Department of Geriatric Medicine, Oslo University Hospital, Oslo, Norway.
Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
BMC Geriatr. 2019 Jan 25;19(1):23. doi: 10.1186/s12877-019-1035-0.
Alterations in autonomic nervous system (ANS) activity might be involved in the pathophysiology of delirium. The aim was to explore autonomic cardiovascular control in older patients with and without delirium.
Fourteen patients (five with delirium) acutely admitted to the geriatric ward with an infection were enrolled in the study. Patients with atrial fibrillation, a pacemaker, or on treatment with beta-blockers, calcium channel blockers or acetylcholinesterase inhibitors were not eligible. Continuous, non-invasive hemodynamic variables were measured during supine rest (5 min) and head-up tilt (HUT) to 15 degrees (10 min). Heart rate (HR), blood pressure (BP) and stroke volume (SV) were recorded beat-to-beat. Cardiac output (CO), total peripheral resistance (TPR), end-diastolic volume (EDV) and heart rate variability (HRV) values were calculated.
Median age was 86 years. HR, BP, SV, CO, TPR and EDV were similar across the two groups at rest, but there was a trend towards a greater increase in systolic BP and HR during HUT in the delirium group. At rest, all HRV indices were higher in the delirium group, but the differences were not statistically significant. During HUT, the delirium group had higher power spectral density (PSD) (representing total variability) (p = 0.06) and a lower low frequency (LF)/high frequency (HF)-ratio (an index of sympathovagal balance) than the control group (p = 0.06). Also, delirious patients had a significantly greater reduction in standard deviation of RR-intervals (SDNN) (representing total variability) from baseline than controls (p = 0.01) during HUT.
This explorative pilot study on autonomic cardiovascular control in delirium suggests that there may be differences in HRV that should be further investigated in larger samples.
自主神经系统（ANS）活动的改变可能与谵妄的病理生理学有关。目的是探讨伴有和不伴有谵妄的老年患者的自主心血管控制。
14 名（5 名患有谵妄）因感染急性入住老年病房的患者入组本研究。患有房颤、起搏器或正在接受β受体阻滞剂、钙通道阻滞剂或乙酰胆碱酯酶抑制剂治疗的患者不符合入选标准。在仰卧休息（5 分钟）和头高位倾斜（HUT）至 15 度（10 分钟）期间，连续测量非侵入性的血流动力学变量。心率（HR）、血压（BP）和每搏输出量（SV）逐拍记录。心输出量（CO）、总外周阻力（TPR）、舒张末期容积（EDV）和心率变异性（HRV）值计算得出。
中位年龄为 86 岁。两组在休息时的 HR、BP、SV、CO、TPR 和 EDV 相似，但在谵妄组，HUT 期间收缩压和 HR 有增加的趋势。在休息时，谵妄组的所有 HRV 指标均较高，但差异无统计学意义。在 HUT 期间，谵妄组的总功率谱密度（PSD）（代表总变异性）（p=0.06）较高，低频（LF）/高频（HF）比值（代表交感神经-迷走神经平衡）较低（p=0.06）。此外，与对照组相比，谵妄组在 HUT 期间 RR 间期标准差（SDNN）（代表总变异性）的下降幅度显著更大（p=0.01）。
本项关于谵妄自主心血管控制的探索性初步研究表明，HRV 可能存在差异，需要在更大的样本中进一步研究。
