脑血管反应性
相关主题
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
0041-1345/04/$–see front matter doi:10.1016/j.transproceed.2004.05.045
Transplantation Proceedings, 36, 1473–1478 (2004)
1473
1474
ARDIZZONE, ARRIGO, PANARO ET AL
From the Department of Anesthesiology-Critical Care, Osp. S. Martino e Cliniche Universitarie Convenzionate, Genova, Italy (G.A., A.A., M.C., M.D., A.P., C.S.); Department of Surgery/ Transplant Surgery, University of Illinois at Chicago, Chicago, Illinois, USA (T.M.J.); Department of Motor Sciences Osp. S. Martino e Cliniche Universitarie Convenzionate, Genova, Italy (A.C.); Department of Transplant Surgery, Osp. S. Martino e Cliniche Universitarie Convenzionate, Genova, Italy (F.P., U.V.).
postreperfusion and neohepatic phase (Wilcoxon signed sum rank test). *P ϭ .004. †P ϭ .002. ‡P ϭ .001.
PATIENTS AND METHODS
The protocol for this study was approved by the institutional committee An informed consent document was signed by each patient. Twenty-three consecutive adult patients (15 men and 8 women of mean age 51.6 ϩ 5.2 years) were included in this study. The reasons for ESLF were as follows: chronic hepatitis (n ϭ 17), alcoholic cirrhosis (n ϭ 4), primary biliary cirrhosis (n ϭ 1), and hepatocellular carcinoma (n ϭ 1). Eight patients were classified as Child’s class C, ten class B, and five class A.14 All OLT were uncomplicated with unremarkable postoperative course.
Just as patients with hepatic encephalopathy secondary to end-stage liver failure (ESLF) or deep coma due to fulminant hepatic failure have alterations in CA, so may those undergoing OLT.6–9 A well functioning autoregulation mechanism is particularly important to provide adequate cerebral oxygenation for OLT recipients. Aaslid et al10 developed a method to correlate the dynamics of autoreg-
AUTOREGULATION of cerebral blood flow (CBF) is a process by which CBF is held relatively constant in spite of changes in cerebral perfusion pressure.1 The phenomenon of the cerebral autoregulation (CA) can be easily disrupted, and failure of this normal physiological reflex may theoretically worsen the neurological outcome of patients undergoing orthotopic liver transplantation (OLT).2 During OLT, dramatic hemodynamic instability is frequently encountered, particularly after reperfusion of the liver graft. At the time of reperfusion, an unchanged cardiac output with a low systemic vascular resistance (SVR) contributes to a marked decrease in mean arterial blood pressure (MABP) that in turn may affect cerebral perfusion.2 The mechanism of this phenomenon is unknown.3 Furthermore, the effects of SVR and MABP on CA have not been well investigated.4,5
Modifications of Cerebral Vascular Resistance and Autoregulation After Graft Reperfusion During Human Orthotopic Liver Transplantation
G. Ardizzone, A. Arrigo, F. Panaro, M. Centanaro, M. Demartini, A. Pellizzari, A. Cifelli, T.M. Jarzembowsky, U. Valente, and C. Siani
Table 1. Values of Pearson Coefficient “r” and Line Slope “S” in the Phases of OLT
Paleohepatic
Anhepatic
Postreperfusion
Neohepaticwk.baidu.com
“r”
0.56 (0.16 Ϭ 0.87)
“S”
© 2004 by Elsevier Inc. All rights reserved.
360 Park Avenue South, New York, NY 10010-1710
ulation by recording mean cerebral blood flow velocity (CBFV) in the middle cerebral artery by transcranial doppler (TCD) versus changes in arterial pressure upon deflating a leg cuff in healthy volunteers. However, because this approach is not possible during OLT, we decided to study CA by analyzing the impact of changes in MABP induced by a slow intravenous infusion of phenylepinephrine upon simultaneous CBFV recorded using continuous TCD monitoring.11–13
ABSTRACT
We have studied cerebral blood flow velocity (CBFV) and cerebral autoregulation (CA) in 23 orthotopic liver transplantation (OLT) patients using transcranial doppler. CBFV was continuously recorded using a fixed (helmet) 2-Mz probe through the trans-temporal window. CA changes were studied using a linear regression analysis of percentile changes in CBFV and mean arterial blood pressure (MABP) after phenylephrine infusion compared with baseline. Pearson’s “r” coefficient was considered an index of CA. In case of autoregulation is lost “r” tends to 1, thus representing complete dependence of CBFV on MABP. We regarded the slope coefficient parameter “S” as an index of cerebral vascular resistance (CVR), namely, the ratio of the corresponding variations of CBFV to MABP. Wilcoxon test showed a significant increase in both “r” and “S” between the anhepatic versus postreperfusion phases (within the first hour) and versus recovery in the neohepatic phase (end of surgery). A decreased CVR was observed within the first hour after graft reperfusion producing a loss of CA. These phenomena lead to an increase of CBFV and exposed the brain to hyperperfusion.
0.63 (0.14 Ϭ 1.41)
0.66 (0.1 Ϭ 0.87) 0.66 (0.13 Ϭ 1.7)
0.84 (Ϫ0.62 Ϭ 0.97)‡ 1.15 (0.18 Ϭ 2.06)‡
0.73 (Ϫ0.4 Ϭ 0.97)* 0.72 (Ϫ0.2 Ϭ 1.6)†
Note: All data expressed as median and range. Statistical significance of the variations of “r” and “S” between anhepatic and postreperfusion phase, and between
Address reprint requests to Dr. F. Panaro, Department of Surgery, Transplant Division University of Genoa, L.go Rosanna Benzi, 10 Genoa 16100, Italy. E-mail: fpanaro@uic.edu
Transplantation Proceedings, 36, 1473–1478 (2004)
1473
1474
ARDIZZONE, ARRIGO, PANARO ET AL
From the Department of Anesthesiology-Critical Care, Osp. S. Martino e Cliniche Universitarie Convenzionate, Genova, Italy (G.A., A.A., M.C., M.D., A.P., C.S.); Department of Surgery/ Transplant Surgery, University of Illinois at Chicago, Chicago, Illinois, USA (T.M.J.); Department of Motor Sciences Osp. S. Martino e Cliniche Universitarie Convenzionate, Genova, Italy (A.C.); Department of Transplant Surgery, Osp. S. Martino e Cliniche Universitarie Convenzionate, Genova, Italy (F.P., U.V.).
postreperfusion and neohepatic phase (Wilcoxon signed sum rank test). *P ϭ .004. †P ϭ .002. ‡P ϭ .001.
PATIENTS AND METHODS
The protocol for this study was approved by the institutional committee An informed consent document was signed by each patient. Twenty-three consecutive adult patients (15 men and 8 women of mean age 51.6 ϩ 5.2 years) were included in this study. The reasons for ESLF were as follows: chronic hepatitis (n ϭ 17), alcoholic cirrhosis (n ϭ 4), primary biliary cirrhosis (n ϭ 1), and hepatocellular carcinoma (n ϭ 1). Eight patients were classified as Child’s class C, ten class B, and five class A.14 All OLT were uncomplicated with unremarkable postoperative course.
Just as patients with hepatic encephalopathy secondary to end-stage liver failure (ESLF) or deep coma due to fulminant hepatic failure have alterations in CA, so may those undergoing OLT.6–9 A well functioning autoregulation mechanism is particularly important to provide adequate cerebral oxygenation for OLT recipients. Aaslid et al10 developed a method to correlate the dynamics of autoreg-
AUTOREGULATION of cerebral blood flow (CBF) is a process by which CBF is held relatively constant in spite of changes in cerebral perfusion pressure.1 The phenomenon of the cerebral autoregulation (CA) can be easily disrupted, and failure of this normal physiological reflex may theoretically worsen the neurological outcome of patients undergoing orthotopic liver transplantation (OLT).2 During OLT, dramatic hemodynamic instability is frequently encountered, particularly after reperfusion of the liver graft. At the time of reperfusion, an unchanged cardiac output with a low systemic vascular resistance (SVR) contributes to a marked decrease in mean arterial blood pressure (MABP) that in turn may affect cerebral perfusion.2 The mechanism of this phenomenon is unknown.3 Furthermore, the effects of SVR and MABP on CA have not been well investigated.4,5
Modifications of Cerebral Vascular Resistance and Autoregulation After Graft Reperfusion During Human Orthotopic Liver Transplantation
G. Ardizzone, A. Arrigo, F. Panaro, M. Centanaro, M. Demartini, A. Pellizzari, A. Cifelli, T.M. Jarzembowsky, U. Valente, and C. Siani
Table 1. Values of Pearson Coefficient “r” and Line Slope “S” in the Phases of OLT
Paleohepatic
Anhepatic
Postreperfusion
Neohepaticwk.baidu.com
“r”
0.56 (0.16 Ϭ 0.87)
“S”
© 2004 by Elsevier Inc. All rights reserved.
360 Park Avenue South, New York, NY 10010-1710
ulation by recording mean cerebral blood flow velocity (CBFV) in the middle cerebral artery by transcranial doppler (TCD) versus changes in arterial pressure upon deflating a leg cuff in healthy volunteers. However, because this approach is not possible during OLT, we decided to study CA by analyzing the impact of changes in MABP induced by a slow intravenous infusion of phenylepinephrine upon simultaneous CBFV recorded using continuous TCD monitoring.11–13
ABSTRACT
We have studied cerebral blood flow velocity (CBFV) and cerebral autoregulation (CA) in 23 orthotopic liver transplantation (OLT) patients using transcranial doppler. CBFV was continuously recorded using a fixed (helmet) 2-Mz probe through the trans-temporal window. CA changes were studied using a linear regression analysis of percentile changes in CBFV and mean arterial blood pressure (MABP) after phenylephrine infusion compared with baseline. Pearson’s “r” coefficient was considered an index of CA. In case of autoregulation is lost “r” tends to 1, thus representing complete dependence of CBFV on MABP. We regarded the slope coefficient parameter “S” as an index of cerebral vascular resistance (CVR), namely, the ratio of the corresponding variations of CBFV to MABP. Wilcoxon test showed a significant increase in both “r” and “S” between the anhepatic versus postreperfusion phases (within the first hour) and versus recovery in the neohepatic phase (end of surgery). A decreased CVR was observed within the first hour after graft reperfusion producing a loss of CA. These phenomena lead to an increase of CBFV and exposed the brain to hyperperfusion.
0.63 (0.14 Ϭ 1.41)
0.66 (0.1 Ϭ 0.87) 0.66 (0.13 Ϭ 1.7)
0.84 (Ϫ0.62 Ϭ 0.97)‡ 1.15 (0.18 Ϭ 2.06)‡
0.73 (Ϫ0.4 Ϭ 0.97)* 0.72 (Ϫ0.2 Ϭ 1.6)†
Note: All data expressed as median and range. Statistical significance of the variations of “r” and “S” between anhepatic and postreperfusion phase, and between
Address reprint requests to Dr. F. Panaro, Department of Surgery, Transplant Division University of Genoa, L.go Rosanna Benzi, 10 Genoa 16100, Italy. E-mail: fpanaro@uic.edu