NEUROTRAUMA CARE IN THE NEW MILLENNIUM

The dawn of the new millennium occurs as the paradigm for the treatment of patients with head injury is changing. The treatment of patients with head injury started in the 1900s as a surgical disease; craniotomy for evacuation of hematoma was the only modality available for the reduction of intracranial pressure (ICP) and the maintenance of cerebral perfusion pressure (CPP). The past 50 years, however, have seen the introduction of surgical modalities for the treatment of patients with traumatic brain injury (TBI), and as the new millennium dawns, surgery is becoming but one modality in what is now seen as the resuscitation of the injured brain. An explosion of research has driven this paradigm shift on the physiology of healthy and injured brains. The understanding of ICP reduction by mass removal was supplemented by the awareness of the role of ischemia in what has come to be known as secondary injury. An investigation of the mechanisms of cerebral edema and ischemic brain injury led to an understanding of secondary injury that was based on cellular physiology. This cellular focus on the mechanisms of secondary injury is providing hope that the new millennium will provide the introduction of pharmacologic therapies for TBI. In the new millennium, ICP reduction and CPP maintenance will be joined by pharmacotherapy as the pillars of the treatment of patients with head injury. The new millennium also will be a new era in the monitoring of the injured brain. ICP monitoring will be supplemented by more sophisticated measurement of cerebral blood flow (CBF). Global monitoring of cerebral oxygen delivery by technologies such as the Jugular Bulb monitor will be supplemented by detailed blood flow maps supplied by technologies such as Xenon CT (XeCT). Local micro Clark electrodes measuring O 2 delivery and pH will monitor regional areas of interest. Local microdialysis catheters will monitor the neurochemical environment for products, such as lactate and glutamate. Metabolic maps of the injured brain may even be available via positron emission tomography (PET) scans that monitor the use of glucose and other substrates by the brain. This vast array of monitors will continue to transform the concept of the injured brain. Our understanding will continue to evolve from an anatomic understanding of TBI, informed only by the CT scan, to a working understanding of CBF and metabolism that will allow therapies that address their postinjury derangements. As our understanding grows, our approach to therapy will change. No one yet knows which of the new monitoring technologies will prove useful or in what combination. Much as the cardiac ICU evolved in the latter part of the 1960s, the new millennium will see a dramatic evolution in the neurologic ICU. As the understanding of the injured brain evolves, so will the types and combinations of data that are demanded. Lastly, the new millennium will see a new emphasis on outcomes. Payers, the public, and the research community will demand to know the efficacy of therapies. Outcomes research will have wide implications because much of the outcome from all trauma, not just neurotrauma, is dictated by cognitive recovery. Emphasis on better rehabilitation strategies and on pharmacologic approaches to better cognitive outcomes will be important in the next century. This article explores these ideas and looks at the path that neurotrauma has taken to the edge of the new millennium, the tools available to it today, and tools that are likely to affect it tomorrow.