Poisoning

Question 1

Name 5 medications with delayed reaction

Answer 1

Aspirin, paracetamol, iron, TCAs, co-phenotrope

Question 2

When should O2 be given at the highest conc possibl?

Answer 2

In carbon monoxide poisoning and irritant gases

Question 3

What happens if BP drops to below 70?

Answer 3

Irreversible brain damage, renal tubular necrosis

Question 4

Which 3 classes of drug are more likely to cause cardiac conduction defects?

Answer 4

TCAs, antipsychotics, antihistamines

Question 5

Management of hyperthermia

Answer 5

Remove all unnecessary clothing, fan, sponge with tepid water

Question 6

What might cause hyperthermia?

Answer 6

CNS stimulants
Serotonin syndrome
Children taking antimuscarinics

Question 7

What might cause hypothermia?

Answer 7

After deeply unconscious for hours
eg OD barbiturates or phenothiazines
(eg secobarbital or prochlorperazine)

Question 8

Management of methaemoglobinaemia?

Answer 8

Methylthioninium chloride if hypoxic despite O2 or conc >30%

Question 9

When is activated charcoal useful?

Answer 9

To prevent absorption if drug taken very recently (up to 1hr post ingestion)
To enhance elimination of drugs such as carbamazepine, dapsone, phenobarbital, quinine, theophylline

Question 10

When should activated charcoal be avoided?

Answer 10

Petroleum distillates, corrosive substances, alcohols, malathion, cyanides and metal salts (including iron and lithium)

Question 11

When is haemodialysis used in poisoning?

Answer 11

Ethylene glycol
Lithium
Methanol
Phenobarbital
Salicylates
Sodium valproate

Question 12

What is done in salicylate poisoning?

Answer 12

Activated charcoal if within 1hr and >125mg/kg ingested
Haemodialysis considered (if>700mg/litre)
Alkalinisation of urine (IV bicarbonate)

Question 13

When is gastric lavage indicated?

Answer 13

Only in severe cases of poisoning where activated charcoal cannot be used
Iron and Lithium

Question 14

What are the features of salicylate poisoning?

Answer 14

Hyperventilation (respiratory alkalosis)
Followed by metabolic acidosis
Tinnitus
Deafness
Vasodilation
Sweating

Question 15

When is salicylate poisoning severe?

Answer 15

> 500mg/L conc

Metabolic acidosis

Question 16

When should activated charcoal be given in salicylate poisoning?

Answer 16

Within 1hr of ingesting >125mg/kg aspirin

Question 17

Features of opioid OD

Answer 17

Coma, resp depression, pin point pupils,

Question 18

Antidote to opioids?

Answer 18

Naloxone hydrochloride

IV infusion and monitoring

Question 19

Danger of paracetamol OD?

Answer 19

Severe hepatocellular necrosis
Renal tubular necrosis
Liver damage maximal 3-4days post ingestion
Encephalopathy, haemorrhage, hypoglycaemia, cerebral oedema, death

Question 20

Management of paracetamol poisoning

Answer 20

Hospital if >75mg/kg
Treat if >150mg/kg in less than 1hr
Acetyl cysteine protect liver if infused up to 24hrs post ingestion. Most effective for 8hrs post ingestion (augments glutathione levels)

Question 21

When do you measure a paracetamol level?

Answer 21

4 hrs post ingestion

Use a graph w/the treatment line

Question 22

Name 11 features of TCA OD

Answer 22

Dry mouth
Coma & convulsions
Hypotension
Hypothermia
Hyperreflexia
Respiratory failure
Conduction defects & arrhythmias
Dilated pupils
Urinary retention

Question 23

Name 8 features of SSRI OD

Answer 23

Agitation
Tremor
Nystagmus
Drowsiness
Sinus tachycardia
Convulsions
n&v

Question 24

What is serotonin syndrome?

Answer 24

Neuropsychiatric effects
Neuromuscular hyperactivity
Autonomic instability
Hyperthermia
Rhabdomyolysis
Renal failure
Coagulopathies

Question 25

What is the antagonist to bezodiazepines?

Answer 25

Flumazenil

Question 26

In massive beta blocker OD what is needed?

Answer 26

Atropine to treat bradycardia IV glucagon if still in cardiogenic shock If still, IV isoprenaline or pacemaker

Question 27

Features of CCB OD

Answer 27

N+v+d Agitation, confusion, coma Metabolic acidosis and hyperglycaemia Hypotension (cardiac depression)

Question 28

Management of CCB OD

Answer 28

Activated charcoal within 1 hr Calcium chloride/gluconate Atropine

Question 29

Management of iron OD

Answer 29

IV desferrioxamine mesilate (chelates iron)

Question 30

Management of lithium OD

Answer 30

Haemodialysis Increase urine output (fluids) Supportive care (electrolytes, convulsions ec) Gastric lavage?

Question 31

Features of lithium OD

Answer 31

Apathy, restlessness Ataxia, weakness, dysarthria, muscle twitching Excess of 2mmol/L = poisoning

Question 32

Stimulant OD?

Answer 32

``` Early stage (mania)-> lorazepam/diazepam Late stage (exhaustion hyperthermia)=> tepid sponging, anticonvulsants, ventilation ```

Question 33

Effects of cocaine

Answer 33

Agitation, dilated pupils, tachycardia, hypertension, hallucinations, hyperthermia, hypertonia, and hyperreflexia; cardiac effects include chest pain, myocardial infarction, and arrhythmias.

Question 34

Serious SE of ecstasy

Answer 34

Delirium, coma, convulsions, ventricular arrhythmias, hyperthermia, rhabdomyolysis, acute renal failure, acute hepatitis, disseminated intravascular coagulation, adult respiratory distress syndrome, hyperreflexia, hypotension and intracerebral haemorrhage Self induced water intoxication

Question 35

Management of theophylline OD

Answer 35

``` Repeated activated charcoal Ondansetron for vomiting KCl for hypokalaemia Lorazepam for convulsions Diazepam for sedation If not asthmatic: B-blocker ```

Question 36

Management of cyanide poisoning

Answer 36

O2 Dicobalt edetate if strong clinical suspicion of severe cyanide poisoning Hydroxocobalamin for smoke inhalation victims

Question 37

Management of ethylene glycol or methanol OD

Answer 37

Fomepizole | Ethanol

Question 38

Management of carbon monoxide poisoning

Answer 38

``` Clear airway 100% O2 NIV? Cerebral oedema-> mannitol ? hyperbaric O2 chamber ```

Question 39

Management of organophosphate poisoning

Answer 39

Atropine | Pralidoxime chloride