Alternations in Circadian Variation in Heart Rate Variability in Patients after Cervical Spinal Injury.

简介：众所周知，颈脊髓损伤患者会因损伤而遭受自主神经系统 (ANS) 衰竭。手术刺激可能会触发病变水平以下不受脊髓上中枢抑制的交感神经和副交感神经传入。这可能会导致手术后 ANS 活性恶化。分析心率变异性（HRV）可以评估 ANS 活动的变化。本研究旨在评估全身麻醉下脊柱手术后的 ANS 活动。方法：经过机构批准和知情同意后，对 12 名患者（ASAPS 1 或 2）进行了评估。对6例颈椎病患者和6例后纵韧带患者进行颈椎固定减压。使用主动示踪剂（AC300，Suwa Trust，东京）对每位患者进行了二十四小时的脑电图记录。测量在手术前 2 天 (PRE) 和术后 -1 (POD1)、3 (POD3)、7 (POD7) 天进行。使用最大熵方法（Memcalc 系统，Suwa Trust，东京）计算功率谱。 HRV的功率谱分为两个不同的频段：高频分量（HF：0.l5-0.40 Hz）、低频分量（LF：0.04-0.15 Hz）和比率（HF/LF）。 HF 用于反映迷走神经药物活动，LF 用于反映交感神经和副交感神经的影响。计算低频/高频比率以反映交感迷走神经平衡。在基线 (PRE)、POD1、POD3 和 POD7 的 24 小时周期以及白天 (8:00-21:00) 和夜间 (21:00-8:00) 中对变量进行分析。通过重复测量单向方差分析分析与基线值的差异，并考虑 p < 0.05 的值的显着性。所有数据均表示为平均值±SD。 结果：与 PRE 相比，POD1 时夜间、白天和 24 小时的 LF 和 HF 有所增加。它们在 POD3 和 POD7 时下降。手术前心率变异性的昼夜节律变化减少在手术后一周内恢复。结论：这些数据表明手术过程和全身麻醉改变了颈髓损伤患者的交感和副交感功能。通过比较白天和夜间 HRV 变量，我们发现患者在手术后一周内出现了昼夜节律模式的改变。手术和麻醉引起的 ANS 活动变化和 HRV 昼夜节律变化的作用尚不清楚，需要对颈髓损伤患者进行进一步研究。较少的

Introduction : Cervical spinal cord injury patients are known to suffer from the autonomic nervous system (ANS) failure as a result of their injury. Surgical stimulation may trigger sympathetic and parasympathetic afferents below the level of the lesion that are not inhibited by supraspinal centers. This can lead to deteriorate the ANS activity after the surgery. Analysis of the heart rate variability (HRV) can assess the changes in the ANS activity.This study was performed to evaluate the ANS activity after the spinal surgery under the general anesthesia.Method : After institutional approval and informed consent, 12 patients (ASAPS 1 or 2) were evaluated. Cervical fixation and decompression was carried out for six patients with cervical spondylosis and six patient with the posterior longitudinal ligament. Twenty-four hour EEG recordings were obtained for each patients with a active tracer (AC300, Suwa Trust, Tokyo). Measurements were performed on 2 day before surgery (PRE) and postope … More rative -1 (POD1), 3 (POD3), 7 (POD7) days. Power spectra were calculated with a maximum entropy method (Memcalc system, Suwa Trust, Tokyo). The power spectrum of HRV was divided into two different frequency bands : high-frequency component (HF:0.l5-0.40 Hz), low-frequency component (LF:0.04-0.15 Hz), and the ratio(HF/LF). The HF was used to reflect the vagally medicated activity and the LF to reflect both sympathetic and parasympathetic influences. The LF/HF ratio was calculated in order to mirror the sympathovagal balance. The variables were analyzed in 24-hours periods and also in daytime (8:00-21:00) and night-time (21:00-8:00) at baseline (PRE), POD1, POD3, and POD7. Difference from the baseline value were analyzed with repeated measure one-way ANOVA and significance was considered for values of p < 0.05. All data were expressed as mean ± SD.Result : LF and HF in night-time, daytime and 24-hours increased at POD1 as compared to PRE. They decreased at POD3 and POD7. The diminished circadian variation in HRV before surgery recovered within a week after the surgery.Conclusion : These data demonstrate that surgical procedure and general anesthesia altered the sympathetic and parasympathtic function in patients with cervical spinal cord injury. We found by comparing daytime and night-time HRV variables, that patients demonstrated alterations in a pattern of circadian rhythm city within a week after the surgery. The role of the changes in the ANS activity and circadian variations of HRV induced by the surgical procedure and anesthesia is still unclear and further studies will be needed in patients with cervical spinal cord injury. Less