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