Abstract
BackgroundAlterations 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.MethodsFourteen 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.ResultsMedian 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.ConclusionsThis 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.
Highlights
Alterations in autonomic nervous system (ANS) activity might be involved in the pathophysiology of delirium
Fourteen participants were included between March 2012 and January 2015 among patients admitted to the acute geriatric ward at Oslo University Hospital (Table 1)
Heart rate variability according to delirium status At rest, all heart rate variability (HRV) indices were higher in the delirium group, but the differences were not statistically significant (Table 4)
Summary
Alterations in autonomic nervous system (ANS) activity might be involved in the pathophysiology of delirium. Delirium is a common disorder among hospitalised older patients, characterised by an acute onset and fluctuating course, altered arousal, inattention and cognitive problems [1]. The clinical features of delirium might suggest aberrations in acute stress responses, involving alterations in autonomic nervous system (ANS) activity [3]. ANS activity can be indirectly assessed by measuring heart rate variability (HRV). The proxy-based Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) [29] and the Clinical Dementia Rating scale (CDR) [30] were used to Autonomic response to HUT 15 degrees Descriptive data for all patients during supine rest and HUT to 15 degrees show that HR and BP values were stable during tilt. Indices indicating increased sympathetic activity (LF-variables and LF/ HF-ratio) increased slightly, but these changes were not significant
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
