Blast injuries primary

All injuries that are the result of an explosion are categorized as primary, secondary, tertiary, and quaternary blast injuries. Casualties with primary blast injuries are a direct result of the blast wave from HEs. The... 

Penetrating and blunt traumatic injuries that occur as the result of an explosion are similar to those associated with other mechanisms of injury. Primary blast injuries present unique situations and affect selected body systems. Every body system may be affected following an explosion and subsequent blast wave, the associated injuries and their care are discussed in a head-to-toe manner. 

Discuss the primary blast injuries in relation to body systems. 

Hue, C.D., Cao, S., Haider, S.R, et al, 2013. Blood-brain barrier dysfunction after primary blast injury in vitro. J. Neurotr. 30, 1652-1663. 

When a detonation occurs, a blast wave is produced which spreads out from the point of detonation like the ripples produced by dropping a stone into a pond. The blast wave travels faster than the speed of sound in air, compressing the air in front of it and producing an almost instantaneous rise in pressure lasting a fraction of a millisecond before falling away to a negative pressure (see Fig. 3.3). Atmospheric pressure is then restored as the blast wave passes. The blast wave is responsible for primary blast injuries (pages 95-96). 

Fluids should be administered with caution. The majority of injuries resulting from blast are conventional (fragment wounds, amputations, impact injuries and crush), and a conventional approach is therefore appropriate using permissive hypotension. Primary blast injuries are unlikely to be clinical priorities in the initial stages of resuscitation and the possibility of their presence should not be allowed to divert attention from where it should properly be focused. It should be noted that conventional personal body armour conveys little or no protection against blast injury and patients who have been wearing it should be considered to be at significant risk of primary blast injury. 

Significant primary blast injury only occurs in those who have been exposed to high blast loading and are consequently very close to the point of detonation (remember the pressure distance curve. Fig. 3.2). As a result, most such casualties will have died from secondary or tertiary injuries. However, reflection and summation in closed spaces may be associated with a significant incidence of primary injuries in survivors of atrocities in areas such as bars and buses. In one Israeli bus bomb incident, incidences of 76% for eardrum perforation, 38% for blast lung and 14% for abdominal blast injury were found. 

Note Injuries to the chest and abdomen are associated with the highest mortality, and soft-tissue Injuries, although common, are not associated with significant mortality. Significant primary blast Injury (Injury due directly to the blast wave) appears uncommon in survivors of civilian terrorist Incidents. ... 

Clinical primary blast injury to the lungs ( blast lung ) appears to be rare in survivors of conventional explosions. There is considerable variation in the incidence of blast lung amongst survivors, depending on the site of the detonation (enclosed or open) and the presence or absence of fragments which themselves could result in fatal injury. 

The signs and symptoms of primary blast injury to the abdomen include ... 

The decision to intervene surgically and the timing of surgery in blast injury without skin penetration are difficult unless there are obvious signs of peritonitis or shock. Primary blast injury produces a number of pathological lesions (Box 3.17). 

Retroperitoneal haemorrhage and solid organ damage are more likely to result from fragmentation (secondary injury) or displacement (tertiary injury) than from primary blast injury. Bowel injuries appear more common in the ileocaecal region. 

In the United States, most of the studies on blast injuries to all types of mammals, including humans, have been done by the staff of the Lovelace Foundation. Their work is summarized in Refs. 43-45, and criteria given for primary air blast lethality levels for humans,... 

Blast injuries to victims are classified as primary, secondary, or tertiary (Figure 6.16). 

Explosions can cause injury by the primary blast wave and heat (primary injury), by the shrapnel thrown by the blast (secondary injury), or by the blast victim being thrown against a fixed object (tertiary injury). 

Nakagawa, A, Manley, G.T., Gean, A.D., et al., 2011. Mechanisms of primary blast-induced traumatic brain injury insights from shock-wave research. J. Neurotrauma 28 (6), 1101-1119. 

Bare charges, e.g. booby traps Small improvised devices (<10 kg) detonated by wire or rodio device Primary blast and characteristically fragment injuries... 

Although not an issue discussed in the small amount of literature available, it is worth pa)fing further consideration to the exact mechanism of primary abdominal injury. It occurs most frequently at density interfaces, which, are usually tissue planes. The blast wave creates a shear force at this point, at which a significant amount of kinetic energy is dumped. The logical conclusion is that in an attack in a confined space, resulting in a complex wave, there is potential for multiple shear forces to be generated near-simultaneously as the... 

Thoracic injuries are common and may be either blimt (from impact) or penetrating (from fragments or impact). In addition, pneumothorax may occur as a primary blast effect. The management of these injuries follows conventional protocols, although some care should be taken if ventilatory support is required (see below). 

Secondary blast injury - injuries due to fragmentation Secondary blast injuries are those caused by fragments energised by the blast wind. A classification is given in Box 3.8. Primary fragments are those incorporated within the explosive device itself. Improvised... 

Head injuries are common following blast exposure. The effects of primary blast on the brain are not clearly established and remain controversial. During World War I, changes in the brain ascribed to primary blast effects were considered to be a potential cause of some of the signs and symptoms associated with shell shock. 

The main direct, primary effect to humans from an explosion is the sudden increase in pressure that occurs as a blast wave passes. It can cause injury to pressure-sensitive human organs, such as ears and lungs. 

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