Cerebrovascular reactivity measured by near-infrared spectroscopy

Jennifer Lee-Summers, Kathleen K. Kibler, Paul B. Benni, R. Blaine Easley, Marek Czosnyka, Peter Smielewski, Raymond C Koehler, Donald Harry Shaffner, Ken M. Brady

Research output: Contribution to journalArticle

Abstract

Background and Purpose-: The pressure reactivity index (PRx) describes cerebral vessel reactivity by correlation of slow waves of intracranial pressure (ICP) and arterial blood pressure. In theory, slow changes in the relative total hemoglobin (rTHb) measured by near-infrared spectroscopy are caused by the same blood volume changes that cause slow waves of ICP. Our objective was to develop a new index of vascular reactivity, the hemoglobin volume index (HVx), which is a low-frequency correlation of arterial blood pressure and rTHb measured with near-infrared spectroscopy. Methods-: Gradual hypotension was induced in piglets while cortical laser-Doppler flux was monitored. ICP was monitored, and rTHb was measured continuously using reflectance near-infrared spectroscopy. The HVx was recorded as a moving linear correlation between slow waves (20 to 300 seconds) of arterial blood pressure and rTHb. Autoregulation curves were constructed by averaging values of the PRx or HVx in 5-mm Hg bins of cerebral perfusion pressure. Results-: The laser-Doppler flux-determined lower limit of autoregulation was 29.4±6.7 mm Hg (±SD). Coherence between rTHb and ICP was high at low frequencies. HVx was linearly correlated with PRx. The PRx and HVx both showed higher values below the lower limit of autoregulation and lower values above the lower limit of autoregulation. Areas under the receiver operator characteristic curves were 0.88 and 0.85 for the PRx and HVx, respectively. Conclusions-: Coherence between the rTHb and ICP waveforms at the frequency of slow waves suggests that slow waves of ICP are related to blood volume changes. The HVx has potential for further development as a noninvasive alternative to the PRX.

Original languageEnglish (US)
Pages (from-to)1820-1826
Number of pages7
JournalStroke
Volume40
Issue number5
DOIs
StatePublished - May 1 2009

Fingerprint

Near-Infrared Spectroscopy
Hemoglobins
Intracranial Pressure
Pressure
Homeostasis
Arterial Pressure
Blood Volume
Cerebrovascular Circulation
Lasers
Controlled Hypotension
Blood Vessels

Keywords

  • Autoregulation
  • Cerebral blood flow
  • Hemoglobin
  • Hypotension
  • Near-infrared spectroscopy
  • Neonate
  • Piglet

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Clinical Neurology
  • Advanced and Specialized Nursing
  • Medicine(all)

Cite this

Lee-Summers, J., Kibler, K. K., Benni, P. B., Easley, R. B., Czosnyka, M., Smielewski, P., ... Brady, K. M. (2009). Cerebrovascular reactivity measured by near-infrared spectroscopy. Stroke, 40(5), 1820-1826. https://doi.org/10.1161/STROKEAHA.108.536094

Cerebrovascular reactivity measured by near-infrared spectroscopy. / Lee-Summers, Jennifer; Kibler, Kathleen K.; Benni, Paul B.; Easley, R. Blaine; Czosnyka, Marek; Smielewski, Peter; Koehler, Raymond C; Shaffner, Donald Harry; Brady, Ken M.

In: Stroke, Vol. 40, No. 5, 01.05.2009, p. 1820-1826.

Research output: Contribution to journalArticle

Lee-Summers, J, Kibler, KK, Benni, PB, Easley, RB, Czosnyka, M, Smielewski, P, Koehler, RC, Shaffner, DH & Brady, KM 2009, 'Cerebrovascular reactivity measured by near-infrared spectroscopy', Stroke, vol. 40, no. 5, pp. 1820-1826. https://doi.org/10.1161/STROKEAHA.108.536094
Lee-Summers J, Kibler KK, Benni PB, Easley RB, Czosnyka M, Smielewski P et al. Cerebrovascular reactivity measured by near-infrared spectroscopy. Stroke. 2009 May 1;40(5):1820-1826. https://doi.org/10.1161/STROKEAHA.108.536094
Lee-Summers, Jennifer ; Kibler, Kathleen K. ; Benni, Paul B. ; Easley, R. Blaine ; Czosnyka, Marek ; Smielewski, Peter ; Koehler, Raymond C ; Shaffner, Donald Harry ; Brady, Ken M. / Cerebrovascular reactivity measured by near-infrared spectroscopy. In: Stroke. 2009 ; Vol. 40, No. 5. pp. 1820-1826.
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AU - Kibler, Kathleen K.

AU - Benni, Paul B.

AU - Easley, R. Blaine

AU - Czosnyka, Marek

AU - Smielewski, Peter

AU - Koehler, Raymond C

AU - Shaffner, Donald Harry

AU - Brady, Ken M.

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KW - Cerebral blood flow

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