Exposure to Toxic Gases

Question 1

The initial approach to any toxic inhalation

Answer 1

• First, scene safety in paramount
• Once the patient is safely accessible for the IDC, the mainstay of patient treatment is supportive care with

Question 2

Inhaled agents manifest their toxic effects by four different mechanisms:

Answer 2

1) Physical particulates
2) Simple asphyxiants
3) Chemical irritants
4) Chemical asphyxiants

Question 3

• Small, solid particles that are carried by gases or
  atmospheric air into the body through inhalation (e.g., dust or combustion soot).
• This situation is encountered most commonly with cases of smoke inhalation.

Answer 3

Physical Particulates

Question 4

(c) Clinical symptoms of upper airway injury, such as difficulty breathing, might not be immediately obvious until edema is severe enough to significantly impair airway diameter.
(d) Symptoms of lower respiratory tract injury may include shortness of breath and productive cough
(e) Physical findings include burns to the face, signed nasal vibrissae, soot in the oropharynx, nasal passages, proximal airways, and carbonaceous sputum.

Answer 4

Physical particulate exposure

Question 5

Treatment of physical particulate exposure

Answer 5

(a) Management is supportive:
1) Remove the patient from the source of the physical particulates and administer oxygen.
2) Patients with signs of reactive airway disease (e.g., wheezing and poor air flow) should be treated with nebulized Albuterol.

Question 6

cause injury by merely being present in an environment and displacing the normal levels of atmospheric oxygen

Answer 6

Simple asphyxiants

Question 7

Types of Simple asphyxiants

Answer 7

1) Carbon dioxide (CO2)
2) Nitrogen
3) Methane
4) Natural gas

Question 8

How do simple asphyxiants affect the body

Answer 8

Simple asphyxiants have no inherent toxic or metabolic effect on the body’s cells,
other than causing hypoxia by default due to lack of adequate oxygen.

Question 9

(a) Signs and symptoms depend on the agent involved and its concentration.
(b) Patients will exhibit such classic signs of hypoxia as agitation, which may rapidly
progress to unconsciousness and then cardiac arrest.
(c) If the asphyxiant is CO2, patients may experience a narcotic-like
sleepiness as the initial effect of exposure.

Answer 9

Simple Asphyxiants

Question 10

Treatment of Simple Asphyxiants

Answer 10

(a) The mainstay of simple asphyxiant management is gaining safe access to the patient
(b) Administration of high-concentration oxygen
(c) Cardiopulmonary support as indicated

Question 11

Express their toxic effects by chemical reaction with the mucus membranes of the eyes and respiratory system

Answer 11

Chemical irritants

Question 12

Two general classes of chemical irritants

Answer 12

Hydrophilic and non-hydrophilic

Question 13

Hydrophilic inhaled agents include

Answer 13

hydrochloric acid and ammonia.

Question 14

Non-hydrophilic agents affect the body how

Answer 14

Don’t readily react with the moist membranes of the upper respiratory tract, they can pass more deeply
into the lungs and cause direct lung injury

Question 15

Example of bib-hydrophilic chemical irritant

Answer 15

phosgene gas, a major industrial chemical used to make plastics and pesticides

Question 16

Sx of non hydrophilic irritant

Answer 16

Sometimes these effect are delayed, and a patient may be relatively stable for a while and then decompensate with respiratory failure due to acute lung injury

Question 17

Treatment of chemical irritant

Answer 17

(a) Treatment of chemical irritant exposures should include supportive care and irrigation of eyes with water or saline.
(b) As with particulate irritants, patients with underlying asthma or COPD will likely benefit from nebulized albuterol treatments if bronchospasm is evident during physical examination.

Question 18

cause injury by asphyxiating patients at the
cellular level by massively deranging normal cellular utilization of oxygen

Answer 18

chemical asphyxiants

Question 19

most common example of a chemical asphyxiant

Answer 19

carbon monoxide (CO).

Question 20

Other examples of inhaled chemical asphyxiants

Answer 20

cyanide gas (HCN)
and Hydrogen Sulfide (H2S).

Question 21

often has a gradual, even insidious, onset of symptoms, which may include headache, chest pain and decreasing mental status. Frequently, the patient
progresses to coma and death.

Answer 21

Carbon monoxide poisoning

Question 22

Patients exposed to H2S and HCN tend to have

Answer 22

very rapid onset and progression of symptoms

Question 23

treatment for CO poisoning

Answer 23

supportive care with high-flow oxygen via a
non-rebreather mask or ET tube for the comatose patient

Question 24

What does hydrogen sulfide smell like

Answer 24

“Rotten eggs”

Question 25

treatment for H2S exposure

Answer 25

• supportive care with high concentration
  oxygen and ETI if indicated
• Additional advanced therapies for the H2S- poisoned patient may include the use of the nitrite component of the standard cyanide kit and hyperbaric oxygen therapy

Question 26

victim classically presents with unresponsiveness, hyperventilation and hypotension without evident
cyanosis.

Answer 26

Cyanide Poisoning

Question 27

Treatment of Cyanide Poisoning

Answer 27

2) The typical cyanide antidote kit has been the standard of emergency care for more than 50 years.
a) The kit contains three drugs designed to be administered in the following sequence:

(1 Inhaled amyl nitrite
(2 IV sodium nitrite and
(3 IV sodium thiosulfate

b) More recently, a safer cyanide antidote has become available in theU.S.
(1 IV hydroxocobalamin, combined with sodium thiosulfate
- supportive care with 100% oxygen should be
used in all cyanide inhalations.