Toxicology/Environmental Flashcards
1
Q
Poisonings
A
- 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
2
Q
How do poisonings present in the ED
A
- 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’
3
Q
how to think through poisonings in the ED
A
- 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
4
Q
ABCDEs of poisonings
A
- 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
5
Q
history of a poisoning
A
- 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
6
Q
physical exam of poisoning
A
- 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
7
Q
management, testing, treatment
A
- 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
8
Q
treatment of poisoning
A
-
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
9
Q
specific treatments - antidotes
A
- 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
10
Q
anion gap and osmolar gap
A
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….
11
Q
special considerations
A
- 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
12
Q
toxidromes
A
- PE findings/syndromes that predictably occur with particular substances
- The major ones to know:
- Anticholinergic
- Cholinergic
- Sympathomimetic
- Opiates
- Serotonergic (Serotonin Syndrome)
13
Q
Anticholinergic toxidrome
A
Mad as a hatter
Blind as a bat
Red as a beet
Dry as a bone
Hot as hell
14
Q
anticholinergic toxidrome
A
- 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
15
Q
Cholinergic toxidrome
A
- SLUDGE
- Salivation
- Lacrimation
- Urination
- Diaphoresis
- GI upset
- Emesis
- Bradycardia ,Wheezing
- Constricted pupils
- Lethargy
- Pesticides
- Organophosphates
- Chemical Warfare agents
- Sarin, VX, etc
16
Q
sympathomemetic toxidrome
A
- Elevated BP, pulse, temp
- Can be really high
- Agitated delirium
- Seizures
- Dilated pupils
- Normal skin or sweating
- Normal bowel sounds
- Bladder not distended
- Cocaine, Amphetamines, Ecstasy
- Multiple formulations
- Caffeine
- Pseudoephedrine, Ma Huang (ephedra)
- Ritalin, Adderall, diet pills
- A note about caffeine – toxic dose is 10g. One Red Bull has 80mg. Caffeine pills have about 100mg.
17
Q
opiate toxidrome
A
- Classic Triad:
- Depressed LOC
- Lethargy to coma
- Decreased respirations
- Pinpoint pupils (miosis)
- Depressed LOC
- Hypotension
- Pulmonary edema
- Heroin, methadone
- Morphine, Dilaudid, Meperidine
- Fentanyl - patches
- Codeine, Hydrocodone, Oxycodone
- Lomotil
- Dextromethorphan
18
Q
Serotenergic toxidrome
A
- Most common w/ dose increase, addition of another to tx or overdose
- Agitated or comatose
- Elevated temperature, pulse
- Hypo- or hypertension
- Normal pupils
- Normal skin signs
- Increased reflexes
- Clonus
- “wet dog” shakes
- SSRI’s, SSNRI’s, MAOI’s
- SSRI’s + triptans
- Combo with pain meds
- Merperidine (Demerol)
19
Q
toxidrome treatment: anticholinergic, cholinergic, sympathomemetic, opiate, serotonin syndrome
A
- Anticholinergic
- Supportive: IV fluids, monitor
- Charcoal, Benzo’s
- Don’t sedate with antipsychoticà enhances anticholinergic effect -> seizure, sicker
- Critical? Physostigmine
- Cholinergic
- Decontamination, supportive
- Atropine – muscarinic effects
- Pralidoxime (2-PAM) – both muscarinic and nicotinic effects
- Sympathomemetic
- IV fluids, Benzo’s, cooling
- Control VS
- Charcoal, Go-Lytely if ingested packets
- Opiate
- Airway management
- Naloxone (Narcan)
- Serotonin Syndrome
- Withdraw offender, supportive
- Benzo’s
20
Q
doesn’t fit a toxidrome?
A
- Toxidrome type ingestion known, but sx’s currently mild or non-existent?
- Non-toxidrome type known ingestion?
- Unknown ingestion? Suspect ingestion?
- Identify class of drugs involved, how much is harmful?
- Predicted effects of overdose? What do you see?
- Consider broad DDx
- Mixed ingestion/exposure
- Head trauma
- Infection
- Shock
- Metabolic imbalance
- Call Poison Control if you suspect a poisoning
21
Q
acetaminophen
A
- Common, silent, deadly: order level in ALL poisoned pt’s.
- 7.5g in adults or 150mg/kg in kids is toxic
- Timing of ingestion is key – 2-4hr first level
- Typically few sx’s first 24hrs
- Then: RUQ abd pain, malaise, nausea
- LFT’s up 24-36hrs after ingestion
- Hepatic failure 72-96hrs
- Labs: ASA, CBC, Chem, UA, Upreg, EKG
- Serial levels every 4-6hrs depending on Hx
- Treatment:
- Charcoal if recent
- N-acetylcysteine (NAC, Mucomyst) for 72hrs
22
Q
aspirin - salicylates
A
- Common, acute or chronic – slowed absorption, concretions
- Early/mild sx’s: tachycardia, tinnitus, n/v, abd pain, tachypnea, diaphoresis
- Late/severe: coma, seziures, resp depression, non-cardiogenic pulmonary edema, dehydration, shock
- Severity = acid base imbalance
- Mild toxicity/first sign: alkalosis
- Progression: resp alkalosis and AG metabolic acidosis
- Severe/progression: severe AG metabolic acidosis
- Labs: ASA, APAP, UA/Upreg, CBC, Chem, ABG, EKG, serial ASA levels
- Tx: ABC’s, IV hydration, charcoal w/o cathartic, alkalinize urine (bicarb)
- Pt with persistent, inexplicable tachycardia? Think aspirin
23
Q
NSAID’s
A
- 70 million Rx’s in U.S. each year
- Add OTC NSAID’s – 30 billion doses taken/year
- 100mg/kg usually benign; co-ingestion?
- GI effects predominate, mild electrolyte abnormalities
- Tx: supportive care
- >400mg/kg may be life-threatening
- ALOC/coma, acidosis, seizures, pulmonary edema
- Toxicity effect depends on which NSAID taken
- Call Poison Control
24
Q
Oral hypoglycemics/insulin
A
- Sx’s: ALOC, diaphoresis, tachycardia, bizarre behavior, paralysis, seizure – can mimic CVA
- Immediate d-stick on ALL altered patients
- Sulfonylureas, Insulin – rapid reversal with 1 amp D50 after d-stick
- Metformin – less profound hypoglycemia but lactic acidosis w/ AG present
- The problem with oral hypoglycemics:
- They last a long time, longer than 1 amp D50
- Pt becomes repeatedly hypoglycemic
- Admit these folks with glucose rich IV drips
- Insulin OD – admit if severe. Can correct, watch for 6hrsàhome if stable, no risks, not suicide
- Feed everyone with hypoglycemic toxicity
25
Tricyclic antidepressants
* Dreaded overdose – big OD’s deadly
* Amitriptyline, nortriptyline, etc
* Anticholinergic toxidrome
* Get EKG early. Classic changes:
* First – sinus tach
* Terminal R-wave in aVR
* Widened QRS
* Ventricular tachycardia
* Coma, seizures, hypotension
* Charcoal, whole bowel irrigation
* Note: Busparone (Buspar) OD:
* Delayed effects – ICU admit
26
Iron
* Common OD in kids – vitamins
* Nausea, vomiting, abd pain, diarrhea
* Estimate amount and which prep
* Signs of toxicity
* AG metabolic acidosis
* WBC’s \>15k
* Glucose \>150
* Serum iron test
* KUB good – Charcoal does not work
* Dexferoxamime, “vin rose” urine = antidote is working
27
cardiac medications
* Digoxin
* Elderly – acute or chronic toxicity
* N/V/D, bradyarrhythmias, hyperkalemia, CNS sx’s, EKG with specific findings
* Dig level, Digibind Fab if arrhythmias
* Beta Blockers
* Brady, hypotensive, ALOC, ventricular arrhythmias
* IV fluids, tx shock, charcoal if indicated
* Glucagon is treatment; atropine, pressors if necessary
* Calcium Channel Blockers
* Sx’s/Tx much like Beta Blockers – add Calcium
* Glucagon works in severe beta blocker OD because it it bypasses the beta receptors for adenyl cyclase (which helps to catalyze ATP to cAMP) and causes inotropic and chronotropic effects to restore cardiac output. Only used in severe OD’s with significant cardiovascular effects. Not studied adequately but accepted treatment. Insulin (high dose) also acts as an inotrope.
* Inotrope = affects force of cardiac contraction (positive or negative, ie...more force or less)
* Chronotrope = affects rate of contraction (positive or negative, ie...higher rate or slower rate)
28
alcohol - ethyl alcohol
* Often co-ingestion - Quantify, you know the Hx questions
* Guard up, protect staff and patient
* Red Flags:
* EtOH level does not match sx’s
* Not “metabolizing” (getting less drunk) with time
* Trauma – do a good exam
* GI bleeding, abd pain, n/v
* Confusion, can’t walk
* Jaundice, bruising
* Chronic: impressive levels
* No need for zero level to d/c! Chronic etoh’ers will experience withdrawal sx’s at zero!
* Refer for alcohol Tx – Benzo’s Rx for mild withdrawal sx’s
29
alcohol withdrawal
* Can be mild shakes to life threatening
* PE Signs:
* Tongue wag, tremor
* Tachycardia
* Low grade temp
* Red Flags:
* Hallucinations, confusion
* Agitated delirium
* Seizure, asterixis
* Jaundice
* Treatment: IV fluids, monitor, EKG, high vis bed
* Give thiamine IV, feed
* Labs: CBC, Chem, PT/INR, Magnesium, Phosphorus
* Benzo’s: Lorazepam 2-4mg IV until sx’s abate or need an airway
* Phenobarbital helps avoid Sz – long acting – give early
* IV 130-260mg q 30min until sedation or 1040mg
* Admit significant withdrawal
30
mushrooms
* Foragers used to eating wild mushrooms
* Folks attempting to get high
* Kids playing outdoors
* Early GI symptoms (w/in 2hrs) usually reassuring
* Delayed symptoms (\>6hrs) associated with liver, kidney, CNS damage
* Amanita phalloides: delayed liver failure (day 3)
* Amanita Smithiana: delayed renal failure (day 3)
* Lepiota: delayed liver failure (day 3)
* Get LFT’s, coags, electrolytes, monitor closely
* Call Poison Control for ALL mushroom toxicity
31
drug facilitated sexual assault "date rape" drugs
* Alcohol is #1 by far
* Benzodiazepines
* Rohypnol (flunitrazepam): pill form, illegal in U.S.
* Sedation, muscle relaxation, amnesia
* 15-30min onset, lasts 4-6hrs; tablets now dissolve with blue color
* GHB (gamma-hydroxybutyric acid): liquid/powder/pill, illegal in U.S.
* 15min onset, lasts 3-4hrs, gone from body in 8hrs
* Sedation, amnesia
* Ketamine: liquid/powder, onset in minutes, lasts up to 4hrs
* Psychoactive, muscle paralysis, amnesia
* OTC drugs – drops in drinks may induce sleep/coma
* Visine (tetrahydrozoline), Afrin (oxymetazoline), others
32
kids - one pill kills
* Peak age of ingestion is 1-3yr olds
* Very small doses of these are very harmful in young kids
* Calcium Channel Blockers – shock, brady arrhythmias
* Clonidine – opiate toxidrome
* Lomotil – opiate toxidrome
* Sulfonylureas – hypoglycemia, seizures, coma
* Cyclic Antidepressants – anticholinergic, dysrhythmias
* Salicylates – same sx’s as adults – more serious
* Pepto Bismal, Oil of Wintergreen
* Illicit drugs: crack, meth - sympathomimetic
* Educate patients, family members
33
carbon monoxide
* Common in winter months, cold climates – multiple sources
* Major contributor to smoke inhalation deaths (cyanide too)
* High index of suspicion required! Groups w/ same, suicide
* CO binds to hemoglobin 200 times better than oxygen
* Also binds to myoglobin, cytochromes P450 and AA3
* Organs needing high O2 – brain, heart – affected
* Sx’s: headache, DOE, vomiting, dizziness, vision change, ataxia, confusion, syncope, red skin – then seizures, coma
* Lab: carboxyhemoglobin (mild \<20%, severe \>40%)
* Labs, lactic acid, ABG, EKG, troponin/myoglobin
* Tx: 100% Oxygen by non-rebreathing mask
* Severe poisonings – hyperbaric oxygen chamber
34
water related emergencies
* Near Drowning/Drowning
* Respiratory impairment from immersion or submersion
* Water swallowed, aspirated, alveolar flooding/loss of surfactant, hypoxia, lose airway reflexes, bradycardia, cardiac arrest, global CNS damage
* Any aspiration may result in non-cardiogenic pulmonary edema
* Cold water survival better than warm water
* History (if possible)
* Predisposing event: trauma, EtOH, hypoglycemia, seizure, MI, suicidal ideation, accidental
* Clean or dirty water? Dove from height? Scuba diving?
* ABC’s first, CXR, +/- Head, C-spine CT, labs, CK, ABG
* If arrive with minimal sx’s and stay stable: may recover
35
hyperthermia
* Hyperthermia
* Heat exhaustion: core temp \<40.5 C (104.9)
* Normal mental status, dehydrated, sweating, weak, n/v, HA
* Heat stroke: core temp \>40.5 C – life threatening
* ALOC, ataxia, dry/hot/flushed skin, +/- sweating
* CNS, coagulation, liver, renal damage
* Drugs associated with increased heat production
* Cocaine, amphetamines, EtOH, salicylates
* Search for infection, thyroid storm, CVA, other tox
* D-stick, CBC, CMP, PT/INR, CK, TSH, UA, Upreg/tox
* Tx: ABCDE’s, cooling (ice packs, fan/wet sheet), Tylenol or NSAIDS do not work here
* Malignant hyperthermia: rare, genetic, precipitated by anesthesia drugs: muscle rigidity, rhabdo
36
hypothermia
* Hypothermia
* Core temp \<35 C, (95 F), severe \<89.6 F
* Primary: exposure, EtOH, elderly, infants, immersion
* Secondary: Sepsis, trauma, CVA, endocrine
* Iatrogenic: IV fluids not warmed, ambient temp
* Conduction, convection, radiation, evaporation
* Metabolism slows – kids: mammalian diving reflex
* Multi-system issues:
* Cardiac – gentle handling to avoid dysrhythmias
* Tachy -\> Brady, Osborn wave on EKG
* CNS – clumsy, confusion, shivering
* Treatment: remove/tx cause, d-stick, EKG, upreg, warm IV fluids and O2, Bear-Hugger rewarming pad, feed
37
Burns
* Extent, location, depth matter
* 1st, 2nd, 3rd degree is now:
* Superficial, Superficial partial/deep thickness, Full thickness
* Estimate BSA: Rule of 9’sà
* Thermal (flame), Chemical (contact)
* Chemical: which one? Irrigate; alkali vs acid? Eyes?
* Minor burns: Cleanse, analgesia, tetanus, silvadine/abx oint, 24hr f/u
* Major burns: IV fluids (Parkland Formula) , analgesia, admit; smoke inhalation, burn center
38
creepy crawler emergencies
* Snake bites
* Crotalidae: rattlesnakes; vipers, cobras, coral snakes
* First Aid: none proven – immobilize/transport best
* Unstable: ABC’s, compartment syndrome, renal fail
* Antivenom: if snake known. Crotalidae antivenom
* Venomous Spiders
* Cause dermonecrosis:Loxosceles - Brown Recluse
* Painless bite, firm skin lesion, blister, eschar
* Fever, chills, n/v, arthralgias – severe is rare
* Neurotoxic sx’s -\> Lacrodectus, “Widow spiders”
* “Pinprick” bite, pain spreads fast, muscle cramps: trunk/back/abd, local reaction
* Hypertension, tachy/tachy, n/v, headache
* Antivenom exists, treats both. Poison Control, Zoo
* Bees/wasps: local ice, remove stinger. Anaphalaxis?
* Tick: Remove beast, Lyme’s rare West coast: Doxycycline is still the tx
