Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CCFP-EM > Toxicology > Flashcards

Toxicology Flashcards

(65 cards)

Start Studying
1
Q

Acetaminophen Measurement Toxicity - Nomogram

A

Rumack-Matthew nomogram - determines treatment line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Acetaminophen treatment levels

A

APAP > Nomogram treatment level
Elevated AST with unknown ingestion time and APAP below treatment line
150 mg/kg ingestion and cannot get APAP level within 8 hours
History of chronic toxicity / repeat supratheraputic and elevated AST or

DO NOT Tx IF:
Ingestion > 4 hours ago and below nomogram threshold
Suspected ingestion > 4 hours ago and undetected APAP and no elevation of AST

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

GI decontamination strategies

A

Whole bowel irrigation
Gastric lavage
Activated Charcoal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Gastric lavage indications and contraindications

A

Ingestion within 1 hour (real life is “reasonable time frame” - also based severity of drugs)
- Usually within first 2-3 hours
Substance not bound by AC and has no antidote
Benefits outweigh risks

Contraindications:
Spontaneous Emesis
altered LOC - intubate first
Hydrocarbons, caustic substances or foreign body
High risk for GI injury (esophageal/gastric sx, GI hemorrhage)

Complications:
Aspiration, perforation, laryngospasm, fluid and electrolytes imbalance, dysrhythmia, hypoxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Activated charcoal indications / contraindications

A

General: Used to adsorb ingested agents
- Ratio of 10-1: 10 g charcoal for 1 g substance or 1g/kg

Indications:
- Within 1 hour of ingestion
- Dangerous amount of poison adsorbed by charcoal
- Multiple dose may be appropriate after 2 hours for some agents (carbamazepine)

Contraindications:
- Not adsorbed by charcoal: metals or alcohols
- If vomiting presents greater danger: caustic agent or hydrocarbons
- Diminished LOC / unprotected airway
- If endoscopy required or patient at risk for perf / hemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Whole bowel irrigation indications / contraindications

A

General: flushes GI tract to decrease transit time
- PEG given at 1-2 L/hr to total of 10 L

Indications:
- Removal of drug packets
- Large ingestion of sustained release drug
- Ingestion of substance not treated by AC
- Lithium and Iron

Contraindications:
- Altered LOC with unprotected airway reflexes
- Decreased GI motility / obstruction / GI hemorrhage / Emesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is enhanced elimination

A

Attempts to increase clearance of a poison after it has been absorbed,
e.g. alkalinization or urine, MDAC, hemodialysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

MDAC

A

Q2-4 hour dosing of AC - reduced enterohepatic circulation / gut dialysis
Indications:
- Sustained release
- Bezoars
e.g. carbemazepine, quinine, phenobarb, valproic acid, theophylline, dapsone

Risk of bowel obstruction

Can do 2 dose of SDAC for ASA, Dig, Bupropion - this is NOT MDAC.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Urinary Alkalinzation

A

Increases renal elimination by ion trapping
- Use bicarb infusion at 1.5 - 2x normal maintenance rate

Indications: Weak acids. ASA, methotrexate, phenobarbitol

Contraindications: Renal insufficiency, CHF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Hemodialysis for toxic ingestions

A

Indications:
- Low molecular weight
- low plasma protein binding
- poor endogenous clearance
- can treat severe acidosis even if the toxin is not dialyzable.

e.g. Alcohols, ASA, Lithium, metformin

ASA
Toxic alcohols
Theophylline
Phenobarb
Lithium
Massive Acetaminophen
Valproic Acid

SANTA - BETA BLOCKERS
Sotalol, Atenolol, Nadalol, Timolol, Acetenolol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Toxidromes: Anticholinergic

A

altered LOC
DRY skin
mydriasis
hyperthermia
seizures
tachycardia
urinary retention

Tx: Benzos and physostigmine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Toxidromes: Sympathomimetic

A

agitation
Diaphoresis
Hallucinations
HTN
Hyperthermia
Mydriasis
Muscular rigidity
Tachycardia

Tx: Benzos
Bicarb for wide complex dysrhythmias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Toxidromes: Cholinergic

A

Altered LOC
Bradycardia
Bronchorrhea
Bronchospasm
N/V/D
Urination
Seizures
Miosis
Salivation

Tx: Atropine, 2-PAM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Toxidromes: Opioid

A

Miosis
Bradypnea
Altered LOC
Hypothermia

Tx: Naloxone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

ECG Changes in Tox: Bradydysrhythmia

A

B-Blockers
CCB
Cardiac glycosides
Clonidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

ECG Changes in Tox: Tachydysrhythmia

A

Sympathomimetics
Stimulants
Anti-cholinerigics

For wide complex - give Bicarb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

ECG Changes in Tox: QRS Wide

A

Na+ channel blockers
Quinidine
Sedating antihistamines
Cocaine
TCA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

ECG Changes in Tox: QTc Long

A

Antipsychotics
SSRI / Antidepressantins
Antidysrhythmics
Hydrofluoric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

ECG Changes in Tox: Ischemia

A

Stimulants
Sympathomimetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

ECG Changes in Tox: TCAs

A

Right axis deviation
Terminal R in aVR
QRS prolongation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

ECG Changes in Tox: Digoxin

A

Downsloping ST depression with a characteristic “reverse tick” or “Salvador Dali sagging” appearance
Flattened, inverted, or biphasic T waves
Shortened QT interval

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

APAP toxicity mechanism

A

APAP converted to NAPQI in liver
NAPQI binds to cellular proteins and causes hepatotoxicity.
- Centrolobular or zone III
Decreased glutathione in chronic EtOH use, Tylenol use, malnourishment or those on P450 inducing agents (INH, anticonvulsants)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

APAP toxic ingestions

A

Acute Ingestions:
> 6 yrs: >10 g (150 mg/kg)
< 6 yrs: >200 mg/kg

In repeated dosing:
>10 g /day for 24 hours - staggered dosing
> 6 g / day for 48 hours

Children < 6:
>200 mg/kg/d over 24 hrs
> 150 mg/kg/d over 24-48 hrs
> 100 mg/kg/d over 72 hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

APAP toxicity treatment

A

N-Acetyl Cysteine NAC
- effective up to 8-10 hrs post.
- ALWAYS GIVE NAC

Oral:
- 140 mg/kg load and 70 mg/kg Q4H for 72 hours
IV
- 150 mg/kg load over 1 hr, then 50 mg/kg over 4 hours then 100 mg/kg over 16 hours.
- Risk of anaphylactoid reactions

If Repeated Supratheraputic doses:
- NAC x 12 hours with repeat APAP and LFTs near end of treatment.

ONTARIO DOSING DIFFERENT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
APAP Toxicity Indications for Liver Transplant
King's College Criteria pH < 7.3 after resus or INR >6.5, Cr > 3.4 mg/dL and grade 3 or 4 hepatic encephalopathy Remember #3 Creatinine > 300 Grade 3 or 4 encephalopthy pH < 7.3 INR 6.6 or greater (3.3. x 2)
26
Mechanisms of NAC
Glutathione precursor Direct NAPQI conversion Sulfonization Free radial Scavenging Reduces APAP to NAPQI
27
Massive APAP Ingestion Def’n and Tx
Greater than 500-1000 mg/kg (> 1 pill / kg) APAP @ 4 hrs > 300 mcg/ml Anion gap metabolic acidosis Altered LOC Tx: Dialysis, AC, NAC, Fomepizole (inhibits CYP 2E1, impairs NAPQI production) Indications for dialysis: - Creatinine > 350 - Elevated lactate > 3.5 - Encephalopathy - Level > 300 mcg/ml - Metabolic acidosis
28
ASA Toxicity Presentation
Hyperventilation and metabolic ALKALOSIS Vomiting AGMA Hyperthermia Tinnitus and hearing loss correlate with ASA level Cerebral and pulmonary edema Early blood gas: Resp Alkalosis Severe Ingestions: metabolic acidosis, hyperthermia, cerebral edema, seizure, hypoglycemia
29
When to consider ASA toxicity
Chronic use Hot and Crazy Tinnitus Tachypneic Resp Alkalosis or Metabolic Acidosis or both
30
Mechanism of alkalinization in ASA
In acidic environment, ASA becomes bound to H+ and can cross BBB. Goal to alkalinize urine to excrete the dissociated ASA
31
Tox: ASA Mgmt
ABC Fluid Resus Urine Alkalinization Repeat ASA level at 2 hours Urine Alkalinization: Bicarb Add K+ - need to avoid H-K exchange in nephron to excrete H+ in urine Add 40 meq in bag
32
ASA Tox Indications for Dialysis
ALOC Renal or Hepatic Failure Pulmonary edema Severe acidosis Inability to alkalinize urine Salicylate > 7 in acute Salicylate > 3? In chronic
33
Toxidrome - Sympathomimetic
Excess catecholamines, hypertension, tachycardia, tachypnea, diaphoresis, mydriasis. Risk for arrhythmias and shock Causes: MDMA, cocaine, ephedrine, caffeine. Mgmt: Benzos, fluids and supportive mgmt
34
Universal antidotes
Dextrose Oxygen Narcan Thiamine DON'T
35
Approach to treatment of poisoned patients
ABCDs Decontamination Prevent absorption Enhanced elimination Give antidotes if indicated
36
For aLOC keep a broad differential - what are the 5 broad categories
Drugs Infection Metabolic Environmental Structural
37
Antidotes for most common poisons
Acetaminophen - NAC Methanol / Ethylene Glycol - Fomepizole/EtOH CO - O2 and hyperbarics Opioids - Narcan / naloxone Anticholinergics - Physostigmine Organophosphates - Atropine and 2-PAM Methemoglobinemia - Methylene blue Cyanide - B12 / cyanokit Iron - Deferoxamine Arsenic / Lead - Dimercaprol Mercury - Succimer Dixogin - Digifab Crotalids - fab fragments Beta Blockers - High dose insulin, Ca2+ and glucagon Salicylates / TCA - Bicarb CCBs - Ca, high dose insulin Oral hypoglycemics - Glucose +/- octreotide Isoniazid - Pyridoxine (B6) LAST - Intralipid
38
6 Radiopaque Toxins
CHIPES Chlorinated hydrocarbons, calcium salts, crack vials Heavy metals (Iron, aresenic, valium, lead) Iodinated (Amiodarone, thyroxines) Psychotropics - lithium, TCA, packers, potassium salts Enteric coated Sodium salts, salicylates
39
Activated charcoal indications - what are the killer C's
Cyanide Colchicine CCB TCA Cardioglycosides Cyclopeptide mushrooms Cocaine Cicutoxin (water hemlock) Calicylates
40
Indications for activated charcoal administration (T's)
Timing - < 1-2 hours Toxic - known lethal toxin Ton of it - massive ingestion Tacky - Adsorption can work Tasty - Willing to take
41
Things that DO NOT BIND or will not work with AC
Pesticides Heavy metals Acids / Alkali Iron Lithium Solvents
42
Anticholinergic toxidrome = antimuscarinic toxidrome = what symptoms ?
Hyperthermia Delerium / aLOC / seizure Anhidrosis Urinary retention Mydriassis Flushing Decreased bowel sounds
43
Anticholinergic meds
Weeds: Jimson Atropine / scopolamine antihistamines (H1) Antiparkinsons (benztropine) TCA
44
Mgmt of anticholinergics
Stabilization: - Supportive care - Treat fever - Benzos for seizure - Intubate if temp not responsive to evaporative cooling Decontamination: - Generally not needed Antidote: Physostigmine - Contraindicated in TCA, wide QRS, AV blocks, bradycardia, co-ingestions
45
7 Effects of TCAs
Na channel blockade - wide QRS K+ channel blockade - Long QTc Antihistamine - hypotension / sedation Anticholinergic - classic tox GABA blockade - Seizure Serotonin and NE uptake inhibition - sympathomimetic Alpha 1 blockade - hyptension
46
ECG findings in TCA
Wide QRS Long QTc terminal R in avR > 3 mm RAD Sinus tach - anti-muscarinic
47
Mgmt of TCA
ABC Decontaminate: - AC if > 2 hrs, avoid if unstable and going to RSI Stabilize: - Bicarb 2meq/kg bolus until QRS narrows and then infusion. Hypertonic if no bicarb - IV lidocaine - Intralipid Seizures: - Bicarb, benzos, propofol Hyperthermia: - Evaporative and ice immersion - Intubate, deeply sedate and paralyze if refractory NO SUCC and NO PHYSOSTIGMINE
48
NMS vs Serotonin Syndrome
Both have Fever Autonomic instability Rigidity / Rhabdo Mental status changes NMS: muscle rigidity (lead pipe) SS: Spastic, tremor, clonus, increased motor activity. Hyperreflexia
49
Drugs that induce serotonin syndrome
Cocaine SSRI MAOI TCAs St. John's Wort Ondansetron SNRI Tramadol Fentanyl
50
Bupropion Toxicity - mechanism and symptoms
NDRI - Seizures are main toxicity - Direct cardiac suppressant
51
8 Drug classes that cause a wide QRS
TCAs Antihistamines Class 1A, 1C and 2 antiarrhythmics Local Anesthetics Antimalarials Antispasmodics Anticonvulsants
52
Digoxin mechanism and toxicity
Inotrope by inhibition of Na K ATPase, increases intracellular Na, secondarily increases Calcium nito sarcoplasmic retic. - Decreased SA and AV node conduction * In toxicity can give tachy/brady AV block sydromes Toxicity: GI symptoms of N/V annd abdo pain. - General weakness, headache, dizziness, alOC, snowy vision, scotomas or yellow-green halos - Acute: Brady and AV block - Chronic: Ventricular dysrhythmias, bidirectional v tach
53
ECGs in Dix Toxicity
Slow a fib. A fib with AV dissociation Atrial tachy with a block Bidirectional VT Junctional tachy
54
Beta-blocker toxicity mgmt
Fluids: If hypotensive - bolus 20-40 mg/kg fluids Atropine: temporize with atropine in HR < 50 Calcium: 4-6 G calcium gluconate High dose insulin therapy - Give 1 amp D50 followed by 1 U /kg of IV insulin. Then 25 g / hr of + insulin at 1 U / kg / hr. Place Central and arterial lines. Increased by 2 U /kg/hr to max of 10 U/kg/hr if still hypotensive. - Target glucose > 12. - Replace K+ 2nd to shifting - Norepi 1st line pressor - Consider pacing/ ECMO If Propanalol: Bicarb boluses 1-2 meq/kg Q3-5 mins If Sotalol: Use lidocaine - Can overdrive pace is isopreteronol and MgSO4 if torsades Beta-Blcokers that can be dialyzed Sotalol Atenolol Nadolol Timolol Acebutolol Out of favor: Intralipid and glucagon but can be used as last ditch effort
55
CCB OD Mgmt
Similar to BB - MOVIE - Atropine if brady - Calcium 3-6g IV - HDI therapy - Vasopressors Last ditch: - Methylene blue - Intralipid - ECMo
56
Clonidine Toxicity and Mgmt
Central Alpha 2- results in decreased NE - Hypotension - Bradycardia - Depressed LOC - Miosis Mgmt: - Generous fluids - Vasopressors (NE) - Naloxone
57
Differential for Low and Slow
CCB tox BB tox Clonidine tox Hypothermia Hypokalemia / Hyperkalemia Myxedema coma Complete HB / Ischemia INferior MI Dig tox Opioid overdose
58
Osmolality Eqn
2xNa + BUN + Glucose + 1.25x EtOH Gap = Measured - Calc normal < 10 but can vary AG affected by Albumin levels
59
Causes of elated Osmolar Gap
Methanol Ethylene Glycol Isopropanol Ethanol Mannitol Acetone Glycerol Propylene Glycol Fructose Sorbitol DKA AKA Sepsis Uremia
60
Causes of Anion Cat
Alcoholic Ketoacidosis Cycanide, CO, Colchicine Acetaminophen in massive OD Toluene Methanol Uremia DKA Paraldehyde Isoniazid (Iron, Ibuprofen) Lactic acidocis Ethylene Glycol Salicylates
61
Causes of double gap - i.e. Osmolar and Anion Gap
Ketoacidosis Uremia Lactic acidosis Toxic alcholos
62
Methanol Metabolism and Toxicity
Methanol - Formic acid - Snowy vision and blindness - metabolic acidosis - Parkinsonism from Putamen poisoning - Can have massive UGIB from gastritis Treatment: Fomepizole or EtOH. - Folic acid for formic acid -Dialysis
63
Ethylene Glycol Met and Toxicity
Ethylene Glycol - Glycolic acid - Oxalic Acid - Renal failure 2nd to crystal in urine - Inebriation, CNS depression, hypotonia and seizure - Nystagmus, ataxia and myoclonic jerks Lab abnormalities: Hypocalcemia, osmolar gap, positive birefringent crystals in urine Treat: - Fomepizole - Thiamine - Pyridoxine - Dialysis
64
Indications for dialysis in toxic OH ingestion
pH < 7.3 Renal fail Vision in methanol Electrolytes in hyperK hemodynamic instability Concentration > 50.
65

CCFP-EM (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions