1. General Management of a Case of Poisoning (1)

7/27/2019 1. General Management of a Case of Poisoning (1)

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POISONING AND TOXIC EXPOSURES

TYPES , DIAGNOSIS AND GENERALPRINCIPLES OF MANAGEMENT

Dr. Neha Kanojia

University College of Medical Sciences & GTB Hospital,

Delhi


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What is a Poison ?

Poison is a substance ( solid/

liquid or gaseous ), which if

introducedin the living body, or

brought into contact with any partthere of, will produce ill health or

death, by its constitutional or local

effects or both.

Ref- The Essentials of Forensic Medicine and Toxicology

Dr. K. Reddy


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Poisoning

The development ofdose

related adverse effects following

exposure to chemicals, drugs or

other xenobiotics.

Ref- The Essentials of Forensic Medicine and Toxicology

Dr. K. Reddy


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EPIDEMIOLOGY

WHO (2004) - 3,46,000 deaths in a year d/tpoisoning.

In 2005 In India 1,13,914 estimated cases

of poisoning with insecticides

Commonest cause in INDIAPesticides

Reasons Agriculture based economy

- Easy availability pesticides- Poverty


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Types of poisoning

1. Acute poisoning excessive singledose, or several smaller doses of a poison

taken over a short interval of time.

2. Chronic poisoning smaller doses over

a period of time, resulting in gradual

worsening eg. Arsenic , Phosphorus ,

Antimony etc.


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Nature of poisoning

1. Homicidal killing of a human being by anotherhuman being by administering poisonous substance

deliberately.

2. Suicidalwhen a person administer poison himselfto end his/ her life.

3. AccidentalEg. Household poisons- nail polishremover , acetone .

Depilatories- Barium sulphide

4. Occupationalin professional workers. Eg.insecticides, noxious fumes.


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Classification of poisons

According to the chief symptoms

produced :-

Corrosives . Systemic

Irritants . Miscellaneous

1. Corrosives

a) Strong acids- H2SO4 , HNO3 , HClb) Strong alkalis- Hydrates & Carbonates of Na+ , K+ &

NH3

c) Metallic saltsZinc chloride, Ferric chloride, KCN ,

Silver nitrate, Copper sulphate.


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Classification continued.

2. Irritants

a) Inorganici) Nonmetallic Phosphorus, IodineChlorine.

ii) Metallic Arsenic, Antimony, Lead.

iii) Mechanical Powdered glass, hair

b) Organic

Vegetable Abrus precatorius, Castor, Croton,

Calotropis.Animal Snake & insect venom, Cantharides


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Classification continued.

3.Systemic

a) Cerebral CNS depressantsAlcohol, opioids, hypnotics,

general anesthetics.

CNS stimulantsAmphetamines, Caffeine

DeliriantDatura, Cannabis, Cocaine

b) Spinal Nux vomica

c)PeripheralConium, Curare

d) Cardiovascular-Aconite, Quinine, HCN

e)Asphyxiants CO, CO2 , H2S

4)MiscellaneousFood poisoning, Botulism.


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Routes of administration

1. Inhalational

volatile gas, chemical dust, smoke, aerosol.

2. Injectable

a) Intra venousBenzodiazepines, barbiturates,

tricyclic antidepressants etc.

b) Intramuscular Benzodiazepines, opioids etc

c) SubcutaneousBotulinum toxin

d) Intra- dermal Local anaesthetics,organophosphates


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3. Oral Corrosives, organophosphorus

4.Through natural orifices- rectum/ vagina/urethra

Abrus precatorius, croton, calotropis

5. Through unbroken skinorganophosphorus, Mercury, Lead


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Diagnosis of poisoning

History patient

witness

Circumstantional evidence

suicide note

containers & potential toxins at scene ofdiscovery

Physical examination

Investigations

-Biochemical investigations-ECG abnormalities

-Radiology

-Toxicologic screening


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Patient

If person is conscious , & immediately broughtto the ED, history may be relevant

Mostly patient estimates of drug/ nature ofsubstance ingested are inaccurate.

Witness

What substance/ substances ?

What route/ routes ?What dose/ doses ?

When and for how long?

H /O psychiatric illness?

History


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Circumstantial evidence

Unconscious adults Empty drug

containers/

wrappers /tablet

neraby

some sort of

poisoning

Tablet particlesstaining mouth /

clothing

Suicide note

Assumption of

poisoning


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Following conditions should arousesuspicion of poisoning :-

Sudden appearance of symptoms after food

or drink in an otherwise healthy personSymptoms uniform in character, rapidity

Sudden onset delirium, paralysis, cyanosis,

collapse etc.


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Physical examination

General appearance

Neurological status- conscious, confused,comatose.

Glassgow coma scale

Pupillary examination

Normal Celphos poisoning

MiosisOpioids, OP poisoning

MydriasisTCA, Theophylline, Dhatura, Methanol

Convulsions- Ethylene glycol, Lithium, SSRI

Muscular fasciculations OP poisoning


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Vital parameters

Cardiorespiratory system -

PR, BP, RR, Temp

Hypotension with bradycardia :-

Beta blockers, Cyanide, Benzodiazepines,

Barbiturates, Opioids, Alchohol , OPinsecticides

Hypotension with tachycardia :- Beta -2 stimulants, Caffeine ,Theophylline,

Amatoxin containing mushroom


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Vital parameters contd.

Hypertension with tachycardia :-

Sympathomimetics, Ergot alkaloids,Anticholinergics, Alcohol withdrawal

Respiratory depression with failure:-

Barbiturates, Benzodiazepines, Opiates,Sedative- hypnotics, Snake venom

Hyperventilation :-

Amphetamines , Salicylates, Hallucinogens,

Cyanide, CO, H2S


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Vital parameters contd..

Body tempearture

Hypothermia :-

Barbiturates, Benzodiazepines, Ethanol,

Opiates, Cyclic antidepressants

Hyperthermia:-

Amphetamines, Alcohol withdrawal, MAO

inhibitors, Anticholinergic agents, Salicylates


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Examination of Skin colour and lesionsColour Toxin/ poison

1. Pink Cyanide2. Yellow ( jaundice) Phosphorus ,hepatotoxins

(Acetaminophen, mushroom )

3. Red Rifampicin

4. Blue (cyanosis) Aniline, Nitrites, . .

Methemoglobinemia

Diaphoresis Salicylate, OP poisoning

Sympathomimetics, serotonin syndrome

Phencyclidine, alcohol or sedative withdrawal


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Examination of Skin colour and lesions contd.

c. BruisingDiffuse ecchymosis:-

Anticoagulant

poisoning

Rodenticides

d. Needle tracks I/V abuse :-

Opiates

Amphetamines

Cocaine

May be hidden in

groin or interdigitalspaces


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Examination of Skin colour and lesions contd.

e. Hair

Hair loss Chemotheapuetic agentsThallium

f. Nails

Mees lines Arsenic poisoning

Thallium


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MEES LINES


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Odours

Most common odour detected- Alcohol

Odour Toxin

1. Garlic Arsenic, Phosphorous,

Selenium , Thallium ,

Organophosphorous

2. Sweet / fruity Ethanol, Chloroform ,Nitrites

3. Bitter almonds Cyanide

4. Acrid ( pear like ) Paralydehyde

Choral hydrate

5. Rotten eggs Hydrogen sulphide,Mercaptans

6. Fishy / musty Zinc phosphide

7. solvent/ glue Toulene, Xylene

8. Smoke Carbon monoxide


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Urine colour

Colour Drug/ toxin

1. Brown Myoglobin, CCL4 ,

Aniline , Methydopa

2. Black Naphthalene, Phenols ,

Cresols

3. Red Rifampicin, Phenytoin,

Phenolphthalein,

Desferoxamine

4. Smoky Phenols

5. Green / blue Copper sulphate,

Methylene blue

6. Green Propofol, Indomethacin


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Biochemical investigations

Hematologic

CBC, Platelet count, Coagulation profile Hemolytic anemia- lead, NSAIDS, Quinidine

Thrombocytopenia- Aspirin, Phenytoin, Procanamide

Coagulopathy- snake venoms, warfarin

Liver function tests

S. bilirubin , enzymes AST,ALT , ALP, coagulation profile

Acetaaminophen, sulfonamides, rifampicin, TCA, INH,

Renal functions tests

Aspirin, lead, barbiturates, alcohol, amphetamines,

copper sulphate


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Other Abnormalities

Hyperkalemia

Digoxin, Cardiac glycosides, Rhabdomyolysis,K + sparing diuretics

Hypokalemia

Theophylline, Amphetamines, Sympathomimetics

Hypernatremia

Uncommon in clinical toxicology

Large dose of NaHCO3 for TCA overdose

Correction of life threatening metabolic acidosis

Hyponatremia

Rare


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Biochemical abnormalities contd

Metabolic acidosis

Acetaaminophen, Ethanol, Methyl alcohol, Toulene

Metabolic alkalosis

Calcium carbonate, Furosemide, Laxative

Anion Gap

Anion Gap = [ Na+ ] { [ Cl] +[ HCO3 ] }

Normal 8- 12 mmol/ lIncreased anion gap :-

Ethylene glycol

Methanol

Salicylate poisoning


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Biochemical abnormalities contd..

Osmolar gap

Detects the presence of osmotically activesusbstances in serum or plasma

Calculated osmolality =

2 [ Na+] + [ urea] + glucose

2.8 18

Eg Ethanol - Osmolality =

2 [ Na+] + [ urea] + glucose + Ethanol

2.8 18 4.6


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Biochemical abnormalities contd..

Increased osmolar gap:- Acetone

Ethanol

Ethylene glycol

Methanol


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ECG abnormalities

Usually non specific

ECG abnormality Drugs/ toxins

1. Bradycardia & AV Block Barbiturates, - blockers,

Antiarrhythmics

2. Ventricular

tachyarrhythmias

Cardiac glycosides,

Fluorides, Membrane activeagents, Sympathomimetics

3. QRS prolongation Amantidine , Hyperkalemia

4. QT prolongation Amantadine, Amiodarone,

Thallium


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Radiological studies

Not particularly helpful in diagnosis.

May be useful in confirming :-

Ingestion of metallic objects.

Packets of heroin / cocaine ( body packing)

Serial chest X-ray - Aspiration pneumonitis, ARDS

Bio assays of drugs Acetaminophen

Acetone

Ethylene glycol

Methanol

Salicylate

Phenobarbital

Theophylline

Lithium


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Toxicologic analysisUrine , blood, gastric contents confirm or rule

out suspected poisoning.

Interpretation requires various methods:-

Thin layer chromatography Acetaminophen

Gas liquid chromatography BZD, Amphetamines

HPLC- BZD

Mass spectrometry- Anticonvulsant

Enzyme assays

RBC cholinestrase , serum cholinestrase OP poisoning

Pseudocholinestrase levels OP poisoning


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Fundamentals of poisoning

management

1. Initial resuscitation and stabilization2. Removal of toxin from the body

3. Prevention of further poison absorption

4. Enhancement of poison elimination5. Administration of antidote

6. Supportive treatment

7. Prevention of re - exposure


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Management of poisoning contd.

Initial resuscitation and stabilization

I/V access I/V fluids

Endo tracheal intubation - to prevent aspiration

Unconscious patients

Respiratory depression/ failure

Convulsions- give anticonvulsants

Removal of toxin from the body

Copious flushing with water or saline of the body

including skin folds, hair

Inhalational exposure

Fresh air or oxygen inhalation


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Prevention of poison absorption

G I decontamination

Performed selectively, not routinely

1. Gastric lavage

Useful IF DONE BEFORE 3 hr of ingestion of a poison

Done with water ( except infants NS), 1:5000potassium permangnate , 4% Tannic acid, saturated

lime water or starch solution

Administering & aspirating 5ml/kg through a No. 40 F

orogastric tube ( No. 28 F children) orEwalds tube Position Trendelenburge & left lateral position

Performed until clear fluid is obtained or a

maximum of 3 L


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Prevention of poison absorption contd.

Complicationsa. Aspiration (common)

b. Esophageal / gastric perforation

c. Tube misplacement in the trachea

Ewalds gastric tube


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Contraindications

a. Corrosive poisoning GE perforation

b. Petroleum distillate ingestants- Aspiration

pneumonia

c. Compromised unprotected airway

d. Esophageal / gastric pathologye. Recent esophageal / gastric surgery

Lavage decreases ingestant absorption by an

average of :- 52 % - if performed within 5 mins of ingestion

26 % - if performed at 30 mins

16 % - if performed at 60 mins

Prevention of poison absorption contd


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2. Ipecac Syrup induced

emesis

Used for home management of

patients with :-

Accidental ingestions

Reliable history Mild predicted toxicity

Aministered orally

Dose :- 30 ml adults

15 ml children

10 ml small infants


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MOA

Ipecac irritates the stomach & stimulates CTZcentre.

Vomiting occurs about 20 min after administration

Dose may be repeated if vomiting does not occur

Side effectsa. Protracted vomiting

Contraindications

a. Gastric / esophageal tears or perforationb. Corrosives

c. CNS depression or seizures

d. Rapidly acting CNS poisons ( cyanide, strychnine,

camphor )



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3. Activated charcoal

Greater efficacy

Less invasive

Given orally as a suspension ( in water ) or

through NG tube

Dose1 g/kg body wt. Charcoal adsorbs ingested poisons within gut

lumen allowing charcoal- toxin complex to be

evacuated with stool or removed by induced

emesis / lavage


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Indications- Barbiturates, Atropine , Opiates,Strychnine

Contraindications- Mineral acids, alkalis, cyanide,fluoride ,iron

Side effectsa. Nausea , vomiting, diarrhoea or constipation

b. May prevent absorption of orally administeredtherapeutic agents

Complications

a. Aspiration vomiting

b. Bowel obstruction


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4. Whole bowel irrigation

Administration of bowel cleansing solutioncontaining electrolytes & polyethylene glycol

Orally or through gastric tube

Rate 2 L/ hr ( 0.5 L /hr in children)

End point- rectal fluid is clear Position sitting

Indication :-

Slow or enteric coated medications

Packets of illicit drugs

Heavy metals

Iron , Lithium


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Contraindications

a. Bowel obstruction

b. Ileus

c. Unprotected airway

Complications:

a. Bloating

b. Crampingc. Rectal irritation


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5. Cathartics

Promote rectal evacuation of GI contents

Most effective

Sorbitol Dose 1-2 g/kg

Salts Disodium phosphate, Magnesium citrate &sulfate, Sodium sulfate

Saccharides Mannitol, Sorbitol

Side effects Abdominal cramps, nauseavomiting

Complications Excessive diarrhoea,HypermagnesemiaC/I Corrosives

Pre existing diarrhoea

E h t f li i ti f i


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Enhancement of elimination of poison

1.Alkalization of urine

Urine pH 7.5 Urine output 3-6 ml/kg

5% Dextrose in 0.45 NS containing 20 35 meq

/L Of NaHCO3 to an IV solution

Uses Chlorpropamide, Phenobarbital,

Sulfonamides, Salicylates

C/I :-a. Congestive heart failure

b. Renal failure

c. Cerebral edema


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2. Acidification of urine Enhance elimination of weak bases such as

Phencyclidine & Amphetamine

Not used anymore

S /E-Metabolic acidosis, Renal damage

3.Extra corporeal removal

Dialysis

Acetone, Barbiturates, Bromide, Ethanol, Ethylene

glycol, Salicylates, Lithium Less effective when toxin has large volume of

distribution (>1 L/kg), has large molecular weight, or

highly protein bound

Eli i i f i d


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Elimination of poison contd.

Peritoneal dialysis

Alcohols , long acting salicylates, Lithium

Exchange transfusion

Indications

a. Fatal , irreversible toxicity

b. Deteriorating despite aggressive supportive therapy

c. Dangerous blood levels of toxins

d. Liver or renal failure Eg. Arsine or Sodium Chlorate poisoning


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Elimination of poison contd.

4. Chelation Heavy metal poisoning

Complex of agent & metal is water soluble &

excreted by kidneys Eg . BAL, EDTA, Desferrioxamine, DMSA

BAL Arsenic, Lead, Copper, Mercury

EDTA- Cobalt, Iron, Cadmium

Desferrioxamine Iron DMSA- Lead, Mercury


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Administration of Antidotes

Not all poisons have antidotes.

Poison Antidote Dose

Acetaaminophen N - acetylcysteine 140mg/kg. then 70 mg/kg every

4 hrs to total of 18 doses over 72

hrs

Benzodiazepine Flumazenil 0.1mg/min infusion to a total of1mg

Anticholinergics Physostigmine 1gm I/M or I/V

Opioid Naloxone 2 mg I/V , repeated every half to

one min to a total of 20 mg I/V

Cyanide Thiosulphate ,nitrite

0.3 g sodium nitrite in 10 mlsterile water iv. 25 g sodium

thiosulphate iv slow

Iron Desferrioxamine 2g im 12 hrly or 10- 15 mg/kg/hr

not to exceed 80 mg /kg /24 hrs


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Administration of antidotes.

Poison Antidote Dose

OP Poisoning Atropine , Oximes Atropine : Loading dose - 2 , 4 ,

6 every 5 mins .Maintenance infusion 2.5 mmol/l with no symptoms KCL 20-40

mmol every 4-6 hr


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Supportive care contd.

Hypernatremia with hemodynamic instability-

NS saline till I/V vol is corrected.

Subsequently replace water with 5% D, or 0.45% NS

Prevention and t/t ofsecondary complications

pulmonary edema , cerebral edema, shock etc.

Pulmonary edema Furosemide IV 0.5- 1 mg/kg

Morphine IV 2-4 mg

Nitroglycerin SL

O2 inhalation / intubation as needed

Cerebral edemaMannitol 1g/kg

Steroids Hydrocortisone, Dexamethasone

Shock crystalloids / colloids

P ti f


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Prevention of re- exposure

Adult education instructions regarding

safe use of medications & chemicals

Notification of regulatory agencies - in

case of environmental or workplaceexposure

Psychiatric referral- depressed or

psychotic patients should receive

psychiatric assessment, disposition &

follow-up

P ti f


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Prevention of re- exposure

Child proofing- In house holdwhere children live or visit,

alcohols, medications,

household products ,non edible

plants should be kept out ofreach or in locked, child proof

containers.


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Summary

Poisoning a common problem in our

countryA high index of suspicion required to

diagnose

For any poisoning the mainstay oftreatment is supportive care

Follow the A, B, C

Dont panic and follow a plan of action Decreasing absorption

Enhancing elimination

Neutralising toxins

REFERENCES


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REFERENCES

1. Critical care toxicology: Diagnosis andManagement of the Critically Poisoned Patient.

Jeffery Brent ;2nd

edition.2. Harrisons Principles of Internal Medicine. 16th

edition, Vol 2: part 16; Poisoning, Drug overdose,and Envenomation.

3. The Essentials of Forensic Medicine andToxicology. Dr. K. Reddy , Section II Toxicology; 25thedition

4. International Programme On Chemical Safety,Guidelines On The Prevention Of Toxic Exposure ;

WHO 20045. www.biomedcentral.com Official data , D.

Gunnell, 2007

6. Critical Care, Joseph M. Civetta ; 4th edition
http://www.biomedcentral.com/http://www.biomedcentral.com/


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1. General Management of a Case of Poisoning (1)