Cerebral Perfusion Pressure Insults and Associations with Outcome in Adult Traumatic Brain Injury.

Fabian Güiza,Giuseppe Citerio,Rob Donald,Iain Chambers,Andrew Maas,Per Enblad,Philippe Jorens,Greet Van Den Berghe,Bart Feyen,Bart Depreitere,Martin U Schuhmann,Ian Piper,Geert Meyfroidt,Pelle Nillson,Laura Moss

doi:10.1089/neu.2016.4807

Abstract

The definition of cerebral perfusion pressure (CPP) secondary insults in severe traumatic brain injury remains unclear. The purpose of the present study is to visualize the association of intensity and duration of episodes below or above CPP thresholds and outcome. The analysis was based on prospectively collected minute-by-minute intracranial pressure (ICP) and blood pressure data and outcome from 259 adult patients. The relationship of episodes of CPP below or above a certain threshold for certain duration with the 6-month Glasgow Outcome Score was visualized separately for episodes of active or deficient autoregulation (AR). In adults ≤65 years, an almost exponential transition curve separates the episodes of CPP associated with better outcomes from the episodes of low CPP associated with worse outcomes, indicating that lower CPP could only be tolerated for a brief time. Analysis of episodes of high CPP again showed a time-intensity dependent association with outcome. When combining the two plots, a safe CPP zone between 60 and 70 mm Hg could be delineated—however, only for AR active insults. The AR status predominantly affected the transition curve for insults of low CPP. Episodes with ICP >25 mm Hg were associated with poor outcome regardless of CPP. In the present study, the CPP pressure-time burden associated with poor outcome was visualized. A safe zone between 60 and 70 mm Hg could be identified for adults ≤65 years, provided AR was active and ICP was ≤25 mm Hg. Deficient AR reduces the tolerability for low CPP.

Highlights

Traumatic brain injury (TBI) is a significant health problem worldwide
The aim of the present study is to assess the effect of cerebral perfusion pressure (CPP) insults, according to varying definitions of intensity and duration, on functional outcome at six months based on prospective data from continuously monitored adult patients with severe TBI
In both instances (Fig. 1a and Fig. 1b), a blue zone and red zone can be observed, separated by a sharply demarcated transition curve

Summary

Introduction

In Europe, the overall incidence of fatal and hospitalized TBI is 262/100,000/year.[1] An estimated 43.3% of hospitalized patients with TBI in the United States experience long-term disability.[2] The management of severe TBI focuses on avoiding additional ischemic damage from preventable or reversible secondary insults. Intracranial hypertension has long been identified as an insult associated with poorer outcomes.[3,4,5] it is recommended that intracranial pressure (ICP) be monitored in salvageable patients with severe TBI and to treat patients with ICP above 22 mm Hg.[6] It is evident that ‘‘22’’ is not a magical number, and it was recently demonstrated by our group that the relation between ICP level and outcome is time dependent, but that ICP tolerability depends on age and pressure autoregulation (AR) capacity.[7]

Objectives

Methods

Results

Conclusion