party-goer: “What do you do?” Thomas V. related to CBF and therefore cerebral oxygen and substrate delivery. Unlike CBF CPP can be very easily and continuously determined in individuals with intracranial pressure (ICP) and invasive arterial blood pressure (BP) screens. Companies in the bedside can then change therapies in real time with CPP-guidance. Because BP CBF and cerebral oxygen usage vary directly with age minimum CPP treatment thresholds have also been BMS-265246 age-scaled.(5) The authors of the 2003 1st edition of the “Recommendations for the acute medical management of severe traumatic brain injury in TG babies children and adolescents”(6) proposed an age-related continuum of CPP thresholds between 40 (babies) and 65 (adolescents) mm Hg. The second edition of the guidelines published in 2012 included the same minimum CPP threshold of 40 mm Hg but the target for older children was modified downward to near 50 mm Hg centered primarily on adult studies published in the interim.(1) Unfortunately no studies to day possess demonstrated that maintenance of CPP above a given threshold improves outcome in children of any age with TBI; however White colored et al reported that supranormal BP is definitely associated with improved end result(7) and several case series have reported very high rates of mortality when CPP is definitely persistently below 40 mm Hg.(8-10) In this problem of Pediatric Critical Care Medicine Allen et al[ref] statement a retrospective analysis of prospectively collected data from the Brain Stress Foundation (BTF) and New York State’s TBI-trac? database. The study was carried out between mid-2000 and mid-2008 and included adults but we will focus our comments within the pediatric data reported. The purpose of the study was in individuals having a post-resuscitation Glasgow Coma Level score < 9 without fixed and dilated pupils to analyze the relationship between the age-specific CPP ranges recorded in TBI-trac? and 14-day time mortality. No point out is made of individuals who did not receive ICP screens even though TBI-trac? study BMS-265246 group has recently published an analysis of adults with severe TBI with and without ICP monitoring.(11) The CPP ranges in the database were based on BTF guidelines published in 2000 before the 1st edition of the pediatric guidelines and were lower than current recommendations for young children but consistent with current recommendations for older children: 30-40 mm Hg for children < 6 years aged 35 mm Hg for children 6-11 years old and 50-60 mm Hg for children more than 11. Individuals were BMS-265246 classified into three exposure organizations: 1) all recorded CPP’s were above the prospective range BMS-265246 (CPP-High) 2 all CPP’s were within or above the prospective range but not below it (CPP-Between) and 3) any CPP was below the prospective range (CPP-Low). Advantages of this study include the sample size which at 317 children with severe TBI is very large and the careful patient selection process which excluded moribund BMS-265246 individuals unlikely to benefit from CPP-directed therapy. Allen et al found that children who experienced any recorded CPP’s below the prospective range (< 30 mm Hg for those <6 years old or < 35 mm Hg for those 6-11 years old) experienced higher 14 mortality than those who only had ideals in the prospective range or above it. This is perhaps not amazing as those ideals are below the minimum amount CPP supported by level III evidence in both editions of the pediatric TBI recommendations. Interestingly no mortality difference was seen between organizations in children 12-17 years old perhaps because the target range of CPP 50-60 mm Hg is definitely less likely to contribute to ischemia at its lower end. The authors also attempted to leverage the duration of the age-specific CPP ideals (high between and low) in the database using Kaplan-Meier analysis. However those numbers present mortality for the lowest CPP group that a patient achieved and don't are the cause of a patient going through different CPP ranges at different times during the hospitalization. A more illuminating analysis might have demonstrated the number of hours in each CPP category for each patient and then analyzed the effect of time in hours below currently recommended thresholds (40 mm Hg in the youngest individuals and 50mm Hg for all other individuals) on mortality. This type of analysis would come closer to the “pressure-time index” analyses reported by Adelson et al(13) and Chambers et al.(14) If the mechanism by which CPP-guided therapy affects outcome is usually prevention of ischemia the ideal.