IRON and STINGS

Rob Hall

Dr. M. Yarema

June 20th, 2002

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

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?

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

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

LOCAL TOXICITY

• Direct GI corrosive/irritant

• Nausea, vomiting, abdominal pain, diarrhea, hematemasis, melena, hematochezia

• Must consider on ddx of gastroenteritis, GI bleed in peds

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

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

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

Complications

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

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

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

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

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

DEFEROXAMINE

• Specific iron chelator

• Derived from Streptomyces pilosus

• Ferric iron + deferoxamine -----------------> ferrioxamine (colors urine red/brown)

• Chelates free iron in blood and intracellular

DEFEROXAMINE

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

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

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

Vin Rose’

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

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

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

APPROACH

H is to ryP h ys ica l

L ab s

M IL D< 2 0 m g /kg

asym p tom atic

M O D E R A TE2 0 - 6 0 m g /kg

u n kn ow n am ou n t"m ild " G I s /s

S E V E R E> 6 0 m g /kg

"severe" G I s /s A G M A or S h ock

D ete rm in e S everity

MILD

• < 20 mg/kg and asymptomatic

• Management– Observe 6-8 hrs– D/C if asymptomatic– No iron levels necessary

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

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

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

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)

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

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

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

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

ED Management

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

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

Three Mechanisms of EnvenomationO h , L ook a t th e cu te lit t le fish y!

O c top iS easn akes

B ites

Je llyfishM an -o-w arS ea w aspF ire co ra ls

N em atocys ts

B on y F ishS ea U rch in /s ta rfish

C on e S h e llsS tin g rays

S tin g s

M arin e E n ven om ationM ech an ism s

BITES

• Octopi– Local wound care: irrigate,

debride, dress, tetanus, analgesia

– Blue - ringed Octopus can be lethal (tetrodotoxin like venom)

BITES

• 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

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)

NEMATOCYSTS

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

NEMATOCYSTS

• Jellyfish– Usually only local reaction

– Remove tentacle, vinegar, credit card scrape, antihistamine, analgesia

NEMATOCYSTS

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)

NEMATOCYSTS

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

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

STINGS

• Starfish – Most nonvenomous

– Crown - of - thorns: severe local reaction

STINGS

• Sea Urchins– Toxic coated spines

– Severity depends on species

– Usually only local reaction

– Imbedded spines problematic

STINGS

• 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

• 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

The Goods on Marine Envenomations

L ook b u t D O N 'T tou ch

L oca l w ou n d careA n tiven om fo r sn akes

B ITE Soc top i

seasn akes

R em ove ten tac lesV IN E G A R

C red it ca rd sc rap eA n tiven om fo r sea w asp s

N E M A TO C Y S TSje llyfish , sea w asp

m an - o f - w ar

R em ove s tin g erIrrig a te

H O T W A TE RA n tiven om fo r s ton e fish

S TIN G Ss ta rfish , u rch in s

s tin g ray, b on yfish

M an ag em en t