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POISONING AND TOXIC EXPOSURES – TYPES , DIAGNOSIS AND GENERAL PRINCIPLES OF MANAGEMENT

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POISONING AND TOXIC EXPOSURES TYPES , DIAGNOSIS AND GENERAL PRINCIPLES OF MANAGEMENT Dr. Neha Kanojia University College of Medical Sciences & GTB Hospital, Delhi – PowerPoint PPT presentation

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Title: POISONING AND TOXIC EXPOSURES – TYPES , DIAGNOSIS AND GENERAL PRINCIPLES OF MANAGEMENT


1
POISONING AND TOXIC EXPOSURES TYPES , DIAGNOSIS
AND GENERAL PRINCIPLES OF MANAGEMENT
  • Dr. Neha Kanojia

University College of Medical Sciences GTB
Hospital, Delhi
2
What is a Poison ?
  • Poison is a substance ( solid/ liquid or
    gaseous ), which if introduced in the living
    body, or brought into contact with any part there
    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
3
Poisoning
  • The development of dose related adverse effects
    following exposure to chemicals, drugs or other
    xenobiotics.

Ref- The Essentials of Forensic Medicine and
Toxicology Dr. K. Reddy
4
EPIDEMIOLOGY
  • WHO (2004) - 3,46,000 deaths in a year d/t
    poisoning.
  • In 2005 In India 1,13,914 estimated cases of
    poisoning with insecticides
  • Commonest cause in INDIA Pesticides
  • Reasons Agriculture based economy
  • - Easy availability pesticides
  • - Poverty

5
Types of poisoning
  • Acute poisoning excessive single dose, or
    several smaller doses of a poison taken over a
    short interval of time.
  • Chronic poisoning smaller doses over a period
    of time, resulting in gradual worsening eg.
    Arsenic , Phosphorus , Antimony etc.

6
Nature of poisoning
  • Homicidal killing of a human being by another
    human being by administering poisonous substance
    deliberately.
  • Suicidal when a person administer poison
    himself to end his/ her life.
  • Accidental Eg. Household poisons- nail polish
    remover , acetone .
  • Depilatories- Barium sulphide
  • 4. Occupational in professional workers. Eg.
    insecticides, noxious fumes.

7
Classification of poisons
  • According to the chief symptoms produced -
  • Corrosives . Systemic
  • Irritants . Miscellaneous
  • Corrosives
  • Strong acids- H2SO4 , HNO3 , HCl
  • Strong alkalis- Hydrates Carbonates of Na , K
    NH3
  • Metallic salts Zinc chloride, Ferric chloride,
    KCN , Silver nitrate, Copper sulphate.

8
Classification continued.
  • Irritants
  • Inorganic i) Nonmetallic Phosphorus, Iodine
    Chlorine.
  • ii) Metallic
    Arsenic, Antimony, Lead.
  • iii) Mechanical
    Powdered glass, hair
  • b) Organic
  • Vegetable Abrus precatorius, Castor,
    Croton,
  • Calotropis.
  • Animal Snake insect venom,
    Cantharides

9
Classification continued.
  • 3. Systemic
  • Cerebral
  • CNS depressants Alcohol, opioids, hypnotics,
  • general
    anesthetics.
  • CNS stimulants Amphetamines, Caffeine
  • Deliriant Datura, Cannabis, Cocaine
  • b) Spinal Nux vomica
  • c) Peripheral Conium, Curare
  • d) Cardiovascular - Aconite, Quinine, HCN
  • e) Asphyxiants CO, CO2 , H2S
  • 4) Miscellaneous Food poisoning, Botulism.

10
Routes of administration
  • Inhalational
  • volatile gas, chemical dust, smoke,
    aerosol.
  • Injectable
  • Intra venous Benzodiazepines, barbiturates,
    tricyclic antidepressants etc.
  • Intramuscular Benzodiazepines, opioids etc
  • Subcutaneous Botulinum toxin
  • Intra- dermal Local anaesthetics,
    organophosphates

11
  • 3. Oral Corrosives, organophosphorus
  • 4. Through natural orifices- rectum/ vagina/
    urethra
  • Abrus precatorius, croton, calotropis
  • 5. Through unbroken skin organophosphorus,
    Mercury, Lead

12
Diagnosis of poisoning
  • History patient
  • witness
  • Circumstantional evidence
  • suicide note
  • containers potential toxins at scene of
  • discovery
  • Physical examination
  • Investigations
  • -Biochemical investigations
  • -ECG abnormalities
  • -Radiology
  • -Toxicologic screening

13
History
  • Patient
  • If person is conscious , immediately brought
    to the ED, history may be relevant
  • Mostly patient estimates of drug/ nature of
    substance ingested are inaccurate.
  • Witness
  • What substance/ substances ?
  • What route/ routes ?
  • What dose/ doses ?
  • When and for how long?
  • H /O psychiatric illness?

14
Circumstantial evidence
  • Unconscious adults
  • Empty drug containers/ wrappers /tablet neraby
  • ?
  • some sort of poisoning
  • Tablet particles staining mouth / clothing
  • Suicide note
  • ?
  • Assumption of poisoning

15
  • Following conditions should arouse suspicion of
    poisoning -
  • Sudden appearance of symptoms after food or drink
    in an otherwise healthy person
  • Symptoms uniform in character, rapidity
  • Sudden onset delirium, paralysis, cyanosis,
    collapse etc.

16
Physical examination
  • General appearance
  • Neurological status- conscious, confused,
    comatose.
  • Glassgow coma scale
  • Pupillary examination
  • Normal Celphos poisoning
  • Miosis Opioids, OP poisoning
  • Mydriasis TCA, Theophylline, Dhatura, Methanol
  • Convulsions - Ethylene glycol, Lithium, SSRI
  • Muscular fasciculations OP poisoning

17
  • Vital parameters
  • Cardiorespiratory system -
    PR, BP, RR, Temp
  • Hypotension with bradycardia -
  • Beta blockers, Cyanide, Benzodiazepines,
    Barbiturates, Opioids, Alchohol , OP insecticides
  • Hypotension with tachycardia -
  • Beta -2 stimulants, Caffeine ,Theophylline,
    Amatoxin containing mushroom

18
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

19
Vital parameters contd..
  • Body tempearture
  • Hypothermia -
  • Barbiturates, Benzodiazepines, Ethanol, Opiates,
    Cyclic antidepressants
  • Hyperthermia -
  • Amphetamines, Alcohol withdrawal, MAO inhibitors,
    Anticholinergic agents, Salicylates

20
Examination of Skin colour and lesions
  • Colour Toxin/ poison
  • Pink Cyanide
  • Yellow ( jaundice) Phosphorus ,hepatotoxins
    (Acetaminophen, mushroom )
  • Red Rifampicin
  • Blue (cyanosis) Aniline, Nitrites,
    . . Methemoglobinemia
  • Diaphoresis
  • Salicylate, OP poisoning
  • Sympathomimetics, serotonin syndrome
  • Phencyclidine, alcohol or sedative withdrawal

21
Examination of Skin colour and lesions contd.
  • c. Bruising
  • Diffuse ecchymosis-
  • Anticoagulant poisoning
  • Rodenticides
  • d. Needle tracks
  • I/V abuse -
  • Opiates
  • Amphetamines
  • Cocaine
  • May be hidden in groin or interdigital spaces

22
Examination of Skin colour and lesions contd.
  • e. Hair
  • Hair loss Chemotheapuetic agents
  • Thallium
  • f. Nails
  • Mees lines Arsenic poisoning
  • Thallium

23
MEES LINES
24
Odours
  • Most common odour detected- Alcohol

25
Urine colour
26
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

27
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

28
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/ l
  • Increased anion gap -
  • Ethylene glycol
  • Methanol
  • Salicylate poisoning

29
Biochemical abnormalities contd..
  • Osmolar gap
  • Detects the presence of osmotically active
    susbstances 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

30
Biochemical abnormalities contd..
  • Increased osmolar gap-
  • Acetone
  • Ethanol
  • Ethylene glycol
  • Methanol

31
ECG abnormalities
  • Usually non specific

32
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

33
  • Toxicologic analysis
  • Urine , 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

34
Fundamentals of poisoning management
  • Initial resuscitation and stabilization
  • Removal of toxin from the body
  • Prevention of further poison absorption
  • Enhancement of poison elimination
  • Administration of antidote
  • Supportive treatment
  • Prevention of re - exposure

35
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

36
  • Prevention of poison absorption
  • G I decontamination
  • Performed selectively, not routinely
  • Gastric lavage
  • Useful IF DONE BEFORE 3 hr of ingestion of a
    poison
  • Done with water ( except infants NS), 15000
    potassium 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) or
    Ewalds tube
  • Position Trendelenburge left lateral position
  • Performed until clear fluid is obtained or a
    maximum of 3 L


37
Prevention of poison absorption contd.
  • Complications
  • Aspiration (common)
  • Esophageal / gastric perforation
  • Tube misplacement in the trachea

Ewalds gastric tube
38
Prevention of poison absorption contd.
  • Contraindications
  • Corrosive poisoning GE perforation
  • Petroleum distillate ingestants- Aspiration
    pneumonia
  • Compromised unprotected airway
  • Esophageal / gastric pathology
  • 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

39
Prevention of poison absorption contd.
  • 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

40
  • MOA
  • Ipecac irritates the stomach stimulates CTZ
    centre.
  • Vomiting occurs about 20 min after administration
  • Dose may be repeated if vomiting does not occur
  • Side effects
  • Protracted vomiting
  • Contraindications
  • Gastric / esophageal tears or perforation
  • Corrosives
  • CNS depression or seizures
  • Rapidly acting CNS poisons ( cyanide, strychnine,
    camphor )

41
Prevention of poison absorption contd.
  • 3. Activated charcoal
  • Greater efficacy
  • Less invasive
  • Given orally as a suspension ( in water ) or
    through NG tube
  • Dose 1 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

42
Prevention of poison absorption contd
  • Indications- Barbiturates, Atropine , Opiates,
    Strychnine
  • Contraindications - Mineral acids, alkalis,
    cyanide, fluoride ,iron
  • Side effects
  • Nausea , vomiting, diarrhoea or constipation
  • May prevent absorption of orally administered
    therapeutic agents
  • Complications
  • Aspiration vomiting
  • Bowel obstruction

43
Prevention of poison absorption contd.
  • 4. Whole bowel irrigation
  • Administration of bowel cleansing solution
    containing 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

44
  • Contraindications
  • Bowel obstruction
  • Ileus
  • Unprotected airway
  • Complications
  • Bloating
  • Cramping
  • Rectal irritation

45
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, nausea vomiting
  • Complications Excessive diarrhoea,

  • Hypermagnesemia
  • C/I Corrosives
  • Pre existing diarrhoea

46
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 -
  • Congestive heart failure
  • Renal failure
  • Cerebral edema

47
  • 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 (gt1 L/kg), has large molecular
    weight, or highly protein bound

48
Elimination of poison contd.
  • Peritoneal dialysis
  • Alcohols , long acting salicylates, Lithium
  • Exchange transfusion
  • Indications
  • Fatal , irreversible toxicity
  • Deteriorating despite aggressive supportive
    therapy
  • Dangerous blood levels of toxins
  • Liver or renal failure
  • Eg. Arsine or Sodium Chlorate poisoning

49
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

50
Administration of Antidotes
  • Not all poisons have antidotes.

51
Administration of antidotes.
52
Supportive care
  • Hemodynamic support- Hypotension unresponsive to
    volume expansion t/t with ionotropes
  • Correction of temperature abnormalities
  • Hypothermia Rewarming of the patient
  • Active / passive methods
  • External / internal methods
  • Passive external rewarming- blankets / sleeping
    bags
  • Active external warming- hot water bottles,
    heating blankets , forced air warming
  • Invasive core rewarming- peritoneal dialysis,
    hemodialysis, gastric or rectal lavage

53
Supportive care contd.
  • Hyperthermia
  • Externally immersion in iced saline bath, tepid
    sponging
  • Internally gastric / peritoneal lavage
  • Correction of metabolic derangements
  • Hyperkalemia
  • Calcium gluconate 10 10-20 ml
  • Insulin 10 units with 50g of 50 dextrose
  • NaHCO3 1mmol/kg , beta-2 agonists
  • Hypokalemia -
  • K lt 2.5 mmol/l with symptoms - I/v KCL 20-30
    mmol/h
  • K lt 3.5 but gt 2.5 mmol/l with no symptoms KCL
    20-40 mmol every 4-6 hr

54
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 of secondary 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 edema Mannitol 1g/kg
  • Steroids Hydrocortisone, Dexamethasone
  • Shock crystalloids / colloids

55
Prevention of re- exposure
  • Adult education instructions regarding safe
    use of medications chemicals
  • Notification of regulatory agencies - in case
    of environmental or workplace exposure
  • Psychiatric referral- depressed or psychotic
    patients should receive psychiatric assessment,
    disposition follow-up

56
Prevention of re- exposure
  • Child proofing- In house hold where children
    live or visit, alcohols, medications, household
    products ,non edible plants should be kept out of
    reach or in locked, child proof containers.

57
Summary
  • Poisoning a common problem in our country
  • A high index of suspicion required to diagnose
  • For any poisoning the mainstay of treatment is
    supportive care
  • Follow the A, B, C
  • Dont panic and follow a plan of action
  • Decreasing absorption
  • Enhancing elimination
  • Neutralising toxins

58
REFERENCES
  • Critical care toxicology Diagnosis and
    Management of the Critically Poisoned Patient.
    Jeffery Brent 2nd edition.
  • Harrisons Principles of Internal Medicine. 16th
    edition, Vol 2 part 16 Poisoning, Drug
    overdose, and Envenomation.
  • The Essentials of Forensic Medicine and
    Toxicology. Dr. K. Reddy , Section II Toxicology
    25th edition
  • International Programme On Chemical Safety,
    Guidelines On The Prevention Of Toxic Exposure
    WHO 2004
  • www.biomedcentral.com Official data , D.
    Gunnell, 2007
  • Critical Care, Joseph M. Civetta 4th edition

59
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