smoke and thermal injury

Question 1

what caused direct thermal injury

Answer 1

caused by the inhalation of hot gases

Question 2

What is the effect of direct thermal injury on distal airway

Answer 2

they are spared due to:
– Ability of upper airways to cool hot gases
– Reflex laryngospasm
– Glottic closure

usually do not occur below the level of the larynx

Question 3

what are the local toxins contain in smoke that cause direct airway damage

Answer 3

acolein, formaldehyde, sulphur dioxide and nitrogen dioxide

Question 4

what is the result of local toxin on direct airway?

Answer 4

an acute inflammatory process mediated by leukocytes, especially neutrophils

Symptoms appear until 24 hours after

Question 5

what are two systemic toxin that cause systemic effect?

Answer 5

CO: most frequent to cause death from inhalation injury

Cyanide: inhibition of cellular oxygenation, causing tissue anoxia through inhibition cytochrome oxidase enzymes (Fe3+)

Question 6

what is the definition of smoke inhalation injury?

Answer 6

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

Question 7

what lead to smoke

Answer 7

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

Question 8

what cause the pathologic change in distal airways and alveoli

Answer 8

–Irritating and toxic gases
–Suspended soot particles
–Vapors associated with incomplete combustion and smoke

Question 9

what happens at early stage (0-24hr after inhalation)

Answer 9

tracheobronchial tree becomes more inflamed resulting in bronchospasm

overabundance of bronchial secretions to move into the airways, resulting in further airway obstruction.

Question 10

smoke effect on mucosal ciliary transport

Answer 10

slow the activity of the mucosal ciliary transport mechanism, causing further mucous retention

Question 11

what else can smoke inhalation cause

Answer 11

ARDS

noncardiogenic high-permeability pulmonary edema –> “leaky alveoli.”

Question 12

what else can cause Noncardiogenic pulmonary edema

Answer 12

overhydration resulting from overzealous fluid resuscitation.

Question 13

what happens during the intermediate stage ( 2 - 5 days)?

Answer 13

1. upper airway injury improve
2. pathologic change deep in leak usually peak
3. mucosa of the tracheobronchial tree frequently becomes necrotic and sloughs (usually at 3 to 4 days).
4. mucous accumulation often leads to bacterial colonization, bronchitis, and pneumonia.
5. ARDS may develop

Question 14

what happen in late stage of smoke inhalation injury (5 or More Days after)

Answer 14

Infections resulting from burn wounds on the body surface are the major concern during this period.

–> can lead to sepsis MODS,pulmonary embolism

Question 15

what are the Anatomic Alterations of the Lungs Thermal Injury?

Answer 15

• Blistering
• Mucosal edema
• Vascular congestion
• Epithelial sloughing
• Thick secretions
• Acute upper airway obstruction

Question 16

how is burning classified?

Answer 16

1st degree burn
2nd degree burn
3rd degree burn

Question 17

what is 1st degree burn

Answer 17

Red with no blister

6-10 day heal to normal

Question 18

what is 2nd degree burn

Answer 18

Damage to epidermis and dermis

Red and blisters

time is between 7 and 21 days.

normal to a hairless and depigmented skin with a texture that is normal, pitted, flat, or shiny.

Question 19

what is 3rd degree burn

Answer 19

Full thickness; dermis, epidermis & underlying tissue

Tissue charred and coagulated
•Healing after 21 days to scarring or may never occur without skin grafting, poor ROM
•May not heal without grafting

resultant damage heals with hypertrophic scars (keloids) and chronic granulation

Question 20

What suggest inhalational injury

Answer 20

facial burns
soot/black mucous
singed nasal hair
wheezing, crackles

Question 21

what suggest upper airway

obstruction

Answer 21

oral & laryngeal edema
painful swallow
stridor
hoarseness
difficulty speaking

Question 22

what are 2 complication associated with inhalation injury

Answer 22

CO poisoning

hydrogen cyanide poisoning

Question 23

what are the Treatment of Inhalational Injury

Answer 23

Mainly supportive:
–100 % O2
–Humidity
–Pain medication
–Monitor for edema or respiratory failure
42

Question 24

how to manage CO Poisioning

Answer 24

o2 reduces half life of CO

Via: hyperbaric chamber and/or 100% O2

half life breathing 21%: 5 hours
half life with 100% : 1 hour
half life breathing 100% at 3 atm: < 1 hour

Question 25

what is Cyanide poisoning?

Answer 25

inability to utilize O2 at cellular level, and shock (vasodilation)

Question 26

what are the treatment protocol for Cyanide poisoning

Answer 26

amyl nitrate inhalation

sodium nitrate injection

Question 27

how does IV sodium thiosulphate

Answer 27

help with clearance of MetHb by forming thiocyanate which can be easily excreted in urine

Question 28

what is the result of HCN?

Answer 28

shift to anaerobic metabolism
metabolic acidosis
decrease O2 transport

Question 29

what is the lab findings for inhalation injury

Answer 29

ABG: Acute Alveolar Hyperventilation (Acute Respiratory Alkalosis)

PFT: primarily restrictive lung pathology then combined (+ obstructive) after recovery

Question 30

what are the radiological findings

Answer 30

• Usually normal (early stage)
• Pulmonary Edema/ARDS
(intermediate stage)
• Patchy of segmental infiltrate (late stage)