Transcript Management of Acute Poisoning - Lectures For UG-5
Slide 1
Slide 2
Among important toxicological principles that are
applied in evaluating the poisoned individual are
Exposure
and aspects related to reducing
absorption
Dose response considerations
Target tissue and systemic effects
Chemical interactions
Chemical antagonism as a management approach
Acute versus Chronic effects
Slide 3
1) Supportive Care (to sustain the vital signs)
A Airway Clearance
B Breathing maintenance
C Circulation enhancement
D Decontamination
2) Treat the patients depressed mental status
3) Rule out or treat hypoglycemia
Slide 4
4) Obtain history of the exposure
What substance was exposed
How much was consumed or exposed
Route of ingestion or exposure
Time since exposure
5) Identify Signs and symptoms of poisoning
Breathing rate, heart rate, dilation of pupil, Fits,
injuries or diseases associated to the symptoms
6) Neurologic Examination
Slurred speech, imbalancement, tremors
unconsciousness, seizures, confusion, headache
Slide 5
Advantages
› Can confirm the poisoning agent
› Predict anticipated toxic effects or severity of
exposure
› Confirm the diagnosis
› Help in guiding therapy
Limitations
› All chemical agents cannot be possibly screened
› These are usually time consuming and cannot be
provided as soon as treatment starts
› The results may not apply to the diagnosis of all
patients alike
Slide 6
Is performed when percutaneous
absorption of a substance may result in
systemic toxicity or when the toxic
substance may produce local toxic effects
e.g. burns caused by acid
Clothing should be removed and skin
should be irrigated by sufficient
quantities of Water
Neutralization should not be attempted.
This will only cause more pain to the
patient and worsen the poisoning
Slide 7
It involves removal or ingestant from the
gastrointestinal system and maybe carried out by the
following
Emesis
› Should not be attempted in Children or Depressed
patients
› Should not be attempted with Acid or Hydrocarbon
poisonings
› Should not be attempted with substances with an
extremely rapid onset of action
› Usually done by Ipecac syrup in a hospital, emesis
starts in 30 minutes and lasts 2 hours and produces 3
episodes of emesis
Slide 8
Gastric Lavage
› It is employed in patients who
have consumed life threatening
amounts of a drug within 1-2 hours
Used in patients who are not
alert or not recommended with
emesis
Lavage is performed after an
endotracheal tube secures the
airways
After aspiration of the gastric
contents 250-300mL of water or
saline is instilled and then
aspirated
The sequence is repeated until
the liquid returning becomes
clear
Slide 9
Activated Charcoal
Adsorbs almost all commonly ingested chemicals and
medicines and usually administered to overdose patients
within 30minutes to 2 hours
It greatly reduces oral absorption of nearly all
pharmaceuticals but should not be given if a patient is
already vomiting
Slide 10
It has been shown to be effective where activated charcoal
lacks efficacy
Usually a cathartic solution like Poly ethyl glycol (PEG) is
given orally through a nasogastric tube (1-2L/hr) until rectal
affluent is clear
Cathartics
Administration of a cathartic agent may help in removal of
toxins from the gastrointestinal tract and reduce absorption
Sorbitol (70%) is the most preferred cathartic agent
Slide 11
Forced Diuresis and urinary pH manipulation
Maybe used to enhance elimination of
substances whose route of elimination is
primarily renal and those that show little protein
binding
› Acid Diuresis by Sodium bicarbonate :
promotes ionization of weak acids thereby
preventing their reabsorption in the kidneys e.g
barbiturates
› Alkaline Diuresis by Ascorbic Acid :
Promotes elimination of weak bases e.g quinolones
Slide 12
Heamodialysis
› For chemicals already
absorbed into the blood and
in severe cases of
intoxication heamodialysis is
recommended
› Substances removed by
heamodialysis generally are
water soluble and have a
small volume of distribution
so are not protein bound
Slide 13
Heamoperfusion
› It is a technique where
anticoagulated blood is passed
through a column containing
activated charcoal or resin
particles.
› this is more rapid than
heamodialysis but it does not
correct fluid or electrolyte
abnormalities as in case of
hemodialysis
Slide 14
An antidote can simply be defined as a clinical
treatment using a chemical to counteract the effects
of another
The ultimate goal is to reduce toxicity by interacting
with the toxicant in ways that
Directly inhibit its effect through modification
of its chemical properties
Inhibit its effect by altering its physical
properties
Reduce effects at its sites of action
Facilitate its elimination
Slide 15
Poison
Antidote
Acetaminophen
N-acetyl Cysteine
Carbon monoxide
Oxygen
Cyanide
Sodium nitrite/sodium thiosulfate
Digoxin
Digoxin immune Fab
Heavy Metals
DMSA (dimercaptosuccinic acid)
Opiates
Naloxone
Slide 16
Rapid assessment of patient with management
Consider need for clinical chemistry
Whether it is possible to limit further absorption or
attempt its elimination
Considering antidotes
Considering further advice and information
Slide 2
Among important toxicological principles that are
applied in evaluating the poisoned individual are
Exposure
and aspects related to reducing
absorption
Dose response considerations
Target tissue and systemic effects
Chemical interactions
Chemical antagonism as a management approach
Acute versus Chronic effects
Slide 3
1) Supportive Care (to sustain the vital signs)
A Airway Clearance
B Breathing maintenance
C Circulation enhancement
D Decontamination
2) Treat the patients depressed mental status
3) Rule out or treat hypoglycemia
Slide 4
4) Obtain history of the exposure
What substance was exposed
How much was consumed or exposed
Route of ingestion or exposure
Time since exposure
5) Identify Signs and symptoms of poisoning
Breathing rate, heart rate, dilation of pupil, Fits,
injuries or diseases associated to the symptoms
6) Neurologic Examination
Slurred speech, imbalancement, tremors
unconsciousness, seizures, confusion, headache
Slide 5
Advantages
› Can confirm the poisoning agent
› Predict anticipated toxic effects or severity of
exposure
› Confirm the diagnosis
› Help in guiding therapy
Limitations
› All chemical agents cannot be possibly screened
› These are usually time consuming and cannot be
provided as soon as treatment starts
› The results may not apply to the diagnosis of all
patients alike
Slide 6
Is performed when percutaneous
absorption of a substance may result in
systemic toxicity or when the toxic
substance may produce local toxic effects
e.g. burns caused by acid
Clothing should be removed and skin
should be irrigated by sufficient
quantities of Water
Neutralization should not be attempted.
This will only cause more pain to the
patient and worsen the poisoning
Slide 7
It involves removal or ingestant from the
gastrointestinal system and maybe carried out by the
following
Emesis
› Should not be attempted in Children or Depressed
patients
› Should not be attempted with Acid or Hydrocarbon
poisonings
› Should not be attempted with substances with an
extremely rapid onset of action
› Usually done by Ipecac syrup in a hospital, emesis
starts in 30 minutes and lasts 2 hours and produces 3
episodes of emesis
Slide 8
Gastric Lavage
› It is employed in patients who
have consumed life threatening
amounts of a drug within 1-2 hours
Used in patients who are not
alert or not recommended with
emesis
Lavage is performed after an
endotracheal tube secures the
airways
After aspiration of the gastric
contents 250-300mL of water or
saline is instilled and then
aspirated
The sequence is repeated until
the liquid returning becomes
clear
Slide 9
Activated Charcoal
Adsorbs almost all commonly ingested chemicals and
medicines and usually administered to overdose patients
within 30minutes to 2 hours
It greatly reduces oral absorption of nearly all
pharmaceuticals but should not be given if a patient is
already vomiting
Slide 10
It has been shown to be effective where activated charcoal
lacks efficacy
Usually a cathartic solution like Poly ethyl glycol (PEG) is
given orally through a nasogastric tube (1-2L/hr) until rectal
affluent is clear
Cathartics
Administration of a cathartic agent may help in removal of
toxins from the gastrointestinal tract and reduce absorption
Sorbitol (70%) is the most preferred cathartic agent
Slide 11
Forced Diuresis and urinary pH manipulation
Maybe used to enhance elimination of
substances whose route of elimination is
primarily renal and those that show little protein
binding
› Acid Diuresis by Sodium bicarbonate :
promotes ionization of weak acids thereby
preventing their reabsorption in the kidneys e.g
barbiturates
› Alkaline Diuresis by Ascorbic Acid :
Promotes elimination of weak bases e.g quinolones
Slide 12
Heamodialysis
› For chemicals already
absorbed into the blood and
in severe cases of
intoxication heamodialysis is
recommended
› Substances removed by
heamodialysis generally are
water soluble and have a
small volume of distribution
so are not protein bound
Slide 13
Heamoperfusion
› It is a technique where
anticoagulated blood is passed
through a column containing
activated charcoal or resin
particles.
› this is more rapid than
heamodialysis but it does not
correct fluid or electrolyte
abnormalities as in case of
hemodialysis
Slide 14
An antidote can simply be defined as a clinical
treatment using a chemical to counteract the effects
of another
The ultimate goal is to reduce toxicity by interacting
with the toxicant in ways that
Directly inhibit its effect through modification
of its chemical properties
Inhibit its effect by altering its physical
properties
Reduce effects at its sites of action
Facilitate its elimination
Slide 15
Poison
Antidote
Acetaminophen
N-acetyl Cysteine
Carbon monoxide
Oxygen
Cyanide
Sodium nitrite/sodium thiosulfate
Digoxin
Digoxin immune Fab
Heavy Metals
DMSA (dimercaptosuccinic acid)
Opiates
Naloxone
Slide 16
Rapid assessment of patient with management
Consider need for clinical chemistry
Whether it is possible to limit further absorption or
attempt its elimination
Considering antidotes
Considering further advice and information