Comparison of ATD to PMHS Response in the Under-Body Blast Environment.

A blast buck (Accelerative Loading Fixture, or ALF) was developed for studying underbody blast events in a laboratory-like setting. It was designed to provide a high-magnitude, high-rate, vertical loading environment for cadaver and dummy testing. It consists of a platform with a reinforcing cage that supports adjustable-height rigid seats for two crew positions. The platform has a heavy frame with a deformable floor insert. Fourteen tests were conducted using fourteen PMHS (post mortem human surrogates) and the Hybrid III ATD (Anthropomorphic Test Device). Tests were conducted at two charge levels: enhanced and mild. The surrogates were tested with and without PPE (Personal Protective Equipment), and in two different postures: nominal (knee angle of 90°) and obtuse (knee angle of 120°). The ALF reproduces damage in the PMHS commensurate with injuries experienced in theater, with the most common damage being to the pelvis and ankle. Load is transmitted through the surrogates in a caudal-to-cranial sequential fashion. Damage to the PMHS lower extremities begins within 2 ms after the initiation of foot/floor motion. The Hybrid III cannot assume the posture of the PMHS in rigid seats and exhibits a stiffer overall response compared to the PMHS. The ATD does not mimic the kinematic response of the PMHS lower extremities. Further, the Hybrid III does not have the capability to predict the potential for injury in the high-rate, vertical loading environment. A new ATD dedicated to under-body blast is needed to assist in the effort to mitigate injuries sustained by the mounted soldier.

Scientific aspects of supplying blood to distant military theaters.

PURPOSE OF REVIEW: Reduction in combat zone morbidity and mortality requires rapid delivery of safe blood products as an integral element of advanced trauma surgical care. This review of the current literature presents scientific aspects of supplying blood for rapid delivery to enhance survival and patient outcome in the combat zone. RECENT FINDINGS: Most deaths due to hemorrhage can be averted by transfusion during the first hour from injury; therefore, maintaining a dependable inventory of blood products in combat support hospitals is essential. Current casualty care in distant geographic locations involves rapid air evacuation to combat support hospitals or fleet hospitals, where massive transfusions may be required. Resuscitation by forward surgical teams utilizing red blood cells before air evacuation or in-flight has also been reported. To improve survival, these massive transfusions should be composed of not only red blood cells but also other blood components and plasma factors. SUMMARY: Rapid on-site combat casualty transfusion support requires specialized blood transport containers and transfusion practices not observed in noncombat settings, such as the mobile walking blood bank and a frozen blood program. Additionally, technology for improved transport containers, cell-free hemoglobin-based oxygen carriers, freeze-dried blood, and recombinant activated coagulation factor has attracted focused interest.