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Edited on Mon Jun-12-06 10:08 AM by igil
(University database access can be fun. For the Zhang, Wang, Leng and Yang article, keep in mind that a concussion wave (or any pressure wave, such as sound) is composed of two alternating parts, underpressure and overpressure. I'm assuming that the underpressure is what ruptures the alveoli.
Blast lung injury. Sasser SM ; Sattin RW ; Hunt RC ; Krohmer J. Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors. (Prehosp Emerg Care) 2006 Apr-Jun; 10(2): 165-72
... "Blast lung" is a clinical diagnosis and is characterized as respiratory difficulty and hypoxia without obvious external injury to the chest. It may be complicated by pneumothoraces and air emboli and may be associated with multiple other injuries. Patients may present with a variety of symptoms, including dyspnea, chest pain, cough, and hemoptysis. Physical examination may reveal tachypnea, hypoxia, cyanosis, and decreased breath sounds. Chest radiography, computerized tomography, and arterial blood gases may assist with diagnosis and management; however, they should not delay diagnosis and emergency interventions in the patient exposed to a blast. ...
Primary blast injury after a bomb explosion in a civilian bus. Katz E ; Ofek B ; Adler J ; Abramowitz HB ; Krausz MM Annals of surgery. (Ann Surg) 1989 Apr; 209(4): 484-8
6-kg explosive charge detonated under a seat in the center of a crowded city bus in Jerusalem, killing three passengers immediately. Of the 55 survivors, all of whom were transferred to two major medical centers, 29 were hospitalized. Among those admitted, a high rate of primary blast injuries was found, including perforated ear drums (76%), blast lung (38%), and abdominal blast injuries (14%). Two of the latter patients suffered bowel perforations, which were diagnosed with considerable delay. Eight patients (31%) had sustained life-threatening trauma, consisting of a combination of primary, secondary, and tertiary blast injuries. The overall mortality rate was 10.3%. The large number of primary blast injuries, including the unexpected finding of bowel perforations, is explained by the high amplitude of the air pressure wave (3.8-5.2 atm) and its relatively long duration (2-3 msec) resulting from the detonation of the high-energy explosive charge in the small, enclosed space of the bus. Besides the usual wounds sustained by victims of an explosion that occurs in a confined space, the possibility of primary blast injury to the abdomen and to the lungs should be taken into account by the treating surgeon.
Zhang J ; Wang Z ; Leng H ; Yang Z Studies on lung injuries caused by blast underpressure. The Journal of trauma. (J Trauma) 1996 Mar; 40(3) Suppl: S77-80This study was designed to determine the effects of underpressure on the lungs of rats and rabbits. An underpressure generator was made to simulate reliably the underpressure parameters at various levels. The peak level and duration ranged from -45.5 kPa to -86.5 kPa and from 21.3 milliseconds to 1,900 milliseconds, respectively. The time to peak negative pressure ranged from 3.5 milliseconds to 7.4 milliseconds. The results showed that underpressure at a certain level could inflict injuries on rats and rabbits. The severity of injury ranged from mild to extremely severe, even to death. These injury patterns were similar to those induced by blast overpressure. The lungs were the organs most vulnerable to underpressure. The pulmonary pathological changes included hemorrhage and edema. The typical hemorrhagic stripes on the lung surfaces resulted from the interfacial impacts of the lungs on the chest wall. The severity of lung injury increased with increased peak pressure and duration levels. This relationship can be expressed with linear regressive equations and the physical parameters of the underpressure can be used to indicate the severity of injury to lungs.
Yang Z ; Wang Z ; Tang C ; Ying Y Biological effects of weak blast waves and safety limits for internal organ injury in the human body. The Journal of trauma. (J Trauma) 1996 Mar; 40(3) Suppl: S81-4
One hundred and seventeen adult sheep of both sexes, each weighing 15.2-42.4 kg, were used for this study. The purpose of this study was to investigate the relationship of the physical parameters of the waves to internal organ injury by exposing sheep to weak blast waves in TNT (trinitrotoluene) explosions, biological shock tube, and gun muzzle blasts. The results showed that the organ most sensitive to the TNT explosion was the lungs, whereas the upper respiratory tract was most sensitive to muzzle blast waves. The injury thresholds of overpressure were 29.0, 29.5, and 41.2 kPa for upper respiratory tract, lungs, and gastrointestinal tract respectively at a single exposure. Repeated exposure to 60 blasts reduced the injury threshold of the internal organs. The injury thresholds for upper respiratory tract, lungs, and gastrointestinal tract were 21.0, 18.0, and 40.4 kPa, respectively. The duration of overpressure of weak blast waves was 2.4-4.2 milliseconds, which did not significantly affect the severity of injury. The safety limits of weak blast waves to internal organ injury of human body were as follows: Ps = 37-3Ln.Tc.N/4(Tc.N < or = 1000) and Ps = 20.4(Tc.N > 1000). The results suggest that repeated exposures decrease the injury threshold of the internal organs. The safety limits proposed could protect 90% of the exposed population against internal organ injury caused by weak blast waves.
Argyros GJ Management of primary blast injury. Toxicology. (Toxicology) 1997 Jul 25; 121(1): 105-15
Blast waves are produced following the detonation of munitions, the firing of large caliber guns, or from any type of explosion. These blast waves can be powerful enough to injure the individuals exposed to them. This type of injury is called primary blast injury (PBI) and the organs most vulnerable to PBI are the gas-filled organs, namely the ear, the lungs and the gastrointestinal tract. The approach to the casualty with PBI is the same as it would be for any trauma victim, i.e. the initiation of life support measures. Attention should be directed to the common life-threatening manifestation of thoracic and abdominal PBI. Pulmonary manifestations would include hemorrhage, barotrauma and arterial air embolism, while abdominal manifestations would include hemorrhage and hollow organ rupture. Therapy is directed at the specific manifestations as well as avoiding additional iatrogenic injury.
There are more ... I heard that a large blast or concussion could create serious internal injuries; now I know a bit more than I wanted. (And what's up with the rabbit and sheep studies? Seriously, they blew up sheep.)
On edit: The point is that any old bomb that's big enough, or where the energy is properly contained/channeled, can cause these injuries. Note that the bus-bombing some Palestinian produced just had a powerful bomb.
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