Clinical Toxicology Overview 2021-2022

Clinical Toxicology Round 2021-2022

• Presenter: Prof. Dr. Heba Youssef
• Vice Dean for Postgraduate Studies Affairs
• Head of Forensic Medicine & Clinical Toxicology Department

Medical Toxicology Overview

• Medical Toxicology is a branch of medicine focusing on the diagnosis, management, and prevention of poisoning and adverse health effects from medications, occupational hazards, environmental toxins, and biological agents.

Subdivisions of Medical Toxicology

• Part I: General Toxicology: Covers general principles and guidelines for managing acute intoxications, common toxicological emergencies, and diagnostic investigations.
• Part II: Systemic Toxicology: Analyzes drugs and toxins in terms of pathophysiology, mechanisms of action, clinical presentations, investigations, complications, and management.
• Part III: Environmental Toxicology: Examines toxins that can be ingested from various environmental sources including homes, workplace, agriculture, food, and marine environments.
• Part IV: Medico-legal Responsibilities of Medical Toxicologists: Outlines professional and legal duties in managing acute intoxicated patients.

Why Competence-Based Diagnosis?

• For an intoxicated patient, the process of diagnosing undifferentiated signs and symptoms to a clear diagnosis is key.
• This accurate diagnosis facilitates proper treatment.

What is Poison/Toxin?

• A substance or agent that, when entering the body in sufficient dose, causes harmful effects or death.
• The severity depends on the dose.

Routes of Poison Ingestion

• Diagram shows various routes; inhalation, ingestion, dermal contact (skin), intravenous injection, intramuscular injection
• Materials are absorbed into blood and lymph, then travel to various organs (lungs, liver, kidneys), and excreted via different routes (urine, sweat, feces).

Factors Affecting Poison Action

• Poison-related: Dose, route, form, cumulation, and time of exposure.
• Patient-related: Stomach, age, disease, tolerance, and hypersensitivity.

Risk Groups/Populations

• Babies, children, pregnant women, and older adults.

When to Suspect Poisoning

• Sudden deterioration of vital functions (neurological, respiratory, cardiovascular).
• History of neuro-psychiatric/psychological diseases.
• Group poisoning, where individuals experience the same symptoms after eating/consuming the same meal.
• Road traffic accidents, with serious injuries.
• Crimes, where there's no clear evidence of cause of poisoning
• Teenagers found comatose, in unusual locations (street, parties, clubs, secluded areas)

General Guidelines for Managing Acute Intoxicated Patients

• Initial management follows a step-by-step process; Airway, Breathing, Circulation.
• The management of any toxicological emergency follows the ABCDEFG steps.

Initial Management of Intoxicated Patients

• Airway: Cervical spine control, suction, removal of foreign bodies.
• Breathing: Artificial respiration, oxygen, mechanical ventilation.
• Circulation: ECG monitoring, correcting hypotension with IV fluids, inotropic drugs, cardiac monitoring, treating dysrhythmias.
• Drugs: Empirical use of "coma cocktail," including glucose, naloxone, and thiamine.
• Decontamination: Removal of ingested poison before entering the body's bloodstream.
• Elimination: Treatment methods like activated charcoal, diuresis, and hemoperfusion.
• General management (supportive care).

Decontamination Procedures

• Dermal: OPC, Carbolic acid; removal of clothing and thorough washing.
• Eye: Washing with running water or saline for 20 minutes.
• Inhalation: Remove to fresh air, respiratory care.
• Gastrointestinal (GIT): Ipecac, lavage, activated charcoal, cathartics.

Gastrointestinal Decontamination

• Ipecac: (Note: outdated)
• Lavage: A procedure to flush the stomach with fluid.
• Activated Charcoal (AC): Used to absorb toxins.
• Cathartics: Substances that induce bowel movements.
• Whole bowel irrigation (WBI): Irrigation to flush out toxins.

Indications for Gastric Lavage

• Recent ingestion (less than 1-2 hours).
• Toxins exceeding the adsorptive capacity of activated charcoal.
• Substances forming concretions.

Contraindications for Gastric Lavage

• Severe corrosive substances.
• Unprotected airway.
• Potential for gastrointestinal bleeding/perforation/complications.

Activated Charcoal

• Administered for up to an hour after ingestion.
• Absorbing agent, used for nearly all toxic ingestions (except hydrocarbons, corrosives).
• Contraindications: If airway is unprotected, or the ingested substance is a corrosive or hydrocarbon.

Drugs Not Absorbed by Activated Charcoal (PHAILS)

• Pesticides
• Hydrocarbons
• Acids/Alkalis/Alcohols
• Iron (Heavy Metals)
• Lithium
• Solvents

Whole Bowel Irrigation (WBI)

• Use of polyethylene glycol (PEG) to flush the intestinal tract.
• For severe cases, or substances that are not adsorbed by activated charcoal.

Elimination Methods

• Multiple-dose activated charcoal (MDAC).
• Diuresis (increasing urine production)
• Manipulating urine pH.
• Hemodialysis (kidney filtering).
• Hemoperfusion (filtering blood outside the body).

Indications for MDAC

• Meds with delayed gut emptying.
• Drugs that form concretions.
• Drugs with slower release mechanisms.

Alkalinization

• Method to increase urine pH to aid in excretion of weak acids like salicylates and phenobarbital.
• Method: Mannitol, NaHCO3, dextrose

Antidotes

• Table provides a list of common poisons and their corresponding antidotes.

Role of Lab in Toxicology

• Diagnosis of acute & chronic toxicities, diagnose and treat substance abuse, and assess treatment outcomes.

Routine Lab Investigations

• Blood routine tests (RBS, S.Na, S.K+)
• Liver Function Tests (LFT) (AST, ALT, KFT).
• Renal function tests (Urea, Creatinine).
• Blood gases (ABGs).
• Blood clotting tests (PT, PTT).
• Electrocardiogram (ECG).
• Toxicology screening tests for ingested substances.

Samples

• Blood, urine, and gastric contents.
• Advantages and disadvantages of each method are presented.

Data on Samples

• Details typically collected include patient information (name, age, sex, nationality), type of poison, clinical presentation (CI/P), location of incident, physician's signature, date/time of intoxication, and sampling.

Bedside Tests for Rapid Diagnosis

• Use of reagents to identify certain types of ingested toxins.

Toxidromes

• A collection of signs and symptoms that characterize poisoning by a specific class of toxins or drugs.
• This allows rapid clinical diagnosis and treatment, especially in emergency settings.
• Anticholinergic: Blocking acetylcholine receptors.
• Cholinergic: Stimulating acetylcholine receptors.
• Sympathomimetic: Mimicking sympathetic nervous system activity.
• Sedative/Hypnotic: Depression of the central nervous system (CNS),
• Opioid: Affecting opioid receptors (narcotics).
• Hallucinogenic: Causing hallucinations.
• Serotonergic: Excess serotonin.

Anticholinergic Toxidromes

• Drugs/toxins blocking acetylcholine receptors.
• Symptoms such as CNS changes, flushed skin, mydriasis (wide pupils), dry mouth (xerostomia)

Cholinergic Toxidromes

• Stimulating acetylcholine receptors.
• Symptoms include: Diarrhea, urination, salivation, lacrimation.

Symptoms for specific types of Toxidromes

• Description of symptoms associated with different types of poisoning (anticholinergic, cholinergic, sympathomimetic, etc.)

Plant Sources (Datura)

• Pictures and information on the plant(s) that produce toxic substances

Explore the essentials of Medical Toxicology through the Clinical Toxicology Round 2021-2022 led by Prof. Dr. Heba Youssef. This quiz covers foundational aspects of toxicology, including general principles, systemic toxicology, and environmental influences on health. Test your knowledge on the critical management and prevention strategies in toxic exposure.