Management of Toxicity

1. Management of Toxicity

2. Causes of self-poisoning: Accidental: Children less than 5 years by sugar coated tablets. Inhalation of organophosphorus pesticides. Overdose.

3. Causes of self-poisoning: • Deliberate: • Suicidal attempts (in response to depression or specific life events).

4. Management Principles: • Immediate and supportive measures. • Absorption prevention. • Elimination of toxicant. • Specific antidote. 1 2 3 4

5. 1) Immediate and Supportive measures • Remove patient from contact with poison, for example gases. • Preserve any evidence, for example bottles, thrown tablets, written notes…. • Assess vital signs (Pulse, body temperature, B.P, respiratory rate & pupil size). • Ensure clear C A B

6. 1) Immediate and Supportive measures • Remove patient from contact with poison, for example gases. • Preserve any evidence, for example bottles, thrown tablets, written notes…. • Assess vital signs (Pulse, body temperature, B.P, respiratory rate & pupil size). • Ensure clear C A B = Airway = Breathing = Circulation

7. 1) Immediate and Supportive measures • Causes of airway obstruction: • Drug-induced mucosal swelling. • Increased salivation. • Posterior displacement of • the tongue. • Swallowing of foreign bodies. • A=Air way

8. 1) Immediate and Supportive measures • Symptoms of airway obstruction: • Dyspnea. • Air hunger. • Hoarseness (stridor). • Cyanosis. • Diaphoresis. • Tachypnea. • A=Air way

9. 1) Immediate and Supportive measures • Management of airway obstruction: • Suction of excessive secretions. • Chin lift maneuver. • A=Air way

10. 1) Immediate and Supportive measures • Management of airway obstruction: • Suction of excessive secretions. • Chin lift maneuver. • Nasopharyngeal intubation  Alert patients. • Oropharyngeal intubation  Comatosed patients. • A=Air way

11. 1) Immediate and Supportive measures • Management of airway obstruction: • Suction of excessive secretions. • Chin lift maneuver. • Nasopharyngeal intubation  Alert patients. • Oropharyngeal intubation  Comatose patients. • A=Air way

12. 1) Immediate and Supportive measures • Management of airway obstruction: • Suction of excessive secretions. • Chin lift maneuver. • Nasopharyngeal intubation  Alert patients. • Oropharyngeal intubation  Comatose patients. • A=Air way In case of comatosed patients, Cuffed endotracheal intubation is required to prevent aspiration because gag reflex is completely absent in unconscious patients

15. 1) Immediate and Supportive measures • Management of airway obstruction: • Suction of excessive secretions. • Chin lift maneuver. • Nasopharyngeal intubation  Alert patients. • Oropharyngeal intubation  Comatose patients. • Finally  Emergency Cricothyrotomy. • A=Air way In case of comatose patients, Cuffed endotracheal intubation is required to prevent aspiration because gag reflex is completely absent in unconscious patients

17. 1) Immediate and Supportive measures • Causes of respiratory depression: • Drug-induced respiratory depression (Sedatives & hypnotic such as barbiturates & BDZs). • Pulmonary edema & pneumonitis. • Bronchospasm. • B = Breathing

18. 1) Immediate and Supportive measures • Management of respiratory depression: • Nasopharyngeal intubation  Alert patients. • Oropharyngeal intubation  Comatosed patients. • B = Breathing In case of comatosed patients, Cuffed endotracheal intubation is required to prevent aspiration because gag reflex is completely absent in unconscious patients

19. 1) Immediate and Supportive measures • The shock is the clinical picture in which the patient shows signs of inadequate tissue perfusion. • Symptoms of shock: • C =Circulation Oliguria ↓ B.P SHOCK Coma

20. 1) Immediate and Supportive measures • Management of shock: • Initially: • Trendlenburg position. • Saline Infusion. • C =Circulation

21. 1) Immediate and Supportive measures • Management of shock: • If the patient doesn't respond to 2L infusion & the signs of shock persist, the vasopressors should be used: • C =Circulation N.B. 1) Dopamine at low dose  stimulates dopamine receptors renal & mesenteric vasodilatation. 2) Dopamine at medium dose  stimulates cardiac β1 receptors ↑cardiac contractility & C.O.P. 3) Dopamine at high dose  stimulates α1 receptors  systemic vasoconstriction. Dopamine vasopressors 2-5 µg/kg/minute infusion up to 20 µg/kg/minute Norepinephrine 0.1-0.2 µg/kg/minute.

22. 2) Preventing absorption (Gut Decontamination) • It is usually not effective more than 4-6 after poison ingestion. • It is used only for orally ingested poisons. • Methods of gut decontamination: Whole Bowel Irrigation Gastric Lavage Activated Charcoal Emesis Cathertics

23. 2) Preventing absorption (Gut Decontamination) • Method: • By the use of syrup of ipeca. • The active ingredients are two alkaloids, emetine • &cephaeline. • Dose: • In children < 1 year  10 ml ipeca syrup + 120 ml water. • 1- 5 years 15 ml ipeca + 120 ml water. • 5 years & adults  30 ml ipeca + 250-350 ml water. • The dose can be repeated if emesis has not occurred in 30 minutes. Emesis

24. 2) Preventing absorption (Gut Decontamination) • Complications: Emesis Prolonged vomiting Lethargy Drowsiness Diarrhea

25. 2) Preventing absorption (Gut Decontamination) • Contraindication: • Children up to 6 months of age. • Comatose patient because of increased risk of aspiration. • Seizures (due to compromised gag reflex). • Certain toxins: • - Hydrocarbons& volatile substances. • Corrosives (Caustics). • Ingestion of sharp objects. Emesis

26. 2) Preventing absorption (Gut Decontamination) • Method: • It is performed by introducing warm water alternating with saline via nasogastric (alert patients & children) or an orogastric (comatose patient) tube into the stomach & the removal of stomach contents by suction. Gastric Lavage

27. 2) Preventing absorption (Gut Decontamination) • Precautions: • Warm water should be used. • Warm water alternating with saline • The patient should be placed on his left side. • G.L can be used in comatosed patients with concurrent insertion of cuffed endotracheal intubation. Gastric Lavage To avoid hypothermic shock To avoid hyponatremia • liver blocks the junction between stomach & small intestine, and therefore the toxin is kept in the stomach available for lavage.

28. 2) Preventing absorption (Gut Decontamination) • Complications: Gastric Lavage Esophageal perforation Epistaxis Empyema

29. 2) Preventing absorption (Gut Decontamination) • Contraindications: • Varicoses. • Gastric ulcers. • Corrosives (Caustics) intoxication. • Ingestion of sharp objects. Gastric Lavage

30. 2) Preventing absorption (Gut Decontamination) • Method: • Activated charcoal effectively adsorbs a variety of drugs & chemicals. • Dose: • 1-2 g/kg • It is mixed with 70% sorbitol to avoid constipation & resorption. Activated Charcoal

31. 2) Preventing absorption (Gut Decontamination) • Complications: Activated Charcoal • Intestinal obstruction. • Constipation.

32. 2) Preventing absorption (Gut Decontamination) • Contraindications: • In comatosed patient unless the cuffed intubation is used. • Activated charcoal doesn't bind well to: • Elemental metals (lead, boron, lithium). • Boric acid. • Pesticides. • Ferrous salts (as ferrous sulphate). • Cyanide. • Caustics. • Alcohols. • Petroleum distillates. Activated Charcoal

33. 2) Preventing absorption (Gut Decontamination) Cathertics Saccharide Salt Oil based Magnesium Citrate Sodium Phosphate Not used now because of increased risk of lipoid pneumonia Sorbitol

34. 2) Preventing absorption (Gut Decontamination) • Complications: Cathertics • Abdominal distention & cramps. • Electrolyte disturbances. • Prolonged diarrhea.

35. 2) Preventing absorption (Gut Decontamination) • Contraindications: • Magnesium cathartics should be avoided in patients with renal failure &/or C.N.S problems. • (Renal failure ↓ Magnesium excretion  Magnesium accumulation Electrolyte disturbance and C.N.S depression) • Sodium salts should be avoided in patients with renal failure, heart failure, &/or hypertension. • Absence of bowel sounds. Cathertics

36. 2) Preventing absorption (Gut Decontamination) • It is the complete irrigation of the bowel by PEG (Colyte®). • The patient receives PEG until clear effluent is attained. Whole Bowel Irrigation (WBI)

37. Whole bowel irrigation is undertaken either by having the patient drink the solution or a nasogastric tubeis inserted and the solution is delivered down the tube into the stomach. • children 9 months to 6 years: 500 mL/h • children 6 to 12 years: 1000 mL/h • adolescents and adults: 1500 to 2000 mL/h. • The patient is usually seated on a toilet and the procedure continues until the rectal effluent is clear. The entire procedure usually takes 4 to 6 hours

38. 3) Elimination Enhancement Extracorporeal system Non Extracorporeal system Hemodialysis Hemoperfusion Exchange Transfusion Peritoneal Dialysis Forced Diuresis

39. 3) Elimination Enhancement • Requirements: • When large amounts of drug are retained in plasma. • The drug molecular weight should be less than 500 Dalton so can pass easily across the dialysis membrane. • The drug should be water soluble. • The drug should be of low protein binding. • Heparin should be administrated before dialysis to avoid blood coagulation. Hemodialysis

40. 3) Elimination Enhancement Hemodialysis

41. 3) Elimination Enhancement • Indications: • Severely intoxicated patients who don't respond to early supportive management. • Renal failure (where forced diuresis can't be applied). • Prolonged coma. • If lethal amounts of drug was absorbed despite gut decontamination. • Presence of significant quantity of a toxin that is metabolized to a toxic metabolite. Hemodialysis

42. 3) Elimination Enhancement • Complications: • Hypotension. • Electrolyte disturbance. • Bleeding. • Air embolism. • Thrombocytopenia. • Infection. Hemodialysis

43. 3) Elimination Enhancement • Contraindications: • Presence of antidote. • Patient receiving anticoagulants (heparin). • Coagulopathy or bleeding ulcer. Hemodialysis

44. 3) Elimination Enhancement • It is a method for removing toxic material by pumping blood through a cartridge of adsorbent material such as activated charcoal or resin. Hemoperfusion Advantages: Hemoperfusion can be used with: - Drugs of high molecular weight. - Protein bound drug (Phenytoin). - Poorly water soluble drugs.

45. 3) Elimination Enhancement • Contraindication & Complications • ??? Hemoperfusion

46. 3) Elimination Enhancement • It is infrequently used. • It is the removal of the patient's blood & replacement with fresh whole blood. Exchange transfusion

47. 3) Elimination Enhancement • Indications: • Iron toxicity. • Chloramphenicol toxicity. • Patients who are refractory to other enhanced elimination methods or antidotes. Exchange transfusion

48. 3) Elimination Enhancement • Complications: • Mismatches. • Chills. • Hypotension. • Infection. • Bleeding. Exchange transfusion

49. 3) Elimination Enhancement • The toxins diffuse from mesenteric capillaries across the peritoneal membrane into a washing solution in the peritoneal cavity. Peritoneal Dialysis

50. 3) Elimination Enhancement • The toxins diffuse from mesenteric capillaries across the peritoneal membrane into a washing solution in the peritoneal cavity. Peritoneal Dialysis • Advantages: • It is well tolerated. • It doesn’t require heparinization.