/s • Order AXR and Fe level (2-6hr) • Consider Gastric lavage or WBI • Fe level < 60 or 60 - 90 and asymptomatic -------> observe 6 - 8 hours and d/c if well • Fe level > 90 or 60 - 90 and symptomatic -------> treat as severe

  26. SEVERE • > 60 mg/kg, severe GI s/s, AGMA, shock • AXR, Fe level, baseline urine • Gastric lavage or WBI based on AXR • Start Deferoxamine: target is 15 mg/kg/hr • Discontinue Deferoxamine when…… • Clinically well • AGMA resolved • No further urine color change

  27. The GOODs on IRON • LOCAL and SYSTEMIC toxicity: 5 stages • Asymptomatic at 6hrs r/o sign. ingestion • Consider with gastro, GIB, AGMA, shock • Absence of pills on AXR does NOT r/o • Rx based on clinical status, amount ingested, and iron levels • Don’t wait for iron level if toxic

  28. HYMENOPTERA • Nasty arthropods: bee, wasp, hornet, yellow jacket, fire ants • 2nd most common cause of anaphylactic deaths • Killer Bees: “normal” bees with a mean streak (not more toxic, just more aggressive)

  29. HYMENOPTERA REACTIONS • Local • pain, erythema, edema, swelling, itching • lasts hours to days; looks like infection • Toxic • N/V/D, lightheaded, syncope, H/A, fever, muscle spasms (NO urticaria or bronchospasm) • Due to toxic nature of venom NOT anaphylaxis • Lasts few hours to 2-3 days

  30. HYMENOPTERA REACTIONS • Allergic/Anaphylactic • Urticarial rash ------------> full anaphylaxis • Delayed Reaction • Serum sickness at 10 - 14 days: fever, malaise, H/A, lymphadenopathy, polyarthritis, urticaria • Often not associated with sting by patient • Usual Reactions • Encephalitis, GBS, neuritis, vasculitis

  31. HYMENOPTERA - Mx • First Aid • Ice bag to site, remove stinger, epipen prn • Local Wound care in ED • Ice, remove stinger, tourniquet, limb down, can inject 0.1 ml of 1:1000 epi into site • Further Mx will depend on severity • Local reaction, allergic reaction, anaphylactic reaction

  32. ED Management • Local Reaction • Local wound care, benadryl po, ibuprofen po • Observe 1hr, d/c if well • Urticarial Reaction • Local wound care, benadryl po, ibuprofen po • Observe 2-3 hrs, d/c if well • Educate, bracelet, Epipen Rx, allergist referral, Rx with benadryl +/- steroid

  33. ED Management • Anaphylaxis • Epinephrine sc, im, iv • Benadryl iv • IV fluids • Ranitidine +/- Cimetidine • Ventolin +/- Racemic epi neb • Methylprednisone • Local wound care • Admit

  34. MARINE ENVENOMATIONS • 2000 species of venemous marine animals • General Mx • Remove from water: drowning MCC of death • Local wound care • ? Specific antivenom • Be prepared to manage anaphylaxis

  35. Three Mechanisms of Envenomation

  36. Octopi Local wound care: irrigate, debride, dress, tetanus, analgesia Blue - ringed Octopus can be lethal (tetrodotoxin like venom) BITES

  37. Seasnakes 50 species, all toxic, 7 fatal Most bites do not result in envenomation b/c fangs short/loose ---> poor delivery of venom Local wound care + polyvalent sea snake antivenom BITES

  38. NEMATOCYSTS • Nematocyst = spring - loaded venom gland that suddenly everts and delivers venom • Often located on tentacles • Remain functional after animals death • May still be “loaded”when in skin • Local reaction, allergic reaction, toxic reaction (N/V/D, CP, cramps, SOB, paralysis, cardiorespiratory collapse)

  39. NEMATOCYSTS • General Mx • Cut off tentacles • Inactivate nematocysts: VINEGAR • Remove nematocyts: credit card scrape • Antihistamine, analgesia • Antivenom only exists for seawasp

  40. Jellyfish Usually only local reaction Remove tentacle, vinegar, credit card scrape, antihistamine, analgesia NEMATOCYSTS

  41. NEMATOCYSTS

  42. NEMATOCYSTS • Box Jellyfish (Seawasp) • Australia, Indian ocean • MOST deadly of all envenomating marine life • 25% fatality rate; more deaths than sharks! • One box can kill 10 humans • Cardioresp arrest within minutes • Mx: ABCs, remove tentacles, VINEGAR, credit card scrape, ANTIVENOM (Chironex)

  43. NEMATOCYSTS

  44. NEMATOCYTS • Portuguese Man -o - war • Southern US coast line • Not a true jellyfish • Usually only local reaction • Potential for full CV collapse • Many deaths reported • Mx: ABCs, remove tentacles, vinegar, credit card scrape, NO antivenom exists

  45. STINGS • Stinger = specialized apparatus that punctures skin and delivers venom • Mx • Remove stinger (? Xray to r/o stinger in tissue) • Irrigate copiously, tetanus, analgesia • HOT WATER for 30 - 90 min (inactivates the heat labile venom; hot as possible) • Antivenom exists for stonefish stings

  46. Starfish Most nonvenomous Crown - of - thorns: severe local reaction STINGS

  47. Sea Urchins Toxic coated spines Severity depends on species Usually only local reaction Imbedded spines problematic STINGS

  48. Stingray Barbs on tail Stepped on in shallow water Tail spines ---> laceration Stinger: local +/- systemic rxn (N/V/D, cramps, CP, SOB) Remove stinger, irrigate, HOT water, tetanus, abx to cover vibrio STINGS

  49. Bony fish (Lionfish, Stonefish) Venomous spins on fins Stepped on or handled Will attack b/f swimming away Severe local rxn: pain, swelling Systemic rxn: N/V/D, syncope, SOB, paralysis, CV collapse ANTIVENOM exists STINGS

  50. The Goods on Marine Envenomations

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