Articles: blood-flow-velocity-drug-effects.
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J Neurosurg Anesthesiol · Jul 2001
Randomized Controlled Trial Clinical TrialCerebral blood flow velocity response to magnesium sulfate in patients after subarachnoid hemorrhage.
Magnesium sulfate therapy, standard in preventing seizures in preeclampsia, is under active investigation as a neuroprotective agent. The authors studied the effect of magnesium as a cerebral vasodilator by measuring the cerebral blood flow velocity (CBFV) response to a 5g intravenous bolus of MgSO4 compared with a saline placebo after subarachnoid hemorrhage (SAH). Transcranial Doppler ultrasonography of the middle cerebral artery (MCA) was measured after each infusion. ⋯ Doubling serum magnesium levels did not affect MCA CBFV but slightly lowered mean arterial blood pressure and systemic vascular resistance. Intravenous magnesium bolus did not reduce elevated CBFV in the subset of SAH patients with clinical vasospasm. The role of magnesium sulfate as a cerebral vasodilator in patients with SAH requires further study.
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Evidence suggests that adenosine (ADN) is a potent vasodilator of cerebral vessels. However, the feasibility of manipulating human cerebral vascular resistance with ADN has not been assessed by means of TCD. The purpose of this study was to quantitatively estimate the change in middle cerebral artery cerebral blood flow velocity (CBFV) in response to intravenous ADN infusion in humans. ⋯ The authors hypothesize that any direct vasodilatory effect of ADN on the distal cerebral peripheral vasculature may be negated by an effect of ADN on depth of respiration resulting in hypocapnia and secondary distal vasoconstriction.
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Ann Thorac Cardiovasc Surg · Apr 2001
Comparative Study Clinical Trial Controlled Clinical TrialEffect of papaverine applications on blood flow of the internal mammary artery.
The aim of this prospective study was to compare the effect of different papaverine applications on the free blood flow in the internal mammary artery (IMA) prepared for coronary artery bypass grafting (CABG). The patients were divided into three groups: group I (n=50; intraluminal papaverine application), group II (n=50; topical papaverine application), and group III (n=50; periarterial papaverine application). The free flow from the distal cut end of the IMA was measured under controlled hemodynamic conditions (Flow 1). ⋯ After papaverine application, the mean blood flow in group I was 129.3+/-10.0 ml/min, in group II, it was 87.7+/-3.8 ml/min, and in group III, it was 130.6+/-9.2 ml/min (p<0.0001). Proportional increases in blood flow observed in group I (106.3%) and group III (116.2%) were higher than in group II (44.2%) (p<0.0001). Consequently, to relieve perioperative spasm of the IMA, application of papaverine injected into the periarterial tissues of its pedicle was considered to be a safe and effective alternative to topical or intraluminal application.
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This study examined possible caffeine-mediated changes in blood flow velocity in the middle cerebral artery (VMCA) induced by tests of cerebrovascular responsiveness. Transcranial Doppler (TCD) sonography provided simultaneous bilateral VMCA measures while healthy college students hypoventilated, hyperventilated, and performed cognitive activities (short-term remembering, generating an autobiographical image, solving problems), each in 31-second tests. ⋯ Time-course analyses showed that VMCA (1) followed a triphasic pattern to increase over baselines during hypoventilation regardless of caffeine condition, (2) slowed below baselines during hyperventilation (with the degree of slowing attenuated under caffeine), and (3) increased over baselines during all cognitive activities (ranges 3.8-6.9%). It is concluded that a large amount of caffeine can suppress VMCA, and this possibility should be anticipated when TCD is used to assess cerebral hemovelocity.
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Anticancer research · Sep 1999
Tumor blood flow modifying effect of electrochemotherapy with bleomycin.
Electrochemotherapy combines administration of the chemotherapeutic drug, followed by application of electric pulses in order to increase drug delivery into the cells. The aim of this study was to determine the tumor blood flow modifying effect of electrochemotherapy with bleomycin and correlate it with its antitumor effectiveness and extent of tumor necrosis. ⋯ The results indicate that Patent blue staining technique is a simple and reliable method for estimation of tumor blood flow and that antitumor effectiveness of electrochemotherapy with bleomycin could be partly attributed to its tumor blood modifying and anti-vascular effect.