Poisoning refers to development of harmful effects following exposure or ingestion of chemicals. Overdose refers to excessive amounts of a substance or drug normally intended for therapeutic use. It may be LOCAL. SYSTEMIC or BOTH.
Self poisoning with pesticides, drugs or parasuicide are the commonest causes of emergency admission in adults whereas in children it is accidental or intentional.
Diagnosis
• History: To include time, route, duration and circumstances of exposure, name and amount of drug or chemical, medical and psychiatric history. The clothes and other patient's belongings, or even suicide note are useful.
• Physical examination: Focus on vital signs, cardiopulmonary and neurologic status -assess pupillary size, mental state, focal deficits, tendon reflexes, nystagmus
• Toxicology studies are not always conclusive.
General and specific measures should be taken prior to toxicology and confirmation |
Management
General Principles
• Identify the poison; container brought or found near patient, history
• Immediate supportive care: (DO NOT DELAY)
- airway protection e.g. lateral position, suction, intubation
- oxygenation/ventilation - avoid mouth to mouth ventilation
- circulatory support -IV line and fluids, maintain Blood Pressure [see 1.10. shock]
- manage convulsions [see 4.2. seizure disorders]
• correct temperature abnormalities
• Prevent further poison absorption:
- skin decontamination - remove all clothes, wash with soap and water
- gastrointestinal decontamination: emesis - contraindicated in infants, unconscious patients, corrosives and petroleum products
- gastric lavage (as above)
Specific Measures
• Enhanced poison elimination
- activated charcoal 1 gm/kg
- Dialysis
- haemoperfusion
- forced diuresis
- chelation.
These should be performed in specialised centres
• Antidotes administration [see table on common poisons and treatment in the next page]
• Prevent re-exposure:
- adult education
- child-proofing
- psychiatric referral
