Management Of Poisoned Patient Flashcards
What is the golden rule for poison management
Treat the patient not the poison
First stabilize the patient and treat the symptoms
Secondly worry about the poison
Many poisons acts as ?
CNS depressants
Common sx of poison that needs to be treated as CNS depressant
Coma
Loss of airway protective reflexes and respiratory drive
Flaccid tongue
Aspiration of gastric content
Respiratory arrest
Other poison sx that can lead to death
Cardiovascular toxicity
Cellular hypoxia
Seizures
Delayed symptoms
Sx of cardiovascular toxicity
Hypotension from depressed cardiac contractility
Hypovolemia from vomiting, diarrhea or fluid sequestration
Peripheral vascular collapse caused by blockage of alpha adrenergics
Cardiac arrhythmia
Signs of lethal arrhythmia
Ventricular tachycardia
What drugs can cause lethal arrhythmia
Ephedrine
Amphetamines
Cocaine
Digitalis
Theophylline
TCA
Antihistamine
Some opioids
What agents can induce hypoxia
Cyanide
H2S
CO
Signs of cellular hypoxia
Cyanosis
Tachycardia
Hypotension
Severe lactic acidosis
What is the initial management of poisoned patients
Treat and stabilize patient
Address coma or seizures
What are the ABCD of supportive measures
Airway
Breathing
Circulation
Dextrose for decreased mental status
How is airway addressed
Cleared of vomit or obstacles
- Insert endotracheal tube if needed
- May need to lay patient on side
- Move flaccid tongue out of airway
How is breathing addressed
Observe and assess oximetry (pulse)
- When in doubt measure arterial blood gas if you have time
- Patients with respiratory insufficiency should be intubated and mechanically ventilated
How is circulation addressed
Continuous monitoring of pulse rate and blood pressure
- Urinary output
- Evaluation of peripheral perfusion
- Use of IV if needed
- Blood drawn for serum glucose and other factors
How is dextrose used as initial management
Use with patients with altered mental status
- Don’t use if you know patient is not hypoglycemic
- Rapid bedside test (treat patient first)
What is the dose of dextrose for adult and children
Adult = 25 g (50 ml 50% dextrose) with IV for adults
Children = 0.5 g/kg (2 mL/kg 25% dextrose)
What is the ER Assessment: Oral Statement
- Amount of drug
- Type of drug
- “House” everybody lies
What is ER assessment: Environment
- Talk to family members
- 1st responders (fire department, paramedics)
- What was the house like?
In ER assessment what should you bring to ER
- Syringes
- Empty bottles
- Household products
- OTCs
What is the standard ER assessment to check for vitals
- Pulse
- Heart rate
- Blood pressure
- Temperature
What other part of the body can be assessed for vital signs during ER assessment
- Eyes
- Reactive
- Dual reaction
- Mouth
- Skin
- Abdomen
- CNS
What medication can induce hypertension or tachycardia
Amphetamines
Cocaine
Anti-muscarinic
What medication can induce hypotension or bradycardia
Calcium channel blockers
Beta-blockers
Clonidine
Sedative hypnotics
What medication can induce hypotension or tachycardia
TCAs
Trazadone
Quetiapine
Vasodilator
Beta agonist
During eye assessment what drugs can induce mitosis- constriction
- Opioids
- Clonidine
- Cholinesterase inhibitors
- Sedatives (coma)
During eye assessment what can drugs can cause mydriasis-dilation
- Amphetamines
- Cocaine
- LSD
- Atropine
- Anticholinergic drugs
During eye assessment what drugs can cause horizontal nystagmus
- Phenytoin
- Alcohol
- Barbiturates
- Sedatives
During eye assessment what drugs can cause both vertical and horizontal nystagmus
Phenycyclidine (PCP)
During ER assessment what signs of nervous system should be assessed
- Focal seizures/motor deficits
- Nystagmus, dysarthria (motor speech problem), ataxia
- Twitching/muscular hyperactivity
- Muscular rigidity
- Seizures
- Flaccid coma with no reflexes
How can electrolytes be used during ER assessment
Calculate ion gap
What is the anion gap
Cations - anions
Cations are usually greater by 12-16 mEq
What drugs can induce anion gap
Aspirin
Methanol
Ethylene glycol
Isoniazid
Iron
How does TCA overdose impact EKG
Widening QRS complex by > 100 msec
What drugs impact EKG by prolonging QTc interval by > 400 msec
Quinidine
New antidepressant
New antipsychotic
Lithium
Arsenic
Which drugs impact EKG through variable AV block
Digoxin
Cardiac glycosides
CO
What is the reality of toxicology screening
Time consuming
Expensive
Unreliable
Not all drugs can be included in screen
Results may take days
Which drugs might not be included in screenings
Beta blocker
Calcium channel blockers
Isoniazid
True or False: Every existing poison has an antidote
False
How is skin decontamination done as an antidote
Remove contaminated clothing and double bag to prevent exposure
What GI approaches are performed as antidote decontamination for GI
Emesis
Gastric lavage
Activated Charcoal
Cathartics
When is GI emptying as an antidote method more effective
Within 1 hour of ingestion
How does activated charcoal work as an antidote
Absorbs poison
What can be used for emesis
Ipecac syrup not extract
When should ipecac Symptoms not used
If toxicants is corrosive, petroleum based or rapid acting convulsant
Should salt water or finger used to induce emesis
No
How can gastric aspiration induced mechanically
Use nasogastric or orogastric tube to remove stomach content
Requires anesthesia and stomach pumping
Use 0.9% saline at body temperature
What is the MOA of activated charcoal
Adsorb many drugs and poison due to large surface area
How is activated charcoal dosed compared to the weight of toxicant
Charcoal: toxicant weight (10:1)
What is the dosage form of activated charcoal
Tablets or powders
Which toxins does charcoal not bind to
Iron
Lithium
Potassium
Which toxins does charcoal bind poorly to
Alcohol
Cyanide
What can repeated doses of activated charcoal do
Enhance systemic elimination of drugs (i.e gut dialysis)
What is another name of Cathartics
Laxatives
What is the mechanism of action Cathartics
May hasten removal of toxins from GI and alter absorption
What are the products are used as Cathartics
Rushpills
Polyethylene glycol electrolyte solution
What procedure can Cathartics be used prior
Colonoscopy
Which toxin does cathartics increase its guts elimination
Iron
What is the two prone approach to designing specific antidotes
Pharmacokinetic
Pharmacodynamic
How does the pharmacokinetic work
Prevent absorption and distribution
Enhance elimination
How does pharmacodynamic work
Pharmacological
Interfere with the binding to target
Antagonistic
What are the non-specific antidotes
Dialysis
Hemodialysis
Forced diuresis and urinary pH manipulation
Renal elimination
Dialysis: peritoneal dialysis
Simple but ineffective and works into the abdominal cavity
What are the benefits of hemodialysis
Assist in fluid correction and electrolyte balances
Enhance removal of toxic metabolite
Efficiency of hemodialysis is dependent on what factor
Molecular weight
Water solubility
Protein binding endogenous clearance
Tissue distribution
Can toxin be eliminated by hemodialysis if it is not in the blood
No
Why has forced diuresis and urinary pH manipulation lost favor
It can cause volume overload and electrolyte imbalance
How does renal elimination work
Can increase by adjusting urinary ph
Salicylate are eliminate by urinary alkalization
Can increase rhabdomylosis
What is rhabdomylosis
Damaged skeletal muscle break down quickly and enters the bloodstream and proteins cause damage to the kidney and cause renal failure
What can cause rhabdomylosis
Seizure
Muscle rigidity
Crush injury
What are the symptoms of rhabdomylosis
Muscle pain
Vomiting
Confusion
Brown-urine house
When is acetaminophen over dose usually seen
Suicide attempts
Accidental poisonings
What are the symptoms of acetaminophen overdose
Initial mild GI
Nausea
Vomiting
When does lever toxicity occurs and what are the signs and symptoms
24-36 hours
Increased aminotransferases
Hypoprothrombinemia
Severe acetaminophen poisoning is characterized by
Liver failure
Hepatic encephalopathy
Renal failure
Come back to the flow chart on slide 25
Sure will
What is acetaminophine overdose concentration after the
> 150-200 mg/L
Who are at greater risk of acetaminophen toxicity
Alcoholics or those taking drugs metabolized by CYP450
What is the antidote of acetaminophen overdose
Acetylcysteine - acetate or mucomyst
MOA of acetadote
Acts like GSH and binds to toxic metabolite of acetaminophen
When is acetadote most effective
When given early (8-10 hours)
What is the antidote in severe cases of acetaminophen toxicity
Liver transplantation
What drugs contribute to amphetamine overdose
Cocaine
Methamphetamine
Methyldioxymethamphetamine (MDMA, ecstasy)
Pseudoephedrine
Ephedrine (Ma-Huang)
Caffeine
When used recreationally, what can a person experience with amphetamine
Sense of power
Euphoria
Well being
What results from amphetamine taking higher doses at
Restlessness
Agitation
Acute psychosis
HTN and tachycardia
Increased muscle activity (dehydration and hypotension)
Seizures ( hyperthermia or rhabdomylosis)
Extreme increase in body temperature 42°C or 107.6°F (brain damage, hypotension, coagulopathy, renal failure )
How is amphetamine overdose treated
Supportive care
No specific antidote
Manage seizures and hyperthermia aggressively
What medication is used to battle amphetamine seizure overdose
IV benzodiazepines
What does anticholinergics do
Inhibit acetylcholine effect on muscarnic receptors
Which anticholinergics do not target cholinergic receptors
Antihistamine
TCAs
What is the muscarnic symptoms of anticholinergic toxicity
Skin flushing
Hyperthermia
Dry mucosal membrane w/o sweating
Blurred vision, cychoplegia
Confusion
Delirium
What are other anticholinergie toxicity
Sinus tachycardia
Dilated pupil
Coma
Seizures (if patient took TCA or anti histamine)
What is the treatment for anticholinergic toxicity
Largely supportive
Agitation is controlled with sedation, benzodiazepine or antipsychotics
Physostigmine
What is the MOA of physostigmine
Inhibits acetycholine esterase activity to increase acetylcholine levels
What receptors does physostigmine work on
Nicotinic and muscarinic
How is physostigmine dosed
0.5-1 mg IV
What is physostigmine ADR
Bradycardia
Seizure
Who should avoid physostigmine use
Patient with TCA overdose due to increased risk of cardiotoxicity and asystole
What dose of antidepressant can be lethal or classified as an overdose
1 g or 15-20 mg/kg
What’s antidepressant such as TCA MOA
Competitive antagonist at muscarinic receptors
What are the ADR of TCA antidepressants
Tachycardia
Dry mouth
Dilated pupils
Strong alpha blockers can lead to vasodilation
What are the symptoms of antidepressant toxicity
- Tachycardia
- Dilated pupils
- Vasodilation
- Seizures
- Depression
- Hypotension
What are quinidine like depressants effect that can be symptoms of antidepressants toxicity
- Slowed conduction
- Wide QRS interval
- Depressed cardiac contractility
- Lead to arrhythmias with ventricular conduction block
- Ventricular tachycardia
What is the antidepressant overdose treatment
- General supportive care
- Endotracheal intubation with assisted ventilation
- IV fluids for electrolyte loss
- Dopamine or norepinephrine if needed
In antidepressants overdose when is norepinephrine used as the initial drug
If hypotension is present
How is quinidine like cardiac toxicity with wide QRS managed
Sodium bicarbonate
Why should physostigmine not used in quinidine like cardiac toxicity
Can aggravate depression of cardiac conduction and cause seizure
What other form can patients overdose with antidepressants
With MAOIs
MAOIs
Tranylcypromine
Phenelzine
Older antidepressants
What are MAOIs Symptoms
Anticholinergic
Severe hypertension
Interact with SSRIs
What new anti depressants can cause toxicity
Fluoxetine
Paroxetine
Citalopram
Venlafaxine
Bupropion
Mostly SSRIs
Generally safer than TCA and MOI
Can cause seizures
Venlafaxine
Not an SSRI but can cause seizures
Bupropion
Old antipsychotics
Phenothiazine
Butyrophenones
New atypical
Clozapine
Quetiapine
Risperidone
What are the symptoms of antipsychotic overdose
Drowsiness - proceeds to coma with brief agitation
QT prolongation
CNS depression
Seizures
Hypotension
What class of antipsychotics can cause parkisonian like disorder
D2 blocker
How is antipsychotic overdose treated
Supportive care
- Gastric lavage
- Activated charcoal
- Saline cathartic
Antidote for antipsychotic induced hypotension
Norepinephrine
Antidote for antipsychotic induced seizures
Diazepam
Antidote for antipsychotic lithium overdose
Dialysis
What accounts for numerous suicide and accidental poisonings
Aspirin
Chronic overdose of aspirin in elderly is usually due to
Forgetting if they took it or not
Aspirin MOA
- Ion gap
- Metabolic acidosis
- Respiratory alkalosis
- Platelet dysfunction and bleeding
Acute aspirin overdose symptoms
- Hyperventilation
- Respiratory alkalosis with medulla stimulation
- Metabolic acidosis
- Increased ion gap from lactate excretion of bicarbonate in urine
- Increase in body temperature from uncoupled oxidative phosphorylation
- Vomiting
- Hyperpnea
Aspirin severe overdose symptoms
Profound metabolic acidosis
- Seizures
- Coma
- Pulmonary edema
- Cardiovascular collapse
Aspirin overdose treatment
Supportive care
Treat ion gap
Treat seizures
Treat fever
Aggressive gut decontamination
Gastric Savage
Repeated activated charcoal
Why is I.V fluid given in aspirin overdose treatment
To replace fluid loss from tachycardia, vomiting and fever
How is moderate intoxication of aspirin treated
• IV with sodium bicarbonate to Alkalizes urine, which increases salicylate excretion by trapping ion
What is considered severe aspirin intoxication
> 100 tablets
How is severe cases of aspirin intoxication managed
Hemodialysis
Restore acid/ base balance
Restore salts
Why are beta blockers administered
Raise BP and HR
Glucagon function of cardiac cells
Increase cAMP independent of b-adrenoreceptor
Treatment of beta blocker overdose
B-agonist
Atropine: won’t work for Na block
Glucagon
Why is the aim to increase cAMP for better blocker over close
Because cAMP inhibits MLCK phosphorylation preventing contraction
Why should one be careful with calcium channel blockers
Toxicity and death can occur at relatively low doses
How can calcium charnel blockers induce toxicity and death
Depress sinus node automaticity
- Slow AV node conduction
- Decrease cardiac output
- Decrease blood pressure
- Serious hypotension
Example of calcium channel blockers
Nifedipine
Dihydropyridines
For calcium channel blocker in sustained released form how can toxicity be addressed
Whole bowel irrigation
Oral activated charcoal
Calcium intravenous at 2-10 g are good to treat what type of calcium channel blocker toxicity
Depressed Cardiac contractility but not for peripheral collapse
What drugs can be given for Cardiac channel blocker toxicity
Glucagon
Vasopressin
Epinepherine
High dose insulin and glucose
What are the types of cholinesterase inhibitor
Organophosphate
Carbamate cholinesterase inhibitors
Insecticides
How can one be exposed to cholinesterase inhibitors
Insecticides/pesticides
Suicides
Rarely food
What tragic event has Cholinesterase inhibitors be used for
Warfare
Tokyo subway 95
What are the muscarinic stimulation Symptoms of cholinesterase inhibitor overdose
- Abdominal cramps
- Excessive salivation
- Sweating
- Increased urinary frequency
- Increased bronchial secretion
What are the CNS effect Symptoms of cholinesterase inhibitor overdose
- Agitation
- Confusion
- Seizures
What are the Nicotinic stimulation Symptoms of cholinesterase inhibitor overdose
- Generalized ganglionic activation
- Hypertension
- Tachycardia or bradycardia
- Muscle twitching and fasciculations
What other Symptoms are shown in cholinesterase inhibitor over dose
- Diarrhea
- Urination
- Miosis and muscle weakness
- Bronchospasm
- Excitation
- Lacrimation
- Seizures, sweating and salivation
Cholinesterase inhibitor treatment
Generalized supportive care
Atropine: muscarnic Only
Pralidoxine; nicotinic and muscarinic receptors
The Rock
What are cyanide forms
CN salts
HCN
Uses of cyanide
- Chemical synthesis
- Rodenticides
- Executions at one time
- Suicide/homicide
Sources of cyanide
- Burning of plastics
- Burning of wool
- Synthetic and natural products
- Plant and seeds
- Apple seeds
- Peach
Cyanide MOA
Bind cytochrome oxidase in mitochondria to induce cellular hypoxia and lactic acidosis
Symptoms of cyanide poisonings
- Shortness of breath
- Agitation
- Tachycardia
- Seizures
- Hypotension
- Death
- Characterized by severe metabolic acidosis
Cyanide treatment
Rapid Administration of activated charcoal
General supportive care
Antidote Kit
Cyanokit (EMD pharmaceuticals)
Cyanide antidote kit
- Forms of nitrite
- Amyl nitrite
- Sodium nitrite
- Sodium thiosulfate
- Induce methemoglobinemia that binds free CN-
* Creates a less toxic cyanomethemoglobin - Thiosulfate
* Enzyme cofactors
* Facilitates conversion to CN to less toxic hydroxocobalamin
Cyanokit
- Concentrated Hydroxocobalamin
* Combines with CN- to form cyanocobalamin (B12)
Symptoms of acute digoxin overdose
- Renal insufficiency
- Diuretics with digoxin
- Vomiting
- Hyperkalemia
- Hypokalemia with long term use
- Cardiac rhythmic distrubances
* Sinus bradycardia * AV block * Atrial tachycardia * Accelerated junctional rhythm
When is atropine used in digoxin overdose treatment
Bradycardia or sinus block occur
What type of antibiotics can be used with digoxin overdose treatment
Digoxin antibodies
- IV administration at indicated dosages
- Symptoms usually improve 30-60 min
- Can be used for other cardiac glycosides
- Oleander
Ethanol and sedative hypnotic drugs
- Ethanol
- Benzodiazepines
- Barbiturates
- G-hydroxbutyrate (GHB)- date rape
- Carisoprodol (Soma)
Symptoms of ethanol and sedative hypnotic drugs
- Drunk
* Euphoria • Rowdy - Dead drunk
* Stupor • Coma
• Decreased respiratory drive
- Decreased protective respiratory reflexes
* Can result in aspiration of gastric contents
* Tracheal aspiration - Hypothermia
* Exposure
* Decreased shivering
Ethanol and sedative hypnotic drugs treatment
- Supportive care
* Protect the airway
* Intubation if needed - IV fluids for hypotension
- Dopamine if needed
Benzodiazepine antidotes
- IV flumazenil
- Benzodiazepine antagonist (Can cause seizures in patients addicted to benzodiazepines)
- Don’t give with patients with TCA overdose
True/False: There is no antidote for ethanol, barbiturates or other sedative drugs
True
Ethylene glycol and methanol description
Metabolized into organic
acids
- Cause CNS depression
- Drunken state similar to Ethanol
Product of methanol metabolism and effect
Metabolized to formic acid and Causes metabolic acidosis
Product of ethylene glycol metabolism and effect
Metabolized to hippuric acid and oxalic acid and causes renal failure
Symptoms of ethylene glycol and methanol overdose
- Drunkenness and altered mental status
- Anion gap
- Severe metabolic acidosis
- Hyperventilation
- Blurred vision and blindness
Treatment of ethylene glycol and methanol
- Fomepizole (4-methypyrazole)
- Inhibits alcohol dehydrogenase
- Don’t use with alcohol
- Hemodialysis
- Ethanol, but hard to get to high enough dose
What was thophylline once used to treat
- Bronchospasm
- Asthma
- Bronchitis
- 20-30 tablets is toxic
What are Symptoms of theophylline toxicity
- Sinus tachycardia
- Tremor
- Vomiting
- Hypotension
- Hypokalemia
- Hyperglcemia
Antidote for opioid overdose
Naloxone: short window of action
Patient can slip in and out of coma
Naloxone dose
0.1-0.4 mg
How is naloxone used to block all effects of heroin
Give on alternate days
Used to maintain addicts
Naloxone