YUGAL JYOTY NEPAL

MODERATOR: Dr. Rabin Sharma

January 26, 2014

CLINICAL MANIFESTATIONS

ORGANOPHOSPHORUS AND ORGANOCHLORINE POISONING

Inactivate Acetylcholinesterase

Choline Acetic acid

Increase Acetylcholine level ACh is found in the central and peripheral nervous system,

neuromuscular junctions, and red blood cells (RBCs)

How do Organophosphates work?

Increased Ach levels result in overstimulation of muscarinic and nicotinic receptors

Overview

of

muscarinic

receptors

Overview

of

muscarinic

receptors

contd…

Overview

of

nicotinic

receptors

Organophosphates can beabsorbed cutaneously ingested inhaledinjected

Routes of absorption

Although most patients rapidly become symptomatic, the Onset and Severity of symptoms depend on

specific compound

amount

route of exposure and

rate of metabolic degradation

Signs and symptoms of organophosphate poisoning can be divided into 3 broad categories

1.muscarinic effects

2.nicotinic effects

3.CNS effects

SLUDGE salivation, lacrimation, urination, diarrhea, GI upset, emesis

DUMBELS diaphoresis and diarrheaurinationmiosisbradycardia, bronchospasm, bronchorrhea emesisexcess lacrimationsalivation

MUSCARINIC effects

Muscarinic effects by organ systems include the following:

Cardiovascular - Bradycardia, hypotension

Respiratory - Rhinorrhea, bronchorrhea, bronchospasm, cough, severe respiratory distress

Gastrointestinal - Hypersalivation, nausea and vomiting, abdominal pain, diarrhea, fecal incontinence

Genitourinary - Incontinence

Ocular - Blurred vision, miosis

Glands - Increased lacrimation, diaphoresis

muscle fasciculations cramping Weakness and diaphragmatic failure

Autonomic nicotinic effects include Hypertension Tachycardia Mydriasis Pallor

NICOTINIC effects

anxiety

emotional liability

restlessness

confusion

ataxia

tremors

seizures

coma

CNS effects

Organic chlorines are strongly lipid soluble and sequester in body tissues with high lipid content, such as the brain and liver

Consequently, blood levels tend to be much lower than fatty tissue levels

The lipophilic tendency of organochlorines accounts for prolonged systemic effects in overdose

ORGANOCHLORINES

Ingestion

Skin absorption or inhalation

Chronic exposure

Routes of absorption

Ingestion produces the following manifestations:

Nausea and vomiting

Confusion, tremor, myoclonus, coma, and seizures

Respiratory depression or failure

Unusual odor

Skin absorption or inhalation produces the following manifestations:

Ear, nose, and throat irritation

Blurred vision

Cough

Acute lung injury (ALI)

Dermatitis

Long-term occupational exposure to organochlorine pesticides may result in various nonspecific symptoms - headaches, nausea, fatigue, muscle twitching, and visual disturbances

In addition, chronic exposure to these agents may be associated with the development of blood dyscrasias, including aplastic anemia and leukemia

Other manifestations of chronic exposure are as follows:AnorexiaHepatotoxicityRenal toxicityCNS disturbances

Onset – abrupt

 CNS excitation and depression are the primary effects observed in acute organochlorine toxicity - The patient may appear agitated, lethargic, intoxicated, or may even be unconscious

Initial euphoria with auditory or visual hallucinations and perceptual disturbances are common in the setting of acute toxicity.

Presentation

Laboratory estimation of blood cholinesterase and OP levels are not available in many developing countries

POP score can assess severity without laboratory investigation

Also patient co-ordination not required

The score is given when the patient first presents in the hospital

Nimal Senanayake, H.J. de Silva Kaealliedeand Laxman Karalleidde (Department of Medicine, Faculty of Medicine, University of Perdeniya, Sri Lanka and Queen

Elizabeth Military Hospital, London, UK)

Peradeniya Organophosphorus Poisoning (POP) scale

Parameter Score

1. Miosis

Pupil size >2mm 0

Pupil size <=2mm 1

Pinpoint pupil 2

2. Fasciculation

None 0

Present but not generalized or continuous 1

Generalised and continuous 2

3. Respiration

Respiratory rate <=20/min 0

Respiratory rate >20/min 1

Respirator rate >20/min with central cyanosis 2

4. Bradycardia

Pulse rate >60/min 0

Pulse rate 41-60/min 1

Pulse rate <=40/min 2

5.Level of consciousness

Conscious and rational 0

Impaired, responds to verbal command 1

Impaired, no response to verbal command 2

If convulsions present, add 1

TOTAL 11

POP score 0-3 : Mild

POP score 4-7 : Moderate

POP score 8-11 : Severe

Based on results from the initial study, severe intoxications (score of 8 to 11) have a higher mortality rate

Require greater need for ventilatory support, and higher dose of atropine in the first 24 hours.

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