73 T. Sundstrøm et al. (eds.), Management of Severe Traumatic Brain Injury, DOI 10.1007/978-3-642-28126-6_15, © Springer-Verlag Berlin Heidelberg 2012 15 Recommendations Level I There are no data supporting an individual prog- nosis at this level. Level II There are no data supporting an individual prog- nosis at this level. There is a prognostic value in age, GCS, GCS motor score, pupillary reactivity, hypotension, hypoxia, CT findings, blood glucose, serum sodium, and ethnic origin. Level III There are some data supporting an individual prognosis, prognosis calculators, at this level. There seems to be a prognostic value in ICP and CPP. There is insufficient evidence for the prognos- tic value of biomarkers and pressure reactivity. 15.1 Overview Prognosis, from Greek prόgnwsh – literally fore-knowing, foreseeing. The prognosis of a disease can be used for discussing the seriousness or likely outcome of a disease. It can as such be used as an aid in the information process to the patient or her/his rela- tives. It also gives information to the treating physician about what she/he could expect. The accuracy of prognosis on group or popu- lation level can be very precise but not at the level of the individual patient. There are several factors that prognosticate for poor prognosis in severe traumatic brain injury, such as age, GCS, pupillary dilation with loss of light reflex, hypoxia, hypotension, mass lesions on CT, presence of subarachnoidal blood on CT, and others. These factors have been used in prognostic models of which two, IMPACT prognosis calculator and CRASH prognosis cal- culator, are available on the World Wide Web. They can be used for individual prognosis. None of these prognostic factors, alone, together, or as prognosis calculators, are strong enough to prog- nosticate outcome or even mortality at the indi- vidual level. They should therefore be used with caution. There is no prognostic factor or associa- tion of prognosis factors that with certainty can tell the treating physician not to initiate treat- ment. Development of such a criterion, as objec- tive as possible, e.g. an initial CPP value, to make the decision to treat or not to treat possible, would be of great advantage. M. Olivecrona Department of Neurosurgery, University Hospital, Umeå 901 85, Sweden e-mail: magnus.olivecrona@neuro.umu.se Prognosis of Severe Traumatic Brain Injury: To Treat or Not to Treat, That Is the Question Magnus Olivecrona