J Trauma
-
The feasibility of using Doppler radar to obtain more accurate measurements of velocity and yaw angle of bullets was investigated. Anesthetized pigs were shot at a range of 9-10 meters, and velocity measurements were obtained using Doppler radar and photocells. The data from the two types of equipment was compared. ⋯ It was possible to detect yaw even with these small calibers, and the radar was not disturbed by additional equipment. Using Doppler radar to measure velocity offers important benefits--simple set up, minimal risk of damage to equipment by stray bullets, and very good accuracy. The results of measuring yaw angles of bullets are promising, as far as determining the point of stability is concerned, but further work is necessary to be able to measure the angle of yaw exactly.
-
We hypothesize that during severe normothermic hemorrhagic shock (HS), induction of profound hypothermic circulatory arrest (PHCA) of 60 minutes to allow repair of otherwise lethal injuries in a bloodless field, can be survived without brain damage. In previous dog studies, normothermic HS with mean arterial pressure (MAP) of 40 mm Hg for 30 minutes, followed by PHCA of 2 hours at brain (tympanic membrane) temperature of 5 to 10 degrees C and core temperature of 10 degrees C, induced and reversed with cardiopulmonary bypass, resulted in survival with mild histopathologic brain damage. This study was designed to determine the severity of HS that can safely allow 1 hour of PHCA. In pilot studies with HS at MAP 30 mm Hg for 90 minutes with or without subsequent PHCA of 60 minutes there were no survivors. ⋯ The critical level of hypotension during 60 minutes normothermic HS that is compatible with survival in dogs is a MAP of between 30 and 40 mm Hg. After otherwise survivable severe normothermic HS of 60 minutes, PHCA of 60 minutes does not add brain damage or mortality, and may allow survival from injuries that would otherwise be irreparable.
-
It is known that blast wave and fragments are the primary causes of casualties from explosive weapons. To study the characteristics of blast-fragment combined injuries, functional and morphological changes were investigated in three groups of anesthetized dogs with blast injury, high velocity fragment extremity injury, and combined injuries of both types. The same parameters were also examined in a control group. ⋯ It is concluded that extremity injury from high velocity fragment will aggravate lung blast injury. Changes in the levels of PGI2 and TXA2, can be used to determine the extent of injury in the three kinds of wounds. This may be useful for early diagnoses and rational treatment of the victims of explosion.