TY - JOUR
T1 - Dynamic cerebral autoregulation estimates derived from near infrared spectroscopy and transcranial Doppler are similar after correction for transit time and blood flow and blood volume oscillations
AU - Elting, Jan Willem J.
AU - Tas, Jeanette
AU - Aries, Marcel J.H.
AU - Czosnyka, Marek
AU - Maurits, Natasha M.
PY - 2020/1
Y1 - 2020/1
N2 - We analysed mean arterial blood pressure, cerebral blood flow velocity, oxygenated haemoglobin and deoxygenated haemoglobin signals to estimate dynamic cerebral autoregulation. We compared macrovascular (mean arterial blood pressure-cerebral blood flow velocity) and microvascular (oxygenated haemoglobin-deoxygenated haemoglobin) dynamic cerebral autoregulation estimates during three different conditions: rest, mild hypocapnia and hypercapnia. Microvascular dynamic cerebral autoregulation estimates were created by introducing the constant time lag plus constant phase shift model, which enables correction for transit time, blood flow and blood volume oscillations (TT-BF/BV correction). After TT-BF/BV correction, a significant agreement between mean arterial blood pressure-cerebral blood flow velocity and oxygenated haemoglobin-deoxygenated haemoglobin phase differences in the low frequency band was found during rest (left: intraclass correlation=0.6, median phase difference 29.5 degrees vs. 30.7 degrees, right: intraclass correlation=0.56, median phase difference 32.6 degrees vs. 39.8 degrees) and mild hypocapnia (left: intraclass correlation=0.73, median phase difference 48.6 degrees vs. 43.3 degrees, right: intraclass correlation=0.70, median phase difference 52.1 degrees vs. 61.8 degrees). During hypercapnia, the mean transit time decreased and blood volume oscillations became much more prominent, except for very low frequencies. The transit time related to blood flow oscillations was remarkably stable during all conditions. We conclude that non-invasive microvascular dynamic cerebral autoregulation estimates are similar to macrovascular dynamic cerebral autoregulation estimates, after TT-BF/BV correction is applied. These findings may increase the feasibility of non-invasive continuous autoregulation monitoring and guided therapy in clinical situations.
AB - We analysed mean arterial blood pressure, cerebral blood flow velocity, oxygenated haemoglobin and deoxygenated haemoglobin signals to estimate dynamic cerebral autoregulation. We compared macrovascular (mean arterial blood pressure-cerebral blood flow velocity) and microvascular (oxygenated haemoglobin-deoxygenated haemoglobin) dynamic cerebral autoregulation estimates during three different conditions: rest, mild hypocapnia and hypercapnia. Microvascular dynamic cerebral autoregulation estimates were created by introducing the constant time lag plus constant phase shift model, which enables correction for transit time, blood flow and blood volume oscillations (TT-BF/BV correction). After TT-BF/BV correction, a significant agreement between mean arterial blood pressure-cerebral blood flow velocity and oxygenated haemoglobin-deoxygenated haemoglobin phase differences in the low frequency band was found during rest (left: intraclass correlation=0.6, median phase difference 29.5 degrees vs. 30.7 degrees, right: intraclass correlation=0.56, median phase difference 32.6 degrees vs. 39.8 degrees) and mild hypocapnia (left: intraclass correlation=0.73, median phase difference 48.6 degrees vs. 43.3 degrees, right: intraclass correlation=0.70, median phase difference 52.1 degrees vs. 61.8 degrees). During hypercapnia, the mean transit time decreased and blood volume oscillations became much more prominent, except for very low frequencies. The transit time related to blood flow oscillations was remarkably stable during all conditions. We conclude that non-invasive microvascular dynamic cerebral autoregulation estimates are similar to macrovascular dynamic cerebral autoregulation estimates, after TT-BF/BV correction is applied. These findings may increase the feasibility of non-invasive continuous autoregulation monitoring and guided therapy in clinical situations.
KW - Dynamic cerebral autoregulation
KW - transcranial Doppler
KW - near infrared spectroscopy
KW - group delay
KW - microvascular transit time
KW - LOW-FREQUENCY OSCILLATIONS
KW - HETEROGENEITY CTH
KW - HEMODYNAMICS
KW - HYPERCAPNIA
KW - METABOLISM
KW - HYPOCAPNIA
KW - CO2
U2 - 10.1177/0271678X18806107
DO - 10.1177/0271678X18806107
M3 - Article
AN - SCOPUS:85059195007
SN - 0271-678X
VL - 40
SP - 135
EP - 149
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
IS - 1
T2 - Journal-of-Cerebral-Blood-Flow-and-Metabolism (JCBFM) Symposium at International Symposium on Cerebral Blood Flow, Metabolism and Function (BRAIN)
Y2 - 7 July 2019
ER -