Management protocol for organophosphorus compounds intoxication

1. BY
KEROLUS EKRAM GAD SHEHATA
• PGY-III IM RESIDENT, AIN SHAMS UNIVERSITY.
• ECFMG CERTIFIED
Management protocol for
Organophosphorus Intoxication

2. General hints
 Frequency of exposure: Very common and usually
seasonal.
 Mode of toxicity: Suicidal or Accidental.
 Most common types: Organophosphorus pesticides e.g.
Malathion and other household products used to kill
home pests.
 N.B. Pyrosol, Baygon, Raid insecticides: They are usually
safe and rarely cause acute systemic toxicity But you
should take care of eye exposure and any respiratory
compromise if inhalation occurs. If fluids manage as a
hydrocarbon with a potential risk for aspiration.

3. Presentation tricks
 History: No clear history or even fake history is given so, a
high depend on the manifestations you see rather than
the story you hear.
 symptoms: Don’t expect to see the full blown picture of
cholinergic or nicotinic manifestations in every case, It
highly depends on many factors e.g. type &
concentration of the toxin, amount, age, any pre-hospital
intervention like giving small dose of atropine that could
mask the symptoms for awhile.

4. Clinical Manifestations
 Cholinergic symptoms: vomiting, diarrhea, salivation
 Nicotinic symptoms: Weakness
 Cholinergic signs: Secretions everywhere But the one you
should assess is the Pulmonary secretions. Also, there will
be miotic +/- pinpoint pupil.
 Nicotinic signs: Weakness and fasciculations.
 N.B. you will see the fasciculations in the small muscles
e.g. peri-ocular, peri-oral, cheeks & platysma.
 Weakness: assess for the possibility of aspiration and the
need for ETT.

5. General concepts in clinical management
 We are managing a patient not a toxin. So, our primary
target is to STABILIZE the patient’s current condition with
the ABCD.
 Retake the history to make sure there is no co-ingestions
e.g. Dormex.
 Once symptomatic, Must be admitted.
 Any one who has been given atropine anywhere as a pre-
hospital management, Must be admitted.
 Borderline cases: Better to be admitted or you can
choose to put under observation for 6 hours.

6. How to proceed..?
 Vitals are VITAL.
 Suctioning of the accumulated chest secretion.
 A Assess the need for ETT e.g. if the patient is
grossly weak + disturbed conscious level = high possibility
for aspiration. N.B. any GCS < 8 = Intubate
 A Atropine as a ( life saving measure ). You will
give it as much as needed till the chest secretions become
dry. Don’t solely depend on Pupil or Pulse.
 Obidoxime loading dose ( 1-2 ampoules slowly IV ) can be
given if there are frank nicotinic manifestations or if the
patient gets intubated in ER.

7. How to proceed..? Cont’d
 After initial stabilization, the patient must get a GI
decontamination measure e.g. Induction of emesis or
gastric lavage.
 Skin decontamination would be a priority before
admission if there is gross soiling of the clothes.
 Then admit the patient. N.B. weak patients or those who
have received > 10-15 atropine ampoules = ICU.
 N.B. the main purposes of admission are Supportive TTT
& Follow up +/- Antidote therapy.

8. Investigations
 Routine labs : Glucose, Na, K for any admitted Pt.
 Pseudocholinesterase level: not as much specific as the
RBCs ChEase but less expensive & more widely available.
 N.B. when to order True ChEase? if there is a high index
of suspicion of OPI ( Hx. & PE ) and the
pseudocholinesterase level is normal or borderline.
 N.B. Be aware of the other conditions associated with
low level of pseudoChEase e.g. Infants, liver failure, renal
failure, malnutrition…etc.

9. Investigations…Cont’d
 Other labs: Liver function tests, Renal function tests.
 Arterial blood gases.
 CXR: if you suspect aspiration, hospital acquired
pneumonia or ARDS and to ensure proper CVP line
position.
 ECG: to monitor for any rhythm abnormalities.
 N.B. In cases where you doubt the diagnosis or cases with
atypical presentation: Atropine challenge test
administer 0.5 : 1 atropine ampoule rapidly IV while
watching the pulse rate on a monitor: if it increases 30
BPM or more = EXCLUDE organophosphorus intoxication.

10. Treatment
 Serial follow up of VITALS / hour.
 IV fluids e.g. Ringer, 0.9 %saline, Dextrose 5 %,
Panthol…etc. q 4h. Guided by fluid chart.
 Atropine maintenance: 1-2 ampoules in every IV fluid
unit and adjusted according to the muscarinic symptoms
& the atropinization symptoms.
 N.B. Avoid severe atropinization e.g. Tachycardia > 120
BPM, hallucinations, urine retention, diplopia…etc.
 If there is vomiting: Antiemetics & H2 blockers
 Correction of the electrolyte abnormalities if present .

11. Treatment…Cont’d
 If there is wheezing & spasm: Nebulized B2 agonists.
 Antibiotics: if there is aspiration or HAP.
 Obidoxime: given if there is frank nicotinic manifestations.
Dose is 1 ampoules / 6h for 48 hours.
 N.B. NO role of Oximes in Carbamate toxicity.
 It may have a role after that in the prevention and treatment
of the Intermediate syndrome due to redistribution of the OP.
 Follow up of the labs. Including pseudocholinesterase level.
 Gradual shift to enteral feeding.

12. When to discharge?
 Symptoms free i.e. both muscarinic and nicotinic for at
least 24 hours.
 Normalization of the labs. Including PseudoChEase level.
 No severe atropinization effects.
 Normal CXR, ECG.
 Normal enteral feeding without vomiting.
 N.B. order follow up PE & ChEase level 1 week later at the
outpatient clinic to detect any late complications of OPI
and manage accordingly.

13. Questions & Comments