A narrative review of the clinical application of pressure reactiviy indices in the neurocritical care unit

  title={A narrative review of the clinical application of pressure reactiviy indices in the neurocritical care unit},
  author={Stephen Copplestone and Jessie Welbourne},
  journal={British Journal of Neurosurgery},
  pages={12 - 4}
Abstract Pressure reactivity indices are used in clinical research as a surrogate marker of the ability of the cerebrovasculature to maintain cerebral autoregulation. The use of pressure reactivity indices in patients with neurological injury represents a potential to move away from population-based physiological targets used in guidelines to individualized physiological targets. The aim of this review is to describe the underlying principles and development of pressure reactivity indices… 
Cerebral Autoregulation in Subarachnoid Hemorrhage
The key clinical aspects of cerebral autoregulation and its disruption in SAH are presented, a mechanistic overview is provided, current clinical methods for measuring autoreGulation are described, and current and emerging therapeutic options for SAH patients are reviewed.
Multimodal neurocritical monitoring
Decision-making for decompressive craniectomy in traumatic brain injury aided by multimodality monitoring: illustrative case
A case in which multimodality monitoring assisted in decision-making for decompressive craniectomy in a severe TBI without mass lesion is presented, and the patient had a satisfactory clinical outcome.


‘Long’ pressure reactivity index (L-PRx) as a measure of autoregulation correlates with outcome in traumatic brain injury patients
Low-frequency sample pressure reactivity index (L-PRx) correlates with the 6-month outcome in TBI patients and may be an alternative algorithm for the estimation of cerebral autoregulation and clinical prognosis.
An optimal frequency range for assessing the pressure reactivity index in patients with traumatic brain injury
The optimal index frequency range for prediction of outcome was identified as 0.018–0.067 Hz (oscillations with periods from 55 to 15 s), and the index based on this frequency range correlated with GOSe with ρ = −0.46 compared to −0.41 for standard PRx, and reduced the 30-min variation by 23 %.
Continuous Monitoring of Cerebrovascular Reactivity Using Pulse Waveform of Intracranial Pressure
PAx is a new modified index of cerebrovascular reactivity which performs equally well as established PRx in long-term monitoring in severe TBI patients, but importantly is potentially more robust at lower values of ICP.
Continuous monitoring of cerebrovascular pressure reactivity in patients with head injury.
The cerebrovascular pressure reactivity index (PRx) showed significant deterioration in refractory intracranial hypertension, was correlated with outcome, and was able to differentiate patients with good outcome, moderate disability, severe disability, and death.
The relationship between cerebral blood flow autoregulation and cerebrovascular pressure reactivity after traumatic brain injury.
To assess to what degree impairment in pressure reactivity (PRx) is associated with impairment in cerebral autoregulation (Mx), a database of 345 patients with traumatic brain injury was screened for data availability including simultaneous Mx and PRx monitoring.
Continuous Monitoring of Cerebrovascular Pressure Reactivity After Traumatic Brain Injury in Children
Intact cerebrovascular pressure reactivity quantified with the PRx is associated with survival after severe head trauma in children and may be useful for defining age-specific and possibly patient-specific optimal targets for CPP after TBI.
Correlation of Clinical Outcome with Pressure-, Oxygen-, and Flow-Related Indices of Cerebrovascular Reactivity in Patients Following Aneurysmal SAH
The results indicate that the present technique of index-determination is not sensitive enough or that there is no strong relation between the measured indices and clinical outcome, and future verification is required of continuous against already established non-continuous monitoring techniques of CR.
Autoregulation monitoring and outcome prediction in neurocritical care patients: Does one index fit all?
PRx was more appropriate for TBI patients, while Mx was better suited for non-traumatic patients and patients with heart failure, and both indexes were significantly associated with 3-month clinical outcome, even in patients with hemicraniectomy.
Optimal cerebral perfusion pressure in patients with intracerebral hemorrhage: an observational case series
Real-time assessment of CPPopt is feasible in ICH and might provide a tool for an autoregulation-oriented CPP management and a larger trial is needed to explore if a CPP opt management results in better functional outcomes.
Short pressure reactivity index versus long pressure reactivity index in the management of traumatic brain injury.
The PRx is superior to the L-PRx for TBI outcome prediction and CPPopt calculation in 307 patients with TBI, and there was a significant difference between the areas under the receiver operating characteristic curves calculated for PRx and L- PRx.