Advanced
Technical
IVT
PRx
Also written as: PRx — Pressure Reactivity Index
A calculated index measuring the correlation between intracranial pressure and cerebral perfusion pressure to assess autoregulation.
Full Definition
The Pressure Reactivity Index is a continuous, computer-calculated parameter that assesses cerebrovascular autoregulation by analyzing the correlation between slow waves in intracranial pressure and cerebral perfusion pressure. Values range from -1 to +1, where negative values indicate intact autoregulation and positive values suggest impaired autoregulation. PRx values above 0.3 are associated with poor outcomes in traumatic brain injury.
Usage
Usage note: Always capitalize both letters; specify normal ranges when documenting
In Context
- "Continuous PRx monitoring revealed impaired autoregulation with values persistently above 0.4." — Research protocol
- "The patient's PRx improved from +0.6 to -0.2 following osmotic therapy." — Clinical assessment
Also known as
Pressure Reactivity Index
autoregulation index
Don't confuse with
CPP
ICP
autoregulation