Reliability and variability of pressure reactivity index (prx) during oscillatory pattern in arterial blood pressure and intracranial pressure in traumatic brain injured patients.

Introduction: Pressure reactivity index (PRx) is used for continuous monitoring of cerebrovascular reactivity in traumatic brain injury (TBI). However, PRx has a noisy character. Oscillations in arterial blood pressure (ABP) introduced by cyclic positive end-expiratory pressure adjustment, can make PRx more reliable.

Embracing uncertainty in cerebrospinal fluid dynamics: A Bayesian approach to analysing infusion studies.

Introduction: Cerebrospinal fluid (CSF) infusion test analysis allows recognizing and appropriately evaluating CSF dynamics in the context of normal pressure hydrocephalus (NPH), which is crucial for effective diagnosis and treatment. However, existing methodology possesses drawbacks that may compromise the precision and interpretation of CSF dynamics parameters.

Research Question: This study aims to circumvent these constraints by introducing an innovative analysis method grounded in Bayesian inference.

Exploration of uncertainty of PRx time trends.

Introduction: PRx can be used as surrogate measure of Cerebral Autoregulation (CA) in traumatic brain injury (TBI) patients. PRx can provide means for individualising cerebral perfusion pressure (CPP) targets, such as CPPopt. However, a recent Delphi consensus of clinicians concluded that consensus could not be reached on the accuracy, reliability, and validation of any current CA assessment method.

Mathematical modelling of cerebral haemodynamics and their effects on ICP.

Introduction: Electrical-equivalence mathematical models that integrate vascular and cerebrospinal fluid (CSF) compartments perform well in simulations of dynamic cerebrovascular variations and their transient effects on intracranial pressure (ICP). However, ICP changes due to sustained vascular diameter changes have not been comprehensively examined. We hypothesise that changes in cerebrovascular resistance (CVR) alter the resistance of the bulk flow of interstitial fluid (ISF).

Optimal Cerebral Perfusion Pressure Assessed with a Multi-Window Weighted Approach Adapted for Prospective Use: A Validation Study.

Background: Pressure reactivity index (PRx)-cerebral perfusion pressure (CPP) relationships over a given time period can be used to detect a value of CPP at which PRx shows the best autoregulation (optimal CPP, or CPPopt). Algorithms for continuous assessment of CPPopt in traumatic brain injury (TBI) patients reached the desired high yield with a multi-window approach (CPPopt_MA). However, the calculations were tested on retrospective manually cleaned datasets.

Comparison of Two Intracranial Pressure Calculation Methods and Their Effects on the Mean Intracranial Pressure and Intracranial Pressure Dose.

This study compared two methods of calculating the intracranial pressure (ICP) in a patient: end-hour ICP and hour-averaged ICP. A total of 1060 patients with traumatic brain injury and a known clinical outcome were studied. For each patient, the end-hour ICP and hour-averaged ICP were calculated.