Hydrocarbons and Inhaled Toxins Flashcards Preview

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Flashcards in Hydrocarbons and Inhaled Toxins Deck (21):
1

List the 4 types of toxic exposures to hydrocarbons

1. Accidental ingestions (generally children younger then 5)
2. Intentional inhalational abuse
3. Accidental inhalation or dermal exposure – often occupational
4. Massive oral ingestion in a suicide attempt

2

List the hydrocarbons most sought by abusers for eurphoria and disinhibition (also confusion and obtundation)?

1. Toluene
2. benzene
3. gasoline
4. butane
5. chlorinated hydrocarbons

3

How do hydrocarbons target the CNS/CV in toxicity

CNS: Work like general anesthetics
GABA activation

CV: sensitizes myocardium
Na channel/K channel blockers (prolong QRS and QT

4

What physical characteristics increase toxicity

1, volatile
2. low viscosity
3. low surface tension

5

How do hydrocarbons cause lung injury

1. asphyxiant (displaces O2)
2. inhibit surfactant production
3. direct damage to alveoli
4. Irritant: bronchospasm and inflammation

6

List 5 neurologic consequences of chronic use of inhaled hydrocarbons.

- Peripheral neuropathy
- Cerebellar degeneration
- Neuropsychiatric disorders
- Chronic encephalopathy
- White matter dementia

7

What is paitner’s syndrome?

- Mostly from chronic toluene exposure
- Ataxia, spacticity, dysarthria, dementia
- Consistent with leukoencephalopathy

8

List 3 subacute complications of HC aspiration / ingestion:

1. Pneumonia
2. PTx
3. Pneumatocele

9

List 4 reasons why patients with HC toxicity can be cyanotic:

1. asphyxiant
2. VQ mismatch
3. methemoglobinemia
4. Hypoventilation from ALOC

10

What hydrocarbons need intestinal decontamination

CHAMP
C: camphor (seizures and status)
H: Halogenated hydrocarbons (dysrhthmias and hepatotoxicity)
A: aromatic hydrocarbons: bone marrow supression and cancer
M: metal containing HC eg arsenic, mercury, lead
P: pesticide containing HC: cholinergic crisis , sz, resp depression)

11

How are inhaled toxins classified

simple asphyxiant: inert gas that displaces O2
pulmonary irritant: produce acid/base or oxygen radical
chemical asphyxiant: eg CO a gas that has higher affinity for Hb than O2

12

What adjunct therapy may provide symptomatic relief after exposure to chlorine or hydrogen chloride gas?

Nebulized 2% sodium bicarb
May have delayed S up to 24 hrs

13

List 3 ways that CO results in toxicity:

- Interacts with deoxyhemoglobin to form carboxyhemoglobin (COHb) (cannot carry oxygen)
- Shift to the left (interfering with ability to release oxygen)
- Interferes with cellular respiration by binding to mitochondrial cytochrome oxidase (increased binding during hypotension and hypoxia)

14

What abnormalities on imaging can be seen with CO toxicity?

CT head: Bilateral hypodensities in globus pallidus and internal capsule, seen after the acute exposure (below)

15

List risk factors that predict poor outcome after CO poisoning?

- Extremes of age
- Pregnancy (poor fetal outcome)
Pre-existing coronary artery / respiratory disease

16

What is the half life of CO

Room air: 5 hrs
100% FiO2: 90 min
HBO 30 min

17

What are the indications for HBO2

GT 25% adult or 15% pregnant/peds

LOC, coma, sz, confusion, cardiac ischemia, GT 24hrs of exposure, fetal distress

18

Where do CN, H2S and CO bind?

Fe3+ containing cytochrome a3 in the electron transport chain. Intereferes with aerobic metabolism leading to lactate generation

19

What are lab findings suggestive of CN toxicity

lactate GT 7
decreased arterial-venous O2 difference

20

What is the dose of hydroxycobalamin

5g IV over 15 min will turn skin, mm and urine red

21

List 4 knockdown toxins

HCN
H2S
volatile nerve agents
CO