Advances in resuscitative trauma care.

Over the last two decades, experimental and clinical data have begun to shape a more discriminating approach to intravascular (IV) fluid infusions in the resuscitation of trauma patients with presumed internal hemorrhage. This approach takes into account the presence of potentially uncontrollable hemorrhage (e.g., deep intra-abdominal or intra-thoracic injury) versus a controllable source (e.g. distal extremity wound). This limitation on fluid resuscitation is particularly applicable in the case of patients with penetrating truncal injury being transported rapidly to a nearby definitive care center. Meanwhile, longstanding debates over the type of fluid that should be infused remain largely unresolved and further complicated by recent clinical trials that did not demonstrate support for either hemoglobin-based oxygen carriers or hypertonic saline. However, there is also growing evidence that does support the increased use of fresh frozen plasma as well as tourniquets, and intra-osseous devices. While a more discriminating approach to fluid infusions have evolved, it has also become clear that positive pressure ventilatory support should be limited in the face of potential severe hemorrhage due to the accompanying reductions in venous return. Controversies over prehospital endotracheal tube placement are confounded by this factor as well as the effects of paramedic deployment strategies and related skills usage. Beyond these traditional areas of focus, a number of very compelling clinical observations and an extensive body of experimental data has generated a very persuasive argument that intravenous estrogen and progesterone may be of value in trauma management, particularly severe traumatic brain injury and burns.

Aromatase is increased in astrocytes in the presence of elevated pressure.

After traumatic brain injury (TBI), a progressive injury and death of neurons and glia leads to decreased brain function. Endogenous and exogenous estrogens may protect these vulnerable cells. In this study, we hypothesized that increased pressure leads to an increase in aromatase expression and estrogen production in astrocytes. In this study, we subjected rat glioma (C6) cells and primary cortical astrocytes to increased pressure (25 mm Hg) for 1, 3, 6, 12, 24, 48, and 72 h. Total aromatase protein and RNA levels were measured using Western analysis and RT-PCR, respectively. In addition, we measured aromatase activity by assaying estrone levels after administration of its precursor, androstenedione. We found that increased pressure applied to the C6 cells and primary cortical astrocytes resulted in a significant increase in both aromatase RNA and protein. To extend these findings, we also analyzed aromatase activity in the primary astrocytes during increased pressure. We found that increased pressure resulted in a significant (P < 0.01) increase in the conversion of androstenedione to estrone. In conclusion, we propose that after TBI, astrocytes sense increased pressure, leading to an increase in aromatase production and activity in the brain. These results may suggest mechanisms of brain estrogen production after increases in pressure as seen in TBI patients.

Revolving back to the basics in cardiopulmonary resuscitation.

Since the 1970s, most of the research and debate regarding interventions for cardiopulmonary arrest have focused on advanced life support (ALS) therapies and early defibrillation strategies. During the past decade, however, international guidelines for cardiopulmonary resuscitation (CPR) have not only emphasized the concept of uninterrupted chest compressions, but also improvements in the timing, rate and quality of those compressions. In essence, it has been a ''revolution'' in resuscitation medicine in terms of ''coming full circle'' to the 1960s when basic CPR was first developed. Recent data have indicated the need for minimally-interrupted chest compressions with an accompanying emphasis toward removing rescue ventilation altogether in sudden cardiac arrest, at least in the few minutes after a sudden unheralded collapse. In other studies, transient delays in defibrillation attempts and ALS interventions are even recommended so that basic CPR can be prioritized to first restore and maintain better coronary artery perfusion. New devices have now been developed to modify, in real-time, the performance of basic CPR, during both training and an actual resuscitative effort. Several new adjuncts have been created to augment chest compressions or enhance venous return and evolving technology may now be able to identify ventricular fibrillation (VF) without interrupting chest compressions. A renewed focus on widespread CPR training for the average person has also returned to center stage with ground-breaking training initiatives including validated video-based adult learning courses that can reliably teach and enable long term retention of basic CPR skills and automated external defibrillator (AED) use.