scholarly journals HOBOE (Head-of-Bed Optimization of Elevation) Study: Association of Higher Angle With Reduced Cerebral Blood Flow Velocity in Acute Ischemic Stroke

2011 ◽  
Vol 91 (10) ◽  
pp. 1503-1512 ◽  
Author(s):  
Abigail Jade Hunter ◽  
Suzanne J. Snodgrass ◽  
Debbie Quain ◽  
Mark W. Parsons ◽  
Christopher R. Levi
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Mean Flow ◽  
Study Association ◽  
Blood Flow Velocities ◽  
Flow Velocities

BackgroundCerebral autoregulation can be impaired after ischemic stroke, with potential adverse effects on cerebral blood flow during early rehabilitation.ObjectiveThe objective of this study was to assess changes in cerebral blood flow velocity with orthostatic variation at 24 hours after stroke.DesignThis investigation was an observational study comparing mean flow velocities (MFVs) at 30, 15, and 0 degrees of elevation of the head of the bed (HOB).MethodsEight participants underwent bilateral middle cerebral artery (MCA) transcranial Doppler monitoring during orthostatic variation at 24 hours after ischemic stroke. Computed tomography angiography separated participants into recanalized (artery completely reopened) and incompletely recanalized groups. Friedman tests were used to determine MFVs at the various HOB angles. Mann-Whitney U tests were used to compare the change in MFV (from 30° to 0°) between groups and between hemispheres within groups.ResultsFor stroke-affected MCAs in the incompletely recanalized group, MFVs differed at the various HOB angles (30°: median MFV=51.5 cm/s, interquartile range [IQR]=33.0 to 103.8; 15°: median MFV=55.5 cm/s, IQR=34.0 to 117.5; 0°: median MFV=85.0 cm/s, IQR=58.8 to 127.0); there were no significant differences for other MCAs. For stroke-affected MCAs in the incompletely recanalized group, MFVs increased with a change in the HOB angle from 30 degrees to 0 degrees by a median of 26.0 cm/s (IQR=21.3 to 35.3); there were no significant changes in the recanalized group (−3.5 cm/s, IQR=−12.3 to 0.8). The changes in MFV with a change in the HOB angle from 30 degrees to 0 degrees differed between hemispheres in the incompletely recanalized group but not in the recanalized group.LimitationsGeneralizability was limited by sample size.ConclusionsThe incompletely recanalized group showed changes in MFVs at various HOB angles, suggesting that cerebral blood flow in this group may be sensitive to orthostatic variation, whereas the recanalized group maintained stable blood flow velocities.

scholarly journals Changes in cerebral blood flow velocity in patients with hypothyroidism

2011 ◽  
Vol 165 (3) ◽  
pp. 465-468 ◽  
Author(s):  
Uygar Utku ◽  
Mustafa Gokce ◽  
Mesut Özkaya
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Hormone Replacement ◽  
Control Group ◽  
Control Groups ◽  
Blood Flow Velocities ◽  
Flow Velocities

BackgroundAt present, hypothyroidism is a well-known risk factor for cardiovascular disorders. The aim of this study was to assess the effects of hypothyroidism on cerebral blood flow velocity with transcranial Doppler (TCD) ultrasonography.Design and methodsIn this study, 30 subjects were enrolled for clinical, subclinical, and healthy control groups. Bilateral middle cerebral artery (MCA) peak-systolic, end-diastolic, and mean blood flow velocities; Gosling's pulsatility index values; and Pourcelot's resistance index values were recorded and compared with each other. TCD was performed in clinical hypothyroid patients after they became euthyroid with thyroid hormone replacement therapy (HRT). The initial and post-HRT results for the clinical hypothyroid group were then compared and evaluated.ResultsThere were 30 subjects in each group. Men/women ratio and mean age in clinical hypothyroid, subclinical hypothyroid, and control groups were 3/27, 4/26, and 5/25, and 37.4, 34.4, and 36.7 respectively. Peak-systolic, end-diastolic, and mean blood flow velocities of bilateral MCA were similar in clinical and subclinical hypothyroid groups but significantly higher when compared with the control group. After adequate thyroid HRT in clinical hypothyroid group, the peak-systolic, end-diastolic, and mean blood flow velocities were significantly decreased.ConclusionsIncreased cerebral blood flow velocities were observed in clinical and subclinical patients with hypothyroidism. The normalization of increased blood flow velocity with thyroid HRT suggests a reversible condition.

Head Position and Cerebral Blood Flow Velocity in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

2014 ◽  
Vol 37 (6) ◽  
pp. 401-408 ◽  
Author(s):  
Verónica V. Olavarría ◽  
Hisatomi Arima ◽  
Craig S. Anderson ◽  
Alejandro M. Brunser ◽  
Paula Muñoz-Venturelli ◽  
...  
Keyword(s):  
Systematic Review ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Meta Analysis ◽  
Head Position

Abstract TP160: The Increasing Treatment Pressure Of External Counterpulsation Continuously Augments Blood Pressure But Not Cerebral Blood Flow Velocity Of Ischemic Stroke Patients

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
WEN HUA LIN ◽  
Li Xiong ◽  
Jinghao Han ◽  
Thomas Leung ◽  
Yannie Soo ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Stroke Patients ◽  
External Counterpulsation ◽  
Treatment Pressure

Background: External counterpulsation (ECP) is a noninvasive method used to augment cerebral perfusion but the optimal use of ECP in ischemic stroke has not been well documented. We aim to investigate the effects of increasing ECP treatment pressure on cerebral blood flow and blood pressure (BP). Methods: We recruited 38 acute ischemic stroke patients with large artery occlusive disease and 20 healthy elderly. Mean cerebral blood flow velocities (CBFV) of bilateral middle cerebral artery were monitored using transcranial dopper. Continuous beat-to-beat BP was measured via finger cuffs. We started ECP treatment pressure from 150mmHg, then gradually increased to 187.5mmHg, 225mmHg and 262.5mmHg. CBFV and BP were recorded before ECP and during each pressure increment respectively for 3 minutes. CBFV data of patients was analyzed based on whether it was ipsilateral or contralateral to the infarct. Results: Median NIHSS of stroke patients was 5.5 and mean time after stroke onset was 5.24 days. Mean BP was significantly elevated from baseline in both groups after ECP started. BP increase percentages of two groups similarly kept augmented following raised ECP pressure and reach maximium at 262.5mmHg (patients 16.9% vs. controls 16.52% compared with baseline). Under different ECP pressures, ipsilateral mean CBFV of stroke patients increased 5.15% (150mmHg), 4.35% (187.5mmHg), 4.55% (225mmHg) and 3.52% (262.5mmHg) from baseline. All were significantly higher than baseline but did not differ among different pressures. Contralateral mean CBFV changed likewise (5.16%, 4.02%, 3.7% and 3.34% increase from baseline). Mean CBFV of controls under ECP pressures did not increase from baseline. Conclusion: The increasing treatment pressure of external counterpulsation continuously augments blood pressure but not cerebral blood flow velocity of ischemic stroke patients with large artery occlusive disease. Cerebral blood flow velocity of stroke patients significantly increases from baseline under ECP pressure of 150mmHg but it reaches a plateau as ECP pressure further raises. Among 4 ECP pressures above, 150mmHg is the optimal treatment pressure for ischemic stroke due to higher risks of hypertension-related complications in acute stroke with higher ECP pressure.

Cerebral Blood Flow Velocity Changes in Preterm Infants After a Single Dose of Indomethacin: Duration of Its Effect

PEDIATRICS ◽  
1989 ◽  
Vol 84 (5) ◽  
pp. 802-807
Author(s):  
Frank Van Bel ◽  
Margot Van de Bor ◽  
Theo Stijnen ◽  
Jan Baan ◽  
Jan H. Ruys
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Preterm Infant ◽  
Flow Velocity ◽  
Preterm Infants ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Cerebral Arteries ◽  
Mean Flow ◽  
Mean Flow Velocity

Indomethacin decreases cerebral blood flow velocity and blood flow in the preterm infant. The duration of this negative effect has not been established. Cerebral blood flow velocity was evaluated in 24 preterm infants with symptomatic patent ductus arteriosus before and during the first 12 hours after a single intravenous dose of indomethacin, 0.1 mg/kg. Cerebral blood flow velocity was estimated by serial Doppler investigations of the anterior cerebral arteries. Indomethacin administration led to an instantaneous decrease of peak systolic flow velocity, temporal mean flow velocity, and end-diastolic flow velocity of the anterior cerebral arteries in all infants, which was maximal between 2 and 40 minutes after indomethacin administration and was followed by a more sustained recovery of all velocities to baseline values. Temporal mean flow velocity was not different from pre-indomethacin values at 3 hours after the administration. It is concluded that indomethacin can impact the cerebral circulation of the preterm infant for at least 2 hours. This may have consequences in preterm infants with unstable hemodynarnics and pulmonary function.

Sign in / Sign up

Export Citation Format

Share Document