Toxicology/Environmental Flashcards
Poisonings
- Poisonings are prevalent
- Poisoned patients are inherently unstable
- Majority survive/recover with supportive care
- How do people get poisoned?
- Intentional – suicide attempt
- Unintentional overdose – too much
- Industrial exposures/accidents
- Plants/critters
- Hand to mouth syndrome - kids
How do poisonings present in the ED
- Ingestion
- Inhalation
- Injection
- Mucous membranes
- Skin - transdermal
- Known route, known substance
- Possible exposure to known substance
- Exposure to unknown substance
- Mystery patient
- Poisoning is on the DDx if:
- Patient with ALOC – no obvious cause
- Inexplicable vital signs
- Inexplicable lab tests, EKG
- Symptoms look like a toxidrome
- Multiple patients w/ same sx’
how to think through poisonings in the ED
- ABCDE’s first – always – sick or not sick?
- Focused Hx – Known, suspected or reported ingestion/exposure?
- Anticipate: What class of substance was ingested? What does it (they) do?
- Focused PE - Evidence of a toxidrome? Evidence of drug/exposure effect?
- Get the labs you need
- REVERSE with antidote, if possible
- REMOVE residual poison, if possible
- NEUTRALIZE circulating poison
- ENHANCE ELIMINATION of the poison
- Call Poison Control Center EARLY: 1-800-411-8080
ABCDEs of poisonings
- Airway first – are they protecting it?
- Breathing - O2 Sat, RR – effectively ventilating?
- Circulation – BP low or high?
- Cardiac rhythm? Tachy? Brady? Wide or narrow? Is it changing?
- D & E is for Disability/Decontamination/Exposure
- Skin decon
- Eye decon
- GI tract decon
history of a poisoning
- Is there a history?
- Is the patient reliable?
- EMS/police/5150 form: info re: scene, behavior
- Bystanders, family, friends
- Who called 911? Why?
- When was the patient last seen?
- What was available to this patient?
- Extended release pills?
- How taken, how much taken?
- That drug, that way, in that amount: is it harmful?
- When was it taken?
- Why was it taken?
- Other toxins? EtOH? Other meds?
- PMH, old medical record
- Past ingestions/exposures
- Existing organ sx problems?
- Liver, renal, lung, cardiac
physical exam of poisoning
- Vital signs
- Cardiac rhythm
- Level of consciousness, gag reflex
- Pupils - size and reactivity
- Miosis = small/pinpoint pupils
- Mydriasis = dilated pupils
- Skin signs – sweaty, dry, hot, rash, track marks
- Bowel sounds – hyper-, hypoactive, are they present at all?
- Bladder distention
- Breath/body odor
- Evidence of trauma, focal neurologic deficit, pre-existing problems
management, testing, treatment
- D-stick, EKG, Upreg right away
- IV access, monitor, O2
- Acetaminophen (APAP) level
- Chem (anion gap, electrolytes, renal, LFT’s), CBC, UA, Blood EtOH, Utox
- A few helpful drug levels in ED
- Digoxin
- Dilantin (ataxia), Carbamazepine, Valproic Acid
- Lithium
- “Comprehensive” drug screens not helpful – take too long
- “Coma Cocktail”
- 50 cc of 50% glucose IV: (“Amp of D50”)
- Naloxone (Narcan®)
- 0.8-2 mg IN, IM, IV
- Thiamine, 100 mg IV**
- KUB for select, ingested radiopaque substances
- Special labs
- Calcium, Magnesium
- Total CK (rhabdomyolysis)
- PT/INR (hepatotoxic, coumadin)
- Serum osmolarity/osmolar gap
treatment of poisoning
-
ELIMINATE:
- Skin, eye, manual decontamination
- HAZMAT, protection for HCP
- Forced emesis**
- Rare: no syrup of ipecac
- Surgical removal
- Skin, eye, manual decontamination
-
NEUTRALIZE:
- Activated Charcoal
- 1 gm / kg administered orally
- Repeat dosing for some drugs
- Give with cathartic (Sorbitol)
- Can be given pre-hospital
- Not always useful, can be dangerous
- Antidote: known ingestion/exposure
- Activated Charcoal
-
ENHANCE ELIMINATION
- Whole bowel irrigation
- Go-Lytely
- Dialysis, Hemofiltration
- Enhance urinary excretion
- Whole bowel irrigation
specific treatments - antidotes
- Opiates - naloxone
- Acetaminophen – N-acetylcysteine
- NAC, Mucomyst
- Digoxin – Digibind Fab-fragments
- Benzos - flumazenil
- Cyanide - Lilly kit
- INH – pyridoxine
- Carbon Monoxide - oxygen
- Anticholinergics - physostigmine
- Cholinergics – atropine, 2-PAM
- Beta blockers - glucagon
- Ca channel blockers - calcium
- Tricyclics - Na bicarbonate
- Metals - chelating agents
- Iron – deferoximine
- Warfarin (Coumadin): Vitamin K
- Over-anticoagulation common
- Hold dose, check bleeding
anion gap and osmolar gap
AG: (Na) – (Chloride + TCO2); Normal 5-15
AG Metabolic Acidosis DDx:
Methanol; metformin
Uremia
DKA, AKA
Paraldehyde; phenformin
Iron; INH
Lactic acid
Ethylene glycol
Renal failure, rhabdomyolysis
Salicylates; sepsis; starvation
Calculated serum osmolarity
2 (Na) + (BUN / 2.8) + (glucose /18)
Normal = 285-295
Gap: Measured – Calculated
Normal = <10
Causes of high Osmolar Gap
Methanol
Ethylene glycol
Ethanol
Isopropyl alcohol
Others….
special considerations
- Charcoal does not work with:
- Iron
- Lithium
- Cyanide
- Pesticides
- Acids and alkalis
- Radiopaque Pills on KUB
- CHIPES
- Chloral hydrate
- Heavy metals
- Iron
- Phenothiazines; Packets of drugs (body packers)
- Enteric coated pills
- Salicylates
- Chloral hydrate: a sedative, no longer used, not approved by FDA
toxidromes
- PE findings/syndromes that predictably occur with particular substances
- The major ones to know:
- Anticholinergic
- Cholinergic
- Sympathomimetic
- Opiates
- Serotonergic (Serotonin Syndrome)
Anticholinergic toxidrome
Mad as a hatter
Blind as a bat
Red as a beet
Dry as a bone
Hot as hell
anticholinergic toxidrome
- Flushed, dry skin
- Elevated temp, pulse
- Agitated delirium
- Hallucinations
- Dilated pupils
- Seizures
- Absent bowel signs
- Distended bladder
- Anticholinergics
- Atropine, scopolomine
- Antihistamines
- Benadryl, etc
- Antipsychotics
- Zyprexa, Thorazine, etc
- Tricyclic antidepressants
- Amitriptyline, etc
- Carbamazepine (Tegretol), Cyclobenzaprine (Flexeril)
- Plants – Jimson Weed, Belladonna
Cholinergic toxidrome
- SLUDGE
- Salivation
- Lacrimation
- Urination
- Diaphoresis
- GI upset
- Emesis
- Bradycardia ,Wheezing
- Constricted pupils
- Lethargy
- Pesticides
- Organophosphates
- Chemical Warfare agents
- Sarin, VX, etc