Blast injuries Martial Ledecq In a modern armed conflict, most of the wounded are victim of bomb explosions. Blast injuries are responsible of two third of injuries during a conventional combat,... And more during terrorism activities. Martial Ledecq

Blast Explosive agents are by far the most common cause of terror-inflicted mass-casualty events globally, which is evident in even the most cursory review of daily news reports over the past 40 years. These numbers continue to rise exponentially. The most common cause of terror-inflicted mass casualty events The number of events rises exponentially

The most common cause of terror-inflicted mass casualty events Explosive agents are by far the most common cause of terror-inflicted mass-casualty events globally, which is evident in even the most cursory review of daily news reports over the past 40 years. These numbers continue to rise exponentially. US Department of State “Country report on terrorism”

The number of events rises exponentially Terrorist attacks rose 43% worldwide in 2013 2012: 11,018 killed 21,652 wounded 1,283 kidnapped 2013: 17,891 killed (16 us citizens abroad) 32,577 wounded ( 7 us citizens) 2,900 kidnapped (12 us citizens) Explosive agents are by far the most common cause of terror-inflicted mass-casualty events globally, which is evident in even the most cursory review of daily news reports over the past 40 years. These numbers continue to rise exponentially. US Department of State “Country report on terrorism”

Blast In a modern armed conflict, most of the wounded are victim of bomb explosions. Blast injuries are responsible of two third of injuries during a conventional combat,... And more during terrorism activities. “A sudden urban mass casualty situation” “A major challenge for civilian hospital”

Musculoskeletal trauma is the most common blast injury In the recent wars, most of penetrating limb injuries were not caused by bullets but by exploding devices or ammunitions such as bombs, grenades, or land mines, whereas most victims of land- mine explosions have extremity wounds, many of which require amputation.   Bowyer, G.W.: Management of small fragment wounds: experience from the Afghan border. J. Trauma 40(3 Suppl), 170–2 (2003) In a modern armed conflict, most of the wounded are victim of bomb explosions. Blast injuries are responsible of two third of injuries during a conventional combat,... And more during terrorism activities.

Blast Sudden overpressure (primary blast wave) Heat Propulsion of fragments An explosion is the sudden release of energy from the conversion of solids and liquids into gas. The over-pressure is the result of the extremely rapid conversion of a solid or liquid explosive into gases. High-energy explosives (TNT, Semtex, C-4, dynamite) are very destructive and are the type commonly used in terrorism. The blast wave spreads radially at supersonic speeds of 3,000–8,000 m/s (an average of 18.000 km/h). The gases expand extrmely rapidly, creating a supersonic « blast wave ». Secondly, the explosion releases a large amont of heat. (High-energy explosions are also characterized by an initial thermal burst, or fireball, as a result of the high magnitudes of energy released.) Finally, the explosion throws metallic fragments (non seulement l’enveloppe métallique de la bombe mais aussi les fragments qui ont été ajoutés à l’intérieur de celle-ci pour augmenter l’effet délétère (vis, clou, boulons …)

Blast wave millisecond The explosion causes a pressure wave which corresponds to an extremely sharp rise of the local pressure followed by a phase of depression and return to normal. This sudden compression - depression is responsible for primary lesions. millisecond

Type of blast injury Primary blast injury: reaction between the shock front and the body Secondary blast injury: propulsion of fragments of the bomb causing penetrating injury Tertiary blast injury: injuries resulting from the displacement of the whole body projected on the ground by the shock wave Quaternary blast injury: psychological morbidity, smoke intoxication, burns, ... Primary blast injury The extremely rapid expansion of the gases after the explosion causes a wave of hyper pressure. This shock wave affects the body, and particularly the air filled organs. The mechanism of injury is direct interaction of primary blast wave with the organ. A single blast wave can inflict multiple persons in its radius of curvature. A person with no apparent mark of blast injury is mandatory to observe. Sometimes primary blast wave manifests with delay. Intensity of primary pressure wave is inversely proportional to the square of the distance of explosion. Secondary blast injury Many IED (Improvised Explosive Device) are constituted of a metal casing containing explosive and multiple metal fragments (screws and nails). When they explode, they cause penetrating wounds. Tertiary blast injury Injuries resulting from collapse of surrounding structures on the body belong to this category as well (Crush Syndrome) Crush syndrome (also traumatic rhabdomyolysis) is a medical condition characterized by major shock and renal failure after a crushing injury to skeletal muscles. It is a reperfusion injury that appears after the release of the crushing pressure. The mechanism is due to the release into the bloodstream of muscle breakdown products—notably myoglobin, potassium and phosphorus—that are the products of rhabdomyolysis (the breakdown of skeletal muscle damaged by ischemic conditions). Tertiary blast injuries are largely blunt traumatic injuries. Quaternary blast injury Quaternary blast injury encompasses other blast injuries that are not described in above type: psychological traumas, burns and asphyxia. Burns occur mainly in victims close to detonation site. Temperatures of 3000 centigrade can be reached in explosions.

Type of blast injury Heat Mine fragment

Type of blast injury Heat Mine fragment On the left, there is a wounded, riddled of bomb fragment, with a traumatic amputation of the thumb and a penetrating chest wound by another fragment. Mine fragment

Primary blast may produce lesions Primary blast injury 15 - 20% of blast injured Involves air-filled organs: ears, GI tract and lungs Primary blast may produce lesions 10 to 15 days later Primary blast injuries involve air-filled organs, like ears, and structures with air fluid interface, like the G-I and the lungs.

Primary blast injury Auditory system: The most common injury: perforation of the eardrum Spontaneous healing: 50 - 80% Permanent hearing loss: 80 - 100%! Perforation of the tympanic membrane is the commonest injury caused by the sudden overpressure to the body. It can be associated with ossicle fracture or dislocation. The eardrum heals spontaneously in more than 50% of injuries.

Primary blast injury Pulmonary injury: The greatest cause of morbidity and mortality Micro haemorrhages in alveoli Air embolism Peri bronchial disruption Small tears of the parenchyma Tension pneumothorax ARDS 2,5% of Primary Lung Injury following the Madrid train bombings in 2004. Air embolism can present as stroke, MI, acute abdomen, blindness, deafness, spinal cord injury, claudication Signs usually present at time of initial evaluation, but may be delayed up to 48 hours

Primary blast injury Pulmonary injury: Treatment - Preventive insertion of bilateral chest tube - Mechanical ventilation - Limited inspiratory pressure - Small volume ventilation - Permissive hypercapnia

Primary blast injury Gastrointestinal tract: The primary blast wave produces a rapid compression-decompression of the intestinal tract (caecum and colon) The commonest injury: haemorrhage beneath the visceral peritoneum The less common: rupture of the caecum and the colon After a G-I tract blast injury, most of the patients will develop an abdominal discomfort with a certain degree of ileus. Rarely, an acute abdomen will occur a few days later. Gastrointestinal injuries were once thought to occur with the same frequency as lung injury. A recent, large Israeli case series found that abdominal injuries were seen only with massive trauma. In this series, all of the patients complained of tenesmus. Blast injury to the gastrointestinal tract should be suspected in anyone who has abdominal pain, nausea, vomiting, hematemesis, rectal pain, testicular pain, unexplained hypervolemia, or any finding compatible with an acute abdomen after exposure to an explosion.

Secondary blast injury Penetrating injuries by metallic fragments High energy missile Irregular permanent cavity Temporary cavity Sucking effect Most bombs with explosive like Semtex, TNT or dynamite, capable of propelling metal fragments at high speed.

Tertiary blast injury Projection of the whole body Collapse of surrounding structures Crush Syndrome Patients with crush injury (muscular tissue compression -> muscle cell damage -> rhabdomyolysis) Complications: Acute Renal Failure (ARF), severe metabolic acidosis, fatal hyperkalemia Tertiary blast injury Injuries resulting from collapse of surrounding structures on the body belong to this category as well (Crush Syndrome) Crush syndrome (also traumatic rhabdomyolysis) is a medical condition characterized by major shock and renal failure after a crushing injury to skeletal muscles. It is a reperfusion injury that appears after the release of the crushing pressure. The mechanism is due to the release into the bloodstream of muscle breakdown products—notably myoglobin, potassium and phosphorus—that are the products of rhabdomyolysis (the breakdown of skeletal muscle damaged by ischemic conditions). Tertiary blast injuries are largely blunt traumatic injuries.

Tertiary blast injury Crush Syndrome Clinical presentation: - Hypotension: massive third space (oedema in the affected areas) - ARF: acute tubular necrosis by myoglobin precipitation - Electrolytes abnormalities: hyperkalaemia & hypocalcemia - Metabolic acidosis: lactic acid released by ischaemic muscles Tertiary blast injury Injuries resulting from collapse of surrounding structures on the body belong to this category as well (Crush Syndrome) Crush syndrome (also traumatic rhabdomyolysis) is a medical condition characterized by major shock and renal failure after a crushing injury to skeletal muscles. It is a reperfusion injury that appears after the release of the crushing pressure. The mechanism is due to the release into the bloodstream of muscle breakdown products—notably myoglobin, potassium and phosphorus—that are the products of rhabdomyolysis (the breakdown of skeletal muscle damaged by ischemic conditions). au cours des rhabdomyolyses ou des hémolyses massives, la précipitation intratubulaire de myoglobine ou d’hémoglobine, ou de chaînes légères d’immunoglobulines est impliquée dans l’IRA. Tertiary blast injuries are largely blunt traumatic injuries.

Tertiary blast injury Crush Syndrome Treatment - IV rehydration: restore volemia & maintain diuresis - IV bicarbonate - Calcium gluconate - Cardiac arrhythmias monitoring Tertiary blast injury Injuries resulting from collapse of surrounding structures on the body belong to this category as well (Crush Syndrome) Crush syndrome (also traumatic rhabdomyolysis) is a medical condition characterized by major shock and renal failure after a crushing injury to skeletal muscles. It is a reperfusion injury that appears after the release of the crushing pressure. The mechanism is due to the release into the bloodstream of muscle breakdown products—notably myoglobin, potassium and phosphorus—that are the products of rhabdomyolysis (the breakdown of skeletal muscle damaged by ischemic conditions). au cours des rhabdomyolyses ou des hémolyses massives, la précipitation intratubulaire de myoglobine ou d’hémoglobine, ou de chaînes légères d’immunoglobulines est impliquée dans l’IRA. Tertiary blast injuries are largely blunt traumatic injuries.

Crush syndrome & acute kidney failure Rescued victims who are seemingly well, can get worse or even die once they are extricated EARLY FLUID ADMINISTRATION (already pre-extrication) K+ containing solutions should NEVER be administered empirically ! Tertiary blast injury Injuries resulting from collapse of surrounding structures on the body belong to this category as well (Crush Syndrome) Crush syndrome (also traumatic rhabdomyolysis) is a medical condition characterized by major shock and renal failure after a crushing injury to skeletal muscles. It is a reperfusion injury that appears after the release of the crushing pressure. The mechanism is due to the release into the bloodstream of muscle breakdown products—notably myoglobin, potassium and phosphorus—that are the products of rhabdomyolysis (the breakdown of skeletal muscle damaged by ischemic conditions). Tertiary blast injuries are largely blunt traumatic injuries.

Crush syndrome & acute kidney failure 50 % of the crush victims will develop some ARF 50 % of the ARF need dialysis Haemodialysis ? Material: consumables, dialysis machines Staff : specialised MD, nurses, technicians

Every wounded is suffering a psychological trauma