Lecture 2 - General Management Principles & Toxidromes

Question 1

May not be easy to determine whether it’s an _____, allergic, or idiosyncratic rxn

Answer 1

overdose

Question 2

If a patient is ______ you must question whether it is a true overdose or trauma

Answer 2

unconscious

Question 3

Should the condition of the patient or the specific agent determine the management strategy?

Answer 3

Clinical condition

“Treat the patient, not the poison”

Question 4

What is used to assess the degree of consciousness?

Answer 4

Glascow Coma Scale

Question 5

Describe the basic algorithm for emergency management

Answer 5

• Supportive care
  
  • Airway management
  • Circulatory support
• Obtain history
• Physical examination
• Determine if toxidrome present
• Laboratory Evaluation
• Management strategies

Question 6

Define toxidrome

Answer 6

A group of signs and symptoms constituting the basis for a diagnosis of poisoning

Question 7

____ ______ provides airway control

Answer 7

endotracheal intubation

Question 8

How does endotracheal intubation provide airway control?

Answer 8

• Minimizes aspiration of gastric contents
• Ability to remove secretions
• Access to lungs to allow optimization of oxygenation and ventilation

Question 9

What can hypotension occur due to?

Answer 9

• Depression of myocardial contractility
• Depress CNS cardiorespiratory centres (ex. clonidine)
• GI fluid losses
• Peripheral vasodilation

Question 10

Rule out other causes of hypotension such as due to _____ or ____ _____

Answer 10

trauma or blood loss

Question 11

How do you manage hypotension?

Answer 11

• Volume expansion (ex. 0.9% NaCl, blood products)

- Vasopressors (ex. dopamine or norepinephrine)

Question 12

What other manifestations do you need to consider?

Answer 12

• Seizures
• Arrhythmias
• Electrolyte disturbances
• Hypoglycemia

Question 13

What are some things you need to try to obtain as part of patient history?

Answer 13

• age
• amount ingested - empty vials: own meds vs someone else’s meds
• medication history - family, friend, pharmacy
• time ingested
• time course of symptoms
• identification of meds or toxin (ex. pill left in vial, empty vials)
• symptoms
• circumstances of poisoning (accidental vs suicide)
• pre-hospital interventions
• associated conditions/past medical history

Question 14

Why is a repeated assessment of physical examination required?

Answer 14

-because patient status can change over time
and
-the time relationship of symptom presentation can be helpful in determining the toxin

Question 15

What is part of physical exam?

Answer 15

• Vital signs
• Temperature alterations
• Skin (ex. needle tracks, flushing, muscle tone)
• Breath (smell can help with identification - ex. alcohol)
• Lungs - ex. aspiration, wheezing
• Heart -arrhythmia
• Abdomen - ex. ileus/bowel sounds
• Neurological - ex. level of consciousness, response to voice/pain, presence of seizure, pupils

Question 16

Toxidrome

Answer 16

A group of signs and symptoms associated with a particular agent or toxin; also known as “symptom complexes”

Question 17

When are toxidromes most helpful?

Answer 17

when reviewing the clinical presentation and formulating the framework for assessment

Question 18

What limits the applicability of lab results?

Answer 18

time constrains

Question 19

What are some indications for laboratory testing?

Answer 19

• Monitoring
• Diagnostic confirmation
• Screening

Question 20

What is a Tox-Screen?

Answer 20

A combination of analytical procedures to help identify multiple common drugs encountered in an overdose

Question 21

What methods can be used for a tox-screen?

Answer 21

• immunoassays, thin-layer chromatography, gas chromatography
• can have long turn-around time
• immunoassays relatively fast

Question 22

Tox screen uses what fluids?

Answer 22

blood, urine, other

Question 23

Tox screen has a major problem of ??

Answer 23

false negatives

• substances which are present but not detected by the lab
• ranges from 10-30%
• a negative test does not rule out a toxic agent being present

Question 24

Describe a false positive

Answer 24

detection of therapeutic medications not contributing to the toxic clinical presentation

Question 25

describe some other lab investigations

Answer 25

• ECG - arrhythmia, QT interval
• abdominal x-ray (radio-opaque pill ex. iron)
• urine osmolality - osmolal gap (ex. ethylene glycol)
• arterial blood gas - acidosis
• electrolytes

Question 26

List some management strategies

Answer 26

• Supportive care
• Empiric Tx for altered mental status
• Decrease absorption of toxin
• Increase elimination of toxin
• Antidote

Question 27

Describe the potential treatment to be considered for patient with altered mental status from a suspected drug overdose

Answer 27

1) Dextrose 0.5-1 g/kg of D50W for an adult - to diagnose and treat or exclude hypoglycaemia
2) Thiamine 100mg IV for an adult (usually unnecessary for a child) to prevent or treat Wernicke-Korsakoff syndrome
3) Naloxone 2mg IV for adults and children with respiratory compromise
4) Oxygen

Question 28

List 4 ways to decrease absorption of a toxin

Answer 28

• Orogastric lavage
• Oral activated charcoal
• Whole bowel irrigation (flushing things through, not giving drugs a chance to be absorbed)
• Emesis with syrup of ipecac (not effective, not really used anymore)

Question 29

List 4 ways to increase elimination of a toxin

Answer 29

• Hemodialysis (only if an agent is dialyzable)
• Charcoal hemoperfusion (useful for theophylline and phenobarbital)
• Multiple dose oral charcoal (charcoal binds to drug, and there is then 0 concentration in stomach, then you have a concentration gradient and it can pull drug from blood back into stomach)