Poisonings Flashcards
As you’re walking toward the room of a suspected poisoning, what actions should you take upon arriving? (3)
- Assess the primary survey
- Order an EKG
- Order a safety companion or standard suicide precautions
- Hypoxia: Place on 100% O2 nonrebreather (also useful prior to intubation)
- Hypoglycemia: obtain a point of care fingerstick blood glucose
- Opioids: administer Narcan 0.4 to 2mg IV to reverse opiates
Coma cocktail, per wiki:
A standard combination included:
- dextrose (1 Amp D50W IV),
- flumazenil (0.2 mg IV),
- naloxone (2 mg IV), and
- thiamine (100 mg IV).
It has been suggested that the use of naloxone and flumazenil be administered more selectively than glucose and thiamine.
What are some key historical questions to ask in a poison pt?
What?
How much?
When?
Why? (accidental or intentional)?
What are important PE things to pay attn to during the exam of a poison pt?
- Vital Signs (there is a reason they are called “vital signs”)
- Mental status (agitated, confused, somnolent?)
- Pupils
- Skin color
- Track marks/skin poppers
- Presence of sweat
- Bladder size (urinary retention)
Describe the classic anticholinergic toxidrome.
- Mad as a hatter (Altered mental status)
- Blind as a bat (mydriasis)
- Hot as Hades
- Red as a beat
- Dry as a bone
List some eg’s of meds that can cause anticholinergic toxidrome
- TCA’s Tricyclic antidepressants
- Antihistamines
- Overactive bladder medication
Describe the classic cholinergic toxidrome.
DUMBBELS
Diarrhea Urination Miosis/Muscle weakness. Bronchorrhea/Broncbhospasm Bradycardia Emesis Lacrimation Lethargy Salivation/Sweating
*What are common causes of cholinergic toxidrome?
organophosphate poisoning (pesticides) and nerve agents
*Tx of cholinergic toxidrome?
Atropine, pralidoxime, decontaminate
Tx of anticholinergic toxidome?
Mostly supportive (except TCA–separate)
Describe the classic the classic sympathomimetic syndrome.
Tachycardia Hypertension Mydriasis Diaphoresis Hyperthermia Agitation
List some drugs that can cause sympathomimetic syndrome.
over-the-counter cold agents (containing ephedrine), illegal street drugs (eg, cocaine, amphetamines, methamphetamine), dietary supplements (ephedra), and illicit designer drugs (eg, 3,4-methylenedioxy methamphetamine (MDMA, “ecstasy”)
Tx of sympathomimetic syndrome?
Involves sedation, hydration, and treatment of complications such as rhabdomyolysis and hyperthermia.
Classic signs of opioid OD?
Tx?
Apnea
Hypoxia
Unresponsiveness
Flash pulmonary edema (rare)
Naloxone
What are some important tests to perform in the toxicology pt?
- EKG
- Tox screen
- Tylneol/ASA testing
- Lytes
- Levels of specific med
- Other (depends)
*What are the causes of AG-metabolic acidosis?
MUDPILES M = Methanol U = Uremia D = DKA or AKA P = Paraldehyde I = Iron, Isoniazid L = Lactate (many causes including carbon monoxide, sepsis, blood loss?) E = Ethylene Glycol S = Salicylates
List some common decontamination methods in poisoning,
Activated Charcoal
Whole Bowel Irrigation
Gastric Lavage (rare)
How does activated charcoal work?
When is it most efficacious (time)?
*What does charcoal NOT bind?
Activated Charcoal is given orally to absorb toxins that are present in the GI tract. Toxins bind to the charcoal and are excreted without being digested.
It is most efficacious if given within the first hour post ingestion but still works beyond that point.
Charcoal does not bind metals (such as iron), alcohols or hydrocarbons. It should be avoided in patients with somnolence as they run the risk of aspiration
What is whole bowel irrigation?
When is it used?
Whole bowel irrigation involves the administration of an osmotically balanced polyethylene glycol electrolyte solution (like Go Lytely) to flush the bowel to prevent the absorption of ingested toxins.
It is used in cases where charcoal is not effective, with certain sustained release products, and in cases of illicit drug packet ingestions (body packers).
What is gastric lavage, and when might it be used?
Lavage involves the application of a very large bore (36 – 40 French) orogastric tube and then flushing the stomach with aliquots of water ideally to obtain pill fragments.
Gastric Lavage is rarely used and carries significant risks with questionable benefit. In some cases, however, such as recently ingest lethal substances or an intubated overdose following recent ingestion, the benefits may outway the risks and warrant use.
What old method of decontamination is no longer recommended?
(syrup of) ipecac
- induces forceful vomiting
How long should poison pts be observed, typically, after their sx are alleviated?
Many patients with potential ingestions may be observed for six hours and then dispositioned (home or psychiatric treatment facility) if clinically asymptomatic (provided the ingestion is not an extended release agent).
The lethal dose of acetaminophen (APAP) is ____mg/kg.
150mg/kg
Describe the pathophysiological mechanism behind acetaminophen tox.
In an acute overdose, APAP is metabolized to NAPQI which combines with glutathione and is excreted. When the majority of the glutathione is used, NAPQI causes hepatic toxicity.
*Describe what do give in acetaminophen OD.
In addition to decontamination with repeated doses of activated charcoal, the antidote N-acetylcysteine (Mucomyst) should be administered if indicated by the nomogram.
What are the typical sx in the 1st 2 stages of acetaminophen OD?
N/V
Describe the appearance of someone with an ASA OD.
usually quite ill appearing, breathing fast, vomiting, confused, and sometimes febrile.
In general, what is the cause, pathophysiologically (cellularly), of ASA poisoning?
The toxic effects are complex and involve an uncoupling of oxidative phosphorylation –> profound AG-metabolic acidosis
*The general approach to aspirin overdose is:
- Management of the airway,
- gastric decontamination,
- the administration of sodium bicarbonate,
- hemodialysis.
List the receptors that TCAs affect and how.
- Anticholinergic
- Direct alpha-adrenergic blockade
- NE and 5-HT re-uptake inhibition
- Blockade of fast sodium channels in myocardial cells
List some of the worrisome symptoms/signs of TCA OD
- tachycardia
- prolongation of the QRS complex
- dysrhythmias
- cardiovascular collapse
- protracted seizures
Treatment of TCA overdose includes close monitoring for a period of at least 6-8 hours in the asymptomatic patient. In the setting of QRS widening, ____________________ should be administered.
Sodium bicarbonate
While any alcohol consumed in great quantities can be dangerous, there are three major alcohols that are considered “toxic”. These “toxic” alcohols include ______________, _______________, and ______________.
- isopropanol
- methanol
- ethylene glycol
Where is isopropyl alcohol typically found?
Many solvents, mouthwashes, and rubbing alcohols
What are methanol and ethylene glycol typically used for?
Fuel, solvent, and antifreeze in pipelines and windshield washer fluid (esp. ethylene glycol), coolants
Which of the following will NOT cause an AG-metabolic acidosis:
- isopropanol
- methanol
- ethylene glycol
Isopropanol
Under what substance ingestion should you apply wood’s lamp to the urine to look for fluorescence?
Ethylene glycol
- The urine can also be examined for the presence of calcium oxalate crystals.
Which of the following ingestions is NOT life threatening and can be managed with supportive care?
- isopropanol
- methanol
- ethylene glycol
Isopropanol
- In rare instances, hemodialysis may be required
*Methanol is metabolized to formaldehyde, and ethylene glycol is broken down into oxalate. All alcohols are metabolized by alcohol dehydrogenase (ADH). Therefore, the initial treatment for methanol and ethylene glycol involves the blockade of ADH. This can be accomplished by either ____________ or ___________.
simple ethanol or fomepizole
- In addition, removal of the toxin may be necessary by hemodialysis. Sodium bicarbonate and glucose may also be necessary.
Even after 6 hours of observation after they have stabilized, what is the danger of discharging poison pts?
May still be danger to themselves.
What route of medication or agent administration should you avoid in somnolent pts?
PO
- Risk of aspiration
True or false:
Aggressive alkalinization and/or antidotal therapy with fomepizole or ethanol are NOT indicated in isolated isopropyl alcohol ingestions.
True
- Supportive care only