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University College of Medical Sciences & GTB Hospital, Delhi

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1 University College of Medical Sciences & GTB Hospital, Delhi
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
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 Hypotension with bradycardia :-
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 Mee’s lines – Arsenic poisoning

23 MEE’S LINES

24 Odours Most common odour detected- Alcohol 1. Garlic
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

25 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

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 Hypokalemia Hypernatremia
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 – 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 Eg Ethanol - Osmolality = 2 [ Na+] + [ urea] + glucose + Ethanol

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

31 ECG abnormalities Usually non specific ECG abnormality Drugs/ toxins
1. Bradycardia & AV Block Barbiturates, ß- blockers, Antiarrhythmics 2. Ventricular tachyarrhythmias Cardiac glycosides, Fluorides, Membrane active agents, Sympathomimetics 3. QRS prolongation Amantidine , Hyperkalemia 4. QT prolongation Amantadine, Amiodarone, Thallium

32 Radiological studies Bio assays of drugs
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 Interpretation requires various methods:-
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), 1:5000 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 Ewald’s 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 Ewald’s 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 Ipecac irritates the stomach & stimulates CTZ centre.
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 Side effects – Abdominal cramps, nausea vomiting
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 (>1 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. 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 of 1mg 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 ml sterile water iv. 25 g sodium thiosulphate iv slow Iron Desferrioxamine 2g im 12 hrly or mg/kg/hr not to exceed 80 mg /kg /24 hrs

51 Administration of antidotes….
Poison Antidote Dose OP Poisoning Atropine , Oximes Atropine : Loading dose - 2 , 4 , 6 every 5 mins . Maintenance – infusion < 3mg/hr PAM – mg/kg IV to be repeated 6-12 hourly Infusion – mg/kg f/b 5-10mg /kg/h Methanol Ethanol , Fomepizole Ethanol 50% 1 ml/kg every 2 hr for 5 days Fomepizole 15 mg/kg loading dose f/b 10 mg/k every 12 h for 4 days

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% ml Insulin 10 units with 50g of 50% dextrose NaHCO3 1mmol/kg , beta-2 agonists Hypokalemia - K < 2.5 mmol/l with symptoms - I/v KCL mmol/h K < 3.5 but > 2.5 mmol/l with no symptoms – KCL 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 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 Don’t 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. Harrison’s 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 – Official data , D. Gunnell, 2007 Critical Care, Joseph M. Civetta ; 4th edition

59 THANK YOU


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