POISONING
I- INTRODUCTION
· Accidental and intentional poisoning or drugs overdose constitute a significant source
of increase morbidity and mortality and health
care expenditure over the world.
· Suspected poisoning in children is common
· Accidental poisoning: most frequently is child 1-5 year olds usually involve
household
substances.
· Children are
rarely intentional poisoned, but by older
children or adults or as part of abuse.
· Intentional overdose: suicide children or adolescent should undergo psychiatric assessment.
II- DEFINITION
· Poisoning occurs when any substance interferes with normal body functions after it
is
swallowed, inhaled, injected, or absorbed.
III- DESCRIPTIONS
³ History difficult, know or
unknown, suspicious
³ Types of Exposure :
o Ingestion
o Ocular (eyes)
exposure
o Topical (skin) exposure
o Inhalation
o Envenomation ( i.e.
Snake bite)
o Tranplacental
IV- EPIDEMIOLOGY
³ Poisoning is a significant global public health problem.
³ In 2004 an estimated 346,000 people died
worldwide from intentional poisoning
and
91% occurred in low and middle income countries.
³ There is no statistic about the incident of poisoning
in Cambodia and no poisoning center available.
V- SIGNS AND
SYMPTOMS OF POISONING
³ Sudden unexplained illness in
the
previous healthy child
o Drowsy or
coma Tachycardia or
flushing
o Convulsion Cardiac arrhythmia
o Ataxia Hypo or hypertensive
o Hypo/hyperthermia Abnormal behavior
o Tachypnea/ bradycardia Pupillary abnormalities
³ Toxidromes
o Sympathomimetic
o Narcotic
o Sedative/hypnotic
o Anticholinergic
o Cholinergic
VI- DIAGNOSIS OF EVALUATION
³ History and clinical features
³ CBC
³ Serum electrolytes, glucose, RFTs(
Urea & Creatinine)
³ LFTs, coagulation parameters ( PT &
APTT)
³ Blood gas: metabolic acidosis
³ Drugs levels (
if possible)
VII- DIFFERENTIAL
DIAGNOSIS
³ Head
injury
³ CNS infection (meningitis, encephalitis..)
³ Hypo or hyperthermia
³ Ictal and post-ictal
³ Metabolic
o Hypo or hyperglycemia
o Hyper or hyponatraemia
o Acute renal failure
VIII- GENERAL
MANAGEMENT
³ Initial assessment and stabilization: Primary survey ABCD
Child suspected
poisoning; the first step
is prompt recognition
and intervention
in
life- threatening
condition.
A: Airway: Look, Listen
and Feel.
B: Breathing: Effort, Efficacy and
Effects of inadequate
respiratory.
C: Circulation:
Pulse,
CRT, BP and cardiac rhythm.
D: Disability: Mental status/ conscious level (AVPU/CGS), Posture and
Pupils
size.
Plus Blood glucose and
Temperature.
³ Secondary survey:
Completed history and examination
o History: More focus history to determine substances, quantity and time of
ingestion.
o Examination: Vital signs and physical examination and Full neurology examination.
§ Mental status / level of
conscious: CGS
§ Pupils size
§ Muscle tone/movement
§ Focal signs
§ Evidence of trauma
§ Skin: color, sweating, bulla or
rashes
§ Bowel sound
§ Urine
³
|
SUPPORTING CARE
|
|
Airway:
Breathing: Circulation: Metabolic:
|
Clear airway, intubation
Oxygen, ventilation
Intravenous fluid, inotrope, control
hypertension
Treat hypoglycemia and electrolytes
abnormality
|
Convulsion/sedation: IV benzodiazepam
Temperature: Warming or
cooling
Renal
function: Hydration, hemodialysis
³ ADMINISTRATION ANTIDOTE
o According to the poison
o Only give when full information and the poison
is available
o Opiate overdose: Naloxone 10mcg/kg IV repeat up to maximum dose 2mg.
o Benzodiazepines poisoning: Flumazenil: 10mcg/kg IV slowly
o If substance is corrosive, there may be serious injury to the mouth, throat,
airway and esophagus or stomach (NaOH/KOH clean fluid
or bleach,
disinfectants):
§ Do not give emetics
§ Give milk or water as soon as possible to dilute the corrosive agent.
³ GASTROINTESTINAL DECONTAMINATION
o Gastric lavage
§ Use large Oro-gastric tube with saline
or water ( 50-100ml in young
children and 150-250ml for
big
child)
§ No definite indications with
studies
showed variable efficacy.
§ Lavage
may consider is ingestion within 1 hour, when emesis is
contraindication.
§ Contraindication: caustic agents,
hydrocarbon, inability to protect
airway.
o Active Charcoal
§ Dose:
1g/kg is effective give early within 4 hours PO or NG-tube
every 1-6 hours.
§ For adolescents or adult give: 50-100g.
§ Be careful use with antidote: at least give one hour apart.
§ More effective if give
within an hour
of
ingestion.
§ Contraindications: corrosive substances/ hydrocarbon and heavy
metals and altered mental status with unprotected airway.
§ Complication: bowel obstruction, bowel perforation, pulmonary hemorrhage and electrolytes disorder.
³ Enhances Elimination
o Repeated dose active charcoal
o Urinary alkalization with force diuresis (Sodium bicarbonate 1-2mEq/kg IV
over 1-2 hours and maintain urine pH 7.5-7.7)
o Hemodialysis and hemofiltration
IX- COMPLICATION PIOSONING
³ Pulmonary aspiration
³ Rhabdomyoysis
³ Acute renal failure/ liver failure
³ Compartment syndromes (snake, spider bite)
³ Hypoxic brain injury
X- SPECIFIC PIOSONING
1- PARACETAMOL
Major toxicity:
hepatic damage and
dysfunction
Toxic dose:
acute ingestion more
than 150mg/kg/dose in healthy children & 7-10g for healthy adult.
³ Clinical
findings:
o First 12-24 hours: nausea, vomiting, anorexia, pallor, diaphoresis
o Patient then develops latent phase
§ Feels well for 1-4 days
§ Gradually develops jaundice
& liver tenderness
o 2-4% of patients with significant overdose develop liver failure
o Risk of severity may be predicted by amount ingested & plasma levels.
o Single ingestions < 150 mg/kg likely to be harmless
o Plasma level at 4 hours after ingestion is the most reliable indicator of
toxicity in single overdoses
³ Managements:
o Decontamination: activated
charcoal: If acute;
not for chronic.
o Antidote: N-acetylcysteine:
Start as soon as possible within 8 hours
of
ingestion.
o Indicated
when levels
are in toxic range
o If no
levels: history is
high-risk for toxicity or signs of liver failure
o Dose: Load
140 mg/kg PO, then
70 mg/kg PO q4 hs
x 17 doses
2- ASPIRINE
Acute toxic dose:
ingestion 150-200mg/kg/dose mild intoxication and severe intoxication ingestion 300-500mg/kg/dose.
Chronic intoxication: ingestion more that 100mg/kg/day for 2days or more
³ Clinical
signs:
o Metabolic acidosis
o Respiratory alkalosis
from hyperventilation
o CNS depression, seizures, hypoglycemia, hyperthermia
o Coagulopathy, nausea/vomiting, dehydration
³ Managements:
o Activated charcoal: multiple doses if
needed
o Blood and urine alkalinization with NaHCO3
§ Blood alkalinization removes ASA from tissues
§ Urine alkalinization promotes excretion
3- ALCOHOLE/GLYCOLS
Ethanol is
the most commonly ingested
alcohol
³ Clinical:
o Adolescents: coma, sensory or motor impairment, intoxication, vomiting, seizures, loss of protective airway
reflexes
o Infants and toddlers: respiratory depression, coma, hypothermia,
hypoglycemia, seizures, metabolic acidosis
³ Managements:
o Fast recognition and evaluation of blood glucose and electrolytes
§ Treat hypoglycemia
§ Treat electrolytes imbalance
o Glucose and Thiamine to treat coma, stupor and seizure s
o Airway and breathing: may need
intubation
o Warm the patient
o Charcoal not effective
³ Alcohols & Glycols: Methanol
o Primary use
is industrial solvent
§ Also found in fuels for stoves,
paint removers
§ Methanol not dangerous but its metabolites are
o Clinical: CNS depression, vision changes, seizures, pancreatitis, metabolic
acidosis, arrhythmias
o Managements:
§ Sodium bicarbonate to correct acidosis
§ Folate and Thiamine to helps eliminate toxic metabolite
§ Fomepizol or
Ethanol to prevent toxic metabolite formation
§ Charcoal not effective
4- HYDROCARBONS
Carbon
compounds - liquid
at room temp
³ Toxicities:
o Chemical
pneumonitis if
aspirated (can be fatal)
o Mental status changes (drowsy, confusion, coma)
o Examples:
§ Solvents ▪
Lamp
oils
§ Fuels ▪ Household cleaners
§ Polishes ▪
Baby oils
§ Lighter fluids ▪
Camphor
§ Organophosphates
³ Managements:
o Prevent vomiting
§ Decrease risk of
secondary aspiration
o CXR if symptomatic or after 6 hours if
asymptomatic
§ May develop to ARDS later
o Skin & eyes contamination: remove the cloth and wash
exposure skin
with
water and soap. Irrigate exposure eyes with water and saline
o Charcoal not effective
5- IRON
³ Directly damages GI mucosa
o Hemorrhagic necrosis of
stomach and intestine
o Ingestion more than 40mg/kg/dosed is considered potentially serious.
³ Clinical:
o Phase 1: GI upset ( Nausea, Vomiting, diarrhea, hemorrhage abdominal pain),
encephalopathy, shock, coma for ~6hrs
o Phase 2: feel better, can resolve
or go to…
o Phase 3: systemic shock, metabolic acidosis, CNS depression, hepatic
dysfunction, coagulopathy.
o If symptomatic: can be life threatening
o If asymptomatic at 6 hours: unlikely to develop systemic illness
o Complications: pyloric stenosis, bowel obstruction.
³ Managements:
o Fluid
resuscitation
o Inotropes support
o Treat hypoglycemia (Dextrose solution: 10-25%)
o If severe signs
of toxic:
emesis, GI bleeding, shock, coma
§ GI Decontamination
( recommend lavage gastric only)
§ Obtain abdominal X-ray
§ Antidote: Deferoxamine :
90mg/kg/dose IM
(
maximum 6g/24h)
q8hs.
If
severe IV infusion 15mg/kg/h (
6g/ 24 hours)
§ Whole bowel irrigation: if iron visible on radiographic.
o Charcoal
not effective
6- ISONIAZID (INH)
³ Isoniazid >20 mg/kg/dose in children can be toxic
o Toxicity from reversal of Vit.
B6 activity
o Decrease effects synthesis of catecholamine and neurotransmitter GABA
(gamma-aminobutyric acid) pathway.
³ Clinical
Triad: seizures, metabolic acidosis , coma
³ Managements:
o Decontamination: Active charcoal
o Lavage gastric: if massive ingestions
o NaHCO3 (treat acidosis)
o Anticonvulsants for seizures
o Pyridoxine (70 mg/kg/day up to
5g )
o The concomitant treat Diazepam and Pyridoxine may improve outcome.
7- ORGANOPHOSPHATES
³ Lipid
soluble insecticides
³ Absorbed by inhalation, ingestion, and skin penetration
³ May have hydrocarbon aspiration as co-morbidity
³ Clinical:
o CNS: dizziness, headache, ataxia, seizures and coma
o Nicotinic signs: sweating, muscle twitching, tremors, weakness, paralysis
o Muscarinic signs: “ DUMBELS”
§ Diaphoresis and Diarrhea
§ Urination
§ Miosis
§ Bradycardia, Bronchospasm, Brochorrhea
§ Emesis ( GI upset)
§ Lacrimation
§ Salivation
³ Managements:
o ABCD
o Decontamination: activated charcoal if ingestion
§ Remove contaminated
clothing and wash
§ Make sure no further exposure to
caregivers & health worker.
o Atropine: 0.05-0.1 mg/kg/dose IV every 5min
§ Can repeat doses until no more cholinergic symptoms and clearing
of bronchial secretions and pulmonary edema
§ Can treat severe poisonings with Pralidoxime
8- INHALANTS
³ Used as recreational drugs
o World-wide problem
o Cheap, easy to get
³ Solvents: paint thinners, gasoline, glue, correction fluid, whiteout
³ Aerosol sprays: hair spray, cigarette lighter
³ Other gases:
ether, nitrous oxide, chloroform
³ Sniffing: direct from the open container
³ Bagging: concentrating vapor in a
bag and inhaling
³ Huffing: cloth soaked in liquid & held to mouth
³ Spraying: spraying directly into the mouth
³ Toxicity:
o Inebriation, light-headedness, euphoria, hallucination, confuse and
disorientation.
o Cardio toxicity, V-fib, respiratory
arrest, suffocation
from “bagging”
o Suddenly sniffing death syndrome
o Chronic use: Leukoencephalomalacia with cerebral atrophy
³ Managements:
o ABCD
o IV access, oxygen
o Cardiac monitoring for arrhythmias
o Electrolytes, blood glucose, LFTs, urea/creatinine
o No need for
charcoal
o Psychosocial evaluation and support
XI-
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SPEC
1-
|
IFIC ANTIDOTES
Isoniazid (INH)
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Pyridoxine
|
2-
3-
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Iron
Acetaminophen
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Deferoxamine
N-acetylcysteine
|
|
4-
|
Salicylate
|
Sodium bicarbonate
|
|
5-
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Amphetamine, Cocaine
|
Benzodiazepine
|
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6-
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Benzodiazepine
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Flumazenil
|
|
7-
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Cyanide
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Na nitrite;
thiosulfate
|
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8-
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Opioids
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Naloxone
|
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9-
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Calcium channel blockers
|
Calcium, Glucagon
|
10-Organophosphates Atropine, Pralidoxime
11-Methanol,
Ethylene glycol Fomepizole, Ethanol
12-Carbon Monoxide Oxygen
13-Heparin Protamine
XII- EDUCATIONS
³
Children’s
education program is
very important as
children
under the age of 6 are
the most frequent victims of
poisonings.
o Teach young children the dangers of
poisons
o Get poison prevention information to children home by distributing
materials at school and day care center.
o Educate parents to keep the drugs or chemical substances out of children reach.
o Health professional provide poisoning education to
the parents.
REFERENCE
1- Pediatric Fundamental Critical care support, August 2011.
2- International Child Health
Care: practices manual for hospitals worldwide.
3-
KENT R. OLSON, Poisoning &
Drugs overdose, 5th edition.
4- Up-to-date website
5- eMedicine website
6- Medscape website
7- WHO website
8- The
Harriet Lane Handbook, 17
edition
9- Guidelines for the management of common illnesses with limited
resources, WHO. Pocket
Book.
10- Position Paper: Gastric Lavage; Journal of Toxicology/Clinical
Toxicology.2004; 42:933-943
11- Emetics, Cathartics and
Gastric Lavage; Perry Shefield: Pediatric in
review 2008;29;214
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