Transcript toxicology i - Calgary Emergency Medicine

OVERDOSE: THE BAND
Mr. RR, 36yo Male
Brought in by EMS/CPS
 Found in appt building foyer asleep
with friend who “escaped”
 Not arousable, no I.D.
 Smells “fruity”
 GCS “3” but non-purposefull
movements of all limbs present
 No signs of trauma, OPA accepted
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TOXICOLOGY I
MANAGEMENT OF O.D. AND
DECONTAMINATION ISSUES
KEVIN HANRAHAN
DR. DAVID JOHNSON
OUTLINE
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GENERAL CONCEPTS
RESUSCITATION
HISTORY
TOXICOLOGY
PHYSICAL
TOXIDROMES
INVESTIGATIONS
GENERAL
DECONTAMINATION
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G.I. DECONTAMINATION
-ORAL REMOVAL
-BINDING
-MECHANICAL
FLUSHING
ENHANCED
ELIMINATION
ANTIDOTES
DISPOSITION
Nontoxic Ingestions
Only one substance in exposure
 Substance absolutely defined
 No hazards on product label
 Unintentional
 Route known
 Approximate amount known
 Asymptomatic with easy follow-up
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Setting
Occupational-eg. xylene
 Recreational
 Medical
 environmental
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I wonder
what this
xylene
would
taste like
Portals of Entry
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Ingestion,most common
historically(76%)
Inhalation(8%)
Cutaneous/mucous
membrane(6%)
Injection-meds
-drugs of abuse
Insufflation
PADIS 03/04
Sting/Bite
1%
Dermal
10%
Ocular
6%
Inhalation
8%
Parenteral
1%
Other, Unknown
0%
Oral
74%
PREVALENCE
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2 Million toxic exposure in U.S.-2000
3rd leading cause of death
Mortality from acute poisoning <1%
Peds account for 80%
10% admitted, usually accidental
Adults-20%,rarely accidental,90%
admitted to hospital
Accounts for 1% admission,10% ICU
PADIS APRIL 04/MAR 05
AGE DISTRIBUTION
>15 year
32%
11-15 year
5%
5-10 year
5%
Unknown
11%
<5 year
47%
CIRCUMSTANCES- PADIS
03/04
Other, Unknown
3%
Intentional
12%
Unintentional
85%
PADIS O3/04
Potentially Toxic, Unknown
2%
OUTCOMES
Medical, Unknown
5%
No Effect
5%
Non-toxic, Unknown
59%
Minor Effect
28%
Death
0%
Major Effect
1%
PADIS 03/04
SUBSTANCE
%KIDS
%ADULT
OTC pain & fever meds
Household cleaning prod
Cosmetics & personal care
Mental health meds
Alcohols
Anti anx & sedatives ??
Fumes/gases/vapors
Plants
Foreign bodies
Pesticides
15.4
11.4
11.1
----------------6.6
5.1
3.6
21.3
7.4
---11.2
9.8
9.1
8.3
-------4.4
RESUSCITATION
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Occurs simultaneously with Dx
Important as support may be only Tx
for most overdoses
Vitals, all 6 critical in toxicology
T/BP/HR/RR/SAT/BS
Airway-patent & protected?
-intubate for GCS<9
Breathing-vitals and auscultate
Circulation-vitals,establish IV,EKG
RESUSCITATION cont’d
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Decide:stable/unstable
:?heavy hitter eg TCA, Bblocker etc
Antidote-rarely takes precedence over
ABC (cyanide toxicity)
Coma Cocktail-hypoxia
-wernicke’s
-opioid intox.
-hypoglycemia
“HEAVY HITTERS”
Largest number of deaths in 2000 in U.S.
-analgesics
-antidepressants
-sedative/hypnotics/antipsychotics
-stimulants
-street drugs
-CV drugs
-alcohols
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RESUSCITATION cont’d
Seizures
-BZD.,phenobarb, not dilantin
 Hypotension
-isotonic fluids,bicarb,hi dose levo/dop
 Vent. Arhythmia
-bicarb bolus,lidocaine,BB in chloral
hydrate
-see ACLS for specific toxins
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COMA COCKTAIL
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Cheap
Minimal risk
Simple
Oxygen as per
need
D50W,50g,adult
4ml/k D25W or
10ml/k D10W
Pediatrics
THIAMINE
Not necessary in kids
 100mg IV/IM qdaily
 ?before D50W?
 Previously thought to prevent
Wernicke’s encephalopathy
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WHERE’S
THE
EVIDENCE
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Thiamine/Glucose
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Originally came from 5 case reports of
Wernicke’s precipitated or made worse by
glucose before thiamine
All 5 had severe nutritional deficiencies,
several comorbid illnesses and received
glucose for several days before thiamine
was administered
Therefore don’t delay glucose in ED for
thiamine
Hack,JB,JAMA 1988
NALOXONE (NARCAN)
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0.1-2.0MG IV/IM, +/- restraints
20-60 min. response time
2nd dose 2/3 of first
Observe 2-3h
Triad of dec. LOC,miosis,resp dep.
Resp status only reliable way to
determine effect of narcan.
Other drugs affect LOC and some opioids
can cause mydriasis
NALOXONE
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730 pts prehospital tapes/sheets
reviewed in AMS pts. for response to
Narcan and clinical presentation.
RR<12,pinpoint pupils,circumstantial
evidence of opiate abuse all predictive of
response
Use of these criteria would decrease
Narcan use by75-90% without missing
any responders
Hoffman,JR,Annals of Emergency Med., 1991
FLUMAZENIL AS PART OF
THE COMA COCKTAIL?
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Retrospective analysis of 35 consecutive
comatose pts
Divided into low and non-low risk for sz.
based on clinical and ECG(proconvulsive
OD’s)
Only 4 were assessed as low risk
High risk of sz. In non-low risk group
Low risk might benefit but very small
minority of pts.
Gueye,PN,Annals of Emergency Medicine, 1996
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Flum. May also precip. Arrythmia in TCA
TOXICOLOGICAL HISTORY
MOST IMPORTANT DIAGNOSTIC TEST
 # of pts/type of exp/
amounts,dose/route/intent
 “all OD’s are liars”
 Corroborate with
MD/pharmacist/EMS/witnesses
 Info on environment:empty bottles,
odours,material,hobbies,notes
 AMPLE
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Toxic Features
History
-suicide, prev. O.D. or abuse
-psychiatric or polypharmacy
 Physical
-arrest,bronchospasm,dysrythm nyd
thermia/tension
-AMS,sz.,rigidity,dsytonia,rotary nystagmus
 Investigation
-anion/osmolar gap, K-Na-gluc
-renal/hepatic failure,rhabdo,aspiration
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TOXICOLOGICAL PHYSICAL
Expose, look for hidden substances
 Waist bands,skin folds,groin
 Watch for sharps
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NEEDLE COLLECTION
Bright yellow disposal
boxes in easily accessible
locations encourage IV
drug users to safely
discard used syringes.
The project collected
22,245 needles in 2001.
GENERAL APPEARANCE
LOC;agitation,obtundation,confus.
 Skin;cyanosis,flushing,diaphoresis
dryness,
 Injuries,injections,bullae,bruising
(may be from trauma,dec LOC
longterm or coagulopathy)
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ODOURS
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Almonds
Eggs
Fish
Garlic
Fresh hay
Geraniums
Swimming pool
Mothball
Violets
Wintergreeen
peanuts
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Cyanide
Hydrogen sulf
Sinc sulfide
Org phosporous
Phosgene
Lewisite
Chlorine gas
Camphor,naptha
Turpentine
Methyl salicylate
vacor
SKIN FINDINGS
Cyanosis
Yellowing
flushing
Gray
Eschar
Bullae
Red skin
Nail lines
Deoxyhemoglobin or
methemoglobin
Carotene veg.,cigs,picric acid,
Dinitrophenol
Antichol,scombroid,rectal F.B,
Disulfiram,niacin,nitratres
Metallic silver or gold
Anthrax,radioactive,brown
recluse spider,
Barbs,chemotherapies
Cholinerg,vanco,CO,boric acid
Arsenic,chemotherapy
CNS
LOC/cognition
 Tone
 Reflexes
 Coordination
 Ambulation
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Toxins Causing Seizures
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Amphetamines
 Antihistamines/
anticholinergics
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Caffeine/theoph
Antipsychotics
Carbamates
CO
 Cocaine
 Hypoglycemics
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Chlorambucil
Propranolol
salicylates
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Cyclic antidepress
Ethylene glycol
Isoniazid
Lead
 Lidocaine
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Lithium
Methanol
Organophosphates
Phencyclidine
 Withdrawal
from
ETOH/sedatives
Toxins Affecting Tone
Dystonic
reactions
Haldol
Dsykinesias
Rigidity
Anticholinergic
Black widow
Metoclopramide Cocaine
Malign hyperth
Olanzapine
Phencyclidine
Neur malig syn
Phenothiazines
Risperidone
Strychnine
Risperidone
Fentanyl
phencyclidine
Toxins Causing AMS
DEPRESSED AGITATED
Sympatholytics
Sympathomim
etics
Adrenergics bl
Adrenergic ag
Antiarrhythmic
Amphet
DELIRIUM
ETOH/drug
withdrawal
Anticholinergics
Antihist
Antihypertens
Caffeine
CO
Antipsychotics
Cocaine
Cimetidine
Cholinergics
Ergots
Heavy metals
Bethanechol
MAOI’s
Lithium
Carbamates
Theophylline
Salicylates
Nicotine
Anticholiner
DEPRESSED
AGITATED
Organophos
antihistamine
Physostigmine
Antiparkinson
Pilocarpine
Antipsychotic
Sedat/hypnot
Antispasmodic
Alchohols
Cyclic antidepr
Barbs
Cyclobezaprine
BZD
Drug withdraw
Gamma Hydrox
B-blockers
Ethchlorvynol
Clonidine
Narcotics
Ethanol
Analgesics
Opioids
Antidiarheal
Sed/hypnotic
DELIRIUM
DEPRESSED AGITATED
Cyanide
Marijuana
Hydrogen
Mescaline
sulfide
Hypoglycem LSD
ic
lithium
DELIRIUM
EYES
Pupils: size, reactivity,equality
 Dysconjugate gaze
 lacrimation
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Toxins Affecting Pupil Size
Miosis
Barbiturates
Carbamates
Mydriasis
Amphetamines
Anticholinergics
Clonidine
Antihistamines
Ethanol
Cocaine
Cyclic antidepressant
Isopropyl alcohol
Organophosphates
Dopamine
Opioids
Glutethimide
Phencyclidine
LSD
Phenothiazines
MAOI’s
Physostigmine
Phencyclidine
Pilocarpine
demerol
MOUTH (with suction)
Retained contents or pills
 Gag
 Dryness/salivation
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Lungs
Air entry
 oxygenation
 wheezing
 bronchorhea
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TOXINS CAUSING
HYPOVENTILLATION
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Alcohols
Barbs
Botulinum
Cyclic
antidepress
Neuromuscular
blockade
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Opioids
Sedative/hypnot
Snake bite
Strychnine
tetanus
HEART/PULSES
Rate
 Rhythm
 Regularity
 Peripheral pulses/perfusion
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TOXINS AFFECTING PULSE
Tachycardia
Common
-TCA
-CO
-anticholinerg
eg. Gravol
-adrenergic
eg. cocaine
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Bradycardia
Common
-opioids
-cholinergics
-BBlockers
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ABDOMEN
Bowel sounds
 Rigidity
 Urinary retention
 tenderness
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TOXIDROMES
Physiological groups
 Based on VS,general appearance,
skin,eyes,mm,etc.
 Also basic labs
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DO THE BASIC FINDINGS
MATCH WITH A POISON ?
Basis for toxidrome
 Eg. Autonomic syndromes
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sympathetic
Adrenergic
symptoms,eg.
cocaine
Tahycardia,htn,
diaphoresis,
mydriasis,etc
parasympathetic
Cholinergic,eg
organophospates
S.L.U.D.G.E
Anticholinergic,
eg. gravol
No bowel
sounds,dry
skin,blurry
vis,fever etc
Autonomic Nervous System
NIC
NIC
NIC
MUSC
NMJ
PS
NE
S
Toxidrome Agent
Opioids
Sympatho
Cholinergic
Antichol
Salicylates
Hypoglyc
Serotonin
Heroine
Cocaine
Findings
Dec. loc,miosis,dec.RR
Agitation,mydriasis,diap
horesis,tachy,etc
Organoph S.L.U.D.G.E.
Atropine Dry,red,AMS,hyper-t etc
ASA
AMS,resp alk,met acid et
Insulin
AMS,diaph,tachy,etc
SSRI
AMS,inc tone,hyper-t
Toxins Affecting Temperature
Hypothermia
-TCA,Li,Phenothiazin
-alcohol,barbs,opium
-hypoglycemics
colchicine,akee fruit
-AMS in winter
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Hyperthermia
-LSD,cocaine,PCP,
amphetamines
-antichol,antihist
-TCA,MAOI,SSRI
phenothiazines
-ASA
-malign hyper/NMS
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TOXINS AFFECTING
BREATHING
Hypoventilation-eg alcohols,BZD.,
opioids
 Bronchospasm- eg cocaine, BB,
aspiration from AMS
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INVESTIGATIONS
PROGRESSIVE TESTING
 CBC&D,CHEM 7,ABG,LFT
 osmolality
 EKG
 CXR
 FLAT PLATE XR
 SPECIFIC DRUG LEVELS
 Tox. Screens
Anion Gap Acidosis Toxins
 Acetominophen
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Amiloride
Ascorbic acid
CO
Colchicine
Nipride
Dapsone
Epi
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Formaldehyde
Hydrogen sulfide
Iron
isoniazid
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Ketamine
Metformin
 Methanol
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 Ethanol
 Ethylene
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glycol
Niacin
NSAIDS
Papaverine
Paraldehyde
Phenformin
Propofol
 Salicylates
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Terbutaline
Tetracycline
Toluene
verapamil
OSMOLAR GAP VARIABILITY
“NORMAL” OSMOLAR GAP 8-10
 Distribution curve puts real normal
between -?1 and +10-11
 Therefore gap of 10 in someone
who’s “resting” gap is 2 may contain
error of 8
 Methanol toxic >6.2mmol/l
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Toxins with Inc. Osmolal gap
Ethanol
 Ethylene glycol
glycoaldehyde
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 Methanol/from
aldehyde
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Glycine
IV immunoglobulin
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Isopropanol
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2(NA)+Gluc+bun
+/-1.25(etoh)
Mannitol
Propylene glycol
Radiocontrast
Hypermagnesemia
sorbitol
EKG
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EKG findings in TCA:sinus tach,inc.
QRS/QTc intervals, inc PR interval
RAD in the T40ms frontal QRS plane
I neg/AVR pos, in T40ms
Due to quinidine like effect on RBBB in
TCA
8.6 times more likely in TCA OD
83%sens, 63% spec
Wolfe, TR, Ann of Emerg Med, 1989
EKG IN TCA
EKG
ACLS Rx of Toxic
Dysrythmias
Stimulant/Sympathomimetics
-consider BZD,Ablockers,Lidocaine
NaHCo3, not Bblockers
 CCB’s
-consider mixed A/B agonists,
pacer, Ca++,insulin euglycemia
 Bblockers
-consider pacer,mixed A/B agonists,
glucagon/insulin euglycemia
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ACLS Handbook of Emerg Card Care 2000
RADIOLOGY
CXR if prompted by Hx, Px or
specific other findings like hypoxia
 Flat plat may be considerred for FB
or ingestions of radiopaque toxins
eg iron
 CT scan for AMS
r/o HI and ICP
if indicated
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TOX SCREENS
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Marijuana/opioids/cocaine/amphetamine/
TCA/barbs/BZD/phencyclidine
Usually does not affect assessment or
outcome acutely
False +:amphet-propranolol,cpz etc
TCA-flexeril,mellaril,etc
False -:opioid-demerol,heroin
amphet-MDMA,
benzo-rohypnol
TOX SCREENS cont’d
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Slow to return
Most OD’s treated with support alone
Chronic ingestion eg. Marijuana may
confuse issue
Less frequent intoxicants not quickly
available
May be helpful in persistant sick without
obvious etiology
In kids may be helpful for neglect/abuse
situations
APAP/ASA/ETOH
Frequent co-ingestants
 Relatively quick
 May help sort out multiple ingestion
scenario
 May help psych. with ongoing
assessment
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GENERAL
DECONTAMINATION
It’s great the fire
department
provides us with
these sprinklers
on hot days
GROSS DECONTAMINATION
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Remove patient from substance
Remove substance from patient
Undress(including jewelry,watches –
biohazard)
Wash, head to toe
In mass casualty done in field or in
isolation area outside ambulance bays in
most hospitals
Staff need full PPE
GROSS DECONTAMINATION
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Colonoscopy
booth
EYES
Copious (usually 2L) irrigation
 Normal saline best but tap will do
 0.5% tetracaine, lid retractors
helpful
 1ml tetracaine in 100ml saline
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EYE IRRIGATION
EYES cont’d
Alkali exposure may require 1-2h of
irrigation given deep penetration
 NS ph 5.6
 After equilibration (10min)
 Tear film ph<8
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GI DECONTAMINATION
Oral removal-emesis
-lavage
 Binding
 Mechanical flushing
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EMESIS
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Derived from
emetine and
cephaline (plants)
Works centrally on
chemotactic
trigger zone and
stomach
Dose 30ml (15ml
in 1-12) with sips
IPECAC cont’d
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Can repeat once
90% vomit in 20m
97% 2nd dose
Ave. 3-5 vomits
Done in 2h
If 30m 18-52%
If 60m 31-36%
IPECAC CONTRAINDICATIONS
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AMS or drugs that can cause
rapid(<60mins) AMS
(TCA,eucalyptus,strychnine)
Active or prior vomiting
Caustic/corrosive ingestion
>pulmonary than GI toxicity
(hydrocarbons)
Ingestion which can cause sz.
Debilitated/elderly or medical made worse
by vomiting
IPECAC COMPLICATIONS
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Boerhaves’
syndrome
Malory-Weiss
tears
Intractable
vomitting
Inability to give
oral treatments
IPECAC INDICATIONS
Very limited in hospital setting
 Rare-larger pills than orogastric tube
in recent ingestion(<60min) that
can’t be absorbed by charcoal on a
Tuesday when the moon is full!
 At home if remote, recent and no
contraindications
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IPECAC INDICATIONS cont’
“syrup of Ipecac should not be
administered routinely in the
management of poisoned patients…There
is no evidence from clinical studies that
ipecac improves the outcome of poisoned
patients and its routine administration in
the ED should be abandonned”
AACT Position paper, Journal of Toxicology, 2004
AMERICAN ACADEMY OF CLINICAL TOXICOLOGY (AACT)
OROGASTRIC LAVAGE
LL decubitus position
 36-40F(adult),22-24F(kids)
 Chin to xyphoid measurement
 Room temp tap water untill clear
 Instillation of charcoal before
removing if indicated
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OG LAVAGE
CONTRAINDICATIONS
Pills too big
 Non-toxic ingestion
 Non-life threatening ingestion
 GI hem, perf or recent Sx
 Airway not assured
 Material lung danger>GI tract
(hydrocarbon,corrosive)
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OG LAVAGE
COMPLICATIONS
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Tracheal lavage
Aspiration, tension pneumo, charcoal
empyema
Atrial/ventricular ectopy
Esoph, trach or gastric trauma or
perforation
Desaturation, laryngospasm
Tube knot formation
fluid/lyte imbalance
OG LAVAGE EVIDENCE
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Prospective study of 808 pts with
presumed OD
Odd/even day gastric emptying(GE) with
either ipecac or lavage based on LOC.
Others got charcoal
GE did not alter LOS,length of
intubation,ICU LOS,
GE increased ICU admits for asp. Pneum
Merigian, KS, Amer. J. of Emerg. Med. 1990
GE EVIDENCE cont’d
PRCT of 876 pts with OD
 Odd/even day randomization for
GE/AC or just AC
 GE was lavage or ipecac
 No difference in outcome regardless
of time to presentation
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Pond,SM,Medical J. of Australia,1995
AACT INDICATIONS
Not routinely recommended
 Not if greater than 60mins
 Not if not life threatenning
 Must have assured airway
 No definite evidence that it improves
outcome and may cause morbidity
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CHARCOAL (GUT TOXIN
ADSORPTION)(GI DIALYSIS)
ACTIVATED CHARCOAL(AC)
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Pyrolysis of carbanaceous material
Steam cleaned to increase the surface
area (activated)
Adsorbs (holds to surface) toxins in the
gut lumen
Improves gut/blood gradient (GI dialysis)
for previously absorbed
Binds substances excreted in bile
interrupting enterohepatic circ.
Toxins Not Adsorbed by AC
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Alcohols
Hydrocarbons
Organophosphates
Carbamates
acids
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Potassium
DDT
Alkali
Iron
lithium
AC cont’d
Decreased benefit with time as toxin
travels beyond pylorus
 At 30 min mean bioavailability
decreased by 70%
 At 60 min by 37%
 No good studies that show clinical
benefit of single dose AC (AACT)
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AC BENEFITS
Decontaminating gut non-invasively
 Rapid administration
 Safe in adults and kids
 Can be administered with juice,
water or by OG
 1g/kg or 50g in most adults
 +/- cathartic with first dose
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AC EVIDENCE
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RCT with 1479 pts. randomized to AC +
supportive measures or support alone
Measured clinical deterioration, LOS in ED
or hospital, complications and length of
intubation
Trial done over 24 mos., lge urban center
Merigian,KS, Amer. J. of Therapeutics, 2002
AC EVIDENCE cont’d



No sig. difference in length of
intubation,LOS for hospital and
complication rate
Longer ED stay (6.2vs5.3h) and more
vomiting (23vs13%)in AC group
No benefit of AC over support alone
Merigian, KS, Am.J.Therepeutics, 2002
AC CONTRAINDICATIONS
Perforation or abnormal GI tract
 If emergency endoscopy planned
e.g. caustics
 Unprotected airway
 Increased risk from aspiration (eg
Hydrocarbons)

AC COMPLICATIONS
Aspiration
 Impaction with abnormal motility
 Vomiting
 Corneal abrasions

AC INDICATIONS
Ingestion of any drug known to be
adsorbed by charcoal with toxic ingestion
 Does not work for lithium, iron, lead
 Unknown ingestion with protected airway
 Lack of good clinical data for or against
Therefore
 Not routine (AACT)
 Best within 1 hour (AACT)
 No evidence it improves outcome (AACT)

MULTIPLE DOSE CHARCOAL
.25-.5G/kg on subsequent doses
 Q1-4h
 Only first dose has cathartic
 Indications-large ingestions
-substances that form
bezoars or are injurious
-slow release toxins
-enterohepatic/enteric
circul. substances

Multi-dosable AC

Amytrityline
Amoxapine
Baclofen?
BZD’s?
Buproprion?

Carbamazepine










Chlordecone
Dapsone
Dig
Disopyramide
Glutethimide
Maprotiline
 Theophylline

sotalol





Meprobamate
Methyprylon
Nadolol
Nortriptyline
Phencyclidine
 Phenobarb

Phenylbutazone
 Phenytoin




Pyroxicam
Propoxyphene
Quinine
Salicylates?
MULTI-DOSE AC cont’d
Contraindicated in non-lifethreatening ingestions and toxins
which slow GI motility as these
increase risk of aspiration from
gastric distention and impaction of
charcoal
 No specific AACT position statement

CATHARTICS
CATHARTICS


Sorbitol 70% (1g/kg) or 250ml of 10%
mag citrate (4ml/kg in kids)
Studies consistently show decreased
transit time for charcoal
Krenzolok,EP,Ann Em Med, 1985
Harchelroad,F,J.Clin. Tox., 1989

Cathartic alone not effective
Minton,NA, J Clin Tox.,1995
Al-Shareef,AH,Hum Exp Tox.,1990

Peak plasma concentrations decrease with
cathartics
Picchioni, AL, J Toxicol Clin Toxicol, 1982
Goldberg, MJ, Clin Pharmacol Ther, 1987
Cathartics Indications
Same as single dose charcoal
 Ingestions unknown or known to be
adsorbed by charcoal with protected
airway
 AACT-not alone, not endorsed
routinely with or w/o charcoal,
single dose if used

Cathartics complications
Nausea, vomitting, abdo cramps
 Volume depletion, electrolyte disturb
 Hypermagnesemia in renal impaired
if magnesium product
 Hypernatremia if Na product

Cathartics Contraindications
Ingestions that cause diarhea
 Kids <1 or very old
 Mag citrate in renal failure
 Obstruction, no BS, abdo
trauma,recent abdo Sx,perf.
 corrosive ingestion
 Heart block
 Hypotense,vol. deplete, lyte imbal.

WHOLE BOWEL IRRIGATION
(WBI)
Electrolyte/osmotic balanced
polyethylene glycol (Golytely)
 Mechanically forces ingested toxins
through the bowel
 2L/h (adult), 50-250ml/h(peds)
 Until clear rectal fluid

WBI Indications-AACT 1997





No controlled clinical studies showing
improved outcomes but some volunteer
studies
Not routine
Consider in slow release or enteric coated
toxic ingestions
Theoretic potential in iron and other nonadsorbables(Li,lead,zinc)
Theoretic in delayed presentation, large
amounts, drug packers(Farmer, JW, J Clin Gastro,
2003)
WBI complications
Nausea, vomiting, cramps,bloating
 Pulmonary aspiration
 Rectal irritation
 Increased nursing care !!

WBI Contraindications
Diarhea or substances that cause it
 Absent bowel sounds
 Intractable vomiting
 Obstruction, ileus,perforation,hem
 Hemodynamic instability
 Compromised airway

ENHANCED ELIMINATION
Urinary-diuresis
-alkalinization
-acidification
 Dialysis
 Hemoperfusion
 hemofiltration

DIURESIS
Not been well studied
 Consists of achieving 3-6ml/k/h u/o
 Isotonic fluids and diuretics
 Not recommended
 Causes electrolyte
imbalance,pulmonary edema,raised
ICP
 Also doesn’t work

Urinary Alkalinization





Helpful in some ingestions
Weak acids held within renal tubule and
excreted with bicarb
3 amps (150 ml) of bicarb in 850 D5W at
250/h
Goal urine pH 7.5-8.0
Must have normal K+ so add 40 meq kcl
to bag after initially correcting hypokal.
URINARY ALKALINIZATION
Tissues
pH 6.8
Plasma
pH 7.4
HA
H+ + A-
Urine
pH 8.0
HA
H+ + A-
(alkalinized)
HA
H+ + A-
GOAL PH
Alkalinizable Toxins
ASA



Uranium
Quinolones
Primidone
Phenobarb

methotrexate




2,4
dichorphenoxyacetic acid
Flouride
Isoniazid
methobarbitol
Urinary Alk. Complications
Dec. K+
 Volume overload (CHF)
 pH shifts

Urinary Alk. Containdication
Can’t tolerate fluid or Na+ load
 Hypokalemia
 Renal failure
 Toxin known not to respond

Acidification of Urine
Virtually never used
 Potential for myoglobinuric renal
tubular injury
 Systemic acidosis additive
 Arginine/lysine hydrochloride or
ammonium chloride
 ? Use in amphetamine/phencyclidine

DIALYSIS
I am sure
happy to
be here
today
Dialysis
Removes both the toxin and it’s
metabolites
 Removes toxins that can’t be
adsorbed by charcoal
 Less effective with lge mol wgt,
protein bound, large vol. dist.

Hemodialysis Indications
Dialysable toxin that is life
threatenning
 Peritoneal dialysis rarely used

Dialysis Contraindications
Hemodynamic instability
 Small children (exchange transfusion
better)
 Poor vascular access
 Profound bleeding diathesis

Dialysis Complications
Fluid shifts
 Electrolyte imbalance
 Bleeding at access site
 Infection
 Intracranial hemorhage

Hemoperfusion
Charcoal filter in dialysis machine
 Works better for large molecule size
and protein bound if adsorbable
 Needs small volume of distribution
 Must not be highly tissue bound
 Rarely used

Hemoperfusion Complications
Cartridge saturation
 Thrombocytopenia (plt dec by 30%)
 Hypoglycemia, hypocalcemia
 Access complications
 Hypothermia (pump not heated)
 Charcoal embolization

Hemoperfusion cont’d
Works
 Phenobarb,phenytoin,theophylline,
carbamazepine,paraquat,
glutethimide
Doesn’t Work
 Heavy metals,ethanol,methanol,CO,
cocaine
Hemofiltration
Removes toxins by convection
through a highly porous membrane
 Works well with toxins with large
volume of distribution, extensive
tissue binding
 Works well for large molecular wgt
substances
 Not well studied

ANTIDOTES
Increases the mean lethal dose of a
toxin or favorably affects the effect
of the toxin
 Specific indications
 Beyond the scope of this lecture

ANTIDOTES eg.
Drug/Poison
Acetominophen
Antichonergics
Anticholinesterases
Benzodiazepines
Black Widow Bite
Carbon Monoxide
Coral Snake Bite
Cyanide
Antidote
N-acetylcysteine
Physostigmine
Atropine
Flumazenil
Equine Antivenin
Oxygen
Antivenin
Amyl Nitrate,etc
Antidotes cont’d
Digoxin
Ethylene glycol
Heavy metals
Hypoglycemics
Iron
Isoniazid
Methanol
Methemoglobinemia
Opioids
Organophospates
Rattlesnake bite
Digibind
Ethanol/fomepizole
Dimercaprol,EDTA
Dextrose
Deferoxamine
Pyridoxine
Ethanol,fomepizole
Methylene blue
Naloxone
Atropine,pralodox.
antivenin
INDICATIONS FOR THE ICU












PaCo2 >45
(Brett, AS, Arch Int Med,1987)
Intubation need
Seizures
Arrhythmias
Prolonged QRS >.12s
SBP <80
2nd or 3rd degree AV block
GCS <12 (unresponsive to verbal)
Dialysis
Staffing (babysitting suicidal)
Hypo/Hyperthermia
Naloxone drip
EXCELLENT REVIEW ARTICLE
Babak, M, Jerrold, BL, Patrick, M,
“Adult Toxicology in Critical Care”
Chest, 2003;123:577-592.

??? QUESTIONS
???