IRON and STINGS

1
IRON and STINGS

• Rob Hall
• Dr. M. Yarema
• June 20th, 2002

2
GOALS

• 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

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 ----gt 32 mg/kg
• 65 mg X 10 pills 650 mg ----gt 65 mg/kg

5
TOXICITY

• Elemental Fe Peak Toxicity
• lt 20 mg/kg lt 30 umol/L none
• 20 - 40 mg/kg 30 - 60 mild
• 40 - 60 mg/kg 60 - 90 mod
• gt 60 mg/kg gt 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 ---gt lactate
• Direct negative ionotropy ---gt lactate
• Direct vasodilation ---gt lactate
• MUST be on ddx of SHOCK and AGMA NYD

8
What causes the increased AGMA in Fe overdose?

• Fe 2 ----------------gt Fe 3 and Hydrogen
• Anerobic metabolism ---------gt lactate
• Hypovolemia from V/D --------gt lactate
• Hypovolemia from GIB ---------gt lactate
• -ve Ionotropy ---------------gt lactate
• Vasodilation ----------------gt lactate

9
FIVE STAGES

• STAGE I (lt 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 gt 15 and Glucose gt 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
AXR

• 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

14
DECONTAMINATION

• NO ipecac
• Doesnt 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 -----------------gt
  ferrioxamine (colors urine red/brown)
• Chelates free iron in blood and intracellular

16
DEFEROXAMINE

• Administration
• iv gt im gt 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 gt 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 -----------gt tx
• -ve no urine color change ---------gtno 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 gt 60 mg/kg
• Iron level gt 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 gt 60 mg/kg is bad
• Iron level gt 90 umol/L is bad

23
APPROACH
24
MILD

• lt 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 mildGI s/s
• Order AXR and Fe level (2-6hr)
• Consider Gastric lavage or WBI
• Fe level lt 60 or 60 - 90 and asymptomatic
  -------gt observe 6 - 8 hours and d/c if well
• Fe level gt 90 or 60 - 90 and symptomatic
  -------gt treat as severe

26
SEVERE

• gt 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
• Dont 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 ------------gt 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 11000 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
BITES

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

37
BITES

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

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 loadedwhen 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
NEMATOCYSTS

• Jellyfish
• Usually only local reaction
• Remove tentacle, vinegar, credit card scrape,
  antihistamine, analgesia

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
STINGS

• Starfish
• Most nonvenomous
• Crown - of - thorns severe local reaction

47
STINGS

• Sea Urchins
• Toxic coated spines
• Severity depends on species
• Usually only local reaction
• Imbedded spines problematic

48
STINGS

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

49
STINGS

• 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

50
The Goods on Marine Envenomations