We have located links that may give you full text access.
Journal Article
Research Support, Non-U.S. Gov't
Impaired cerebral autoregulation in patients with malignant hypertension.
Circulation 2004 October 13
BACKGROUND: In patients with a malignant hypertension, immediate parenteral treatment with blood pressure-lowering agents such as intravenous sodium nitroprusside (SNP) is indicated. In this study, we evaluated static and dynamic cerebral autoregulation (CA) during acute blood pressure lowering with SNP in these patients.
METHODS AND RESULTS: In 8 patients with mean arterial pressure (MAP) >140 mm Hg and grade III or IV hypertensive retinopathy at hospital admission, middle cerebral artery blood velocity (MCA V) and blood pressure were monitored. Dynamic CA was expressed as the 0.1-Hz MCA V(mean) to MAP phase lead and static CA as the MCA V(mean) to MAP relationship during SNP treatment. Eight normotensive subjects served as a reference group. In the patients, the MCA V(mean) to MAP phase lead was lower (30+/-8 degrees versus 58+/-5 degrees , mean+/-SEM; P<0.05), whereas the transfer gain tended to be higher. During SNP treatment, target MAP was reached within 90 minutes in all patients. The MCA V(mean) decrease was 22+/-4%, along with a 27+/-3% reduction in MAP (from 166+/-4 to 121+/-6 mm Hg; P<0.05) in a linear fashion (averaged slope, 0.82+/-0.15% cm x s(-1) . % mm Hg(-1); r=0.70+/-0.07).
CONCLUSIONS: In patients with malignant hypertension, dynamic CA is impaired. An MCA V(mean) plateau was not detected during the whole SNP treatment, indicating loss of static CA as well. This study showed that during the whole rapid reduction in blood pressure with SNP, MCA V(mean) decreases almost one on one with MAP.
METHODS AND RESULTS: In 8 patients with mean arterial pressure (MAP) >140 mm Hg and grade III or IV hypertensive retinopathy at hospital admission, middle cerebral artery blood velocity (MCA V) and blood pressure were monitored. Dynamic CA was expressed as the 0.1-Hz MCA V(mean) to MAP phase lead and static CA as the MCA V(mean) to MAP relationship during SNP treatment. Eight normotensive subjects served as a reference group. In the patients, the MCA V(mean) to MAP phase lead was lower (30+/-8 degrees versus 58+/-5 degrees , mean+/-SEM; P<0.05), whereas the transfer gain tended to be higher. During SNP treatment, target MAP was reached within 90 minutes in all patients. The MCA V(mean) decrease was 22+/-4%, along with a 27+/-3% reduction in MAP (from 166+/-4 to 121+/-6 mm Hg; P<0.05) in a linear fashion (averaged slope, 0.82+/-0.15% cm x s(-1) . % mm Hg(-1); r=0.70+/-0.07).
CONCLUSIONS: In patients with malignant hypertension, dynamic CA is impaired. An MCA V(mean) plateau was not detected during the whole SNP treatment, indicating loss of static CA as well. This study showed that during the whole rapid reduction in blood pressure with SNP, MCA V(mean) decreases almost one on one with MAP.
Full text links
Related Resources
Trending Papers
Systemic lupus erythematosus.Lancet 2024 April 18
Should renin-angiotensin system inhibitors be held prior to major surgery?British Journal of Anaesthesia 2024 May
Autoimmune Hemolytic Anemias: Classifications, Pathophysiology, Diagnoses and Management.International Journal of Molecular Sciences 2024 April 13
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app