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1

EM: Toxicology
Initial Evaluation
4

1. ABC’s
2. Obtain ABGs as soon as practical
3. Obtain IV access
4. Treat coma promptly

2

How should we treat coma promptly? 3

1. Give Glucose 50ml of 50% solution IV
2. Give naloxone (Narcan) 0.4-2.0 mg IV
3. If ETOHism is suspected, give 100mg Thiamine IM or IV

3

COMA TX for narcotic overdose
1. Give____ mg IV STAT,
2. if there is mild response or you know a narcotic is involved; give what how many minutes later?

1. 0.8
2. 1.6mg IV 3 minutes later (Max of Narcan is 10mg)

4

EM: Toxicology
Initial Evaluation
1. Maintain circulation
-If 20-30ml/kg of crystalloid does not stabilize BP, you must do what?

2. Very real risk of what? 2

Treat seizures
3. First line?
4. Failure of this?
5. Who do we put on all pts? 2

1. get a Swan in and check PCWP

2.
-over-hydration and
-pulmonary edema

3. Diazepam 0.1-0.2 mg/kg IV over 1-2 minutes

4. Failure of diazepam, give phenobarbital 15mg/kg not faster than 50mg/min

5.
-Cardiac monitoring
-pulse oximeter on ALL

5

EM: Toxicology
Decontamination
1. Emesis only in who?
2. Emesis may have limited efficacy if how long since ingestion?
3. Most useful when?
4. Emesis is indicated in the ED for what kind of drugs?
5. When should you not induce emesis? 2
6. How should you induce it?

1. only in patients with intact gag reflex

2. > 1 hour
3. Most useful if initiated at home within a few minutes of ingestion (home ipecac during your well baby visits)
4. Emesis is indicated in the ED for drugs not adsorbed by charcoal (eg, iron, lithium)

5.
-Do NOT induce emesis if caustics or low-viscosity hydrocarbons have been ingested
-Do NOT induce emesis if rapid-acting convulsants have been ingested (amphetamine, cocaine, cyclic antidepressants, strychnine)

6. Ipecac syrup 30ml (adults) or 15ml (children) followed by 1-2 liters of water (water until they vomit)

6

EM: Toxicology
Decontamination


1. Gastric Lavage
Indications: 4

2. Ideally place pt in what position?

3. Must use what equipment?

4. Use tap water or saline at body temperature in 250ml increments and continue until when?

1.
-Suspected serious ingestions when emesis has failed
-When patients are lethargic or otherwise uncooperative
-When the gag-reflex is markedly depressed
-When patients have ingested rapid-acting convulsants

2. Ideally, place patient in left lateral decubitus position with head down (if gag is depressed, protect airway)

3. Must use a large bore nasogastric or orogastric tube at least 36Fr (Cannot remove pill fragments with standard NG tube)

4. fluid returns clear and free of pill fragments

7

EM: Toxicology
Decontamination

Activated Charcoal
1. Following what give 50-100g of charcoal as slurry by mixing with equal amounts of water? 2

2. Can give before or after lavage/emesis; however need residual charcoal left in gut (when in doubt – ?)

3. Mixing charcoal with what of 70% improves taste of charcoal and provides cathartic action?

4. Charcoal has great adsorptive properties and binds most poisons (EXCEPT: ??? 4)

5. If the ingested dose of the poison is known, give at least ____ times that weight in activated charcoal

Whole Bowel Irrigation
6. Useful with what?
7. What until rectal effluent is clear?

1. emesis or lavage

2. do BOTH)

3. sorbitol 1ml/kg

4. PAIL
-alcohols,
-potassium,
-lithium
-iron

5. 10

6.
-sustained release and
-enteric coated tabs

7. Golytely 1-2L/h

8

EM: Toxicology
Initial Laboratory Studies
1. ______ as soon as practical
2. Draw blood for what? 3
3. Obtain ECG and monitor for what? 2
4. CXR looking for evidence of what?
5. Flat plate of abdomen looking for what?
-disadvantage with this?

6.What for toxicology screen besides blood?

7. Draw and HOLD serum tox screens; order only what?

1. ABGs

2.
-Chem 7 and
-calculate anion
-osmolar gap

3.
-wide QRS or
-pronlonged QT

4. pulmonary edema

5. radiopaque pills
-High false negative rate

6. Urine

7. those levels that are indicated (ie-acetaminophen)

9

EM: Toxicology
Toxicokinetics

1. Management of the patient requires understanding of? 3

2. Dissolution and absorption of toxin or gastric emptying time may be seriously altered so peak effect is quite what?

1.
-Absorption
-Distribution
-Elimination


2. delayed (ie – anticholinergics)

10

EM: Toxicology
Toxicokinetics

1. Management of the patient requires understanding of? 3

2. Dissolution and absorption of toxin or gastric emptying time may be seriously altered so peak effect is quite what?

1.
-Absorption
-Distribution
-Elimination


2. delayed (ie – anticholinergics)

11

EM: Toxicology
Toxicokinetics

1. What is the definition of half life?
2. What is first order kinetics?
3. Zero order?

4. All that being said: Many times in an overdose situation, the elimination pathways are saturated and a drug which normally has first-order kinetics develops what?

1. The time required to eliminate one-half of the toxin
2. FIRST-ORDER KINETICS – a fixed percentage of the toxin is removed per unit of time (Example- Barbs)
3. ZERO-ORDER KINETICS – a fixed amount of toxin is removed per unit of time (Example- Alcohol)

4. zero-order kinetics

12

EM: Toxicology
Toxicokinetics

1. What is clearance?
2. Includes what components? 2
3. Important to understand this process: A drug that is normally 95% metabolized and 5% renally cleared; forced diuresis will have what kind of effect on clearance?

4. Toxins with large volumes of distribution (tissue bound rather than plasma bound) are not efficiently removed by what?

1. Volume of plasma that can be cleared of toxin per unit time
2. Includes both renal and metabolic components

3. minimal effect on clearance
4. dialysis or diuresis

13

EM: Toxicology
Enhanced Elimination

Hemodialysis
1. The toxin must be relatively _______ soluble and ______ protein bound

2. Toxin is removed from blood into what?

3. Drugs need to have a what? 2

4. Indicated for: (MELS) 4

1. water, not highly

2. dialysate solution across a semipermeable mebrane

3.
-small volume of distribution
-slow rate of intrinsic clearance

4.
-Methanol,
-Ethylene glycol,
-Lithium
-Salicylate

14

EM: Toxicology
Enhanced Elimination

Hemoperfusion
1. Advantage over hemodilaysis?

2. Drugs need to have a ______ volume of distribution and _____ rate of intrinsic clearance

3. What are not limiting factors? 3

4. Commonly associated with what and will not correct electrolyte imbalances or adjust pH?

5. Useful for: (TRI PEP-TD) what? 6

1. Drug or toxin is in direct contact with adsorbent material

2. small, slow

3.
-High molecular weight,
-poor water solubility, and
-plasma binding proteins

4. thrombocytopenia

5.
-Tricyclic antidepressants,
-paraquat,
-ethchlorvynol,
-phenobarbital,
-theophylline,
-digitoxin

15

Antidotes
1. Acetaminophen?
2. Anticholinergics?
3. Benzos?
4. Cyanide?
5. Methanol/Polyeth. glycol?
6. Narcotics?

1. Acetaminophen: Acetylcysteine
2. Anticholinergics: Physostigmine
3. Benzodiazepines: Flumazenil (DANGER)
4. Cyanide: Na nitrite and Na thiosulfate
5. Methanol/Polyeth. glycol: Ethanol
6. Narcotics: Naloxone

16

EM: Toxicology
Laboratory Clues
1. Calculation of osmolar gap may be helpful in determining what?
2. Osmolar gap (Δ osm) is determined by what?

3. Equation?

4. Serum osmolality can be increased by what?

1. “intoxicant” a patient has used

2. subtracting the calculated osmolality from the measured osmolality

3.
-Calculated: 2(Na) + Glu/18 + BUN/2.8
-Measured (from lab) – Calculated = Δ osm (Normal is

17

EM: Toxicology
Laboratory Clues

1. Serum concentration of an alcohol can be calculated?

2. The following are the molecular weights, lethal concentrations, and corresponding Δ osm:
-Ethanol?
-Methanol?
-Ethylene?
-Isopropanol?

3. The most common cause of Δ osm?

1. Serum concentration (mg/dl) = Δosm x Mol weight/10

2. The following are the molecular weights, lethal concentrations, and corresponding Δ osm:
-Ethanol: 46 (MW); 350 (LC); 75 (Δ osm)
-Methanol: 32 (MW); 80 (LC); 25 (Δ osm)
-Ethylene Glycol: 62 (MW); 200 (LC); 35 (Δ osm)
-Isopropanol: 60 (MW); 350 (LC); 60 (Δ osm)

3. The most common cause of Δ osm is Ethanol
Example: Δ osm = 30; 30 x (46/10) = 138 mg/dl BA

18

EM: Toxicology
Acetaminophen (Tylenol)

1. One of the metabolites is very toxic how?

2. Saturates the _______ detoxification system

3. Accumulates in liver and causes what?
- When?

4. Toxic dose of acetaminophen is > _____mg/kg
-LOWER in patient with what? 2

5. Dx?

1. hepatotoxic

2. glutathione

3. delayed hepatotoxicity
-24-72 hours post ingestion

4. 140
-chronic liver disease or
-alcoholism

5. Draw levels

19

EM: Toxicology
Acetaminophen (Tylenol)
Tx? 3

1. Decontaminate and give activated charcoal
2. Estimate severity:
3. Acetylcysteine therapy can be life-saving!

20

EM: Toxicology
Acetaminophen (Tylenol)

Treatment:
1. Estimate severity by? 3

Acetylcysteine therapy can be life-saving!
2. MOA?
3. Dose?
4. Follow up with what doses in what time period?
5. What is the key to treatment here?

1.
-ANY acetaminophen level is helpful
-The BEST level is 4 hours post-ingestion
-Trends are as important as initial value

2. Substitutes for glutathione and binds the metabolite
3. 140mg/kg orally of a 10%-20% solution
4. Follow-up with a 70mg/kg dose every 4 hours for 18 doses or until the Tylenol level is O (zero)
5. Key is it must be given EARLY: Do not wait for initial level; MUST be given within 12-16 hours and preferably within 8-10 hours

21

EM: Toxicology
Cocaine/Amphetamines
1. All are CNS stimulants and cause what?

2. Some may produce significant vasoconstriction and cause what? 2

3. Hypertension may be accompanied by what kind of arrhythmias?

4. Seizure and hyperthermia may produce what? 2

5. All significant cocaine overdoses will have symptoms: such as? 9

1. sympathetic hyperactivity

2.
-hypertension
-bradycardia

3. ventricular

4.
- rhabdomyolysis
- myoglobinuria

5.
-euphoria,
-excitement,
-restlessness,
-toxic psychosis,
-seizures,
-hypertension,
-tachycardia,
-hyperthermia
-possible MI

22

EM: Toxicology
Cocaine/Amphetamines

1. Dx?
2. Short half- lives and peaks effects occur within?

3. Treatment: _____ decontamination as indicated?

4. Severe agitation or psychosis?

5. -Treat seizures with?

6. If DBP > 120 or HTN encephalopathy?

7. Tachycardia/Vent Arrhythmias?

8. Monitor what? 3

9. DO NOT ACIDIFY URINE= ? 2

1. Significant toxicity will always have symptoms
2. Short half-lives and peak effects occur within 1-2 hours

3. GI
4. Diazepam 0.1-0.2mg/kg IV
5. diazepam
6. Nitroprusside

7. Beta Blocker??? (are you sure???) - be careful

8.
-temperature
-ECG;
-May need CT of head

9.
-Myogloburia
-ARF

23

EM: Toxicology
Anticholinergics
1. Which drugs? 5
2. Also seen in plants like? 3
3. MOA?
4. Significant poisoning always has some symptoms. Such as?
(whats the saying?)

1.
-Atropine,
-scopolomine,
-belladona,
-many antihistamines, and
-tricyclic antidepressants

2. Also seen in plants:
-jumsonweed,
-nightshade, and
-Amanita muscaria mushrooms

3. Block cholinergic receptors both centrally and peripherally

4. Significant poisoning always has some symptoms
Delerium, blurred vision, mydriasis, hallucinations, coma, dry mucous membranes, inhibition of sweating, hyperthermia, tachycardia

“Hot as a hare, red as a beet, dry as a bone, blind as a bat, and mad as a hatter”

24

EM: Toxicology
Anticholinergics

Treatment? 3

1. Supportive care
2. Gastrointestinal decontamination
3. Physostigmine, 0.01-0.03mg/kg slowly IV BUT should be reserved for those patients with severe symptoms

25

1. When you administer Physostigmine?
2. Must be placed on what?
3. Never use with what? 3
4. Peak effects may be delayed due to what?

1. Must have atropine readily available
2. Patient MUST be on cardiac monitor
3. NEVER use with
-tricyclic overdose,
-asthma
-mechanical bowel or bladder obstruction

4. significantly delayed gastric emptying and slowed peristalsis through GI tract

26

EM: Toxicology
Anticoagulants

1. What is the primary oral anticoagulant used therapeutically?
2. What are are common rodenticides?
3. Inhibits blood clotting by blocking what? 4

1. Warfarin (Coumadin) is the primary oral anticoagulant used therapeutically
2. The super-warfarins
-brodifacoum and
-indanediones are common rodenticides
3. Inhibit blood clotting by blocking Vitamin-K dependant clotting factors: II, VII, IX, X

27

EM: Toxicology
Anticoagulants

Inhibit blood clotting by blocking Vitamin-K dependant clotting factors: II, VII, IX, X

1. Only the synthesis of ____clotting factors is affected?

2. Effects may be seen ____ post ingestion as Factor II only has a 6-hour half life

3. PEAK EFFECTS are not seen for how long due to the long half-life of the other clotting factors (24-60 hours)?

4. Warfarin is highly bound to albumin with half-life of ____ hours/Metabolized by liver

1. new

2. 8-12

3. 1-2 days

4. 35

28

EM: Toxicology
Anticoagulants

1. A single overdose of Warfarin does not usually cause any significant problems because of?

2. Extremely-potent, long-acting anticoagulants (brodifacoum, indanediones) may produce what?

3. Excessive anticoagulation may present with: ? 8

1. the half-life of Warfarin is shorter than most of the clotting factors

2. severe bleeding disturbances for several weeks to months following a single overdose.

3.
-ecchymosis,
-hematuria,
-uterine bleeding,
-melena,
-epistaxis,
-gingival bleeding,
-hemoptysis or
-hematemesis.

29

EM: Toxicology
Anticoagulants
Tx? 4

TREATMENT
1. Supportive therapy/GI decontamination
2. Obtain baseline prothrombin time and repeat in 24-48 hours
3. Vita K 1-2mg IV which can restore clotting factors in 6-8h
4. In bleeding emergency; give Fresh Frozen Plasma (FFP)

30

EM: Toxicology
Arsenic
1. Many what contain trivalent arsenic? 3
2. What food may contain pentavalent arsenic (less toxic) which can cause a positive urine arsenic level but is not associated with clinical toxicity?

3. Highly-toxic Arsine gas is produced by what?

4. Arsenic is well absorbed from where? 2
-and avidly binds with what and accumulates in where?

5. Lethal dose of trivalent arsenic is about ______ mg in an adult

6. Clinical syndromes are divided into what? 2

1.
- insecticides,
-rodenticides
-wood preservatives

2. Shellfish

3. burning arsenic containing ores and is used in the electronic industry


4. respiratory and GI tract
-tissue proteins, tissues

5. 100-200

6. Arsenic salt ingestion (acute and chronic) and Arsine gas inhalation