1. History and Physical Examination11
History and Physical Examination
Accurate identification of ingestants is particularly important in the patient exposed to agents that have delayed onset of toxic effects, such as acetonitrile, which is metabolized to cyanide, or MAOIs.

2. Physical Examination
The physical examination gives important clues to both the severity and the cause of poisoning.
Examples include the respiratory depression of barbiturate or opioid poisoning and the tachycardia and hypertension of poisoning with sympathomimetic agents.

3. Decontamination
The decision to evacuate the GIT or administer activated charcoal should be based on:
the type of ingestion
estimated quantity
size of pill or tablet
time since ingestion
concurrent ingestions
age and size of the patient.

4. PREVENTION OF ABSORPTION OF POISON
Induce emesis in the following ways:
mechanically by stroking posterior pharynx;
use of syrup of ipecac, 15ml for children and 30ml for adults followed by one glass of water;
use of apomorphine parenterally

5. PREVENTION OF ABSORPTION OF POISON
Inducing emesis by Syrup of ipecac is used rarely in the prehospital setting, and virtually never in hospitals.
Limited indications for the use of orogastric lavage, nasogastric suction, and whole-bowel irrigation exist.

6. PREVENTION OF ABSORPTION OF POISON
Chemical Adsorption
activated charcoal will adsorb many poisons thus preventing their absorption, it used within 1 hour of ingestion.
adsorbent in intestines may interrupt enterohepatic circulation.

7. PREVENTION OF ABSORPTION OF POISON
Purgation
Used for ingestion of enteric coated tablets when time after ingestion is longer than one hour
Use saline cathartics such as sodium or magnesium sulfate
The use of cathartics has never been shown to alter clinical outcome. However, their inappropriate use has been associated with significant morbidity and mortality, and their routine use is no longer recommended.

8. PREVENTION OF ABSORPTION OF POISON
Chemical Inactivation
Not generally done, particularly for acids or bases or inhalation exposure
For ocular and dermal exposure as well as burns on skin; treat with copious water

9. Dermal decontamination
is best accomplished with large amounts of water. However, the use of water on skin contaminated with metallic sodium, metallic potassium, or phosphorus (white, yellow) may result in further skin injury owing to heat generation and explosive injury.
Irrigation of phenol burns with low molecular weight polyethylene glycol is effective.

10. Other therapies, such as topical calcium salts for hydrofluoric acid burns, may be indicated following initial water decontamination.
Ocular decontamination can be accomplished with water or normal saline irrigation.

11. Diagnostic Testing serum electrolytes calculated anion gap glucose
arterial blood gases
serum creatinine
liver function tests
Electrocardiograms (ECG): cardiac dysrhythmias or conduction delays
Routine radiographs: pulmonary injury

12. Antidotes

13. Antidotes

14. Antidotes Digoxin Digoxin-specific antibody fragments (Fab) Digitalis
Other cardiac glycosides, e.g., bufodienalides (Bufo toads)
Oleander
Dimercaprol
Arsenic
Lead
Mercury
Ethanol
Diethylene glycol
Ethylene glycol
Methanol
Experimental: sodium monofluoroacetate
Flumazenil
Benzodiazepines
Venlafaxine

15. Antidotes Folic acid/tetrahydrofolic acid (leucovorin) Methanol
Methotrexate
Fomepizole
Ethylene glycol
Glucagon
Beta-adrenergic receptor antagonists
Calcium channel antagonists
Hyberbaric oxygen
Carbon monoxide
Experimental: carbon tetrachloride
Cyanide, hydrogen sulfide
Methylene blue
Methemoglobin-producing agents

16. Antidotes N-Acetylcysteine Acetaminophen
Experimental: carbon tetrachloride, chloroform, pennyroyal oil
Naloxone, nalmefene, naltrexone
Opioids
Physostigmine
Anticholinergic agents, e.g., diphenhydramine, Jimsonweed (Datura spp.), scopalamine
Pralidoxime
Organophosphates
Protamine
Heparin
Pyridoxine
Isoniazid
Monomethylhydrazine mushrooms (Gyrometra esculenta)

17. Antidotes
Sodium bicarbonate
Myocardial sodium channel blockers, e.g., cyclic antidepressants, cocaine, norpropoxyphene, class Ia and Ic antidysrhythmics, piperidine phenothiazines (thioridazine, mesoridazine)
Altered tissue distribution/enhanced elimination: chlorophenoxy herbicides, chlorpropamide, formic acid (methanol), methotrexate, phenobarbital, salicylates
Neutralization: inhaled chlorine gas, hydrogen chloride, phosgene
Succimer
Arsenic
Lead
Mercury
Vitamin K
Anticoagulants, e.g., warfarin, long-acting anticoagulant rodenticides

18. Increase Elimination Of Toxic Agents
Increasing urinary excretion by acidification or alkalinization
Decreasing passive resorption from nephron lumen
Diuresis
Cathartics
Peritoneal dialysis
Hemodialysis
Hemoperfusion

19. Forced diuresis and pH alteration
It is useful when compounds or active metabolites are eliminated by the kidney and diuresis enhances their excretion.
Mannitol and furosemide are generally used.
This method is no longer indicated because it increase the excretion of chemical only two fold.
Alkaline diuresis is achieved by administration of sodium bicarbonate, 1-2 mEq/kg every 3-4 hr.

20. The potential uses of urine alkalinization have been with weak acid such as salicylates and phenobarbital.
Acid diuresis is possible by using ammonium chloride, 75mg/kg/24hr.
Acid diuresis increase the elimination of weak bases, such as amphetamine, phencyclidine, and quinidine. This procedure is no longer recommended.

21. Dialysis and hemoperfusion
Peritoneal Dialysis
The procedure is undertaken by inserting a tube through a small incision made in the abdominal area into the peritoneum.
The peritoneal membrane serves as the semipermeable (dialyzing) membrane. The dialyzable chemical diffuses from blood across the peritoneal membrane into the dialyzing fluid (from higher concentration to lower concentration).

22. Peritoneal Dialysis Advantages:- Easy. Lowest risk for complications.
Disadvantages:-
The least effective method for removing most poisons. It is 5-10 time less efficient than hemodialysis.
Not suitable when rapid removal of a toxic substance is needed.
Complications include:- abdominal pain, intraperitoneal bleeding, intestinal, bladder, liver, or spleen perforation; peritonitis; water and electrolyte imbalance; and protein loss.

23. Procedure for peritoneal dialysis

24. Hemodialysis
Two catheters are inserted into the patient’s femoral vein. Blood is pumped from one catheter through the dialysis unit, across the semipermeable membrane, and back through the other catheter.
The procedure is continued for 6-8 hr. the solubilized chemical diffuses across the semipermeable membrane into the dialysis solution.
Clearance of the toxic agent is based on differences in osmotic and concentration gradients.

25. Procedure for hemodialysis

26. Procedure for hemodialysis

27. Disadvantages
The chemical that removed by this way must have a low molecular size.
Less effective for drug that are highly protein-bound.
Useless for chemicals that are extensively taken by the tissues.
Complications include clotting, and seepage of blood from around connections, hypotension, convulsions, arrhythmias, infection, and hematologic defects.

28. Hemoperfusion
The passage of blood through columns of adsorptive material, such as activated charcoal, to remove toxic substances from the blood.
It is more effective than peritoneal dialysis and hemodialysis for removing compound that are:
Lipid soluble.
Protein bound.
Poorly dialyzable.
Complications include:- trapping of white blood cells and platelets and microembolization. Newer systems solved this problem.

29. Procedure for hemoperfusion

31. Pediatric poisoning
Approximately 54% of childhood exposures are to xenobiotics that are commonly found around the house, such as cleaning products, cosmetics, plants, hydrocarbons, and insecticides; approximately 46% are to pharmaceuticals.
In older children and adolescents, approximately 49% of exposures are to non-pharmaceutical xenobiotics, and approximately 51% are to pharmaceuticals.

32. Who is more prone to toxicity? Children less than 5 years old. Why?

33. The environment: includes the area around the home.
Children are curious and investigative.
Many household products are marked in attractive packages.

34. 4. The natural tendency of children to place everything into their mouth.

35. 5. Taking medication in the presence of children “If I see it, I can do it,” 6. Dosing errors 7. Poisons are often left in easy view and accessible. Poisoning also occur because many products are used in unvented areas. Another factor that increase toxicity is the absence of information about the constituents of many products.

36. The leading causes of reported exposures in children and adolescents

37. The leading causes of reported exposures in children and adolescents