title: Heart rate variability in intensive care unit patients with delirium.
abstract: Sympathovagal balance, assessed with heart rate variability (HRV), may be altered in intensive care unit (ICU) delirium. HRV was measured in the frequency domain [low frequencies (LF)=0.04-0.15 Hz and high frequencies (HF)=0.15-0.40 Hz] with HF in normalized units (HFnu) to evaluate parasympathetic tone and LF:HF ratio for sympathovagal balance. The authors assessed 726 ICU patients and excluded patients with conditions affecting HRV. No difference could be found between patients with (N=13) and without (N=12) delirium by comparing the mean (±standard deviation) of the HFnu (75±7 versus 68±23) and the LF:HF ratio (-0.7±1.0 versus -0.1±1.1). This study suggests that autonomic function is not altered in ICU delirium.
authors.affiliation: From the Depts. of Intensive Care Medicine, Brain Centre Rudolf Magnus, University Medical Centre Utrecht, Utrecht, the Netherlands (IJZ, AWvdK, AJCS); the Dept. of Medical Technology and Clinical Physics, University Medical Centre Utrecht, Utrecht, the Netherlands (LJvS); and the Dept. of Neurology and Neurosurgery, Brain Centre Rudolf Magnus, University Medical Centre Utrecht, Utrecht, the Netherlands (PLO).
authors.forename: Irene J
authors.initials: IJ
authors.lastname: Zaal
authors.forename: Arendina W
authors.initials: AW
authors.lastname: van der Kooi
authors.forename: Leonard J
authors.initials: LJ
authors.lastname: van Schelven
authors.forename: P Liam
authors.initials: PL
authors.lastname: Oey
authors.forename: Arjen J C
authors.initials: AJ
authors.lastname: Slooter
mesh_terms: D000328:Adult; D000368:Aged; D003693:Delirium / Q000453:epidemiology / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018709:Statistics, Nonparametric