Poisonning

Question 1

How can be exposed to poisons

Answer 1

Oral
Inhaled
Percutaneous - cyanide, organophosphates
Ocular - industrial

Question 2

Types of poisonning

Answer 2

Acute, chronic, acute on chronic
Deliberate or accidental

Question 3

What is digoxin poisoning time wise?

Answer 3

Chronic - elderly too high a dose -> renal failure

Question 4

Epidemiology of poisoning UK

Answer 4

180,000 cases a year
100,000 aditted
300 die
3,500 deaths outside of hospital

Question 5

What age groups are most comonly affected by poisonings

Answer 5

1-5 year olds (male>female)
-accidental, daytime
Adolescents, young adults (male=female)
Deliberate self harm, overdose, evening/night, alcohol ass

Question 6

Top 10 substances poisonings UK

Answer 6

1 - paracetamol (25% all overdoses involve)
2 - ibuprofen
3 - citalopram
zopiclone, fluoxetine, co-codamol, asirin, diazepam, codeine, diclofenac

Question 7

Most common causes of death from poisoning

Answer 7

Paracetamol
TCAs
Opiates - IV heroin, methadone
Carbon monoxide - house fires

Question 8

ABC assessment in poisoning

Answer 8

-AW and gag reflex, coma position
B - RR, O2, ABG
C - pulse, BP, perfusion, IV access, IV fluids for hypotension

Question 9

What medications esp need to watch for circulatory collapse in

Answer 9

Cardiac medications eg B blockers, CCBs
Amphetamines, ecstasy, cocaine, cannabis

Question 10

What immediate history information need

Answer 10

WHEN
WHAT
Mode and duration of exposure
Symptoms

Question 11

Later information gathering in poisoning

Answer 11

WHY
Self harm?
Was it concealed
Consider - timing, precautions aainst discovery, medical help, final acts,

Question 12

Examination in poisoning

Answer 12

Skin colour
Temperature
Pulse rate and rhythm
BP
Coma scale = GCS
Pupils
Muscle tone
Tendon refleces
Resp rate
Needle marks - IVDU, hep, HIV
Blisters
Lacerations, other causes of presentation

Question 13

What would high temp signify in terms of posionings

Answer 13

Cocaine, amphetamine, ecstasy poisnoning

Question 14

What may bradycardia suggest about a poisoning

Answer 14

CCB or digoxin

Question 15

Hypertension after drug overdose what drug

Answer 15

Cocaine

Question 16

Coma/reduced RR suspect which toxins

Answer 16

Benzos, opiates

Question 17

Meoisis cause

Answer 17

Opiates
Organophosphates

Question 18

What causes dilated pupils

Answer 18

Stimulants, anticholinergics, synthetics, cannabis

Question 19

Routine investigations for overdose presentation

Answer 19

FBC, U+Es, LFTs, creatinine, blood glucose, ABG, ECG, CXR

Question 20

Tests for specific poison concentrations in drug overdose

Answer 20

Paracetemol
Salicyclate (aspirin)
CarboxylHb - CO
lithium
iron
Methanol
General urine toxicology screen has limited use

Question 21

What test for CO poisoning

Answer 21

Carboxyl Hb

Question 22

Management strategies for overdose

Answer 22

Support physiology
Prevent absorption
Specific antidote
Chelation
Enhance elimination

Question 23

What is time frame for gastric deconatmination methods

Answer 23

Little evidence useful unless used within one hour (may still use within a few hours)

Question 24

Methods for gastric decontamination

Answer 24

Activated charcoal (99%)
Gastric aspiration/lavage
Induced emesis - no longer used - perforation asp etc

Question 25

What patients cant gastric decontamination be used in

Answer 25

Unconscious or drowsy unless AW protected

Question 26

When is gastric lavage/aspiration sued

Answer 26

very large and life threatening overdoses Poisons not absorbed by activated charcoal

Question 27

What should note with gastric lavage

Answer 27

More difficult and hazardous in children Cuffed endotracheal tube in reduced GCS or drowst patients Rare niw

Question 28

Complications of gastric lavage

Answer 28

Gut perforation Aspiration Laryngospasm Water intoxication (hyponatremia) Dysrhythmias Pneumothorax Enhanced early drug absorption

Question 29

Contraindications gastric lavage

Answer 29

Hydrocarbon ingestion Caustic substance - risk of aspriation pneumonitis or perforation

Question 30

What is activated charcoal

Answer 30

Charcoal heated in steam air or CO at 600-900 degrees C - increases surface area

Question 31

How does activated charcoal work

Answer 31

Adsorbs poison in GI tract by direct contact - reduces absorption

Question 32

What is activated cahrcoal to drug ratio required to be effective

Answer 32

Variable - 8:1 Give 10 x dose of poison taken up to 50g

Question 33

How is activated charcoal administered

Answer 33

Unpalatable - suspend in flat cola NG tube - protect with cuffed endotracheal tibe if gag reflex inadequate

Question 34

Complications of activated charcoal

Answer 34

Aspiration pneumonitis Reduced absorption of therapeutic agents eg methionine Briquette formation -> bowel obstruction

Question 35

Contraindications for activated charcoal

Answer 35

Absent bowel sounds - ileus Impaired gag reflex Unsafe swallow

Question 36

What poisons is activated charcoal ineffective for

Answer 36

Elemental metals/salts - Lithium, iron, boron, salts Insecticides - malathion, DDT, N-methyl carbamate Cyanide Strong acids/alkalis alcohols Hydrocarbons

Question 37

Methods to increase drug elimination

Answer 37

Multiple dose activated charcoal Chelation Urinary alkalinisation RRTs

Question 38

Renal replacement therapies for overdose

Answer 38

Haemodialysis Haemoperfusion Haemofiltration Combined - haemofiltration, MARS

Question 39

How give MultiDACharcoal

Answer 39

50g activated charcoal further 25g every 3 hours

Question 40

What need to give with MDAC

Answer 40

Laxative/stool softener to prevent constipation

Question 41

Mechanism of MDAC

Answer 41

Reduced elimination half life by interfering with enterohepatic circulation (removes drug onto charcoal) 'GI dialysis' - onto charcoal, conc gradient OUT of lumen into GI tract nto charcoal

Question 42

What drugs does MDAC work well for

Answer 42

Carbamazepine Dapsone (antibiotic) Phenobarbitone Quinine Theophylline May use in - salicyclate, phenytoin

Question 43

When is haemodialysis and haemoperfusion useful

Answer 43

small vol of distribution Low inherent clearance rate (not naturally cleared well by kicneys) Sufficiently toxic Small enough to cross dialysis membrane More free than protein bound Can bind to activated charcoal - jaemoperfusion

Question 44

Haemodialysis and haemoperfusion

Answer 44

Haemodialysis - diffusion gradient allow poison to diffuse across semi permeable membrane Haemoperfusion - activated charcoal filter directly adsorbes poison

Question 45

Haemofiltration

Answer 45

Suction rather than filtration gradient

Question 46

What poisons is haemodialysis (on tis own) used for

Answer 46

Toxic alcohols - ethylene glycol, isopropanol, ethanol Salicyclate - aspirin Sodium valproate Lithium THallium

Question 47

What drugs can be cleared by haemodrialysis OR haemoperfusion

Answer 47

eg activated charcoal works Theophylline Phenytoin Carbamazepine Barbituates

Question 48

Paracetemol antidote

Answer 48

Acetylcysteine Methionine (glutathione repleters)

Question 49

Ethylene glycol, methanol antidotes

Answer 49

ethanol, fomepizole Aim to slow down metabolism - metabolites are toxic Competitive antagonist

Question 50

Flumexanil side effects

Answer 50

Mainly seizures

Question 51

What are chelating agents or fixing agents used to treat

Answer 51

Iron, heavy metals, cyanide

Question 52

Chelating agents

Answer 52

Desferrioxamine, dimercaprol, edetate (dicobalt or Na Ca), hydroxycalbamin

Question 53

Antidote for dapsone

Answer 53

Methylene blue

Question 54

Organophosphates atnidote

Answer 54

Pralidoxime

Question 55

Digoxin antidote

Answer 55

Digibind

Question 56

Snake bites antidote

Answer 56

Zagreb antivenom