Blast Injuries

Question 1

How is the shock wave from a blast transmitted?

Answer 1

• It is transmitted radially from the source into the surrounding medium.

Question 2

What are the 3 phases of a blast wave?

Answer 2

• Positive phase
• Negative phase
• Mass movement of wind (blast wind)

Question 3

What is the defining characteristic of a conventional explosive?

Answer 3

• The variation in ambient pressure over time

Question 4

What happens to ambient air pressure during the positive phase?

Answer 4

• It causes a rapid increase in ambient air pressure

Question 5

What two factors affect the biological effects of a conventional blast?

Answer 5

• Peak overpressure

- Duration of positive phase

Question 6

What are the categories of blast injury?

Answer 6

• Primary
• Secondary
• Tertiary
• Combined

Question 7

What structures are most susceptible in a primary blast injury?

Answer 7

• Gas filled structures

- Lungs, GI tract and middle ear

Question 8

What are characteristics of secondary Blasts?

Answer 8

• They are the results from flying debris and bomb fragments

Question 9

What types of injuries would be suspected in Secondary blast injuries?

Answer 9

• Penetrating ballistic or blunt injuries

- Eye penetration

Question 10

What are the characteristics of a tertiary blast?

Answer 10

• The result of individuals being thrown by the blast wind.

Question 11

What types of injuries are suspected in tertiary blasts?

Answer 11

• Fractures and traumatic amputations

- Closed and open brain injury

Question 12

What are the characteristics of a quaternary blast?

Answer 12

• All other injuries that could be related to the blast, that is not due to primary, secondary and tertiary.

Question 13

What types of injuries will be seen in quaternary blast injuries?

Answer 13

-	Burns
o	Flash, partial and full thickness
-	Crush injuries
-	Closed and open brain injury
-	Asthma, COPD, or other breathing problems
-	Angina
-	Hyperglycaemia
-	Hypertension

Question 14

What is the greatest cause of morbidity and mortality in blast injuries?

Answer 14

• Lung issues

Question 15

What is the most consistent sign of a pulmonary blast injury?

Answer 15

• Haemorrhage

Question 16

What is air Emboli?

Answer 16

• It is the result from a traumatic alveolar- venous fistulae

Question 17

What is a GI blast injury more likely to occur?

Answer 17

• After a blast wave propagation in water

Question 18

What section of the GI tract is most common to GI haemorrhage from blast damage?

Answer 18

• The lower small intestine or cecum, where gas accumulates.