TRAUMATIC BRAIN INJURY (TBI) is a major cause of disability, death, and economic cost to our society. One of the central concepts that emerged from research is that all neurological damage from TBI does not occur at the moment of impact, but evolves over the ensuing hours and days. Furthermore, improved outcome results when these secondary, delayed insults, resulting in reduced cerebral perfusion to the injured brain, are prevented or respond to treatment. This is reflected in the progressive and significant reduction in severe TBI mortality from 50% to 35% to 25% and lower over the last 30 years, even when adjusted for injury severity, age and other admission prognostic parameters. This trend in reduced mortality and improved outcomes from TBI has been subsequent to the use of evidence-based protocols that emphasize monitoring and maintaining adequate cerebral perfusion.

In preparation for the revision of the 2^nd edition of these Guidelines, a systematic review of the literature was conducted to assess the influence of the use of the Guidelines on mortality and morbidity from TBI. The results indicated that consistent application of ICU-based protocols improves outcomes, and reduces mortality and length of stay.

This is the third edition of the evidence-based Guidelines for the Management of Severe Traumatic Brain Injury, following the first and second editions in 1995 and 2000. These Guidelines address key topics useful for the management of severe TBI in adult patients with a Glasgow Coma Scale score of 3-8. The following are notable changes from the second edition:

• Six new topics were added and two topics were assigned to the pre-hospital Guidelines. This is not an exhaustive review of all TBI management but rather a focus on interventions that have an impact on outcome and have sufficient scientific data specific to TBI to warrant the development of new topics.
• The Levels of Recommendation were changed from "Standard, Guideline, and Option" to "Level I, Level II, and Level III," respectively. The previous language did not lend itself to clear operational definitions. Recommendation Levels I, II, and III, are derived from Class I, II, and III evidence, respectively.
• The classification of certain publications included in previous editions has been changed. Publications were classified both by design and quality (see Methods section and Appendix A).
• This is the first edition of these Guidelines for which a meta-analysis was conducted, for the topic of Prophylactic Hypothermia.

In 2004, the Brain Trauma Foundation (BTF) called a meeting of all the TBI Guidelines contributing authors for the purpose of formalizing a collaborative process of Guidelines updates, publication, and implementation shared by those with a stake in acute TBI care. A partnership of interested professional associations was formed to review, endorse and implement future editions of the Guidelines. The mission of this TBI Partnership is to improve the outcome of TBI through collaboration and the promotion of evidence-based medicine.

For these and future Guidelines projects, contributing authors agreed to establish a Center for Guidelines Management (Center), which would be responsible for generating new guidelines as well as updating those that exist. The participants endorsed the BTF proposal to establish the Center to be located at Oregon Health & Sciences University (OHSU). A collaboration was established between the Center and the Oregon Evidence-based Practice Center (EPC). The Oregon EPC conducts systematic reviews of various healthcare topics for federal and state agencies and private foundations. These reviews report the evidence from clinical research studies, and the quality of that evidence, for use by policy makers in decisions about guidelines and coverage issues. The collaboration made the expertise and personnel of the EPC available to the Center.

The TBI partnership further agreed to adopt and explicitly adhere to a systematic process and set of criteria for reviewing, assessing, and synthesizing the scientific literature. The process and criteria (see Methods Section) are derived from work by the U.S. Preventive Services Task Force the National Health Service Centre for Reviews and Dissemination (U.K.) and the Cochrane Collaboration. The goal was to establish a process for Guidelines development that was scientifically rigorous, consistent across all topics, and independent of the interests and biases of contributing authors.

The partnership also recommended appointing a Review Committee to consist of a small number of individuals who would serve as liaison between the guidelines development process and the key medical societies related to TBI. These representatives of neurosurgery, trauma, neurointensive care, pediatrics, emergency medicine, and prehospital care, as well as international organizations, are standing members of the Committee across all Guidelines updates. The current members of this Committee, listed at the front of this document, reviewed this edition of the Guidelines.

In order to continue to improve outcomes for TBI patients, it is necessary to generate strong research capable of answering key questions, and to assess, synthesize, and disseminate the findings of that research so that practitioners have access to evidence-based information. Therefore, this document should not only be used as a roadmap to improve treatment, but also as a template from which to generate high quality research for future use. The primary marker of the success of the 3^rd edition of these Guidelines will be a sufficient body of Class I and II studies for Level I and II recommendations in the 4^th edition.

The BTF maintains and revises several TBI Guidelines on an annual basis resulting in a 5-year cycle, approximately, for each Guideline:

• Guidelines for Prehospital Management of Traumatic Brain Injury
• Guidelines for the Management of Severe Traumatic Brain Injury
• Guidelines for the Surgical Management of Traumatic Brain Injury
• Prognosis of Severe Traumatic Brain Injury

These BTF Guidelines are developed and maintained in a collaborative agreement with the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS), and in collaboration with the AANS/CNS Joint Section on Neurotrauma and Critical Care, European Brain Injury Consortium, other stakeholders in TBI patient outcome.