Management Of Toxicity PDF

Poison (Toxicant): any substance or agent capable of producing a deleterious response in a biological system or living organism. Poisoning= overdose toxicity intoxication= toxicity due to foreign substance  All substances are poisons: there is none which is not a poison. The right dose differ...

Poison (Toxicant): any substance or agent capable of producing a deleterious response in a biological system or living organism. Poisoning= overdose toxicity intoxication= toxicity due to foreign substance  All substances are poisons: there is none which is not a poison. The right dose differentiates a poison from a remedy. Highly toxic chemicals can be life saving when given in appropriate doses. (Poisons are not harmful at a sufficiently low dose) An apparently non-toxic chemical can be toxic at high doses. (Too much of a good thing can be bad!). ❑ “Synthetic” does not mean toxic or poisonous ❑ “Natural” does not mean safe or even low risk  Poisoning episodes Accidental: Children less than 5 years by sugar coated tablets. Inhalation of organophosphorus pesticides. Overdose. Suicidal: in response to depression or specific life events. Homicidal Parasuicide: attention seeking behavior or attempt at suicide. It is typically classified as a low lethality method i.e. aim is not death  Routes of toxicant entry: Injection: Through cuts or hypodermic needles into the skin, usually cause highest blood conc Inhalation: Through mouth/nose into respiratory system, 2nd highest blood level concentration. Ingestion: Through mouth into stomach and GIT, produces 2nd lowest blood level. Dermal (Skin): By absorption through skin membrane, lowest in blood level Management of Toxicity Management Principles: 1 Immediate and supportive measures. 2 Absorption prevention. 3 Elimination of toxicant. 4 Specific antidote.  1) Immediate and Supportive measures First: Ensure clear A B C  1) Immediate and Supportive measures First: Ensure clear A B C = Airway It is of 1st = Breathing priority = Circulation  1) Immediate and Supportive measures A=Air way Causes of air way obstruction: ✓ Mucosal swelling. ✓ Increased salivation (↓ Conscious). ✓ Posterior displacement of the tongue. ✓ Swallowing of foreign bodies (ex: Fish bone).  1) Immediate and Supportive measures A=Air way Symptoms of airway obstruction: Dyspnea. Air hunger. Hoarseness (stridor). Cyanosis. Diaphoresis. Drooling. Tachypnea.  1) Immediate and Supportive measures A=Air way Management of airway obstruction: Head tilt and Chin lift maneuver. Jaw thrust maneuver.  1) Immediate and Supportive measures A=Air way Management of airway obstruction: Nasopharyngeal or Oropharyngeal intubation  1) Immediate and Supportive measures Management of airway obstruction: In case of comatosed patients: Cuffed endotracheal intubation is required to prevent aspiration because gag reflex is completely absent in unconscious patients  1) Immediate and Supportive measures A=Air way Management of airway obstruction: Excessive mucosal secretions &/or salivation: Suction of excessive secretions by the aid of intubation. In Emergency Cases: Finally → Emergency Cricothyrotomy.  1) Immediate and Supportive measures B = Breathing Causes of respiratory depression: Drug-induced respiratory depression (Sedatives & hypnotic such as barbiturates & BDZs). Pulmonary edema & pneumonitis. Bronchospasm.  1) Immediate and Supportive measures B = Breathing Management of respiratory depression: ✓ Give supplemental oxygen ✓ If necessary positive pressure ventilation ‘artificial respiration’· ✓ Respiratory stimulants for severe respiratory depression  1) Immediate and Supportive measures C =Circulation The shock is the clinical picture in which the patient shows signs of inadequate tissue perfusion. Symptoms of shock: SHOCK Coma  1) Immediate and Supportive measures C =Circulation Management of shock: 1-Trendlenburg position. 2-Saline Infusion.  1) Immediate and Supportive measures C =Circulation Management of shock: If the patient doesn't respond to 2L infusion & the signs of shock persist, the vasopressors should be used: 2-5 µg/kg/minute infusion N.B. up to 20 µg/kg/minute 1) Dopamine at low dose → stimulates Dopamine dopamine receptors→ renal & mesenteric vasodilatation. 3-vasopressors 2) Dopamine at medium dose → stimulates cardiac β1 receptors →↑cardiac contractility & C.O.P. Norepinephrine 3) Dopamine at high dose → stimulates α1 0.1-0.2 µg/kg/minute. receptors → systemic vasoconstriction.  1) Immediate and Supportive measures After instituting ABC interventions, more detailed evaluation is required: Second: A. HISTORY: Collect any evidences (thrown tablets, empty bottles, any syringes, written notes.. etc).  1) Immediate and Supportive measures After instituting ABC interventions, more detailed evaluation is required: Second: B. PHYSICAL EXAMINATIONS - Careful evaluation of S&S searching for toxidromes TOXIDROMES It is a group of signs and symptoms and/or characteristic effects associated with exposure to a particular substance or class of substances. Use all your senses, search for the clues LOOK – Pupil Size FEEL – Temperature, Sweating SMELL – Alcohol  1) Immediate and Supportive measures After instituting ABC interventions, more detailed evaluation is required: Second: B. PHYSICAL EXAMINATIONS - Careful evaluation of vital signs (B.P, pulse, respiration, temperature): Hypertension Cocaine, amphetamines … etc Rapid respiration Carbon monoxide. Hypothermia C.N.S depressants.  1) Immediate and Supportive measures After instituting ABC interventions, more detailed evaluation is required: Second: B. PHYSICAL EXAMINATIONS - Pinpoint miosis is a typical sign of opioids toxicity. Eye: - Mydriasis is very common with cocaine. Mouth: - Ulcers/signs of burns with corrosives. - Bitter almond odor with cyanide toxicity. - Gingival lead lines with lead intoxication.  1) Immediate and Supportive measures After instituting ABC interventions, more detailed evaluation is required: Second: B. PHYSICAL EXAMINATIONS Skin: - Cyanosis may be caused by airway obstruction and methemoglobinemia. Abdomen: - Hyperactive bowel sound, cramping and diarrhea are associated with arsenic intoxication. 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: Gastric Activated Whole Emesis Cathertics Bowel Lavage Charcoal Irrigation Most clinical toxicologists recommend administration of activated charcoal. 2) Preventing absorption (Gut Decontamination) For alert Pt Emesis Method: By the use of syrup of ipeca. The active ingredients are two alkaloids, emetine &cephaeline. Previous popular methods (fingertip stimulation, salt water, apomorphine) are ineffective. Dose: In children → 5-15 ml ipeca syrup + 120 ml water. adults → 15-30 ml ipeca + 240 ml water. The dose can be repeated if emesis has not occurred in 30 minutes. If vomiting does not occur gastric lavage or activated charcoal is decided. 2) Preventing absorption (Gut Decontamination) Emesis Complications: Prolonged Lethargy Drowsiness Diarrhea vomiting 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.