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Compliance with this guideline is recommended Page 1 of 9

Guideline

Organophosphate Poisoning: Emergency Department

Management of Organophosphate Poisoning

Document No: SSW_GL2007_003

Functional Sub-Group: Clinical GovernanceCorporate Governance

Summary: This guideline is for use only in the case of knownorganophosphate exposure.

Approved by: Director Clinical Governance / Clinical Quality Council

Publication (Issue) Date: November 2007

Next Review Date: November 2009

Replaces Existing Guideline: Yes (distributed as correspondence)

Previous Review Dates: November 2006

Note: Sydney South West Area Health Service (SSWAHS) was established on 1 January 2005 withthe amalgamation of the former Central Sydney Area Health Service (CSAHS) and the formerSouth Western Sydney Area Health Service (SWSAHS).

In the interim period between 1 January 2005 and the release of single Area-wide SSWAHSguidelines (dated after 1 January 2005), the former CSAHS and SWSAHS guidelines wereapplicable as follows:-

SSWAHS Eastern Zone : CSAHS

SSWAHS Western Zone: SWSAHS


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Sydney South West Area Health Service Guideline No: SSW_GL2007_003Date Issued: November 2007


ORGANOPHOSPHATE POISONING: EMERGENCY DEPARTMENT

MANAGEMENT OF ORGANOPHOSPHATE POISONING

CONTENTS

1. Background............3

2. Outcome..3

3. Guideline Statement...3

4. Triage Process3

4.1 Decontamination Advice4.2 General Notes Regarding Nosocomial Risk for Staff Involved in Treatment

5. Clinical Information to guide the treatment of the Poisoned Patient..5

5.1 Poisoning5.2 Excretion5.3 Mode of Action / Response5.4 Systems Affected5.5 Symptoms and Signs of Cholinergic Excess

6. Grading of Severity of Poisoning.6

7. Emergency Department Initial Management..7

8. Laboratory Tests.7

9. DrugTherapy.7

10. Monitoring and Observation..8

11. Transfer from ED8

12. Holding and Disposal of Poison and Clothing / Leather Items8

13. References...9


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ORGANOPHOSPHATE POISONING: EMERGENCY DEPARTMENT MANAGEMENT OF

ORGANOPHOSPHATE POISONING

1. Background

This guideline should be used only in the case of known organophosphate (OP)exposure and does not apply to the situation of exposure to an unknown toxicsubstance.

2. Outcome

The safety of all staff, patients and visitors to the Health Service is maintained duringthe acute treatment of a patient with suspected or known organophosphate exposure.

The person presenting to the Emergency Department will receive timely, efficient andeffective health care.

3. Guideline Statement

All care provided within the Sydney South West Area Health Service(SSWAHS) will be in accordance with infection control guidelines, manualhandling guidelines and minimisation and management of aggressionguidelines.

Resuscitation and further treatment should ideally take place in a well-ventilated area with regular rotation of staff.

Only staff treating the patient should be within the immediate proximity of thepatient.

All staff with direct patient contact should observe standard precautions normal gloves, gowns, eye protection and normal mask (where required).Staff must have protective equipment on prior to commencing treatmentincluding mask, gloves, gowns and eye protection

Patients with skin exposure should undergo external decontamination assoon as practicable: clothes removed and bagged, and the person washedwith soap and water. This process should take place immediately but not tothe detriment of timely resuscitation and medical assessment.

Patients with internal exposure (inhalation / ingestion) should be triaged andmoved immediately to the resuscitation area for initial assessment andmanagement.

Staff who are in direct contact with patients bodily secretions shouldimmediately and thoroughly wash the affected area with soap and water.

Other patients particularly those who have respiratory problems should beremoved from the area

4. Triage Process

Treatment is to be instituted immediately based upon the clinical picture of

organophosphate poisoning.

In the case of dermal / inhalation exposure:


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If stable at presentation, the patient should be sent to a supervised showerfor decontamination.

If unstable, triage immediately to resuscitation area for treatment anddecontamination after stabilisation.

Samples of the product brought with the patient should be placed in anappropriately sized and sealed bag and clearly labelled with the patient'sidentification label and be clearly marked as POISON.

Senior clinical advice should be sought early by the use of local clinical expertise(where available). An alternate source of clinical expertise and advice is thePoisons Information Centre on 13 11 26: an on-call clinical toxicologist isavailable 24hours, 7 days a week.

4.1 Decontamination Advice

If the person has skin contamination, then the persons clothes should beremoved and placed in a contaminated waste bag and the person washed withsoap and water.

Skin - contamination of skin, clothing, hair, eyes.

Flush the chemical from the eyes with copious amounts of sterile0.9% sodium chloride solution.

Remove clothing and wash patient / shampoo hair, using copiousamounts of soap and water.

Ensure skin folds and underneath of f ingernails are cleansed. Contaminated leather articles should be removed (including watch

bands) and placed with the patient's clothing in an appropriately sizedand sealed bag and clearly labelled with the patient's identificationlabel and be clearly marked as Contaminated Personal Belongings.

Soapcontaining chlorhexidine and alcohol helps remove lipophiliccompounds.

For ingestion, there may be minor contamination from spillage or vomitusthat may require local decontamination.

4.2 General Notes Regarding Nosocomial Risk for Staff Involved in Treatment

There are no case reports of actual poisoning occurring when staff care fora patient with OP poisoning.

However, the hydrocarbon solvent (not the organophosphate compound)associated with OPs may cause self limiting symptoms for staff caring forthe OP poisoned patient. The hydrocarbon is commonly associated with anoxious odour.

Staff should be rotated out of the clinical area if they become symptomaticfrom this exposure.


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5. Clinical Information to Guide the Treatment of the Poisoned Patient:

5.1 Poisoning

Organophosphates are toxic chemicals that may be ingested, inhaled or

absorbed.

5.2 Excretion

Metabolism is via hydrolysis in the liver.

Some organophosphates are readily stored in body fat and are releasedslowly and intermittently, resulting in delayed symptoms.

5.3 Mode of Action / Response

Organophosphates cause irreversible inhibition of the enzyme

acetylcholinesterase. Carbamates (including physostigmine, neostigmine and edrophonium

(Tensilon) are reversible inhibitors of the enzyme acetylcholinesterase.

Inhibition of acetylcholinesterase allows the neurotransmitter acetylcholine(ACh) to remain active in the synapse - resulting in sustaineddepolarisation of the post-synaptic neuron.

5.4 Systems Affected

1. Central Nervous System: Sensory and behavioural disturbances,incoordination, depressed motor function, coma and possible seizureactivity.

2. Muscarinic Sites in the Peripheral Nervous System: Sustainedstimulation of the parasympathetic nervous system where nerve junctionswith smooth muscle and gland cells are stimulated causing:

Contraction of intestinal and bronchial smooth muscle - diarrhoea,vomiting, bronchospasm, bronchorrhoea.

Decreased pupil size - miosis, absent pupillary reflex.

Increased secretions from all secretory glands - lacrimation,salivation.

Decreased sinus node activity, bradycardia, AV conduction defects,occasional ventricular arrhythmias.

3. Nicotinic sites in the sympathetic and parasympathetic ganglia and

nicotinic sites at the neuromuscular junction these sites arestimulated and then depressed:

Excess ACh may be excitatory (causing muscle twitching) but athigher levels it may also weaken and paralyse the cell by depolarisingthe motor endplate.

Sympathetic stimulation may result in tachycardia, hypertension, thenhypotension.

Respiratory depression and pulmonary oedema are the usual causes of deathwithout prompt intervention.


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5.5 Symptoms and signs of cholinergic excess:

Secretions: tears, saliva, sputum, gastric acid and perspiration.

Respiratory symptoms: wheeze, cough, shortness of breath, large mucous

production (bronchorrhea), decreased respiratory muscle function. Neurological symptoms: seizure, coma, delirium, respiratory centre

depression, fasciculation, ataxia, long-term neuropsychiatric sequelae,depression, and peripheral neuropathy.

GIT: diarrhoea, vomiting, pancreatitis (spasm of the sphincter of Oddi,check serum amylase).

CVS: increased and unbalanced autonomic outflow (especially vagal),tachy and brady arrhythmias, Torsades de Pointes VT, hypo/hypertension.

Onset of symptoms is usually within 12 hours of exposure (exception:highly fat-soluble OP esters).

6. Grading of Severity of Poisoning

Mild Moderate Severe

Walks and talks.

Headache, dizzy.

Nausea andvomiting.

Abdominal pain.

Sweating,salivation.

Rhinorrhoea.

Serumacetylcholinesteraseenzyme (ACHe) is20-50% of normal.

Cannot walk.

Soft voice.

Muscle twitching.(fasciculation)

Weakness.

Anxiety,restlessness.

Small pupils(miosis).

Serumacetylcholinesteraseenzyme (ACHe) is10-20% of normal.

Unconscious, nopupillary reflex.

Muscle twitching,flaccid paralysis.

Increased bronchialsecretions.

Dyspnoea,crackles/wheeze.

Possibleconvulsions.

Respiratory failure.

Serumacetylcholinesteraseenzyme (ACHe) is < 10%of normal.

7. Emergency Department Init ial Management

Airway:goal of therapy - airway protection, prevention of aspiration, clearance ofsecretions and adequate ventilation.

If unable to protect airway - intubate and ventilate.

If using non-depolarising NMBs, there may be delayed onset with higherdosage required to obtain the desired effect.

Breathing:risk of weakness / paralysis of respiratory muscles combined withsecretions leading to respiratory failure.Improve tissue oxygenation withsupplemental oxygen and administration of atropine eliminating hypoxiaminimises the risk of ventricular fibrillation.


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Pralidoxime is used in moderate / severe poisoning where impaired respiratoryfunction or seizures / coma occur.

Do not use in carbamate poisoning (as in neostigmine, physostigmine, Tensilon).

Delayed presentation of a symptomatic patient is not a contraindication to theuse of pralidoxime.

Initial dose of 2grams IV over 30 minutes. In mild to moderate poisoning, administer 1gram IV every 8 hours.

In severe poisoning the infusion rate is at 500mg/hour: 1gram in 40mL (total of50mL) at 25mg/hour (20mL/hour).

Pralidoxime is metabolised by the liver and excreted by the kidneys.

Drug Contraindications: Do not prescribe / administer morphine, theophylline,phenothiazines, reserpine.

Pain Relief: Administer paracetamol and non-opioid analgesia for relief of musclepain.

10. Monitor ing and Observation:

Observations should include continuous ECG, NIBP and SpO2monitoring.

The patient may require intra-arterial BP and CVP monitoring if more severelyaffected.

Observe for deterioration post reduction of drug therapies, auscultate lung basesfor crackles.

Continuous monitoring is required for 72 hours or longer.

11. Transfer from ED

The patient should be admitted under the care of a Toxicologist or Physician (asper usual local arrangements).

Ensure admission is to the Intensive Care.

There is no need for isolation of the patient.

The odour due to hydrocarbons can be managed by regular staff rotations.

Where intentional harm relating to OP poisoning is considered, ensurepsychiatric referral for later assessment is made.

The ED bay is to be cleaned with dilute hypochlorite (bleach) solution.

12. Holding and Disposal of Poison and Clothing/Leather Items

Patients bringing into the ED a container with the OP that has occasioned thepoisoning are to have the item placed in an appropriately sized and sealed bagand clearly labelled with the patient's identification label and be clearly marked asPoison.

This bag is retained within the ED until such time as it is no longer required forforensic examination, as per the ED consultant (and police investigators - whereindicated).

The patient's clothing and all leather items (watch band, necklaces, shoes etc)are to be placed in an appropriately sized and sealed bag and clearly labelledwith the patient's identification label and be clearly marked as ContaminatedPersonal Belongings.


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These belongings are retained within the ED until such time as they are nolonger required for forensic examination, as per the ED consultant (and policeinvestigators - where indicated).

Once Forensic Examination has been satisfied (and there is no need for theclothing / leather to be given over to Police Investigation) or is not required, the

clothing and leather is to be disposed of in general waste. Family / Carers are to be informed of the necessity for the disposal of clothing

and leather items, and their disposal and conversation with the familyrepresentative / carer is to be documented in the health care record.

The name of the person to whom you have explained the need for disposal ofclothing and leather items is to be documented in the health care record.

13. References

Consensus statement: Risk of nosocomial organophosphate poisoning in emergency

departments. M.Little. L Murray, EMA:(2004) 16, 456458.Liverpool ICU Policy and Procedure manual.

Guideline Author(s):Dr John Sammut, on behalf of OP Working Party for SSWAHS

Guideline Reviewers:ED Directors, ED CNCs, ED Nurse Practitioners, Area/ZoneToxicologist.

Guideline Publication Date: January 2007. Date for Review:January 2009.

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