ORGANOPHOSPHATE/CARBAMATE POISONING PROTOCOL
KAMUZU CENTRAL HOSPITAL
Objectives:
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To monitor and support patients with organophosphate/carbamate poisoning
To minimise the risk of secondary contamination to healthcare workers and carers
Overview:
Organophosphates are an extremely toxic group of chemicals, commonly found in many pesticides. There are
many different compounds, but all are very well absorbed, whether ingested, which is the most serious,
or via skin, mucous membranes or inhalation. Poisoning with organophosphate insecticides commonly occurs
from accidental or intentional ingestion or over exposure of users during spraying.
The organophosphates exert their toxicity by binding to (phosphorylating) and therefore inactivating
body acetylcholinesterases. This leads to a build-up of acetylcholine (local toxicity of acetylcholine), which
causes mixed autonomic effects and paralysis at the neuromuscular junction. The binding is initially reversible,
but with time “ages” and becomes irreversible.
Onset and duration of AChE inhibition varies depending on the organophosphorous agent. The great
variability in toxicity and treatment response among organophosphorous agents, however, is not well
understood.
MANAGEMENT:
General Considerations
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Large doses of atropine and pralidoxime will be required in severe poisoning – ensure adequate supply
in Poisons Box.
Admit patient to HDU
Organophosphates are well absorbed from skin, oral mucous membranes, conjunctiva, respiratory and
GI routes. Until decontamination minimal staff necessary should come in contact with the patient.
All body fluids (eg. vomitus, faeces) once external are contaminates and can be regarded as chemical
spills and should be considered poisonous.
On Admission
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All staff involved in the admission must wear long-sleeved gowns, Masks, goggles and gloves
The first priority is patient stabilisation
Patient decontamination should be carried out as soon as possible once the patient is stabilised
and concurrently with resuscitation.
Initial Resuscitation and decontamination
AIRWAY/RESPIRATORY
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Likely to require short term ventilation if significant but survivable exposure  contact ICU for urgent
consult
Respiratory compromise can occur secondary to muscle weakness, decreased central drive, increased
secretions or bronchospasm.
References:
1. COLLINS, S. 2012. RDH ICU: Guidelines - ORGANOPHOSPHATE POISONING. Darwin, Australia.
2. Uptodate Online Topic 339 Version 10.0
Other readings:
1. Leikin, J. et al: a review of nerve agent exposure for the critical care physician. Crit Care Med
2002; 30(10) 2346-2353
2. Stacey, R. Morfey, D. and Payne, S. Secondary contamination in organophosphate poisoning: analysis of
an incident. Q J Med 2004; 97:75-80
3. Little, M. and Murray, L. Consensus Statement: risk of nosocomial organophosphate poisoning in
emergency departments. Emergency Medicine Australasia 2004; 16 456-458
4. Wiener, S. and Hoffman, R. nerve agents: a comprehensive review. Journ Intens Care Med 2004; 19 2236