ENTROPY OF INTRACRANIAL PRESSURE

POSE, FERNANDO E.; CIARROCCHI, NICOLAS MARCELO; CHRISTOS LAZARIDIS; GOLDEMBERG, FERNANDO; ALI MANSOUR; REDELICO, FRANCISCO O.

Atlanta

Conferencia; The 39th Annual Symposium of the National Neurotrauma Society,including the AANS/CNS Joint Sectionon Neurotrauma and Critical Care; 2022

Background:A reduction intracranial pressure (ICP) waveformcomplexity has been reported during intracranial hypertension in pa-tients with acute brain injury. The domain of non-linear dynamics canbe utilized to explore complexity of such physiologic phenomena.One such analysis is entropy which ultimately describes the system’srandom behavior or unpredictability.Objective:We compare different ICP waveform entropy derivationsin a porcine model of intracranial hypertension (ICHTN) . Specificallywe explore: Sample Entropy (SampEn), Approximate Entropy (ApEn),Permutation Entropy (PEn) and Wavelet Entropy (WEn).Methods:We previously developed a porcine model of intracranialhypertension. ICHTN is achieved by the gradual inflation of a cerebralintraparenchymal foley catheter while concomitantly recording ICPthrough an intraparenchymal pressure monitor. All four entropy calcula-tions were computed during 16 episodes where ICHTN was induced andthen reversed by deflation of the foley catheter balloon. We recorded timesfrom balloon inflation to the decrease in each entropy (DB), as well as thetime from of entropy change to the time ICP reached 20 mmHg (DP).Results:At baseline (before ICHTTN), the mean and standard devi-ation for each entropy was: 0.23(0.01) WEn; 0.07(0.01) PEn; 0.08(0.01)SampEn; 0.03(0.06), ApEn. During ICHTN, DB times(s) were: 79(16)WEn; 184(73) PEn; 286(95) SampEn; 288(89) ApEn, and DP times(s)were 290(68) WEn; 185(69) PEn; 83(24) SampEn; 81(21) ApEn.Conclusions:WEn demonstrates the fastest change in associationwith ICHTN. Physiologically, it is related to the ICP pulse waveform.The role of WEn as a predictor for ICHTN is promising and warrantsfurther investigation