Approach To A Case Of Poisoning

Dr. Arif Khan

Department of Pediatrics

• INTRODUCTION

• COMMON POISONING IN CHILDREN AND ADOLESCENTS

• HISTORY

• GENERAL PHYSICAL EXAMINATION

• GENERAL MANAGEMENT

• SPECIFIC POISONING AND THEIR MANAGEMENT

CONTENT

Poisoning• Poisoning represents one of the most common medical

emergency encountered in young children and adolescents.

• Children <11 years usually have accidental poisoning of

single substance while adolescents ingest voluntarily large

amount of one or more substance.

• Pattern of sign and symptom of ingestion or exposure to a

toxin is called Toxidrome.

• Poison is any agent of self-injury absorbed into the body

through epithelial surfaces like skin or gut.

• Toxins are poisons produced by a biological process in

nature.

• Venoms are toxins that are injected by a bite or sting to

cause their effect.

Common Poisoning in Children and Adolescents

• Kerosine and other Hydrocarbons

• Household Products: Insecticides, Rodenticides, Phenol,

Caustic Soda, Neem Oil, Camphor, Alcohol, Copper Sulphate

• Pharmaceutical Products: Paracetamol, Iron Opiates,

Phenothiazines, Barbiturates, Aspirin, Anticonvulsants,

Antihypertensives

• Plants and Plant Products: Datura, Yellow Oleander,

White Oleander, Caster Seeds

• Environmental Poisoning: Elapidae(Cobra,Krait),

Viperdae(Russel Viper, Saw-scaled Viper,

Scorpion/Bee/Wasp Stings, Insect bite

• What was ingested?

• Time since ingestion

• How much amount ingested? check the container or

remaining no. of tablets

• Route of ingestion; skin or mucosa, iv or im

• In which form (gas,solid or liquid) the poison ingested

History

History

• Circumstance(location and intent) of exposure

• Time, nature and severity of symptoms

• Timing of first aid measures

• Family history of diseases and drug therapy

General Physical Examination

• Assess general condition

• Level of consciousness(GCS) and Pupillary size-

constricted or dilated, reactive or non reactive

• Vitals- heart rate, blood pressure, temperature,

peripheral perfusion, respiratory rate, SpO2

• General signs and symptoms

• Identifying toxidromes

General Physical Examination

General sign and symptoms

• Miosis: cholinergics, barbiturates, nicotine, opium,

morphine, parasympathomimetics

• Mydriasis: cocaine, datura, thallium, cyanide, carbon

monoxide, benzene, sympathomimetics

• Partial or Total blindness: methyl alcohol

• Blurring of vision: cholinergics, datura, alcohol,

digitalis

• Alopecia: thallium, arsenic, ergot, lead

• Facial twitching: lead, mercury, phenothiazines

• Pallor: aniline derivatives, symathomimetics, insulin,

pilocarpine

• Cyanosis: carbon monoxide, morphine, sulphonamide

• Yellow discolouration: paracetamol, carbon

tetrachloride

• Sweating: physostigmine, cholinergics, nicotine,

pilocarpine

• Dry hot skin: datura, botulism

• Flushed skin: carbon monoxide, cyanide

• Diaphoresis: organophosphates, salicylates

• Seizures: carbon monoxide, mushroom, cyanide,

salicylates, nicotine, lead, cholinergics, datura, cocaine

• Coma: salicylates, mushroom, cholinergics, carbon

monoxide, cyanide, lead, barbiturates, morphine, nicotine

• Bradycardia: digitalis, organophosphates, beta-blockers,

opioids

• Tachycardia: atropine, salicylate, amphetamine

• Tachypnoea: salicylate, ethylene glycol

• Apnoea: barbiturates, alcohol, opioids

• Hypertension: anticholinergics, phenylpropanolamine

• Paralysis: botulism, heavy metals

• Characteristic smell: kerosine, alcohol,

organophosphates and arsenic (garlic odour),

metanol(acetone), cyanide( bitter almonds)

Initial Assessment

• Assess GCS, Pupils and skin colour

• Airway:-

• check for patency of airway

• proper positioning- head tilt and chin lift

• suction of vomitus, secretions from oropharynx

• removal of obstructing objects, if any

• falling back of tongue is prevented by suitable airway tube

• Breathing:-

• O2 by mask: if spontaneous respiration

• Insert endotracheal tube if gag or cough reflex absent

• Intermittent positive pressure ventilation with proper

monitoring when ventilation remains inadequate by above

measures

• Respiratory stimulants like nikethamide or doxapram are

used for severe respiratory depression. doxapram is most

effective.

• Circulation:-

• Shock is initially managed with fluid boluses

• Dopamine is vasopressor of choice if shock remains

unresponsive

• Maintenance of fluid and electrolyte balance

• Administrating iv drugs for treatment

Prevention of further absorption of Poison

• Dilution

• Gastric Emptying- Emesis, Gastric Lavage

• Binding Agents- Activated Charcoal, Bentonite, Fuller’s

Earth, Kaolin and Pectin

• Cathartics

• Whole Bowel Irrigation

• Enhancing Excretion- Diuresis, Dialysis and

Hemoperfusion

Dilution

• Dilution Agents:- water and milk

• Indication: when toxin causes local irritation in oral,

esophageal or gastric mucosa like acids, alkalis and

household cleansing agents

• Contraindication- medicinal toxin like tablets or

capsules as it increases the dissolution

Emesis

• Emetic:-syrup ipecac dose@30ml for

adolescents,15ml for children and 10ml for infants

• Contraindication:-Hydrocarbon

ingestion,corrosive,comatose or those with absent

gag reflex

• Not used now

Gastric Lavage• Gastric Lavage is preferred in patients presented early

in hospital, <6 months age, impaired level of

consciousness and mercury poisoning

• In comatose it should be done after intubation with

cuffed endotracheal tube

• 36 French tube used in adolescents and 22-24 French

tube in children

• Lavage with NS @15ml/kg until clear fluid drained

• Contraindicated in hydrocarbon and corrosive poisoning

Activated Charcoal• Most appropriate agent to decontaminate GI tract

• Single dose is sufficient with greatest effect within 1hr of

ingestion

• Adsorbs toxin in gut lumen

• Benefits include capability to decontaminate without requiring

invasive procedures

• Dose 1-2g/kg (400mg tablet should be crushed before

administration) through oral or nasogastric tube

• Contraindicated in iron poisoning, cyanide poisoning and oral

antidotes

Multi-Dose Charcoal• One dose usually sufficient

• Indications for multi-dose activated charcoal:

ingestion of large doses, slow release toxins, toxins

that slow gut function, toxins with enterohepatic

circulation like cyclic

antidepressants,diazepam,carbamazepine

• Repeat dose is 0.25-0.5 g/kg

Whole-Bowel Irrigation• It removes the unabsorbed drug from entire gut and possibly

partially absorbed poison from gastrointestinal mucosa

• Polyethylene glycol is used for whole bowel irrigation

• Common indications: Heavy metals, Iron, Lithium, Sustained

or enteric coated preparations

• Dose is 30ml/kg/hr in children, 2 litres/hr in adolescents by

nasogastric tube or through oral route upto 4 to 6 hours

• Contraindication: Intestinal obstruction and Gastro-intestinal

perforation

Urinary Alkalization

• It is useful in salicylate and barbiturate intoxication

• Alkalization achieved by IV dose of sodium

bicarbonate at 1-2 mEq/kg, followed by intermittent

boluses or continuous bicarbonate infusion for target

urine pH >8.0

Hemodialysis/Hemoperfusion

• Dialysis reserved for specific toxins: salicylates,

methanol, ethylene glycol, lithium, theophylline

• Benefits: removal of toxins already absorbed, ability

to remove parent compound and active metabolite

Investigations• Complete blood count

• Urine:- Routine and Microscopy

• Chest Xray PA View

• RBS

• ABG

• ECG

• LFT

• KFT

• Serum Electrolytes

Kerosine Poisoning

• Kerosine poisoning is common in communities where

kerosine is a major household fuel.

• The circumstance is usually accidental ingestion (mistaken

for water).

• Ingestion of 30ml of kerosine is lethal.

• The earliest sign with kerosene ingestion may be

choking,coughing and gasping respiration.

• Respiratory distress occur in the form of tachypnea,

nasal flaring,grunting and chest retractions.children

who are asymptomatic for 6 hrs are less likely to

develop pneumonia later.

Clinical features

• Convulsion or Coma.

• Gastrointestinal symptoms like

nausea,vomiting,abdominal pain and diarrhoea may

occur.

• Fever may occur and can persist for 10 days.

• Renal injury is uncommon but may manifest as

tubular necrosis,hematuria,proteinuria and

glomerulonephritis.

Perihilar opacity Bilateral basal infiltration

• Initially the chest radiograph may be normal but positive findings develop over the first few hours after ingestion of kerosine. Common findings include perihilar opacities and bilateral basal infiltration.

Management of Kerosine Poisoning

• Maintenance of airway, breathing and circulation. • Symptomatic treatment and preservation of the airway is

always the first priority of treatment.

• Gastric lavage and induction of emesis ( e.g. use of

Ipecac) should not be considered in the management of

kerosene poisoning as these may cause aspiration and

worsens the condition.Gastric lavage is indicated when

amount of hydrocarbon exceeds 1ml/kg.

Paracetamol Poisoning• Very common, often asymptomatic• Hepatotoxicity may occur when a dose of more than

150mg/kg is ingested.

• Hepatic damage occur due to increased formation of

highly reactive intermediate(N-acetyl-p-

benzoquinonimine) which is produced by its metabolism

through p-450 cytochrome oxidase. N-acetyl-p-

benzoquinonimine is normally detoxified by endogenous

glutathione,but the increased production induced by

paracetamol overdose deplete glutathione stores• Death may occur within 2 to 7 days.

• Stage 1 (6-24hrs): anorexia, nausea, vomiting, pallor and

excessive sweating with cold skin

• Stage 2 (24-48hrs): hepatorenal injury, jaundice, tender

hepatomegaly, elevated liver enzymes, prolong

prothrombin time, oliguria, raised serum urea and serum

creatinine

Stages of Paracetamol Toxicity

Stages of Paracetamol Toxicity

• Stage 3(48-96hrs): stage 1 symptoms reappear,

hepatic coma

• Stage 4(4 days-2 weeks): after supportive and

specific therapy recovery starts with return of

consciousness with improvement in liver function

tests.

Management of Paracetamol Poisoning

• Specific antidote: N-acetyl cysteine(NAC)

• Supportive treatment: correct hypoglycaemia,

maintenance of hydration, electrolyte balance,

treatment of coagulopathy, hemodialysis for acute

renal failure and management of fulminant hepatic

failure

N-acetyl cysteine(NAC)

• Most effective within 8 hours of ingestion

• Precursor for glutathione production

• Can cause anaphylactic reactions

• Dose:-Loading dose 140mg/kg followed by 70mg/kg

every 4hrs for 68 hrs(17 doses) as oral solution

mixed with fruit juice

Organophosphorus (insecticides and pesticides) Poisoning

• Organic phosphate cause irreversible inhibition of the

enzyme cholinesterase. As result acetylcholine

accumulates in various tissues. Excessive

parasympathetic activity occurs.

• These agents are absorbed by all routes including skin

and mucosa.

Clinical features

• Symptoms manifest quickly usually within a few hours are

weakness, blurred vision, headache, giddiness, nausea

and pain in chest.

• These patients have excessive secretion in the lungs and

they sweat profusely.

• Salivation, lacrimation, urination and diarrhoea are

present.

• Pupils are constricted and papilledema may occur.

• Muscle twitching, convulsions and coma occur in

severe cases. Reflexes are absent and sphincter

control is lost.

• Death occurs usually due to respiratory failure.

Management of Organophosphates

• If the insecticide was in contact with skin or eyes, these

are thoroughly washed. Stomach wash is done.

• Atropine sulphate: 0.05 mg/kg IV. Repeat half the dose

in 15 minutes and then after every hour (until signs of

toxicity appear), subject to a maximum of 1 mg/kg in 24

hours.

Management of Organophosphates

• Pralidoxime Aldoxime Methiodide (PAM) is given in

dose of 25-50 mg/kg IM or IV over 30 min infusion,

then at 6-12 hour intervals as needed. Monitor for

hypertension.

Iron Intoxication• Ingestion of tablets of ferrous sulphate causes acute

poisoning.

• Iron is an essential mineral but in excess it acts as

metabolic poison in body.

• Acute iron intoxication exerts its primary effect on git,

liver and cardiovascular system.

• Fatal dose is 10 tablets of iron i.e. 650mg of elemental

iron. absorption of 60mg/kg causes significant iron

poisoning.

• Gastrointestinal tract- nausea, vomiting, diarrhoea,

abdominal pain, hematemesis and blood mixed stool.

• Then circulatory shock with metabolic acidosis and

myocardial dysfunction.

• Hepatic fibrosis and gastric scarring is longterm effect.

Clinical features

Management of Iron Poisoning

• Gastric lavage should be done with sodium

bicarbonate.

• IV sodium bicarbonate @ 3ml/kg diluted twice with 5%

dextrose is given for acidosis.

• Deferoxamine is a chelating agent used iv @

15mg/kg/hr until the total serum iron falls to less than

300μg/dl.

• Atropine

• Indication- organophosphate poisoning

• Dose- @0.05mg/kg iv; repeat dose until atropinisation

• N-acetyl cysteine

• Indication- paracetamol poisoning

• Dose- loading dose @140mg/kg followed by

maintenance dose @70mg/kg every 4 hourly for 17

doses oral solution mixed with fruit juice

Antidotes

• Deferoxamine

• Indication- iron poisoning

• Dose- @15mg/kg/hr iv until the serum iron is

<300μg/dl or until 24 hr after the child has stopped

passing ‘vine rose’ colour urine.

• Physostigmine

• Indication- anticholinergics like datura poisoning

• Dose- @0.02mg/kg slow iv

• Pralidoxime aldoxime methiodide (PAM)

• Indication- organophosphate poisoning

• Dose- @25-50 mg/kg im or iv over 30 minutes, then

repeat after 6-12 hourly

• Naloxone

• Indication- opioid poisoning

• Dose- 0.1mg/kg iv (upto 2mg) repeat every 2 minute

till reversal ( upto 10mg)

• Sodium bicarbonate

• Indication- salicylate poisoning

• Dose- @ 150 mEq/l + 40 mEq KCl/l of 5% dextrose

• Digoxin immune antibody fragment

• Indication- digoxin (digitalis) poisoning

• Dose- 10-20 vials iv bolus

Thank You