Toxicology

1. Toxicology Dr. Miada Mahmoud Rady

2. Introduction • A poison : is a substance that is toxic by nature, no matter how it gets into the body or how much is taken. • A drug : is a substance that has some therapeutic effect when given in the appropriate circumstances and in the appropriate dose. • An “overdose” : occurs when a drug is taken in excess.

3. Methods of poisoning • Poison gain an access to human body via the following routes: • Ingestion . • Inhalation . • Injection • Absorption

5. Poisoning by ingestion • popular way for suicide • May produce immediate damage or delayed effects • Generally provides time for identification and treatment • Little absorption occurs in the stomach, and the substance may stay there for a while. • Management aims to remove or neutralize the poison before it gains access to the intestines.

6. Poisoning by inhalation • occur when the toxic agent is present in the surrounding environment • Patient will continue to inhale the toxin as long as he/she remains in the environment. • Paramedics will also inhale the toxin if not wearing the proper protective breathing apparatus.

7. Likely to find more than one patient • Window of opportunity for problem identification and treatment is limited. • First general management consideration is scene safety

8. Poisoning by injection • Usually gain access as the result of : • Stings or bites from insects and animals • Abuse of intravenously administered drugs • Injected poisons produce either systemic or localized reactions. • Physical findings will provide clues.

9. Surface Absorption • Entry through skin or mucous membranes • Contact with poisonous plants • Pesticides e.g. organophosphates

11. Toxidromes • Toxic syndrome or toxidrome: A group of signs and symptoms consistently associated with a particular toxin. • Useful for remembering the assessment and management of different substances in the same group. • Diagnosis can be developed by looking at: a. History b. Physical signs

12. Six major Toxidromes exist: a. Stimulants b. Narcotics c. Cholinergics d. Anticholinergics e. Sympathomimetics f. Sedative/hypnotics

13. Toxidromes

14. Patient Assessment • Toxicologic emergencies are generally considered medical emergencies. • General assessment approach is the same for all patients.

15. Scene Size-Up • Patients who have taken an overdose may be dangerous. • Call for law enforcement or a crisis unit if necessary.

16. Primary Assessment • Form a general impression. • Identify concerns or life threats. • Identify MOI or NOI. • Identify need for additional resources. • Set the priority.

17. History Taking • Use OPQRST and SAMPLE history and obtain the following: • What is the agent? • When was poison taken? • How much was taken? • Has the patient vomited or aspirated? • Why was the substance taken?

18. Emergency Medical Care of toxicological case • Ensure scene safety. • Maintain the airway and ensure that breathing is adequate. • Ensure that circulation is not compromised and establish vascular access. • Be prepared to manage shock, coma, seizures, and dysrhythmias. • Transport the patient as soon as possible

19. Alcohol • Red flags pointing to alcoholism include : • Drinking early in the day, alone or in secret • Loss of memory or “blackouts” ,restlessness and anxiety • Cigarette burns on clothing • Chronically flushed face and palms • Green tongue syndrome: caused by the use of chlorophyll-containing compounds to cover the smell of alcohol on the breath.

20. Pathophysiology of alcoholism • Problem drinking : Alcohol is used more often to relieve tensions or other emotional difficulties then some degree of psychological dependence develops . • Physical dependence : results from the regular consumption of large quantities of alcohol , if the person abruptly stops consuming alcohol, withdrawal symptoms will occur.

21. Emergency presentation of alcoholism • Withdrawal syndrome. • Withdrawal seizers • Acute alcohol intoxication . • Chronic complication of alcoholism. • Delirium tremens .

22. Withdrawal syndrome • Minor (1) Restlessness (2) Anxiety (3) Sleeping problems (4) Agitation (5) Tremors • Major (1) Increased blood pressure (2) Vomiting (3) Hallucinations (4) Delirium tremens

23. Withdrawal seizers • Occurs as result of abrupt discontinuation after prolonged use • Usually occur within 12 to 48 hours of last drink • Use the same care described for alcohol intoxication. • Consult with medical control about administering benzodiazepines.

24. Chronic medical problem • Chronic malnutrition and hypoglycemia • Frequent falls and balance problem • Deterioration in higher mental functions • Decreased sensation in the extremities • Gastritis, GERD and GIT bleeding • Increased risk of cancer of the mouth and esophagus • Coagulopathies and liver damage

26. Acute alcohol intoxication • Due to relatively rapid consumption of alcohol . • Major complication : death from : • Respiratory center depression • Aspiration of vomitus or stomach contents.

27. Management of acute alcohol intoxication • Establish and maintain the airway: ( A) • With an intact gag reflex, place the patient in the recovery position and be prepared to suction. • With no gag reflex, intubate. • Give high concentration oxygen and assist ventilations as necessary. ( B) • Establish vascular access. ( C)

28. Monitor ECG rhythm . ( C) • Assess blood glucose level. ( C) • Administer thiamine 100 mg via slow IV push if directed to do so by medical control. ( MEDICATION ) • Transport to an appropriate facility. ( TRANSPORT )

29. Delirium tremens • Start 48 to 82 hours after the last alcohol intake. • Signs and symptoms include: • Confusion and hallucinations. • Tremors and restlessness. • Fever and sweating . • Hypotension (often due to dehydration). • Complication : mortality rate is 15%.

30. Management • Treatment is aimed at protecting the patient from injury and supporting the cardiovascular system. • Try to keep the patient calm. • Administer supplemental oxygen by nasal cannula. • Establish vascular access and manage hypotension with an infusion of normal saline. • Check breath sounds during reassessment.

31. 2. Stimulant

32. Stimulants • Stimulant addiction is characterized by : • Users may become addicted within just a few days. • Success of overcoming addiction is low. • Increasing paranoia makes encounters risky So stay alert for signs of violence.

33. Examples of stimulants : • Caffeine • Nicotine • Cocaine • Amphetamines

34. Clinical presentation of stimulant substances Usual dose effects includes: • Excitement • Delirium • Tachycardia • Hypertension • Dilated pupils • Toxic ( over dose ) presentation : • Psychosis • Hyperpyrexia • Tremors • Seizures • Cardiac arrest

36. Cocaine • Naturally occurring alkaloid • Rapidly absorbed across mucosal membranes, allowing it to be applied: • Topical • Insufflated (snorted) • Swallowed • Injected intravenous

37. Pathophysiology • Action : local anesthetic and a CNS stimulant. • Crack cocaine: Cocaine mixed with baking soda and water that is cooked or baked. • Effects are felt between 8 seconds to 1 minute. • When the effects wear off, the user experiences a “crash” which to be avoided the patient take more cocaine or sedatives

38. COMPLICATION OF COCAINE • Lethal ECG dysrhythmias and acute myocardial infarction • Seizures and stroke. • Apnea , pneumothorax and pneumomediastinum • Hyperthermia.

41. Amphetamine, methamphetamine, and amphetamine-like drugs • Have a number of legitimate clinical applications • Nasal decongestants • Diet pills • Drugs used to treat narcolepsy, attention-deficit disorder (ADD), and attention-deficit/hyperactivity disorder (ADHD)

42. Management of stimulant abuse • Address ABCS : • Maintain patent airway • Give high flow oxygen • Apply ECG monitor , pulse oximeter • Establish I.V access and treat shock with normal saline • Apply ice packs for hyperthermia

43. Drugs : • Administer benzodiazepines for convulsions • Administer nitroprusside for hypertension • Administer haloperidol for violent behavior. • Transport to appropriate facility : contain dialysis unit.

44. Marijuana and cannabis compounds • Derived from Cannabis sativa. • Clinical uses: • Treatment of glaucoma. • Relief of nausea and appetite loss from chemotherapy. • Usually smoked, but can be ingested.

45. Clinical presentation • Distorted sense of time and space and a feeling of unreality. • Bronchodilation and tachycardia. • Drowsiness and Decreased short-term memory. • Diminished motor coordination • Increased appetite. • Bloodshot eyes.

46. Hallucinogens • Substance that causes some distortion of sense perception an effect that is termed “psychedelic effects” • Manifestation is affected by: i. User’s previous drug experience ii. Dose taken iii. User’s expectations iv. Social setting

47. Classified into two categories : i. Synthetic (a) LSD (b) PCP (c) Ketamine ii. Naturally occurring (a) Mescaline (b) Psilocybin mushroom (c) Seeds of the Jimson weed plant

48. LSD (Lysergic acid diethylamine ) • Pathophysiology : • Primarily affects the senses • Physiologic effects may include: • Mild tachycardia • Mild hypertension • Dilated pupils • Assessment and management • Treatment is primarily supportive. • Limit sensory stimulation as much as possible

49. Phencyclidine (PCP) • Pathophysiology: • Typically smoked or snorted (can be injected) • Small doses can produce symptoms of intoxication. • Manifestation: • Mind-body separation • Hallucinations • Violent outbreaks

50. Phencyclidine (PCP) • Assessment and management • Try to calm the patient, and address wounds. • Administer high-flow oxygen. • Monitor vital signs. • Provide safe transport.