scholarly journals Wavelet pressure reactivity index: a validation study

2018 ◽  
Vol 596 (14) ◽  
pp. 2797-2809 ◽  
Author(s):  
Xiuyun Liu ◽  
Marek Czosnyka ◽  
Joseph Donnelly ◽  
Danilo Cardim ◽  
Manuel Cabeleira ◽  
...  
Keyword(s):  
Validation Study ◽  
Reactivity Index ◽  
Pressure Reactivity Index ◽  
Pressure Reactivity

scholarly journals Non-Invasive Pressure Reactivity Index Using Doppler Systolic Flow Parameters: A Pilot Analysis

2019 ◽  
Vol 36 (5) ◽  
pp. 713-720 ◽  
Author(s):  
Frederick A. Zeiler ◽  
Peter Smielewski ◽  
Andrew Stevens ◽  
Marek Czosnyka ◽  
David K. Menon ◽  
...  
Keyword(s):  
Reactivity Index ◽  
Non Invasive ◽  
Pressure Reactivity Index ◽  
Flow Parameters ◽  
Pressure Reactivity

scholarly journals Short pressure reactivity index versus long pressure reactivity index in the management of traumatic brain injury

2015 ◽  
Vol 122 (3) ◽  
pp. 588-594 ◽  
Author(s):  
Erhard W. Lang ◽  
Magdalena Kasprowicz ◽  
Peter Smielewski ◽  
Edgar Santos ◽  
John Pickard ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Outcome Prediction ◽  
Fatal Outcome ◽  
Reactivity Index ◽  
Pressure Reactivity Index ◽  
Arterial Blood ◽  
Pressure Reactivity ◽  
Significant Difference ◽  
Spearman Test

OBJECT The pressure reactivity index (PRx) correlates with outcome after traumatic brain injury (TBI) and is used to calculate optimal cerebral perfusion pressure (CPPopt). The PRx is a correlation coefficient between slow, spontaneous changes (0.003–0.05 Hz) in intracranial pressure (ICP) and arterial blood pressure (ABP). A novel index—the so-called long PRx (L-PRx)—that considers ABP and ICP changes (0.0008–0.008 Hz) was proposed. METHODS The authors compared PRx and L-PRx for 6-month outcome prediction and CPPopt calculation in 307 patients with TBI. The PRx- and L-PRx–based CPPopt were determined and the predictive power and discriminant abilities were compared. RESULTS The PRx and L-PRx correlation was good (R = 0.7, p < 0.00001; Spearman test). The PRx, age, CPP, and Glasgow Coma Scale score but not L-PRx were significant fatal outcome predictors (death and persistent vegetative state). There was a significant difference between the areas under the receiver operating characteristic curves calculated for PRx and L-PRx (0.61 ± 0.04 vs 0.51 ± 0.04; z-statistic = −3.26, p = 0.011), which indicates a better ability by PRx than L-PRx to predict fatal outcome. The CPPopt was higher for L-PRx than for PRx, without a statistical difference (median CPPopt for L-PRx: 76.9 mm Hg, interquartile range [IQR] ± 10.1 mm Hg; median CPPopt for PRx: 74.7 mm Hg, IQR ± 8.2 mm Hg). Death was associated with CPP below CPPopt for PRx (χ2 = 30.6, p < 0.00001), and severe disability was associated with CPP above CPPopt for PRx (χ2 = 7.8, p = 0.005). These relationships were not statistically significant for CPPopt for L-PRx. CONCLUSIONS The PRx is superior to the L-PRx for TBI outcome prediction. Individual CPPopt for L-PRx and PRx are not statistically different. Deviations between CPP and CPPopt for PRx are relevant for outcome prediction; those between CPP and CPPopt for L-PRx are not. The PRx uses the entire B-wave spectrum for index calculation, whereas the L-PRX covers only one-third of it. This may explain the performance discrepancy.

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