Articles: blood-flow-velocity-drug-effects.
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Perioperative hypovolemia arises frequently and contributes to intestinal hypoperfusion and subsequent postoperative complications. Goal-directed fluid therapy might reduce these complications. The aim of this study was to compare the effects of goal-directed administration of crystalloids and colloids on the distribution of systemic, hepatosplanchnic, and microcirculatory (small intestine) blood flow after major abdominal surgery in a clinically relevant pig model. ⋯ Goal-directed colloid administration markedly increased microcirculatory blood flow in the small intestine and intestinal tissue oxygen tension after abdominal surgery. In contrast, goal-directed crystalloid and restricted crystalloid administrations had no such effects. Additionally, mesenteric venous glucose and lactate concentrations suggest that intestinal cellular substrate levels were higher in the colloid-treated than in the crystalloid-treated animals. These results support the notion that perioperative goal-directed therapy with colloids might be beneficial during major abdominal surgery.
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Nicardipine has been used to treat cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage. Intra-arterial (IA) infusion of high concentrations of nicardipine decreases procedure time, but it may affect hemodynamic parameters. In addition, a quantitative measurement of improvement of vessel diameter on the angiograms has not been performed. ⋯ High concentrations of IA nicardipine infusion have a reversible effect on blood pressure and heart rate. IA nicardipine results also in a significant improvement in vessel diameter in patients with vasospasm after aneurysmal subarachnoid hemorrhage.
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Occlusion or high grade stenosis of the internal carotid artery may be asymptomatic depending on the collateral patterns in the circle of Willis and the reserve capacity of the microvascular (arteriolar) system. The distensibility of the cerebral arterioles may be described quantitatively by the vasomotor reactivity. We present three patients with severe stenosis of an internal carotid artery associated with more severe stenosis or occlusion of the contralateral internal carotid artery. ⋯ Blood flow velocity decreased after acetazolamide administration in all patients in the middle cerebral arteries on the side of the more severe occlusive carotid disease, while increased on the contralateral side. We assume that the exhausted arteriolar system on the more severely affected side was not able to further dilate and the open collateral system could have driven blood towards the other side with preserved reserve capacity. The reduced blood flow velocity in the middle cerebral arteries after acetazolamide may reflect this intracerebral steal phenomenon.
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J. Diabetes Complicat. · Mar 2008
Randomized Controlled Trial Multicenter StudyEndothelial and neural regulation of skin microvascular blood flow in patients with diabetic peripheral neuropathy: effect of treatment with the isoform-specific protein kinase C beta inhibitor, ruboxistaurin.
This article aims to study the effects of ruboxistaurin (RBX) on skin microvascular blood flow (SkBF) and evaluate the relationship between endothelial and neural control of SkBF in patients with diabetic peripheral neuropathy (DPN). ⋯ RBX demonstrated no effect on SkBF or sensory symptoms after 1 year in this cohort. The correlation between C fiber-mediated and endothelium-dependent SkBF at baseline suggests that improving endothelial function could affect the microcirculation not only locally but also via the neurovascular arcade.
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Dexmedetomidine reduces cerebral blood flow (CBF) in humans and animals. In animal investigations, cerebral metabolic rate (CMR) was unchanged. Therefore, the authors hypothesized that dexmedetomidine would cause a decrease in the CBF/CMR ratio with even further reduction by superimposed hyperventilation. This reduction might be deleterious in patients with neurologic injuries. ⋯ The predicted decrease in CBFV/CMRe ratio was not observed because of an unanticipated reduction of CMRe and a decrease in the slope of the Paco2-CBFV relation. CBFV and Bispectral Index increases during arousal for hyperventilation at 1.2 ng/ml suggest that CMR-CBF coupling is preserved during dexmedetomidine administration. Further evaluation of dexmedetomidine in patients with neurologic injuries seems justified.