Neurocritical care patients may benefit from personalized treatment based on their cerebral autoregulatory function. The pressure reactivity index is an important, prevalent metric used to estimate the state of a patient’s cerebral autoregulation and guide clinical decision-making. However, the pressure reactivity index is highly sensitive to hyperparameter choices and intrapatient variability. In this manuscript, we develop a new personalized pressure reactivity index methodology (pPRx) that increases robustness and reduces the noise of the pressure reactivity index calculation. Using data from traumatic brain injury patients and simulated data, we first show that pressure reactivity index sensitivity to hyperparameters and interpatient variability is large enough to influence clinical interpretation of cerebral autoregulatory function. We identify that patient heart rate is closely related to errors in the pressure reactivity index, which has vital implications for extending the use of PRx to patients with different regular heart rates, such as pediatric populations. We then remove this heart rate specific sensitivity in the pPRx methodology by adjusting for patient heart rate at resolutions of single heartbeats. Implementing the pPRx methodology decreases error, noise, and sensitivity, and allows the pressure reactivity index to be more robust to variability across patient populations. We also leverage our data and analysis to identify ideal averaging windows in the standard method.
Minimizing Uncertainity and Error in Pressure Reactivity Index to Aid in Clicial Decision Support
