Toxicology Flashcards
1
Q
What is a toxin?
A
- a poisonous substance
- anything can be a toxin (based on route, dose, duration of exposure)
2
Q
What is a toxidrome?
A
-constellation of physical findings (syndrome) that supports the clinical diagnosis of poisoning (exposure to a toxin)
3
Q
Toxidrome with Decreased PNS
A
anti-cholinergic
4
Q
Toxidrome with Increased PNS
A
cholinergic
5
Q
Toxidrome with Decreased CNS
A
opiate/sedative
6
Q
Toxidrome with Increased CNS
A
sympathomimetic
7
Q
Toxidrome with Altered PNS and CNS
A
serotonin syndrome
8
Q
What are some cholinergic agents that might cause poisoning?
A
- organophosphates (pesticides and commercial/industrial products)
- carbamates (home cleaning products)
- some mushrooms
- nerve agents (Sarin)
9
Q
Symptoms of Cholinergic Toxidrome
A
- SLUDGE: salivation, lacrimation, urination, diarrhea, GI complaint, emesis
- miosis
- bronchorrhea
- bradycardia or tachycardia
- mydriasis
10
Q
What muscarinic symptoms are present in cholinergic toxidrome?
A
- diarrhea, urination
- miosis
- bronchorrhea
- bradycardia
- emesis
- lacrimation, salivation
11
Q
What nicotinic symptoms are present in cholinergic toxidrome?
A
- mydriasis
- tachycardia
- weakness
- HTN
- fasciculations
12
Q
What central effects are present in cholinergic toxidrome?
A
- agitation, anxiety
- coma
- confusion
- seizure
13
Q
Symptoms of Anti-Cholinergic Toxidrome
A
- hot as a hare (hyperthermia)
- blind as a bat (blurred vision, mydriasis)
- dry as a bone (impaired sweating)
- red as a beet (flushing)
- mad as a hatter (agitation, psychosis, delirium, coma)
- bloated as a bladder (urinary retention)
- also tachycardia, HTN, muscle fasciculations, seizure, ileus
14
Q
What are some anti-cholinergic agents that might cause a toxidrome?
A
- anti-cholinergics (scopolamine, atropine)
- anti-histamines
- anti-psychotics (Haldol)
- anti-emetics (compazine, phenergan)
- antidepressants (TCA, SSRI)
- plants (Jimson weed, deadly nightshade)
15
Q
What are some anti-cholinergic agents that might cause a toxidrome?
A
- anti-cholinergics (scopolamine, atropine)
- anti-histamines
- anti-psychotics (Haldol)
- anti-emetics (compazine, phenergan)
- antidepressants (TCA, SSRI)
- plants (Jimson weed, deadly nightshade)
16
Q
What are some opiate/sedatives that might cause a toxidrome?
A
- morphine, heroin, oxycodone, codeine, methadone
- barbiturates
- benzodiazepines
- ethanol
17
Q
Symptoms of Opiate/Sedative Toxidrome
A
- everything is turned down (turns OFF flight/fight)
- miosis
- bradycardia, HoTN
- decreased LOC, coma
- decrease RR/effort
- hypotonia, hyporeflexia
- decreased bowel sounds
18
Q
What are some sympathomimetic agents that might cause a toxidrome?
A
- cocaine, amphetamine, MDMA (ecstasy), PCP
- ephedrine, pseudoephedrine
- theophylline
- caffeine
- withdrawal from EtOH or benzodiazepines
19
Q
Symptoms of Sympathomimetic Toxidrome
A
- everything turned up (exaggerates fight/flight)
- hyperthermia
- HTN, tachycardia
- mydriasis
- urinary retention
- psychosis, seizure
- diaphoresis
- hyperactive bowel sounds
20
Q
How can you distinguish anti-cholinergic and sympathomimetic toxidromes?
A
- sympathomimetic will have sweating and hyperactive bowel sounds
- anti-chol CAN’T sweat and might develop paralytic ileus
21
Q
How can you distinguish anti-cholinergic and sympathomimetic toxidromes?
A
- sympathomimetic will have sweating and hyperactive bowel sounds
- anti-chol CAN’T sweat and might develop paralytic ileus
22
Q
What might cause serotonin syndrome?
A
- MAOIs, linezolid
- SSRIs, cocaine, dextromethorphan, TCAs, trazodone, meperidine, tramadol
- LSD, buspirone
- lithium, amphetamines, MDMA
23
Q
Symptoms of Serotonin Syndrome
A
- cognitive/behavioral: confusion, agitation, coma, anxiety, hypomania, lethargy, seizures
- neuromuscular: hyperreflexia, muscle rigidity, tremor, ataxia, shivering, nystagmus
- autonomic: hyperthermia, diaphoresis, sinus tachycardia, HTN, tachypnea, non-reactive pupils
24
Q
What are the first 2 steps in treating a poisoned patient?
A
- stabilize the patient (BLS, ALS)
- ABCs
25
What labs should you consider for poisoned patient?
- CBC, coags, LFTs, CPK, ABG/VBG
- UA, urine tox
- serum levels: salicylate, APAP, digoxin
26
Treatment of Cholinergic Overdose
- atropine: indicated in all cholinergic crisis pts; repeat every 5 minutes until secretions clear
- pralidoxime (2 PAM): for organophosphate poisoning and other cholinergic crisis with severe weakness and respiratory compromise
27
Treatment of Anti-Cholinergic Overdose
- diazepam
- repeat PRN
- manage anxiety/agitation
- hyperthermia: cool mist, ice, cooling blanket, fans
28
Treatment of Opiate/Sedative Overdose
- naloxone: may need to repeat often, higher doses needed for methadone OD
- flumazenil: usually reserved for pts WE overdose; will induce seizures in abusers and those who use it therapeutically
29
Treatment of Sympathomimetic Overdose
- diazepam
| - cooling
30
Treatment of Serotonin Syndrome
- diazepam
- cooling
- antipyretics
- cyproheptadine: serotonin antagonist; does not decrease duration, but can reduce severity of sxs
31
What are the options for GI decontamination? (list them)
- activated charcoal
- gastric lavage
- whole bowel irrigation
32
Activated Charcoal:
When is it effective?
What is it not effective for?
When is it contraindicated?
- most effective within first hour
- not effective for iron, lead, lithium, alcohols, corrosives
- contraindicated in pts who are high risk for aspiration
33
What is Gastric Lavage?
-2-4 liters of warmed saline into stomach
34
Risks of Gastric Lavage
-risks: hypothermia, electrolyte imbalance, mechanical damage to esophagus, aspiration)
35
CIs of Gastric Lavage
-CI unless pt has a protected airway; CI for hydrocarbons and corrosives
36
What is whole bowel irrigation?
-polyethylene glycol passed through GI track
37
Indications for WBI
-for extended release meds and those that do not bind charcoal
38
CIs for WBI
- GI bleeding
- ileus
- obstruction
- perforation
39
CIs for WBI
- GI bleeding
- ileus
- obstruction
- perforation
40
APAP Toxicity
- primary cause of acute liver failure in US
- pts may be asymptomatic at first
- progresses to liver damage with hypoglycemia, jaundice, scleral icterus, hepatomegaly
41
Tx of APAP Toxicity
N-acetylcysteine
42
Initial Management of Anticholinesterase Insecticides
- decontaminate first! (these products can absorb through skin)
- ABCs
- protect the airway (high risk of decreased resp drive)
43
Treatment of Anticholinesterase Insecticides
- atropine: for all symptomatic pts; not a reversal agent
| - pralidoxime: for pts with severe toxicity
44
Calcium Channel Blocker Overdose Symptoms
- vasodilation
- decreased cardiac contractility
- decreased conduction velocity
- impaired insulin release leads to hyperglycemia and impaired cellular metabolism
45
Interventions for CCB Overdose
- IV calcium chloride for pts with persistent HoTN, arrhythmias
- infusion of insulin and dextrose can correct metabolic disturbance
- close monitoring of blood glucose, serum K+, calcium, acid/base balance
- glucagon
- intralipid
46
Iron Toxicity Sxs
- intense GI distress: N/V/D
- period of relative improvement or absence of sxs
- progression w/ continued GI symptoms, poor perfusion and decreased urine output
- also hepatic injury, hypoglycemia, acidosis, seizure, coma, ARDS
47
Treatment of Iron Toxicity
- ABCs, supportive care, airway, fluid resuscitation
| - IV deferoxamine
48
What is deferoxamine?
- highly selective iron chelator
| - removes excess iron from circulation
49
What are AEs of IV deferoxamine administration?
- HoTN
- tachycardia
- shock
- exacerbate ARDS
50
What are AEs of IV deferoxamine administration?
- HoTN
- tachycardia
- shock
- exacerbate ARDS
51
TCA Toxicity Sxs
- QRS widening, AV block, ventricular tachy, decreased contractility
- vasodilation, HoTN
- urinary retention, ileus, dry mucus membranes, hyperthermia
- agitation, delirium, lethargy, coma, seizure
52
TCA Toxicity Sxs
- QRS widening, AV block, ventricular tachy, decreased contractility
- vasodilation, HoTN
- urinary retention, ileus, dry mucus membranes, hyperthermia
- agitation, delirium, lethargy, coma, seizure
53
Treatment of TCA Overdose
- ABCs, supportive care
| - BICARB BICARB BICARB
