Smoke Inhalation

Question 1

T/F 50% of fire related deaths are from smoke inhalation and not from the burns.

Answer 1

FALSE–80% from smoke inhalation

Question 2

What does smoke include?

Answer 2

vapors, gases, fumes, heated air, particulate matter, liquid and solid aerosoles

Question 3

_____ animals are more likely to present for smoke inhalation.

Answer 3

younger (pets

Question 4

What factors play into the LD50 for smoke inhalation?

Answer 4

substances burning, combustion products, temp of fire, length of exposure, availability of oxygen, size of animal

Question 5

Toxicity of smoke inhalation is due to?

Answer 5

burns in resp tract enhance toxicity, super heated air and steam cause thermal burns to resp tract (higher temp and humidity increase injury), benzopyrene (carcinogen)

Question 6

Name the 3 categories that combustion products are classified as.

Answer 6

simple asphyxiants, irritants and chemical asphyxiants

Question 7

MOA of simple asphyxiants?

Answer 7

space occupying at the expense of oxygen, combined w/ consumption of environmental oxygen by the combustion

Question 8

MOA of irritants?

Answer 8

chemically react on contact w/ MM to cause local effects–ex: sulfur oxide–>sulfurous acid

Question 9

MOA of chemical asphyxiants?

Answer 9

produce toxic systemic effects at tissue distant from lung

Question 10

Simple asphyxiants include?

Answer 10

CO2, methane, oxygen deprived environment

Question 11

Irritants include?

Answer 11

High water solubility (upper airway injury)–>acrolein, sulfur dioxide, ammonia, hydrogen chloride
Intermediate water solubility (upper and lower airway injury)–>chlorine, isocyanates
Poor water solubility (pulmonary parenchymal injury)–>phosgene, nitrogen oxides

Question 12

Describe soot?

Answer 12

finely divided carbonaceous particulate matter suspended in the gases and hot air of smoke–contains carbon, aldehydes, acids, reactive radicals–sulfur dioxide adheres highly to soot

Question 13

Effects of inhaling soot?

Answer 13

enhances effect of other irritant toxins, soot binds to resp mucosa allowing materials to adhere and react, small particles (1-3 microns) reach alveoli

Question 14

T/F Solubility of the toxin is the most important determinant of respiratory injury.

Answer 14

TRUE

Question 15

MOA of highly soluble particles?

Answer 15

injury to mucosa, inflammatory mediators, free radicals–>increased permeability–>edema (affect the upper airways)

Question 16

MOA of low water soluble particles?

Answer 16

slower reaction, delayed effect (affect the lungs)

Question 17

Initial injury from smoke inhalation causes?

Answer 17

inflammatory response, increased secretions, bronchospasm, mucosal sloughing

Question 18

Chemical asphyxiants include?

Answer 18

CO, hydrogen cyanide, hydrogen sulfide, nitrogen oxides

Question 19

What is the most serious systemic agent w/ smoke inhalation?

Answer 19

carbon monoxide–changes oxygen-hemoglobin binding

Question 20

Clinical signs of smoke inhalation?

Answer 20

resp signs, cardiovascular signs, signs of irritation, CNS signs, resp compromise, surface burns

Question 21

Respiratory clinical signs of smoke inhalation?

Answer 21

cough, dyspnea, tachypnea–on auscultation: rales, wheezing, decreased breath sounds (bronchospasm), crackles (edema)

Question 22

Cardiovascular clinical signs of smoke inhalation?

Answer 22

tachycardia, hypoxemia, hypotension, dysrhythmias

Question 23

Signs of irritation due to smoke inhalation include?

Answer 23

conjunctivitis, pharyngitis, rhinitis, drooling, dysphagia, hoarseness–edema, mucosal ulcerations, soot on nose/mouth/throat–corneal abrasions common

Question 24

CNS signs due to smoke inhalation include?

Answer 24

agitation, confusion, ataxia, abnormal posturing, transient loss of consciousness, seizures

Question 25

Initial workup for smoke inhalation includes?

Answer 25

history (type of combustibles) and initial presentation (altered mentation, ataxia, collapse–>CO, cyanide)–vitals–oxygenation status (hypoxia, hypercapnia, SPO2)–thorough ophthalmic evaluation–acid/base status–carboxyhemoglobin or methemoglobin measurement–thoracic rads (recheck 24-36 hrs)

Question 26

Lesions due to smoke inhalation?

Answer 26

burns (skin, MM), pulmonary changes (presence of soot, pulmonary edema, pneumonia, chronic sequelae–fibrosis, bronchiolitis, neoplasia), cerebral edema and lesions attributed to CO poisoning (caudate nucleus, globus plaids and substantial nigra, cerebellum, cerebral cortex, dorsal thalamus)

Question 27

Treatment of smoke inhalation?

Answer 27

removal from smoke, oxygen support, inhaled B2 agonist to tx bronchoconstriction, remove soot from skin surface, early intubation, NSAIDs, antioxidants, inhaled nitric oxide, hyperbaric oxygen, hydroxocobalamin, methylene blue, IV fluids

Question 28

What is contraindicated in the treatment of smoke inhalation?

Answer 28

cough suppressants, opioids (bc suppress cough), steriods (higher mortality and infection rates)–also don’t give prophylactic abx wait until pneumonia develops

Question 29

Purpose of hydroxocobalamin in treatment of smoke inhalation?

Answer 29

tx cyanide toxicosis–displaces the hydroxo ligand to form cyanocobalamin

Question 30

Purpose of methylene blue in treatment of smoke inhalation?

Answer 30

tx methemoglobin

Question 31

Potential indications for early intubation after smoke inhalation?

Answer 31

aggressive fluid therapy (edema), SPO2 50mmHg), pulmonary edema, depressed mentation, full thickness neck or facial burns, failure to improve with oxygen mask

Question 32

Monitor closely for _____ hrs post exposure and recheck within ____ hrs.

Answer 32

6-8 hrs–72 hrs