Cerebral Perfusion Pressure (CPP) Management Information Feedback and Nursing

Prevention or reduction of secondary brain injury is a key component in the critical care management of patients with a variety of brain insults. Current clinical management emphasizes maintaining cerebral perfusion pressure (CPP) at or above 70 mm Hg to minimize such secondary brain injury. However, due to poor ergonomics in clinical monitoring displays it is likely that short episodes of decreased CPP are missed by attending nurses in the course of necessary patient repositioning, suctioning, and other routine therapeutic activities. Given the crucial role of neuronal perfusion in preventing secondary injury beyond that of the original brain insult, refining the nurse's ability to visualize and manage CPP on a moment-to-moment basis may allow measurable improvement in short and long-term patient functional outcome. Computer interfaces that provide highly visible information about CPP will be randomly allocated to intensive care unit beds of patients with closed head injury (CHI) or subarachnoid hemorrhage (SAH) in whom intracranial pressure monitors and arterial lines have been placed for medical management, stratified by primary diagnosis (CHI or SAH) and severity. Continuous data will be collected from 150 patients with and 150 patients without the interface monitor for the duration of CPP monitoring. The primary hypothesis being tested is that the Glasgow Outcome Score (GOS) 6 months after acute care discharge will be significantly better in those monitored with the continuous CPP display. Secondary endpoints are GOS at discharge and 3 months after discharge, Functional Independence Measure (FIM) score at discharge, and the Functional Status examination at 3 and 6 months. The percentage of CPP below set levels during hospital monitoring will be determined.

No CPP thresholds have been established that adequately predict how well children who survive a brain injury will do. Thus we will describe the association between various CPP thresholds and children's outcome up to one year after their brain injury. The target number of children to be enrolled is 65.

Studies suggest that the regularity or variability of physiologic measures, for example, heart rate, may give information about how well the system can respond to challenges. Changes in variability may be associated with disease. Describing physiologic variability may therefore be useful to identify critically ill individuals with brain injury who are less able to adapt to challenges and may be a greater risk for further brain injury and poorer outcome.

Measures of the value that individuals place on the various health states are used to calculate quality adjusted life years and assess the cost-effectiveness of treatments. While measures have been developed to assess how individuals value different outcomes, information regarding the value placed on outcomes following brain injury is lacking. We will use these measures to carry out interviews of both brain injury survivors and those who have not had a brain injury to add to the knowledge in this area.

Inclusion criteria

• Traumatic brain injury or subarachnoid hemorrhage
• Age 16 years or older
• Admitted to intensive care unit
• Invasive intracranial pressure and arterial blood pressure monitoring

Exclusion criteria

• Impending death

Inclusion criteria

for second phase of study (determination of CPP threshold in children):

• Traumatic brain injury
• Age 15 years or younger
• Able to communicate by telephone
• Admitted to intensive care unit
• Intracranial pressure monitoring

Inclusion criteria

for second phase of study (quality adjusted life years assessment):

• Hospitalized for a traumatic brain injury or subarachnoid hemorrhage at an academic medical center within the last 10 years
• Age 18 years or older at the time of hospitalization