TY - JOUR
T1 - Effect of Hyper- and Hypocapnia on Cerebral Arterial Compliance in Normal Subjects
AU - Carrera, Emmanuel
AU - Kim, Dong Joo
AU - Castellani, Gianluca
AU - Zweifel, Christian
AU - Smielewski, Peter
AU - Pickard, John D.
AU - Czosnyka, Marek
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/4
Y1 - 2011/4
N2 - Changes in partial pressure of carbon dioxide (PaCO2) are associated with a decrease in cerebral blood flow (CBF) during hypocapnia and an increase in CBF during hypercapnia. However, the effects of changes in PaCO2 on cerebral arterial compliance (Ca) are unknown. METHODS: We assessed the changes in Ca in 20 normal subjects using monitoring of arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV). Cerebral arterial blood volume (CaBV) was extracted from CBFV. Ca was defined as the ratio between the pulse amplitudes of CaBV (AMPCaBV) and ABP (AMPABP). All parameters were recorded during normo-, hyper-, and hypocapnia. RESULTS: During hypocapnia, Ca was significantly lower than during normocapnia (10 ± .04 vs .17 ± .06; P < .001) secondary to a decrease in AMPCaBV (1.3 ± .4 vs. 1.9 ± .5; P < .001) and a concomitant increase in AMPABP (13.8 ± 3.4 vs. 11.6 ± 1.7 mmHg; P<.001). During hypercapnia, there was no change in Ca compared with normocapnia. Ca was inversely correlated with the cerebrovascular resistance during hypo- (R2= 0.86; P<.001), and hypercapnia (R2= 0.61; P<.001). CONCLUSION: Using a new mathematical model, we have described a reduction of Ca during hypocapnia. Further studies are needed to determine whether Ca may be an independent predictor of outcome in pathological conditions.
AB - Changes in partial pressure of carbon dioxide (PaCO2) are associated with a decrease in cerebral blood flow (CBF) during hypocapnia and an increase in CBF during hypercapnia. However, the effects of changes in PaCO2 on cerebral arterial compliance (Ca) are unknown. METHODS: We assessed the changes in Ca in 20 normal subjects using monitoring of arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV). Cerebral arterial blood volume (CaBV) was extracted from CBFV. Ca was defined as the ratio between the pulse amplitudes of CaBV (AMPCaBV) and ABP (AMPABP). All parameters were recorded during normo-, hyper-, and hypocapnia. RESULTS: During hypocapnia, Ca was significantly lower than during normocapnia (10 ± .04 vs .17 ± .06; P < .001) secondary to a decrease in AMPCaBV (1.3 ± .4 vs. 1.9 ± .5; P < .001) and a concomitant increase in AMPABP (13.8 ± 3.4 vs. 11.6 ± 1.7 mmHg; P<.001). During hypercapnia, there was no change in Ca compared with normocapnia. Ca was inversely correlated with the cerebrovascular resistance during hypo- (R2= 0.86; P<.001), and hypercapnia (R2= 0.61; P<.001). CONCLUSION: Using a new mathematical model, we have described a reduction of Ca during hypocapnia. Further studies are needed to determine whether Ca may be an independent predictor of outcome in pathological conditions.
KW - Cerebral arterial blood volume
KW - Cerebral arterial compliance
KW - Hypocapnia
KW - Transcranial Doppler
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U2 - 10.1111/j.1552-6569.2009.00439.x
DO - 10.1111/j.1552-6569.2009.00439.x
M3 - Article
C2 - 19888933
AN - SCOPUS:79953041173
VL - 21
SP - 121
EP - 125
JO - Journal of Neuroimaging
JF - Journal of Neuroimaging
SN - 1051-2284
IS - 2
ER -