Mini-Tox: Liberia

Management of common and commonly problematic

toxicological emergencies

Andrew Shannon, MD MPH

Jacobi Medical Center Emergency Medicine Residency

Albert Einstein College of Medicine, Yeshiva University

Objectives and Outline

Brief overview of important initial steps in managing intoxications

History Toxicological physical exam and adjuncts Toxidromes Gastric decontamination Approach to coma Specific poisonings

Acetaminophen (APAP) Salicylates CO / CN Caustics / Iron Alcohols Drugs of abuse

Special psychiatric overdoses

Toxic bradycardia Pesticides Heavy Metals

Helpful Resources Poison Centers in the US: 1-800-222-1222 Vaults of Erowid: www.erowid.org Lycaeum: www.lycaeum.org MMWR: www.cdc.gov/mmwr Medwatch: www.fda.gov/medwatch Emergency Preparedness and Response: www.bt.cdc.gov Household Products Database:

http://housholdproducts.nlm.nkh.gov Cornell Univ. Poisonous Plants Informational Database:

www.ansci.cornell.edu/plants Dartmouth Toxic Metals Research Program:

www.darmouth.edu/~toxmetal

History

Pts p/w ingestions may not be reliable

SI/HI who called EMS? why?

altered mental status (AMS)

Family EMS (check ACR!) MiSys- prior visit/med hx

AMPLE Hx allergies, medications (recent

changes), procedures, last po intake, what led up to incident

Ingestion Hx chemicals/meds available to pt? (ie

Soc Hx) how much, when, why?

SI/HI, accidental med OD, abuse/Munchausen by proxy

paraphernalia/bottles at scene last time Pt noted to be at baseline?

Physical Exam

ABC’s “D”- Disability/(Dextrose)

GCS - not prognostic “E” – Exposure/(EKG)

Dry if wet, warm if cold, cool if hot Re-address decon and staff

safety/contamination

Vital Signs (VS) Count/repeat yourself

do not rely on a “Nurses’ 20” for RR

If you can’t get a BP, there probably isn’t one

FSBG is 6th VS!

HEENT signs of trauma MMM; burns nystagmus, pupils

Skin diaphoresis; piloerection cyanosis track marks

CV Chest

rales Abd

bowel sounds Neuro

MS (O x ?); gag gait tremor, fasciculation, DTRs

Adjuncts to Physical Exam FSBG

by now you’ve realized this is important

EKG Arrhythmias Intervals End-organ effects (ischemia)

CXR/AXR Aspiration Free-air / perforation Radio-opaque ingestants

body packers/stuffers halogenated hydrocarbons Fe, K, I or heavy metal compounds enteric coated preparations

Lab tests Order:

APAP / ASA level bHCG

Consider: anion gap anti-convulsant level CO level EtOH level CPK ABG / VBG / lactate NH4

osmolality

“Toxidromes”

Sympathomimetic Hyperthermia Tachycardia Hypertension Mydriasis Diaphoresis AMS – agitated/combative,

hallucinations, seizure

Narcotic Pinpoint pupils (variable) AMS – obtundation Decrsd RR

Sedative/Hypnotic AMS – obtundation Normal VS!

CAUTION: toxidromes are generalities, and intoxications may not present classically, especially in mixed ingestions

“Toxidromes” Cholinergic

Muscarinc – “leaky” SLUDGE: salivation,

lacrimation, urination, diarrhea, GI cramps, emesis

“Terrible B’s”: bradycardia, bronchorrhea, bronchospasm

Nicotinic Autonomic: diaphoresis,

mydriasis, tachycardia, HTN Neuromuscular: fasciculation,

weakness, paralysis

Anti-cholingergic hyperthermia tachycardia/HTN dry/flushed skin; dry MM mydriasis decrsd bowel sounds urinary retention AMS – agitation,

hallucination, seizure “Red as a beet, dry as a

bone, hot as hell, blind as a bat, mad as a hatter”

Classically, cholinergic toxidrome includes constricted pupils (miosis), but this is variable (agent; predominating effect)

Gastric Decontamination

Ipecac ~20 min to V onset No role in ED setting

Gastric lavage Consider if <1 hr, critical toxin, protected airway Contraindicated: caustics, large or sharp FBs

L lat decub/Trendelenberg, suction, intact gag or ETT Measure nose to xiphoid, confirm position, lavage until clear 36-40 Fr in adults; 22-24 Fr min in children

“critical toxin” = a small decrease in toxin burden may have large impact on clinical status; i.e. TCAs, CCBs, colchicine, Li…

Activated Charcoal

Adsorbs many toxins optimal charcoal: toxin ratio 10:1

Initial dose in unkn ingst 1 g/kg Must mix slurry well! (actual

charcoal is in bottom of bottle) NOT USEFUL in…

small molecules (Li, Fe, Pb) hydrocarbons, alcohols when endoscopy indicated

(caustics)

MDAC (multi-dose) phenobarb, dapsone,

theophylline, digitoxin, phyentoin, carbamazepine

ensure cathartic only w/ 1st dose!

Cathartics sorbitol (0.5g/kg), Mg citrate

or sulfate

AC contraindicated: gut perforation or ileus sig aspiration risk

Whole Bowel Irrigation

Rarely indicated large burdens poorly adsorbed (AC) agents (Li, Pb, Fe, Zn)

or SR/ER preps In consultation w/ GI for body-packers (“mules”)

metaclopramide; NGT; dose of AC minimum 1.5-2 L/hr (adult) or 25 mL/kg/hr (child) PEG

Golytely, Nulytely, Colyte until rectal effluent is clear (? rectal tube) re-dose AC

Contraindications No bowel sounds; obstruction or perf; unstable pt;

unprotected compromised airway

Coma Care of the undifferentiated coma patient is EM

distilled‘As a rule,’ said Holmes, ‘the more bizarre a thing is the less mysterious it

proves to be. It is your commonplace, featureless crimes which are really puzzling, just as a commonplace face is the most difficult to identify.’

ATLS / ACLS / PALS protocols are key C-spine stabilization? HCT to r/o chronic subdurals? Roll the patient

so you don’t miss the bullet hole… Infxn, SAH, CVAs, MIs, Ao dissections leading to CVAs

can all affect a Pt’s “responsiveness” Coma due to toxins should be treated in the same way,

with emphasis placed on above measures and observations

Coma “Cocktail” Thiamine

100 mg iv prior to dextrose

Dextrose 0.5-1.0 g/kg D50 – “1 amp” (50cc of 5% dextrose = 25 g)

4 kcal/g = ~100kcal (less than ½ a candy bar! Food is next!) D10 in children

Narcan 0.05-0.1 mg IVP initially; textbook dose (0.01 mg/kg) Indicated when RR < 11 & AMS ½ life 60-90 min

duration of action 20-90 min; less than most opiates

Flumazenil (?) Risk of precipitating seizure severely limits routine use

Acetaminophen (APAP) N-acetyl-para-aminophenol; aka paracetamol

#1 cause acute liver failure in US; #1 cause tox fatalities peak serum lvls 30-60 min; hepatic metabolism

in OD, NAPQI metabolite becomes toxic as glutathione is depleted APAP lvls are sent on unknown ingestions/SAs

toxic, treatable, time dependent, commonly co-ingested, ASYMPTOMATIC

½-24 hrs: N/V, no sxs, (? APAP OD interferes w/ FSBG) 24-48 hrs: RUQ pain, elevated LFTs, PT/INR, bilirubin 48-96 hrs: hepatic dysfxn, acidosis, coagulopathy, LFTs

peak, hypoglycemia, jaundice, cerebral edema death 4-14 days: resolution

APAP

Hx- time of ingestion & amnt 150 mg/kg : potentially toxic dose (~

7.5 g adults) within 24 hr Rumack-Matthew nomogram: acute

ingestions only obtain 4-hr level (or as soon after as

possible) in unknown time frame, if initial lvl is zero, the 4hr lvl will not rise to toxic

AST sens for hepatic injury prognostic markers in acute injury

PT/INR, CO2/pH, lactate, renal function, phosphate

“extended relief” APAP: sequential release in same pillif 4 hr lvl above nomogram, treat; if not, repeat in another 4 hrs

APAP N-acetylcysteine (NAC) “mucomyst”

multiple mechanisms greatest benefit if started < 8 hrs; benefit for late start

charcoal (AC) binds po NAC, but likely not significant po load 140mg/kg

maint dose 70mg/kg q 4hrs x 17doses; 1330mg/kg/72hrs antiemetics, sweetners, etc.; ? po in asthmatics/anaphylactoid rxn risk

iv load 150mg/kg in 200cc D5W ovr 1hr then 50mg/kg in 500cc x 4hrs; 100mg/kg in 1L x 16hrs separate protocol for children <40kg 2/2 fluid concerns; or give po

Indicated in h/o ingestion presenting >8hrs out while awaiting lvl chronic large ingestions (>4g/day; >120mg/kg/day) high APAP lvl (nomogram) late (>24hrs) presentations w/ detectable APAP or high LFTs

Salicylates ASA (acetylsalicylic acid) Methyl salicylate - “oil of wintergreen”

1 mL 98% m.s. = 1.4 g salicylate; 5 mL potentially fatal in 2 yo

max serum lvls ~ 1hr; in OD, ~ 4-6 hrs Michaelis-Menten (“saturation”) kinetics: from 1st to 0 order elimination

initial resp alkalosis 2/2 direct stim of medulla not present in young children, so present later w/ severe acidosis

AG met acidosis 2/2 dcrsd renal excret of acids & uncoupling of oxidative phosphorylation, et al.

resp acidosis superimposed on 10 mixed resp alk/met acidosis when ventilation fails-- from fatigue or ASA induced ALI

Pre-terminal event

“Salicylism” N/V, ALI, tachy, tinnitus, vertigo, cerebral edema, hepatitis,

dehydration, hypoglycemia, hypokalemia ASA lvl

>30mg/dL = s/sxs present : >100mg/dL requires HD repeat lvl hourly during Rx

MDAC 2-4 doses; IVF for dehydration RSI & subsequent impairment of hyperventilation may worsen

acidosis Urine alkalinization: goal urine pH 7.5-9.0, ABG 7.45-7.55

for symp salicylism, lvl > 40 mg/dL Hemoperfusion removes salicylate most efficiently HD can also correct lytes, H+ status

ALI, AMS, coagulopathy, ARF, unable to tol IVF, acute lvl > 100 mg/dL

Carbon Monoxide (CO) colorless, odorless tasteless gas

mild exposure– HA, N, malaise sig exposure– chest pain, focal neuro signs, dysrhythmias,

syncope venous carboxyhemoglobin (CO-Hb) lvl, beta-hcg

?EKG, ?CPK, ?UA, ?chem-7 nml CO-Hb 1-2%; smokers 5-10%

poor correlation w/ sx’s ME uses >50% lvl is min lvl for lethality – “CO poisoning death”

CO-Hb dcrs’s O2 carrying capacity shifts curve to the left (dcrsd O2 offloading to tissues) binds myoglobin inducing cardiac/skeletal muscle hypoxia binds cytochrome oxidase, blocking (not uncoupling!) mitochondrial

oxidative phosphorylation induces CNS lipid peroxidation

CO Rx

O2 therapy at highest conc possible Hyperbaric O2 (HBO2): best effect if within 6 hrs

primarily to prevent delayed neurological sequelae absolute indications for HBO2

pregnant w/ lvl >10% or fetal distress (3rd trimstr) CO-Hb > 25% unconscious/syncope on scene or ER, AMS, cerebellar signs,

seizure or confusion end-organ ischemia (EKG chngs, chest pain, pH < 7.1)

Asymp Pts or those asymp in 4-6 hrs w/ (-) lab/EKG findings d/c home

Ongoing study to correlate CO finger sensor and blood levels!

Cyanide (CN) suicide, homocide, nitroprusside, jewelry production, fumigants, combustion

of inorganic materials, artificial nail remover suspect in acidotic CO poisonings w/ high lactate (ie >10mmol/L)

blockade of electron transport chain anaerobic metabolism lactic acidosis

high AG, lactate, & central venous O2 sat CN antidote kit

1) induce methemoglobinemia to bind CN: 20-30% metHb tolerable amyl nitrite pearls – inhaled while awaiting iv access sodium nitrite (3%) - 0.33 mL/kg to max 10mL ovr 2-4min

2) sodium thiosulfate (25%) – 1.65 mL/kg to max 50mL (adults); may repeat dose Cyanokit – hydroxycobalamin 5g (70mg/kg) ovr 15 min

cyanocobalamin (B12) formed, chelating CN initial hypotn possible; subsequent dosing uses longer infusion (6-8hrs)

CO & CN poisoning avoid metHb in setting of CO-Hb; use only the sodium thiosulfate and HBO2

Caustics Acid – H+ donator – pH < 3; coagulation necrosis Base – H+ acceptor – pH >11; liquefactive necrosis Pts w/ sx’s require w/u incld bloods & CXR (r/o perf)

endoscopy intentional ingestions, stridor, pain, vomiting, drooling within 12 hrs, no later than 24 Grade I – hyperema/edema, w/o ulceration

med clear if can eat/drink; no incrsd risk for stricture/CA Grade IIa/IIb – submucosal lesions, exudates not/near-

circumferential Grade III - deep ulcers/necrosis into peri-esophageal tissues

IIa; soft diet as tol; NGT under direct visualization prn IIb/III; risk for perf/infxn (days to wks); all form strictures; ?Surg consult

airway inspection (direct/fiberoptic laryngoscopy); ?ETT, ? dexamethasone

Caustics Gastric decon contraindicated except

large acid ingestions, ZnCl2, HgCl2 ? gastric emptying w/ narrow NGT if < 30 min

severity of systemic absorption may outweigh risks

bleach (sodium hypochlorite, NaOCl)

ammonia (ammonium hydroxide, NH4OH); 3-10% household, 28% industrial str

lrg industrial str exposures or those w/ sx’s require w/u otherwise clear if tol po

Ophthalmic exposures immediate high vol irrigation for at least 15 min check pH (UA, litums paper, nitrazine paper), goal pH 7.4 ?ant chamber irrigation; d/w Ophtho

Iron

Direct GI irritant, vasodilator, neg ionotrope, disrupts electron transport chain & aerobic metabolism

Min/no sxs- observe 6 hrs; if no sxs, d/c Mild/mod tox- emesis, mild tachy, mild acidosis

local effects N/V/D onset < 6 hrs from ingestion Rx if: Fe on KUB, persistent clin toxicity (>4 episodes emesis),

acidosis, serum Fe > 350 mcg/dL, estimate of elemental Fe >20-60mg/kg

sulfate 20% eFe; gluconate 12%, fumarate 33% Severe tox – GIB, acidosis, AMS, hypotn, coagulopathy

IVF, RBCs, lavage/WBI if feasible; ICU admission iv deferoxamine: start 5mg/kg/hr, titrate up to 15mg/kg/hr as BP allows

obtain pre-Rx and 4-6hr post-Rx UA when urine color returns to baseline, no more free Fe is being

chelated DFO Rx should stop @ 24hrs; safe in pregnancy

Alcohol Intoxication

“Intoxicated” is a clinical diagnosis 1 g/kg EtOH = serum lvl 100mg/dL ~ 1 hr later

12 oz beer (5%EtOH) x (30 mL/oz) x 0.8 g/mL = 14.4 g EtOH 5 oz wine (12%EtOH) = 14.4 g EtOH 1.5 oz liquor (40%EtOH) = 14.4 g EtOH “proof” ~ 2 x %EtOH

unhabituated patients eliminate EtOH 15-20mg/dL/hr

alcoholics avg 25-35 mg/dL/hr

Alcohol Intoxication

Withdrawal from EtOH 6-24 hrs after last drink - "the shakes“

tremor, tachycardia, diaphoresis, anorexia, insomnia

4-24 hrs – hallucinosis persecutory auditory, visual, tactile hallucinations w/o delirium

6-72 hrs – “rum fits” generalized seizures

3-10 days - delirium tremens (DT) disorientation, fever, visual hallucinations

Managing Alcohol

High incidence of infection/trauma ?HCT, ?c-collar & c-spineCT, ?LP, ?CXR

Dehydration w/ osmolar gap VS, FSBG, ?chem-7, ?CPK, ?EtOH lvl (prognostic), ?osms

“Banana bag”/“Osler bag”/“Rally pack” – expensive D5NS or ½NS, 2g MgSO4, 10mL MVI, 1mg folate, 100mg

thiamine thiamine only vitamin affecting outcome (dcrsd incidence DTs)

Alcohol Withdrawal

diazepam 10mg ivp shorter time to peak onset of action

lorazepam 2mg ivp no active metabolites (liver pts)

phenobarbital 130 mg iv (up to 390mg) failure to respond to benzos (200mg / 40mg) in first 3-5 hrs prepare for intubation; arrange ICU admission

IVF, MgSO4

phenytoin – no role in w/d sz’s unless a proven focus chlordiazepoxide – mild/early w/d

50-100 mg/d single or divided dose Elderly/debilitated: Initial 10 mg PO/IV/IM Detox: 25 mg PO q6h for 1 d, q8h for 1 d, q12h for 1 d, qhs for 1 d

Toxic Alcohols

Ethylene glycol – antifreeze, coolants; “sweet” tasting LD 1-1.5 mL/kg

cardiac depression, ATN (Ca oxalate crystals in UA), AG acidosis, hypo-Ca UA can fluoresce under UV (Wood’s lamp) light; poor Sens/Spec Glycolic acid (metabolite) may cross-react with some lactate assays!

Detox cofactors - pyridoxine (B6) 50mg q6hr; thiamine (B1) 100mg q6hr HD indications – serum lvl >25mg/dL, acidosis, pulm edema, renal failure, VS instability

Methanol – “wood alcohol” solvents, windshield washer fluid, paints/removers, varnishes, “canned heat”

LD 15-30mL; metabolized into formaldehyde/formic acid Ocular toxicity “snowstorm” vision, ARF/myoglobinuria, CNS dep & seizures, N/V Optic disc hyperemia

Detox cofactors – folic or folinic (leucovorin) acid 1 mg/kg up to 50 q 4-6 hrs iv HD – serum 20-50mg/dL, acidosis, visual impairment, renal failure, VS instability

Toxic Alcohols NaHCO3 to alkalinize urine may enhance metabolite

excretion Fomepizole – ADH competitive inhibitor

witnessed ingestion/strong history; lvl >25mg/dL; lrg osmol gap w/ suspicion; significant unexplained AG acidosis

load 15mg/kg over 30 min; 10mg/kg q 12 for 48hrs; then 15mg/kg q 12 reload post-HD

Isopropyl alcohol – “rubbing alcohol” solvent, disinfectant, window cleaners, skin/hair products

LD (70% soln) 1 mL/kg metabolized to acetone significant ketosis w/ minimal acidosis

CNS dep, unstable VS, N/V, ATN, hemolytic anemia, myoglobinuria HD indications- uncorrectable hypotn, deep coma, VS instability, serum lvl > 400-500mg/dL supportive care

Drugs of Abuse

Opiates (natural); Opioids (semi-/synthetic) CNS,CV & respiratory depression, histamine release

miosis common, not universal (esp. w/ coingestant) hypoventilation, rhabdomyolysis, hypothermia, concomitant APAP

toxicity, lung injury (talc pneumonitis, ALI ?2/2 naloxone) Lomotil (diphenoxylate) and Imodium (loperamide)

poorly absorbed, may give acute toxicity Narcan (naloxone)- typically needed if RR < 11

0.05mg test dose, escalate prn, lowest effective dose q 2-3min If infusion needed, use 2/3 of dose giving a response / hr

Clonidine overdose may appear identical 50% pediatric clonidine ODs may respond to naloxone

Opiates

Withdrawal – if iatrogenic, do not give opioid! unpleasant, not dangerous

piloerection, mydriassis, incrsd BS, yawning, diaphoresis, larcimation, N/V

Methadone- 10mg IM; 20mg po (dissolved) effective regardless of abuse pattern use antiemetics prn DO NOT give full methadone maint dose, esp if unverified

if diverting, “prescribed” dose potentially an acute OD Clonidine 0.1mg-0.3mg po q1hr until sx’s improve

? maint dose 0.3mg bid/tid watch for hypotn

Sympathomimetics Cocaine, amphetamines

CVA, szs, MI, hypo-/hypertn, hyperthermia, bronchospasm, pneumothorax/mediastinum, rhabdomyolysis, quinidine effect (dysrhythmias, interval prolongation), placental abruption (2nd/3rd trimester)

Chest pain AMI risk in 1st hr after cocaine use 24x normal 6% pts w/ cocaine CP have CE elevations EKGs less sens/spec for MI in recent cocaine users cocaine prothombotic

“Crack lung” 1-48hrs s/p smoking - hypersensitivity pneumonitis acute pulm infiltrates, pain, eosinophilia

benzos (diazepam 2.5mg), external cooling nitroglycerin, ASA, ?CCBs in pts w/ concern for ACS

withdrawal – lethargy, dysphoria

Benzodiazepines “Coma with normal vital signs”

RR should be normal DDx: head trauma, stroke, hypoglycemia, CO poisoning, multi-

substance ingestion EKG, FSBG, bHCG, EtOH lvl

ABCs: ?ETT “Anyone who can tolerate a nasopharyngeal airway probably deserves

one” if awake, activated charcoal

most pts are arousable within 12-36 hrs w/ supportive care Flumazenil: use only to avoid an intubation!

0.5mg slow IVP 1-2 hrs to max 5.0 mg w/d similar to EtOH

predictable based on pharmacokinetics chronic use of long-acting agents (diazepam) may delay w/d 4-10 days

Psychiatric Overdoses TCAs: NE/DA/5-HT reuptake blockade

anti-cholinergic effects, antihistamine effect, Na channel blockade

ABCs; orogastric lavage if < 1 hr; AC 1-2 doses (q4hrs) EKG as screen: QRS

<100ms = no toxicity >100ms = 1/3 pts w/ szs: ADMIT, think about ICU >160ms = ½ pts w/ ventricular dysrhythmia: ADMIT to ICU

NaHCO3 2 amps (1-2mEq/kg) bolus – observe response on rhythm strip

3 amps in 1 L D5W @ 2-3x maint; goal narrow QRS or max pH 7.55 replete Mg, K consider 24 hr tele admission for pts w/ persistent HR > 120, or QTc

> 480 No Sz, nml EKG (exept tachy that resolves) observe 6 hrs to clear

terminal 40 ms R axis deviation: aVR R wave > 3mm (~ 81% PPV for poisoning) w/ R/S ratio in aVR > 0.7 ; deep slurred S wave in I & aVL

long QT, sinus tach

Mood Stabilizers Lithium

precipitants- dehydration, renal dysfunction, preeclampsia, Na depletion, thermal stress, drug interactions

NSAIDs, carbamazepine, ACE-Is/ARBs, metronidazole, antipsychotics, diuretics

tremor, slurred speech, ataxia, hyperreflexia/clonus, sz, CV collapse, EPS acute- dilute urine, prolonged QT, hypothyroid, inc WBCs chronic- nephro DI, interstitial nephritis, aplastic anemia, dermatitis

IVF; WBI if SR preparations ingested repeat Li lvl 2 hrs after initial draw in acute (6 hrs in chronic) OD

HD: call nephrologist w/ 2nd lvl value S/Sxs neurotoxicity (AMS); unable to eliminate Li (ARF); unable to tol

IVF load (CHF); Li lvl > 4.0mEq/L (acute) or > 2.5mEq/L (chronic)

“re-bound”- tissue redistribution requires post-HD lvl and again 6 hrs later

Mood Stabilizers Valproic acid (VPA)

carnitine depletion leads to hyperammonemia 11% pts w/ asymp chemical hepatitis risk for (rare) fulminant hepatic failure, hypoglycemia

OD usually benign, self-limited drowsiness > 30mg/kg coma, respiratory depression poor correlation w/ serum lvls; repeat in 2-3 hrs for downward trend consider NH4 lvl, lytes, lactate if AMS

MDAC in lrg acute OD w/ rising lvls HD: deterioration, hepatic dysnfxn, rising lvls, VPA > 1000mg/L carnitine supplement: VPA-induced hepatotoxicity, NH4 > 35

micromol/L, peds <2 yo or on ketogenic diets 100mg/kg (max 6g) ovr 30 min iv 100mg/kg/day (max 3g) divided q6hrs po

Toxic Bradycardia

CCBs rapid onset 1-2 hrs IR, SR 12-18 hrs

verapamil – nodal (HR, CO) nifedipine – peripheral (SVR)

BBs CHF, low HR, bronchospasm, hyper K, hypoglycemia

(children) early onset of effect (<6hrs); peak 1-4 hrs

(sotalol may delay >24hrs)

Clonidine onset 30-60 min; peak 2-3 hrs naloxone, IVF, atropine, pressors

Toxic Bradycardia atropine 0.5-1.0mg (0.02mg/kg) q2-3min, max 3mg

hypotn 2/2 myocard dep, not incr vagal tone slows gut in pts receiving WBI

CaCl2 10-20 cc 10% soln (1-2 amps); slow IVP ovr 3-5min 3-6 amps Ca gluc q 15-20min; up to 5 gms w/o serial Ca, PO4

peds 10-20 mg/kg Ca gluc (10% soln ~ 0.1cc/kg) glucagon 2-5mg slow IVP, q5-10min; 10mg max; BB>CCBs

gtt to follow; mg/hr = effective initial dose mg peds 50-150 mcg/kg; gtt 50mcg/kg/hr

pressors (NE) pacing – often ineffective

Pesticides

200,000 deaths/yr leading cause of suicide/unintentional poisonings Vomiting, diarrhea resp distress LOC

Cholinesterase inhibitors cholinergic toxidrome (miosis, SLUDGE, “killer ‘B’s”)

bradycardia is muscarinic, but bronchorrhea/constriction induced hypoxia may cause tachycardia

organophosphates penetrate latex/vinyl; leather is reservoir; 0.5% hypochlorite bleach or

alcohol based soap for dermal decon “age” – irreversible inactivation of AChE

carbamates reversible binding- no aging muscarinic > nicotinic effects

Pesticides atropine

0.5-1.0 mg (0.02 mg/kg) initial; double dose q2-3min titrate to drying of bronchial secretions 0.5mg min adult dose (0.1mg peds) 2/2 paradoxical brady no effect on nicotinic neuromuscular junction (paralysis)

pralidoxime (2-PAM) frees un-”aged” AChE 1-2 g in 100 cc NS (25mg/kg, max 1 g) ovr 15-30min; then q6-12hr WHO regimen: 30 mg/kg iv bolus; then > 8mg/kg/hr gtt

glycopyrrolate/ipratropium periph-acting/inhaled anti-muscarinics may be considered as

adjuncts to atropine for clearing lung secretions

Pesticides

Sxs usually unlikely if not developed in 6-12 hrs exceptions: fenthion, VX gas (nerve agent) ~ 24 hrs

Sequelae of organophosphate/carbamates “Intermediate Syndrome”

acute prox/resp muscle wkns; cranial neuropathy 24-96 hrs following poisoning; up to 1st few wks unpredictable occurrence supportive care; pralidoxime/atropine as indicated

persistent sensory/motor neuropathy occasionally

Pesticides

Organochlorines DDT, benzene hexachloride (Lindane), aldrin, etc.

supportive Rx for agitation, szs; decon

Pyrethrins and Pyrethroids permethrin, deltamethrin, fenvalerate

supportive Rx; paresthesias self-limited (top vit E)

Nicotine/neonicotinoids nithizaine, dinotefuran, thiacloprid

irritant, szs, resp dep decon (skin), supportive care

Marine toxins

Ciguatera tropics/subtropics; reef dwelling tropical fish

barracuda, moray eel, amberjack, grouper, mackerel, parrot fish, red snapper

GI (N/V), CNS (palsies, paresthesias, hot/cold reversal), CV (heart block, brady), fatigue/malaise

Scombroid tuna, mackerel, skip-jack, bonito, mahi mahi, bluefish,

amberjack flushing, rash, palpitations, tachycardia anti-H1,2, epinephrine, beta-agonists

Heavy Metals

Multi-system toxicity Acute

GI: N/V/diarrhea – most metal salt ingestionsRenal: proteinuria, aminoaciduria, ATNCV: response to volume loss, dysrhythmia, congestive CMCNS: dMS; periph neuropathies in hours to daysHair/skin/nail changes: lag days -wks behind acute exposure

ChronicCNS/PNS: predominateHeme: anemias, cytopeniasRenal: CRI/CRFCA: variousSkin: rashes, colored lines on nails/gums

Heavy Metals Arsenic

inhaled dusts; copper/lead/zinc ore smelting; pesticides/herbicides; naturally occurring well water

ABCs, gastric emptying/AC KUB to r/o residual GI content

IM Dimercaprol (BAL) if can’t take po; ?add DMSA (meso-2,3-dimercaptosuccinic acid) when GI tract clear

Mercury Elemental- medical, Ore processing, mining, jewelry/battery making Inorganic salts- batteries, calomel, dyes, fireworks Organic- antiseptics, fungicides, by-products

supportive/ABCs; AC for HgCl Milk, NAC, egg whites- may bind salts in gut

BAL: acute (esp GI) tox- not in organic Hg DMSA: organic Hg, chronic or mild tox, when tol po

Heavy Metals

Lead crystal, solder, glaze, batteries, traditional meds

wrist-drop (PNS effects); Fanconi-like nephropathy; plumbism-gout

ABCs/supportive care R/o GI burden; DMSA for sxs or elevated levels; BAL followed by Ca

EDTA if encephalopathy present

Thalium: semi-conductors, insecticide/rodenticide, jewelry salts; elemental/organic v. rare

GI absorp; ~ 1 g lethal dose in adults MDAC likely helpful Prussian Blue enhances gut elimination via K exchange

BAL, EDTA, etc. not effective

References

New York City Poison Control Center. An intensive review course in clinical toxicology; March 13-14, 2008. All Rights Reserved.

Toxicology and Pharamacology. In Emergency Medicine: A comprehensive study guide, 6th ed. Tintinalli JE, Kelen GD, Stapczynski JS Eds. McGraw-Hill Companies, Inc. 2004