T60.0 + (X48.99/X68.99/Y18.99)
*Notifiable condition.
DESCRIPTION
Absorption occurs through the skin, when the agent is taken orally, or by inhalation.
Patients present with muscarinic and nicotinic manifestations of intoxication.
- Peripheral effects:
- Muscarinic overstimulation: bradycardia, hypotension, salivation, lacrimation, vomiting, diarrhoea, increased bronchial secretions, bronchospasm and miosis (pin point pupils).
- Nicotinic overstimulation: muscle weakness and fasciculations, tachycardia, hypertension, mydriasis (dilated pupils).
- Central effects: coma, confusion, convulsions
Diagnosis is supported by low serum pseudocholinesterase levels.
Intermediate syndrome can occur within 1-4 days after recovery from cholinergic crisis. Patients develop weakness or paralysis predominantly affecting the muscles of respiration (including the neck flexors and bulbar muscles) and proximal limb muscles, sparing the distal muscles. Cranial nerves may also be affected. Supportive care is the mainstay of therapy.
Refer if ventilatory support is unavailable.
Where the history is of an unspecified rat poison or pesticide ingestion, consider other active ingredients such as super-warfarin anticoagulants and amitraz.
GENERAL MEASURES
Ensure use of personal protective equipment for staff – gloves, gowns and eye protection. If staff come into contact with body fluids, wash off immediately.
Decontamination procedures for the patient should only be done once the patient is fully resuscitated.
Remove patient’s clothes and wash the body with soap and water. Place clothes in closed bags.
Maintain adequate ventilation and circulation. Ventilatory support in ICU may be required. Suction secretions frequently. If using suxamethonium for intubation, consider that metabolism may be delayed and prolonged respiratory support may be required. Use alternative agents if possible (See Muscle relaxants ).
MEDICINE TREATMENT
- Activated charcoal, once patient is stabilised.
For bronchorrhoea, bronchospasm or bradycardia:
- Atropine bolus, IV, 2–5 mg,LoEII [62]
- Reassess after 3–5 minutes for evidence of atropinisation as indicated by reduced bronchial secretions, dry skin, increasing heart rate and blood pressure, and dilating pupils (note: pupil dilatation may be delayed)
- Give repeated atropine boluses incrementally doubling the dose until adequate clinical response achieved, e.g. 2 mg, 4 mg, 8 mg, 16 mg etc.
- If no clinical response, give double the dose.
- If some response, give the same or reduced dose.
- Follow with infusion. Calculate the total dose of atropine given as boluses (as described above). Give 10–20% of this dose per hour.
- Reassess frequently and adjust atropine infusion as follows:
- Bronchial secretions, bronchospasm or bradycardia recurs: increase dose.
- Good control of bronchial secretions and signs of atropine overdose (tachycardia, mydriasis, agitation, pyrexia, reduced bowel sounds and urinary retention): decrease dose.
- No recurrence of bronchial secretions and no signs of atropine overdose: reduce dose slowly.
Note: Do not stop atropine infusion abruptly, but wean over at least 24 hours. Tachycardia and mydriasis are not contraindications for giving atropine in the acute resuscitation setting.
For severe agitation:
- Diazepam, IV, 5–10 mg, immediately.
- Repeat after 30–60 minutes if needed.
REFERRAL
Refer if ventilatory support is unavailable.