Relationship between Intracranial Pressure or Cerebral PerfusionPressure and Prognosis in Patients with Severe Traumatic Brain InjuryTreated with Mild Hypothermia

Abstract

Aims: The purpose of this study was to predict the clinical course by intracranial pressure (ICP) or cerebral perfusion pressure (CPP) in the acute phase and prognosis in patients with severe head trauma who underwent therapeutic mild hypothermia (HT). Methods: A consecutive 143 patients treated with HT for intracranial hypertension (ICH) in two trauma centers were included in this study. The pressure measured after computed tomography scanning was defined as the initial ICP or CPP. Outcome was assessed at 6 months according to the Glasgow Outcome Scale. ROC analysis was performed to clarify the threshold value of ICP/CPP predictive of ICP uncontrollable by HT. Results: The cutoff value of ICP for uncontrollable ICP obtained from ROC analysis was 32.5 mmHg (sensitivity: 0.545, specificity: 0.875), and that for CPP was 56.5 mmHg (sensitivity: 0.813, specificity: 0.663). Fifty-three (96.4%) of 55 patients whose initial ICP was greater than 32.5 mmHg and 67 (95.7%) of 70 patients whose initial CPP was less than 56.5 mmHg had developed uncontrollable ICP. Conclusion: The cutoff values predictive of ICP uncontrollable by HT from ROC analysis were 32.5 mmHg for ICP and 56.5 mmHg for CPP. For those patients with initial ICP greater than the cutoff value or an initial CPP less than the cutoff value, it may be harmful to prolong HT. The knowledge obtained from this study may be useful for considering the treatment strategy for severe traumatic brain injury.