do you need to identify the poison before treating someone?
NO! Attempts to identify the poison should NOT delay care!
if someone has an altered mental status or depressed GCS, what three things can we give them?
the “coma cocktail” - DTN
D50 (for possible hypoglycemia)
thaimine (for possible alc. caused wernickes enceph.)
narcan aka naloxone (for possible opiod OD)
4 part general management for suspected overdose
- Ensure adequate airway: oral, nasal, intubate if necessary
- Ensure adequate oxygenation: high-flow O2, treat bronchospasm
- IV access: two large-bore lines
- Cardiac, VS & SpO2 monitor
what things can cause an altered mental status?
“AEIOU TIPS”
Alcohol, Endocrine, Epilepsy, Intoxication, Oxygen (hypoOx) , Uremia
Trauma, Tumor, Infection, Psychological, Shock, Stroke
Dx workup for suspected OD/tox?
labs: urine drug screen, CMP
imaging: Abdominal Xray
EKG: for conduction delays or ischemia
what is a toxidrome?
A collection of symptoms and signs that consistently occur after ingestion of a particular toxin or drug class or agent
how is a toxidrome Dx?
history and PE
5 classic toxidromes
Sympathomimetic (cocaine, decongestants, MDMA, etc) Opiate Anticholinergic Cholinergic Sedative-Hypnotic
what are the various mechanisms of sympathomimetic toxidromes?
- direct alpha & beta receptor agonists
- indirectly release catecholamines
- prevent metabolism & reuptake of catecholamines
what are the effects of a sympathomimetic toxidrome?
Increased temp, diaphoresis
Tachycardia & hypertension, Palpitations, chest pain
Mydriasis
CNS excitation, Hyperactivity, seizures
3 part txt for sypathomimetic toxidrome?
ABC
supportive care: lots of BENZOS!, temp control
consider GI decontamination
*txt HTN unresponsive to benzos
what are the 3 CNS receptors that opiods bind to? what are the effects of each?
Mu – analgesia, resp depression, euphoria
Kappa – sedation, analgesia, mioisis
Sigma – dysphoria, hallucinations
what are the effects of an opiate toxidrome?
CNS depression & Respiratory depression Bradycardia, Hypotension Miosis Hypothermia Nausea/vomiting Flaccidity
opiate toxidrome txt?
ABCs, supportive care, narcan!
what is the half life of narcan?
60-90 min in adults (shorter than opiod drugs)
what are the effects of an anti-cholinergic toxidrome?
“RED as a beet, DRY as a bone, BLIND as a bat, HOT as a hare, MAD as a hatter, FULL as a flask”
what is the antidote for anti-cholinergic toxidrome? when would you use it? why is this?
Physostigmine: ONLY if Severe agitation or psychosis unresponsive to other therapy
-NO history of seizures
-w/ normal EKG
-not on TCAs (b/c chol. syndrome)
why? Can cause cholinergic syndrome (if you go too far with txt)
these are all examples of what kind of toxidrome?
organophosphate & carbamate pesticides, nerve agents, edrophonium, pilocarpine, pyridostigmine
some ‘shrooms -muscarine containing
cholinergics
what are the effects of cholinergic toxidrome?
D - diaphoresis, diarrhea, decr BP U - urination M - miosis B - bronchorrhea, bronchospasm, brady E - emesis, excitation of skeletal muscle L - lacrimation S - salivation, seizures
what is the pathophys of the cholinergic toxidromes?
Inhibition of acetylcholinesterase: leads to increased acetylcholine
Muscarinic activation
bradycardia, incr secretions, bronchospasm
Nicotinic
fasciculations, HTN, weakness
what antidote can you give for cholinergic toxidrome?
atropine (antichol)
these are all what type of toxidrome? ETHANOL!! anticonvulsants barbiturates benzodiazepines GHB Ambien
sedative=hypnotics
what are the effects of sedative-hypnotic toxidrome?
ataxia, decr reflexes, slurred speech, APNEA! confusion, sedation, coma delirium, hallucinations blurred vision/diplopia dysesthesias/paresthesias
pathophys of sedative-hypnotic toxidromes
direct & indirect GABA agonists resulting in CNS inhibition
sedative-hypnotic mgmt (4 step)
- ABC, supportive care
- Be prepared to intubate
- Activated charcoal
- No agent-specific antidotes. . . .except Romazicon® (flumazenil)
when is the ONLY time you would use flumazenil? why?
if you caused the benzo-OD
- if benzos were not the causative agent, flumazenil can put them in status epilepticus
what are the 4 general routes we can get rid of a poison ? what are these all trying to do?
Prevent or decrease further absorption
Increase elimination
Antagonize effects
*all trying to minimize the bioavailability
what are the 4 general routes we can get rid of a poison ? what are these all trying to do?
Prevent or decrease further absorption
Increase elimination
Antagonize effects (antidotes)
*all trying to minimize the bioavailability
how much charcoal do we give? when does it have the greatest effect?
1g/kg
greatest benefit within ONE HOUR of ingestion (effect is minimal after 2 hours b/c already passed the pylorus)
when can you use gastric lavage?
ONLY if < 1 hour from ingestion and life-threatening drug or dose
when would you use whole bowel irrigation on? who can’t you use it on?
Especially useful for metals or other things not well adsorbed by charcoal
Avoid in patients with obstruction or ileus
what are 3 ways we decrease abs of a toxin?
charcoal, gastric lavage, whole bowel irrigation
what are 2 ways we increase elimination of a toxin?
- alkaline/forced diuresis
2. extracorporeal removal
what is is alkaline/forced diuresis? when is it used for toxin elimination?
- infusion of LOTS of saline + bicarb
Used to eliminate acidic drugs mainly excreted by the kidneys (salicylates, barbs, INH)
*danger of serious fluid and electrolyte derangements
what is extracorporeal removal?
for active metabolites or poor organ clearance will include…. Hemodialysis Hemofiltration Hemoperfusion
what are the antidotes to these 3: Acetaminophen, Anticholinergics, Anticholinesterases?
Acetaminophen - N-acetylcysteine
Anticholinergics- physotigmine
Anticholinesterases - atropine
what are the antidotes to these 3: Benzodiazepines
Carbon Monoxide, Cyanide?
Benzodiazepines- flumazenil
Carbon Monoxide- O2
Cyanide- amyl nitrite
what are the antidotes to these 3: Benzodiazepines
Carbon Monoxide, Cyanide? (kinds weeds)
Benzodiazepines- flumazenil
Carbon Monoxide- O2
Cyanide- amyl nitrite
what are the antidotes to these? Arsenic, copper, gold, lead, mercury (weeds)
Dimercaprol, EDTA, penicillamine
what are the antidotes to these 2?Iron, Isoniazid (weeds)
Iron- Deferoxamine
Isoniazid- Pyridoxine
what are the antidotes to these 4? Methanol
Methemoglobinemia, Opioids, Organophosphates (weeds)
methanol - Ethanol, fomepizole
metheblog.- Methylene blue
opiods- Naloxone
organophosphates- Atropine, 2-PAM-Cl
what is the mainstay of most treatments for toxicology?
Supportive care and decontamination
what is the toximetabolite of acetaminophen? what does it do?
Toxic metabolite NAPQ1
NAPQ1 binds to hepatocytes and causes necrosis
acetaminophen toxic threshold in adults? what about ASA?
acetaminophen: Toxic threshold adults - 7.5-10g
ASA: Adult lethal dose - 10-30g
acetaminophen poisoning signs: phase I < 24 hours
Anorexia, malaise, N/V, diaphoresis
how many days after acetaminophen poisoning is hepatic and renal failure?
2-4 days
txt for acetaminophen poisoning?
charcoal and N-acetylcysteine
txt for alcohol poisoning?
- Inhibit alcohol dehydrogenase( Ethanol or Fomepizole)
2. Removal of alcohol & it’s metabolites: Hemodialysis
salicylate (ASA) poisoning txt ?
- Activated charcoal
- Supplemental glucose
- Alkalinization of serum & urine
- Dialysis (hemodialysis)
what do we give for TCA overdose? why?
give Magnesium! prevents torsades!
what can TCA overdose cause? (4)
- Cardiac: QRS prolongation (can become torsades)
- Hypotension, Decreased CO
- CNS: Delerium, seizures, coma
- Anticholinergic tox effects
TCA overdose txt (4)
ABCs
Activated charcoal
Gastric decontamination
NaHCO3 - most effective therapy!
BB overdose txt
ABCs Activated charcoal Temporary pacing/vasopressors prn Glucagon High dose insulin/glucose drip **Atenolol is dialyzable**
CCB overdose txt
ACBs Activated charcoal ?Gastric lavage Ca gluconate Glucagon Insulin/glucose infusion
CO poisoning txt?
ABCs
100% FiO2
Hyperbaric O2
what is phencyclidine?
PCP- a sympathomimetic
what type of drug is ecstasy?
MDMA- a sympathomimetic
what type of drugs are pesticides?
nerve agents/organophosphates- cholinergics