Ellenby M S, McNames J, Lai S, McDonald B A, Krieger D, Sclabassi R J, Goldstein B
Division of Pediatric Critical Care, Doernbecher Children's Hospital, Oregon Health Sciences University, Portland 97201, USA.
Shock. 2001 Oct;16(4):274-7. doi: 10.1097/00024382-200116040-00007.
Healthy physiological systems exhibit marked signal variability and complexity, whereas diseased systems generally show a loss of variability, decreased complexity ("decomplexification"), and increased regularity. The goal of this study was to evaluate the uncoupling and recoupling phenomenon in children with septic shock by observing serial changes in heart rate variability metrics. Data were collected from 7 children with septic shock by using the computer system in the Complex Systems Laboratory at Oregon Health Sciences University. Heart rate time series were constructed and analyzed by using the Hales Research System at intervals of 6 h during pediatric intensive care unit (PICU) hospitalization. These power spectral values were then plotted vs. time. Six of seven patients showed an increase over time in low-frequency heart rate power and the low-/high-frequency ratio, whereas high-frequency heart rate power decreased. We also compared the change in mean heart rate, heart rate standard deviation, and power spectral values during the first 24 h of PICU hospitalization vs. the remainder of the PICU stay (for the 5 patients with a PICU length of stay > 48 h). Compared to the initial 24 h in the PICU, low-frequency power and the low-/high-frequency ratio increased, whereas high-frequency power decreased over the course of the illness. This report shows the potential value of monitoring the uncoupling and recoupling phenomenon in patients with septic shock. Our results are in agreement with other investigators who report evidence of decomplexification both in experimental models of sepsis and in clinical studies and provide direction for further work.
健康的生理系统呈现出显著的信号变异性和复杂性，而患病系统通常表现为变异性丧失、复杂性降低（“去复杂化”）以及规律性增加。本研究的目的是通过观察心率变异性指标的系列变化来评估脓毒性休克患儿的解耦联和再耦联现象。数据是从7名脓毒性休克患儿中收集的，使用的是俄勒冈健康与科学大学复杂系统实验室的计算机系统。在儿科重症监护病房（PICU）住院期间，每隔6小时使用黑尔斯研究系统构建并分析心率时间序列。然后将这些功率谱值与时间作图。7名患者中有6名随着时间的推移低频心率功率和低频/高频比值增加，而高频心率功率降低。我们还比较了PICU住院的前24小时与PICU住院剩余时间（针对5名PICU住院时间>48小时的患者）期间平均心率、心率标准差和功率谱值的变化。与PICU最初的24小时相比，在疾病过程中低频功率和低频/高频比值增加，而高频功率降低。本报告显示了监测脓毒性休克患者解耦联和再耦联现象的潜在价值。我们的结果与其他研究者一致，他们在脓毒症实验模型和临床研究中均报告了去复杂化的证据，并为进一步的研究提供了方向。
