1. ACUTE POISONING Major C J Porter RAMC Emergency Medicine Registrar
Army Medical Directorate
Emergency Medicine Registrar
Bristol Royal Infirmary

2. Outline of lecture Epidemiology Toxidromes
History, examination and detective work
General management
Specific management
Antidotes
Scenarios

3. EPIDEMIOLOGY 4000 UK deaths per year (1/3 CO)
Most deaths outside hospital
100,000 Hospital admissions (12%)
Not just overdoses: Illicit drugs, Alcohol

4. EPIDEMIOLOGY Self poisoning:
F>M
1/3 >one drug
Taken with alcohol: F: 40% M: 60%
Repeated self-poisoning: 11% of admissions

5. SUICIDE 2% of male deaths 1% of female deaths Method:
Female: Poisoning 40%
Male: Gas / Hanging / Suffocation
Self-harm parasuicide:
1% dead after 12 months
3-5% dead after 5-10 years

6. Toxidromes Patterns of signs and symptoms
Useful to help in diagnosis and treatment of unknown poisons

7. Opiates Respiratory depression Cardiovascular depression
Reduced level consciousness
Pinpoint pupils
Pulmonary oedema
Hypothermia
(Rapid response to Naloxone)

8. Common causes
Opiates – heroin, morphine etc

9. Sympathomimetics / Stimulants
Agitation/delusions/paranoia
Fight/Flight response
Tachycardia
Hypertension
Arrhythmias
Dilated pupils
Seizures
Hyperpyrexia

10. Common causes
Cocaine
Amphetamines
Decongestants
Ecstasy

11. Anticholinergic Tachycardia Arrhythmias
Pupils: mid-point or dilated / divergent
Confusion / drowsiness / coma
Seizures
Dry flushed skin
Urine retention
Hypertonia, Hyper-reflexia, Myotonic jerks

12. Anticholinergic signs
Hot as a hare
Blind as a bat
Dry as a bone
Red as a beet
Mad as a hatter

13. Common causes Antidepressants-Tricyclics Antihistamines Atropine
Antipsychotics
Antispasmodics

14. Serotonin Syndrome Similar to anticholinergic syndrome Agitation
loss of consciousness: uncommon
sweating and tremor: common
Agitation
Delirium
Hypertonia / myoclonus
Tachycardia
Tachypnoea

15. Common Causes
SSRIs
MAOIs (Hyperpyrexia / Hypertensive crisis)

16. Cholinergic Brady/tachycardia Confusion/reduced GCS Pinpoint pupils
Seizures
Weakness
SLUDGE
Pulmonary oedema

17. SLUDGE S sweating salivation L lacrymation U urinary frequency urgency
D diarrhoea
G gastrointestinal discomfort
E eyes pinpoint

19. Common causes Organophosphates Physostigmine Some mushrooms
Nerve agents

20. Salicylism: Aspirin Impaired hearing Tinnitus Sweating Warm skin
Hyperventilation
Cinchonism: Quinine (salicylism + blindness)

21. MANAGEMENT

22. Management Overview A B C D DEFG Supportive care (O2, IV Fluids)
History & assessment of vital signs
ANY concerns: move patient to RESUS
A B C D
DEFG
Supportive care (O2, IV Fluids)
Prevent absorption
Increase elimination
Antidotes
PSYCHOLOGICAL ASSESSMENT

23. History
What?
When?
How much? (mg/kg)
What else?
Why?

24. Collateral history Paramedics Family / friends Notes
Look in pockets – carefully!!!

26. Detective work BNF Toxbase Tablet identification aids: TICTAC
Poisons advice: NPIS
Plant identification books
National teratology information service

29. Initial examination Treat problems as you find them!! Airway Breathing
Circulation
Disability – GCS/AVPU and Pupils
DON’T EVER FORGET GLUCOSE

30. Observations Saturations and respiratory rate Pulse and blood pressure
GCS
Pupils
Temperature
GLUCOSE

31. Investigations All Patients As indicated Urine toxicology screen
Glucose
U&E
Paracetamol & Salicylate
As indicated
LFT
Co-ag / INR CK
ABG / VBG
ECG
CXR
Urine toxicology screen

32. Reduce absorption Emesis – No role Activated charcoal within 1 hour
Gastric lavage – rarely
Whole bowel irrigation - rarely

33. Increase elimination Urinary alkalinisation
Multi-dose Activated Charcoal
Haemodialysis
Haemoperfusion
Plasma exchange
Forced alkaline diuresis (no longer recommended)

34. Paracetamol Very common: 40% poisons admissions Often asymptomatic
Can be lethal – deaths/year
Check blood level at 4 hours
Two treatment lines normal and high risk
Given IV N-acetylcysteine

35. Paracetamol metabolism
Metabolised by glucuronidation (60%),
Sulphation (35%) and oxidation (10%)
Cytochrome p450 produces NAPQI
NAPQI toxic causes hepatocellular necrosis – irreversible binding
NAPQI detoxified by conjugation with glutathione

36. Prescott Nomogram

37. High Risk Increased oxidation Reduces glutathione stores
Chronic alcohol use
Drugs
Reduces glutathione stores
Malnutrition
Eating disorders
Chronic liver disease

38. N-acetylcysteine Most effective within 8 hours
Precursor for glutathione production
Can cause anaphylactoid reactions
Consider starting before paracetamol result if:
Presenting > 8 hrs & >150mg/kg taken
Staggered overdose

39. To treat or not to treat?

40. Patient 1 20 year old woman who takes a handful of paracetamol tablets
No drug history
No alcohol use
Fit and well
Blood level is 80mg/l

41. No need to treat Patient is not high risk
Level at 4 hours is below even the high risk line

42. Patient 2
70 year old man
Takes 20 paracetamol 6 hours before presenting
Alcoholic
No drug history
Blood level 100mg/l

43. Treat Patient is high risk Level is above the high risk line
Delayed presentation means need to act fast

44. Patient 3 17 year old epileptic
25 codydramol 2 hours before attendance
Taking carbamazepine
Blood level at 4 hours is 120mg/l

45. Treat
High risk patient
Level above the high risk line

46. Patient 4
35 year old man who presents after taking 24 paracetamol over a period of 24 hours
No drug history
Fit and well
Blood level 20mg/l

47. Treat Staggered overdoses are difficult
Poisons advice is to give IV acetylcysteine
Levels are not that helpful
Need to monitor Liver function, clotting and renal function
May need discussing with Liver Unit if abnormal

48. PARACETAMOL DEADLY PITFALLS The Prescott Nomogram High Risk Line
Staggered Overdoses
Management of late presentation
Recheck U&E, LFT, INR after N-acetylcysteine

49. Tricyclics Antidepressants Dangerous: US 60-70% fatal ODs
UK commonest fatal OD per prescription
10% unconscious patient will fit
Treat fits with diazepam/lorazepam

50. Tricyclic effects Anticholinergic toxidrome The 3 C’s Coma Convulsion
Cardiac

51. Tricyclics cardiac effects
Quinidine effects lead to arrhythmias
ECG
Sinus tachycardia
Broad QRS: RBBB
Prolonged QT interval
Right axis deviation
Severe poisoning – VT, bradycardia, heart block
QRS > 160mS = ↑↑risk of seizures and cardiac toxicity

52. Tricyclics
ABG
Hypoxaemia
Metabolic acidosis
Respiratory acidosis

53. Tricyclics Management: EARLY ITU REFERRAL SODIUM BICARBONATE
If hypotension resistant to fluid challenge
Dysrhythmias
Convulsions
Consider IV Magnesium for resistant dysrhythmia

54. Salicylate Salicylism Dehydration Confusion /coma Seizures
Haemetemesis
Hypoglycaemia

55. Salicylate Metabolic and acid-base disturbance Complex
Respiratory alkalosis – direct stimulation to over breathe
Metabolic acidosis- acid, impaired normal metabolism, production of lactic acid
Check ABG / VBG

56. Salicylate Severity of ingested dose: >150 mg/kg: mild
>250 mg/kg: moderate
>500 mg/kg: severe

57. Salicylate management
Tailor treatment to symptoms
Fluids
Reduce absorption:
Activated charcoal
Gastric lavage (>500 mg/kg and <1 hour)
Increase elimination:
Urinary alkalinisation
Cooling
Glucose if hypoglycaemic

58. Salicylate management
<350mg/L: oral fluids
>350mg/L: urinary alkalinisation
>700mg/L: haemodialysis
DISCUSS WITH NPIS

59. Salicylate DEADLY PITFALL
Salicylate levels can continue to rise following admission (10% of cases)
Repeat levels every until peaked

60. Opiates Common Act on μ-receptors Reversible with Naloxone
Naloxone pure opioid antagonist
Naloxone
Short half life: may need repeated doses
Give IV +/- IM & may need IVI

61. Antidotes Opiates – naloxone Paracetamol – acetylcysteine/methionine
Beta-blockers – glucagon
Insulin – glucose
Iron – desferrioxamine
Carbon monoxide – oxygen
Methanol - ethanol
(Benzodiazepines – flumazenil)

63. Scenario 1 20 year old IVDU found by ambulance crew unconscious
Needle lying by side
Resp rate 6, Sats 94% on air
60bpm BP 100/55
Responds to pain

64. What next? A – Give naloxone B – Check airway C – Take history
D – Give flumazenil

65. Check airway Check airway patent Give oxygen Call for senior help
Check glucose
Give naloxone IM and IV

66. Scenario 2 30 year old woman Taken some white tablets 4 hours earlier
Feels completely well
Felt depressed after argument with partner
Usually fit and well

68. What next? A – Start N-Acetylcysteine
B – Discharge as she is obviously well
C – Find out what the tablets are
D –Take blood for paracetamol levels

69. Take bloods Early treatment is essential in paracetamol overdose
Need to know what her levels are as soon as possible

71. Scenario 3 45 year old man works in local aquarium
Put right hand into tank and got stung by a lion fish
Respiratory rate 16 sats 100% on air
Pulse 100 bpm 160/80
Fully conscious
Extreme pain in hand

72. Lion fish

73. What next? A – Panic you know nothing about lion fish!
B – Look on Toxbase
C – Ring local zoo
D – Ask a senior who also knows nothing about Lion fish!

74. Toxbase Patient needs cardiovascular monitoring Analgesia
Hand in water as hot as can tolerate
Lion fish toxin is heat labile
Carefully remove spines if present
Few hours later patient feels much better goes home

75. Summary Common Approach using: A B C D DEFG Consider the toxidromes
Early senior help / Early ITU referral
Supportive Care
Antidotes
Psychological assessment

76. Questions ?