Poisoning

Causes

Organophosphates (carbamate)
Local medicines
Petroleum compounds: paraffin
Carbon monoxide
Plants ("magic mushrooms")
Bleach
Snake bite
Iron Poisoning
Salicylate overdose

Important points in history

Remember there may not be a clear history

Sudden unexplained illness in previously healthy child
Unusual behaviour
Try to establish the potential poison that the patient may have had exposure to
Enquire about quantity exposed to/ taken
Earliest possible exposure time
Ask if container or sample of poison available
Other children involved? If so, what symptoms do they have?
Ask about access to "poisons"

Important points in examination

Drowsiness/ coma/ BCS
Convulsions (organophospates)
Diarrhoea (if a child is dehydrated, but salivating ++ consider organophosphate poisoning, with pin point pupils)
Hypersecretions and noisy wet breathing: organophosphate poisoning
Pupillary abnormalities - pin-point pupils (organophosphate poisoning, sometimes mushooms); dilated pupils (barbiturates)
Ataxia
Tachypnoea/ tachycardia or flushing/ bradycardia (organophosphate poisoning)
Wheezing (paraffin inhalation)
Cardiac arrhythmia or hypotension
Presence of burns within the mouth (bleach or acid with oesophageal injury)
Stridor (laryngeal damage)
Abdominal distension (local medicine intoxication)
Acidotic

Investigations

Mainly depend on the presentation and specific poison exposure

Indications for admission

Exposure to potentially fatal poison
Ill/ haemodynamically unstable patient
Deliberate poisoning
Consider observation in short stay if well otherwise

Management

Primary assessment (ABCD) to recognize life-threatening emergencies
Resuscitate/ stabilize the patient if necessary
Assess potential lethality of the overdose
Definitive management of specific condition once stabilized
Reassess ABCD at frequent intervals to assess progress/ detect deterioration
Test for hypoglycaemia, if present treat with 5 ml/kg 10% glucose IV or PO
Treat convulsions
Give maintenance IV fluids
Use antidote for specific poison if available (see below)
Use activated charcoal (1g/kg), except for heavy metals, if available
Gastric lavage (used occasionally for ferrous sulphate poisoning) only if:
a potentially fatal dose has been taken
the airway is protected
Avoid if reduced level of consciousness, and in hydrocarbons or corrosives

DO NOT induce vomitingTreatment of specific poisonsOrganophosphate compounds

Cholinergic signs: DUMBELS: Defecation, Urination, Miosis, Bronchorrhea/Bronchospasm/Bradycardia, Emesis, Lacrimation, Salivation. Also, fasciculations, muscle weakness and paralysis

Get rid of poison
Eyes (irrigation)
Skin (remove clothing) and bathe
Specific treatment
Atropine 20 micrograms/kg IV or IM every 15 min until secretions have stopped and the chest is dry
Monitor regularly (respiratory rate, coma score, heart rate, secretions) e.g. every 15 minutes initially, then every 30 minutes
Assisted ventilation if necessary

Local medicines

Usually taken for diarrhoea and vomiting. May lead to acidosis, respiratory distress, paralytic ileus.

Rehydration i.e. give IV fluids and glucose
Pass an NGT and leave on free drainage

Petroleum compounds (Paraffin)

Frequently presents with features of respiratory distress. May cause pneumonitis, pneumomediastinum, pneumothorax and subcutaneous emphysema.

Do not induce vomiting
Give oxygen if necessary
Chest x-ray if symptomatic
Antibiotic therapy may be needed for secondary chest infections

Carbon monoxide poisoning

Toxic effects are due to hypoxia. Oxygen saturations can be misleading.

Give 100% oxygen

Poisonous plants

Usually only small quantities are ingested

Mainly supportive and activate charcoal if available

Bleach

Liberal fluids and milk
Do not induce vomiting

Snake bite

Check for fang marks, note if scarifications present or not
Look for evidence of use of a tourniquet
Ask about time of bite
Check bitten limb for swelling, pulses, colour and viability
Check for systemic evidence of envenoming - fever, altered coma score, shock, anaemia
Mark with a pen, the level of swelling on a limb so that further swelling can be assessed

Management

ABC
FBC and diff, blood culture and blood clotting time (see how long it takes for blood to clot in a plain tube)
Group and cross match and hold blood unless anaemic
Place an IV infusion of normal saline
Check that tetanus toxid immunisation is up to date; if not give it. Immunisation protocol

If local swelling is marked or there is evidence of systemic envenoming:

Inform senior. Anti snake venom will be required
Give 40mls in 200mls of normal saline IV over 1hr but have adenaline standing by: anaphylactic reactions are not uncommon.
If circulation is threatened inform the surgical team on call as compartment syndrome may need fasciotomy.
Treat pain appropriately - morphine may be needed

Iron poisoning

Gastrointestinal (GI) phase: 30 minutes to 6 hours after ingestion
Latent, or relative stability, phase: 6 to 24 hours after ingestion
Shock and metabolic acidosis: 6 to 72 hours after ingestion
Hepatotoxicity/hepatic necrosis: 12 to 96 hours after ingestion
Bowel obstruction: 2 to 8 weeks after ingestion
Supportive therapy to maintain adequate blood pressure and electrolyte balance is essential
I.V. fluid resuscitation
May need potassium and glucose supplementation
Consider desferrioxamine 15mg/kg/hr I.V. if available
If oliguria or anuria develop, take sample for U&E, monitor BP, catheterise andconsider peritoneal dialysis

Salicylate overdose

Presents with tachypnoea, metabolic acidosis, and to a lesser extent, tachycardia. Early symptoms include tinnitus, vertigo, nausea, vomiting, and diarrhoea.

More severe intoxication can cause fever, altered mental status, coma, non-cardiogenic pulmonary oedema, and death.

ABC
Administer multiple doses of activated charcoal (first dose: 1 g/kg orally up to 50 g)
Administer supplemental glucose in patients with altered mental status, even if serum glucose concentration is normal: IV dextrose 50 g as 100 mL of 50 percent dextrose
Send U&E and RBS
Correct electrolyte abnormalities
Consider peritoneal dialysis