organophosphorus and organoochlorine poisoning clinical features
TRANSCRIPT
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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