thermal and heat lung injury

Question 1

What are the 2 categories of fire related pulmonary injuries?

Answer 1

thermal

smoke

Question 2

What are 4 MOA”?

Answer 2

Direct Thermal,
Hypoxic Gas Inhalation
Local Toxins
Systemic Toxins

Question 3

What is Direct Thermal injury ?

Answer 3

• injury caused by the inhalation of hot
  gases
• do not occur below the level of the larynx, except in the rare instance of steam inhalation.

Question 4

what part of the airway does direct thermal injury affect?

Answer 4

upper airway
– Nasal cavity
– Oral cavity
– Nasopharynx
– Oropharynx
– Laryngopharynx

Question 5

how about the distal airway in direct thermal injruy ?

Answer 5

-spared serious injury

– Ability of upper airways to cool hot gases
– Reflex laryngospasm
– Glottic closure

Question 6

What is Hypoxic Gas Inhalation

Answer 6

During combustion FiO2 drops progressively until the fire is extinguished

• drops of Fio2 depends on type of fuel & the duration of the process varies
• Less than 5% is considered incompatible with
  life

Question 7

What is local toxins?

Answer 7

these inhaled substance can cause direct airway damage

• acolein,
• formaldehyde
• sulphur dioxide
• nitrogen dioxide

Question 8

what is the effect of local toxin on airway?

Answer 8

acute inflammatory
process mediated by leukocytes, especially
neutrophils

Question 9

when does symptom appear after inhaling local toxin?

Answer 9

may not appear until 24

hours

Question 10

what is systemic toxins

Answer 10

Two gases that cause systemic effects which are associated with high rate of mortality & morbidity
morbidity)

• CO
• ->cause death from inhalation injury (decrease CaO2)
• cyanide
  –>caused by inhibition of cellular
  oxygenation
  –>causing tissue anoxia through
  inhibition of cytochrome oxidase enzymes (Fe3+)

Question 11

what is smoke inhalation injury?

Answer 11

the aspiration of superheated gases,
steam or noxious substances of incomplete
combustion

Question 12

the effect of smoke inhalation injury?

Answer 12

smoke inhalation dramatically increases the mortality rate for burn victims

burn victims have complex involvement of major organ systems (skin, renal, cns, lung)

Question 13

What is the cause of smoke inhalaiton injury?

Answer 13

result from:

• pyrolysis
• ->smoldering in a low-oxygen environment
• combustion
• -> burning, with visible flame, in an adequate-oxygen environment)

Question 14

what is smoke composed of?

Answer 14

1. chemical makeup of the material that is burning

2. amount of oxygen being consumed by the fire.