PDF(Pubmed)
Abstract：
UNASSIGNED: 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. However, if oscillations are introduced by the cycling process of an anti-decubitus-mattress the effect on PRx is confounding, as they affect directly also intracranial pressure (ICP). In our routine monitoring in TBI patients we noticed periods of highly regular, slow, spontaneous oscillations in ABP and ICP signals.
UNASSIGNED: We set out to explore the nature of these oscillations and establish if PRx remains reliable during the oscillations.
UNASSIGNED: 10 TBI patients\' recordings with oscillations in ICP and ABP were analysed. We computed PRx, PRx variability (hourly-average of standard-deviation, SD), phase-shift and coherence between ABP and ICP in the slow frequency range. Metrics were compared between oscillation and peri-oscillation periods.
UNASSIGNED: During oscillations (frequency 0.006 ± 0.002Hz), a significantly lower variability of PRx (SD 0.185vs0.242) and higher coherence ABP-ICP (0.618 ± 0.09 vs 0.534 ± 0.09) were observed. No external oscillations sources could be identified. 34 out of 48 events showed signs of \'active\' transmission associated with negative PRx, indicating a potential positive impact on PRx reliability.
UNASSIGNED: Spontaneous oscillations observed in ABP and ICP signals were found to enhance rather than confound PRx reliability. Further research is warranted to elucidate the nature of these oscillations and develop strategies to leverage them for enhancing PRx reliability in TBI monitoring.
UNASSIGNED: We set out to explore the nature of these oscillations and establish if PRx remains reliable during the oscillations.
UNASSIGNED: 10 TBI patients\' recordings with oscillations in ICP and ABP were analysed. We computed PRx, PRx variability (hourly-average of standard-deviation, SD), phase-shift and coherence between ABP and ICP in the slow frequency range. Metrics were compared between oscillation and peri-oscillation periods.
UNASSIGNED: During oscillations (frequency 0.006 ± 0.002Hz), a significantly lower variability of PRx (SD 0.185vs0.242) and higher coherence ABP-ICP (0.618 ± 0.09 vs 0.534 ± 0.09) were observed. No external oscillations sources could be identified. 34 out of 48 events showed signs of \'active\' transmission associated with negative PRx, indicating a potential positive impact on PRx reliability.
UNASSIGNED: Spontaneous oscillations observed in ABP and ICP signals were found to enhance rather than confound PRx reliability. Further research is warranted to elucidate the nature of these oscillations and develop strategies to leverage them for enhancing PRx reliability in TBI monitoring.
摘要：
■压力反应性指数（PRx）用于连续监测创伤性脑损伤（TBI）中的脑血管反应性。然而,PRx有一个嘈杂的字符。循环呼气末正压调节引起的动脉血压（ABP）振荡，可以使PRx更可靠。然而,如果振荡是由抗褥疮床垫的循环过程引入的，对PRx的影响是混杂的，因为它们也直接影响颅内压（ICP）。在我们对TBI患者的常规监测中，我们注意到，慢,ABP和ICP信号的自发振荡。
■我们着手探索这些振荡的性质并确定PRx在振荡期间是否保持可靠。
■分析了10例TBI患者的ICP和ABP振荡记录。我们计算了PRx，PRx变异性(标准差的小时平均值，SD),ABP和ICP在慢频率范围内的相移和相干性。在振动和周围振动周期之间比较了指标。
■在振荡期间（频率0.006±0.002Hz），观察到PRx的变异性显著较低(SD0.185vs0.242)和ABP-ICP的相干性较高(0.618±0.09vs0.534±0.09).无法识别外部振荡源。48个事件中有34个显示出与负PRx相关的“活跃”传输的迹象，表明对PRx可靠性有潜在的积极影响。
■发现在ABP和ICP信号中观察到的自发振荡增强而不是混淆PRx可靠性。需要进一步的研究来阐明这些振荡的性质，并制定策略来利用它们来增强TBI监测中的PRx可靠性。
■我们着手探索这些振荡的性质并确定PRx在振荡期间是否保持可靠。
■分析了10例TBI患者的ICP和ABP振荡记录。我们计算了PRx，PRx变异性(标准差的小时平均值，SD),ABP和ICP在慢频率范围内的相移和相干性。在振动和周围振动周期之间比较了指标。
■在振荡期间（频率0.006±0.002Hz），观察到PRx的变异性显著较低(SD0.185vs0.242)和ABP-ICP的相干性较高(0.618±0.09vs0.534±0.09).无法识别外部振荡源。48个事件中有34个显示出与负PRx相关的“活跃”传输的迹象，表明对PRx可靠性有潜在的积极影响。
■发现在ABP和ICP信号中观察到的自发振荡增强而不是混淆PRx可靠性。需要进一步的研究来阐明这些振荡的性质，并制定策略来利用它们来增强TBI监测中的PRx可靠性。
