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61st Annual Meeting of the German Society of Neurosurgery (DGNC) as part of the Neurowoche 2010
Joint Meeting with the Brazilian Society of Neurosurgery on the 20 September 2010

German Society of Neurosurgery (DGNC)

21 - 25 September 2010, Mannheim

Reduced heart-rate variability in brain-dead patients as compared to comatose patients with and without brain stem lesions and healthy volunteers

Meeting Abstract

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  • Imre Bondar - Klinik für Neurochirurgie, Universität Magdeburg, Deutschland
  • André Stegemann - Klinik für Neurochirurgie, Universität Magdeburg, Deutschland
  • Raimund Firsching - Klinik für Neurochirurgie, Universität Magdeburg, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 61. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC) im Rahmen der Neurowoche 2010. Mannheim, 21.-25.09.2010. Düsseldorf: German Medical Science GMS Publishing House; 2010. DocP1823

DOI: 10.3205/10dgnc294, URN: urn:nbn:de:0183-10dgnc2949

Published: September 16, 2010

© 2010 Bondar et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Objective: Heart rate variability (HRV) is defined as variation of the beat-to-beat R-R time interval between consecutive heart beats in the electrocardiogram (ECG). HRV reflects autonomic control of the cardio-vascular system, which may be impaired in patients with lesions of brain stem areas associated with autonomic control functions. The aim of the present study was to compare the HRV between patients exhibiting the clinical criteria of brain death and comatose patients without and with a brain stem lesion as verfied by MRI and with healthy volunteers

Methods: HRV was assessed in 11 healthy volunteers, in 20 comatose patients without a brain stem lesion in the MRI, in 24 comatose patients with a brain stem lesion verified by MRI and in 21 patients fulfilling the clinical criteria of brain death. The ECG was digitized by means of an analog-to-digital converter and sampled for a period of 30 minutes once a day (500 Hz sampling rate, 12 bit resolution). For each patient, consecutive normal R-R time intervals [s] were determined from these time-series and used to calculate the standard deviation of beat-to-beat intervals (SDNN) and the root mean square of successive differences (RMSSD), two common HRV parameters. Analysis of variance (ANOVA) was used to compare group differences for statistical significance

Results: Patients exhibiting the clinical criteria of brain death showed a marked and statistically significant (p<0.05) reduction of both HRV-paramerters (SDNN=0.0056±0.0054, RMSSD=0.003) as compared to comatose patients with (SDNN=0.019±0.018, RMSSD=0.018) and without a brain stem lesion (SDNN=0.031±0.027, RMSSD=0.032) and healthy volunteers (SDNN=0.080±0.028, RMSSD=0.059).

Conclusions: Our results show that HRV is markedly reduced in patients exhibiting the clinical criteria of brain death as compared to comatose patients with and without brain stem lesions. The assessment of HRV might provide a novel noninvasive approach to confirmation of the cessation of brain stem function.