Clinical Toxicology Management

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Questions and Answers

Which type of antagonism refers to the presence of a substance that competes with another for the same binding site?

Non-Competitive Antagonism

Physiological Antagonism

Competitive Antagonism (correct)

Chemical Antagonism

Which of the following describes the mechanism by which chelating agents function?

Convert poisons into volatile gases

Neutralize the pH of toxins

Unite metallic poisons to form soluble compounds (correct)

Accelerate the absorption of toxins

What is the primary purpose of forced diuresis in toxicology?

Restore normal kidney function

Prevent further absorption of the poison

Facilitate the removal of toxins from the body (correct)

Increase the rate of drug metabolism

Which method of enhancing poison excretion uses a semi-permeable membrane?

Dialysis Signup and view all the answers

What differentiates hemoperfusion from hemodialysis?

Hemoperfusion removes toxins by passing blood through charcoal or resin. Signup and view all the answers

What is the primary aim of management in cases of poisoning?

To provide supportive care and prevent poison absorption Signup and view all the answers

Which factor is most commonly associated with death from poisoning?

Loss of airway-protective reflexes Signup and view all the answers

In cases of hypotension during the initial evaluation, which solution is preferred for intravenous infusion?

Normal saline or another isotonic solution Signup and view all the answers

What should be evaluated to assess disability in the context of drug overdose?

Level of consciousness and blood sugar level Signup and view all the answers

What is the correct action if a patient has seizures and a blood sugar level of < 72 mg/dL?

Administer 50ml of 50% dextrose IV Signup and view all the answers

During the exposure assessment, what should be considered concerning toxic syndromes?

Hyperthermia associated with toxic levels of certain drugs Signup and view all the answers

What is an important step in the definitive care of poisoning?

Identify the poison as a priority Signup and view all the answers

Which source is NOT typically relevant for obtaining an accurate history in poisoning cases?

The patient only Signup and view all the answers

Which of the following is NOT a method used for the prevention of further poison absorption via the gastrointestinal tract?

Antibiotics Signup and view all the answers

What should be avoided when inducing emesis to prevent complications?

Corrosive substances Signup and view all the answers

For activation of charcoal to be indicated, which of the following must be true?

It has been more than 2 hours since ingestion. Signup and view all the answers

Which of the following conditions would contraindicate the use of gastric lavage?

Recent oral antidote administration Signup and view all the answers

What is the primary purpose of using cathartics in poison management?

To promote faster elimination of toxins Signup and view all the answers

What is the appropriate adult dosage of activated charcoal in case of poisoning?

1 gm/kg Signup and view all the answers

In what case should the use of Ipecac syrup be avoided for inducing vomiting?

Less than 6 months of age Signup and view all the answers

Which of the following substances is NOT effectively adsorbed by activated charcoal?

Opioids Signup and view all the answers

What is the primary focus of clinical toxicology?

The effects of chemicals and drugs on humans and other animals. Signup and view all the answers

Which approach should be taken towards all poisoned patients?

Consider them to have potentially life-threatening intoxication. Signup and view all the answers

What is the first goal in the treatment of acute poisoning?

To keep the poison concentration as low as possible. Signup and view all the answers

Which strategies are emphasized in managing poisoned patients?

Maintaining respiration and circulation is primary. Signup and view all the answers

For which condition should you recognize that poisoning has occurred?

Regardless of visible symptoms. Signup and view all the answers

What percentage of poisoning exposures is accounted for by prescription and over-the-counter medications?

Nearly one half. Signup and view all the answers

Which of the following statements is true regarding supportive care in poisoning incidents?

Supportive therapy is essential regardless of toxin type. Signup and view all the answers

Which of the following best describes 'Routine poison management'?

A generic framework applied to all poisoned patients. Signup and view all the answers

What is a critical step in the risk assessment process for acutely poisoned patients?

Calculating the dose of ingested agents Signup and view all the answers

Which of the following vital signs is NOT typically considered during a physical examination for toxicology?

Ear temperature Signup and view all the answers

What is the primary goal of managing poisoning cases?

To prevent further poison absorption Signup and view all the answers

Which of the following is considered an important clinical feature when performing risk assessments for poisoning?

Time since ingestion of the agent Signup and view all the answers

Upon examining a patient, which neurological factor would be crucial to assess?

Pupil size Signup and view all the answers

Which of the following steps is NOT part of the prevention of further poison absorption?

Administering an antidote Signup and view all the answers

What is an important patient factor to consider in risk assessment for poisoning?

Patient’s weight and co-morbidities Signup and view all the answers

Which type of investigation is NOT typically conducted in assessing a poisoning case?

Psychometric testing Signup and view all the answers

What is the primary goal of Whole Bowel Irrigation (WBI)?

To clean the GIT from non-absorbed ingested toxins Signup and view all the answers

Which of the following is NOT a contraindication for Whole Bowel Irrigation?

Mild food poisoning Signup and view all the answers

Which category of antidote works by forming a nontoxic complex with a poison?

Chemical antidotes Signup and view all the answers

What is an example of a physical antidote?

Activated charcoal Signup and view all the answers

Which antidote is used to accelerate the detoxification of poisons?

N-acetylcysteine Signup and view all the answers

How does Fomepizole function as an antidote?

By competing with the poison for certain receptors Signup and view all the answers

Which of the following substances can be classified as a chemical antidote for cyanide toxicity?

Amyl Nitrite Signup and view all the answers

What type of antidote includes agents like starch that create a blue precipitate with iodine?

Precipitating antidotes Signup and view all the answers

Study Notes

Clinical Toxicology - Initial Evaluation & Management

Clinical toxicology focuses on the effects of drugs and chemicals on humans (and animals). It often involves drug overdoses and poisonings, identifying the substance and its amount in the body.
It works alongside other sciences like biochemistry, pharmacology, and pathology.
Clinical toxicology examines the adverse effects of various agents, including drugs and chemicals.
All poisoned patients should be managed as if they have a life-threatening condition, even if they appear normal. The initial approach should be uniform, irrespective of the ingested toxin. This is termed "routine poison management".

Outline

Clinical Toxicology
Approaches and Initial Evaluation
Management
Definitive care with poisoning
Supportive Care and Monitoring

Approach to Poisoned Patients

All poisoned patients must be managed as having a potentially life-threatening condition, regardless of outward appearance.
The initial approach remains essentially the same, no matter what toxin was ingested.

Common Poisoning Sources

Poisoning can result from various substances, ranging from household cleaners to pesticides.
Prescription and over-the-counter medications account for nearly half of poisoning exposures.

Important Strategies

Treat the patient promptly, not the poison.
Supportive therapy is essential: maintain respiration and circulation.
Monitor intoxication by measuring and recording vital signs and reflexes.
Treatment goal 1: keep poison levels low by preventing absorption and increasing elimination.
Treatment goal 2: counteract toxic effects at the affected site (if possible).

Initial Evaluation (ABCDEs)

Airway

Maintain a patent airway.
Remove any obstructions.
Loss of airway reflexes is a significant cause of poisoning death in many cases. This can lead to obstruction caused by flaccid tongue or aspirated gastric contents.

Breathing

Evaluate respiratory rate and oxygen saturation.
If no oxygen monitor is available, consider supplemental oxygen if respiratory rate is elevated.

Circulation

Promptly assess vital signs and hydration status.
Check blood pressure, pulse rate, and rhythm.
Start continuous ECG monitoring
Secure venous access.
Draw blood for routine studies.
Administer normal saline (or similar isotonic solution) if the patient is hypotensive.

Disability (Neurological)

Assess level of consciousness.
A decreased level of consciousness is a common severe complication of drug overdose/poisoning.
In seizure cases, check blood sugar levels. If less than 72 mg/dL, an IV of 50mL of 50% dextrose should be administered.
Treat toxic seizures with IV benzodiazepines; refractory seizures can use barbiturates.

Exposure (Temperature)

Assess temperature.
Consider toxic syndromes associated with hyperthermia.
Some drugs at toxic levels can cause a significantly elevated body temperature.

Definitive Care with Poisoning

Identify the poison.
Gather an accurate history from alternative sources (family, friends, pharmacist, scene).
Determine the time and amount of ingestion.

Supportive Care & Monitoring

Acute poisoning is a dynamic condition; patients' conditions can change over time.
Repeated examinations and ongoing clinical assessment/management are essential

Physical Examination

Vital signs (pulse, respiration, blood pressure, temperature, oxygen saturation).
Neurological exam (including pupil size, Glasgow Coma Scale, mental state, reflexes, clonus, focal signs).
Skin condition (color, sweating).
Moisture in the mouth/salivation; bowel sounds; urinary retention.
Evidence of trauma (injuries).

Risk Assessment

Early, accurate risk assessment is vital to manage acutely poisoned patients.
Assessment predicts likely clinical course, identifies potential complications, and guides management plans.
5 steps of risk assessment include:
- Agent identification (toxicity potential).
- Dose calculation (mg/kg body weight).
- Time since ingestion.
- Clinical features and progress.
- Patient factors (weight, comorbidities).

Investigations

Blood sugar levels
ECG monitoring (rate and rhythm).

Management

The goal in poisoning management is to:
Prevent further poison absorption.
Increase poison elimination.
Administer antidote (if indicated).

Prevention of Further Poison Absorption

Dermal exposure:
- Remove all clothing.
- Wash skin thoroughly with soap and water for at least 30 minutes.
Eye exposure:
- Flush the eyes with running water or saline for 20 minutes.
- Remove solid corrosives with forceps.
Gastrointestinal (GI) tract exposure:
- Emesis induction (if appropriate, and not contraindicated).
- Gastric lavage (if appropriate).
- Activated charcoal (if appropriate and not contraindicated).
- Cathartics.
- Whole bowel irrigation (if appropriate).

Induction of Emesis (Vomiting Induction)

Ipecac syrup can induce vomiting but should only be given within 30 minutes of ingestion.
Regular use of ipecac syrup as a home poison treatment is now discouraged.
Contraindications for ipecac include seizures, corrosive ingestions, hydrocarbon exposures, coma, and age less than 6 months.

Gastric Lavage

A method to remove ingested poisons from the stomach.
It is most effective within 4-6 hours of ingestion.
An assistant with a suction device is needed.

Activated Charcoal

Absorbs toxins, preventing their absorption.
1 gram per kilogram (1g/kg) adult dose is commonly used.
Must be administered within one hour of ingestion.
Not appropriate for patients at risk of airway compromise, or in cases where an oral antidote was already given, cases of seizures, coma or corrosive ingestions.

Cathartics (Laxatives)

Enhance the passage of materials through the gastrointestinal tract, reducing contact time between the toxin and digestive system cells.
Types include osmotic (like magnesium sulfate) and irritant (like castor oil) cathartics.
Contraindications include gastrointestinal (GI) bleeding, recent bowel surgery, or intestinal blockages.

Whole Bowel Irrigation (WBI)

Used for substances that are poorly absorbed.
Uses polyethylene glycol electrolyte solutions.
Used in situations where massive quantities of drugs, sustained-release drugs, or enteric-coated preparations have been swallowed, or in the removal of illegal drug packets (body packers).

Antidotes

Substances used to counteract the harmful effects of a poison.
Categories include:
- Physical: Interfere with the poison through physical means (e.g., activated charcoal).
- Chemical: Interact chemically with the poison (e.g., oxidizing, reducing, precipitating agents).
- Physiological: Antagonism (e.g., competing for receptor sites) or chelation (binding to form an easily excreted complex).

Enhancement of Poison Excretion

Forced diuresis: manipulates urine pH to increase the rate of toxin excretion, e. g. mannitol, fluid diuresis
Dialysis: employs semipermeable membranes to remove toxins when renal function is hindered, examples include peritoneal and hemodialysis
Hemoperfusion: using equipment similar to hemodialysis, where blood is pumped through a column with adsorbent material (charcoal or resin)

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Description

This quiz covers the essential aspects of initial evaluation and management in clinical toxicology. Participants will learn about the approaches for assessing poisoned patients and the importance of treating all cases as critical. The quiz aims to reinforce knowledge on routine poison management and supportive care strategies.