Evidence based guidelines - and in the absence of evidence, consensus recommendations - supplement our training and experience and together provide the foundation for why an intervention should or should not be offered. The majority of past guidelines efforts fail to bridge the limitations of recommendations emanating from an evidence report with the realities and complexities of care at the bedside. Traditionally guidelines have thus left a heavy burden on the clinician to determine how best to integrate evidence-based recommendations into clinical practice. Though early Brain Trauma Foundation guidelines incorporated treatment algorithms1,2 which were very popular, algorithms did not accompany the 3^rd3 of 4^th4 edition of the adult coma guidelines. As methodologic rigor increased it was recognized that as these algorithms - which cannot be evidence based given a virtual absence of literature informing how to sequence or combine treatments for TBI - would need to be derived through a distinct process. Thus, following the publication of the 4^th edition of the Brain Trauma Foundation's Adult Severe Traumatic Brain Injury Guidelines4, the Seattle International severe traumatic Brain Injury Consensus Conference (SIBICC) used a rigorous Delphi consensus process to generate the first widely agreed-upon algorithms for TBI management to be produced in a generation5,6. The product was a series of sophisticated and thoughtful algorithms intended to provide comprehensive assistance with severe TBI management. These algorithms, and the methodology used to develop them provide the inspiration and template for what we present here.

The purpose of any management algorithm is to provide to clinicians immediate, easily accessible and practical guidance emanating from expert opinion and grounded in best evidence where possible. Management algorithms can be particularly useful in circumstances where clinicians have limited experience and the timeframe for decision making is short. This certainly applies to the early decision making in patients with penetrating traumatic brain injury (pTBI) which is rarely encountered by most clinicians. The overall purpose of this document is to save lives, in part, by combating nihilism with information. There are many misconceptions in medicine, and the idea that all penetrating brain injury is uniformly non-survivable is certainly one of them. There are two main points that the clinician should internalize prior to reviewing this document:

• Patients with penetrating brain injury who survive to reach a trauma center, and in whom care is not considered futile (see Futility Assessment Toolkit), often have the same or better outcomes than comparably injured patients with closed traumatic brain injury7.
• Penetrating traumatic brain injury, in nearly every circumstance, is a surgical disease.

As pTBI is complex and diverse we felt that an approachable structure that would facilitate complex and comprehensive care was to have a Master Care Pathway that would apply to all pTBI patients. This would be accompanied by "Toolkits" targeted to specific care issues important for only a subset of those patients. We thus hope that our algorithms are practical, just complex enough and convenient to use during the management of pTBI cases that are a unique combination of high complexity and high emergency.