The Experts below are selected from a list of 6 Experts worldwide ranked by ideXlab platform
Franz H. Messerli - One of the best experts on this subject based on the ideXlab platform.
-
Comparative Tolerability Profile of Hypertensive Crisis Treatments
Drug Safety, 1998Co-Authors: Ehud Grossman, Avi N. Ironi, Franz H. MesserliAbstract:Hypertensive crisis is defined as a severe elevation in BP and is classified as either urgency or emergency. In hypertensive urgency there is no end-organ injury and no evidence that acute BP lowering is beneficial. Indeed, rapid uncontrolled pressure reduction may be harmful. Therefore, in hypertensive urgencies BP should be lowered gradually over 24 to 48 hours using oral antihypertensives. When the cause of transient BP elevations is easily identified, appropriate treatment should be given. When the cause is unknown, an oral antihypertensive should be given. The efficacy of available treatments appear similar; however, the underlying pathophysiological and clinical findings, mechanism of action and potential for adverse effects should guide choice. Captopril should be avoided in patients with bilateral renal artery stenosis or unilateral renal artery stenosis in patients with a solitary kidney. Nifedipine and other dihydropyridines increase heart rate whereas Clonidine, β-blockers and labetalol tend to decrease it. This is particularly important in patients with ischaemic heart disease. Labetalol and β-blockers are contraindicated in patients with bronchospasm and bradycardia or heart blocks. Clonidine should be avoided if mental acuity is desired. In hypertensive emergency there is an immediate threat to the integrity of the cardiovascular system. BP should be immediately reduced to avoid further end organ damage. Sodium nitroprusside is the most popular agent. Nitroglycerin (glyceryl trinitrate) is preferred when there is acute coronary insufficiency. A β-blocker may be added in some patients. Loop diuretics, nitroglycerin and sodium nitroprusside are effective in patients with concomitant pulmonary oedema. Enalaprilat is also theoretically helpful, especially when the renin system might be activated. Initial treatment of aortic dissection involves rapid, controlled titration of arterial pressure to normal levels using intravenous sodium nitroprusside and a β-blocker. If β-blockers are contraindicated, Urapidil or Trimetaphan Camsilate are alternatives. Hydralazine is the drug of choice for patients with eclampsia. Labetalol, Urapidil or calcium antagonists are possible alternatives if hydralazine fails or is contraindicated. For patients with catecholamine-induced crises, an α-blocker such as phentolamine should be given; labetalol or sodium nitroprusside with β-blockers are alternatives. There are few, if any, comparative or randomised trials providing definitive conclusions about the efficacy and safety of comparative agents. Some investigators recommend decreasing the diastolic BP to no less than 100 to 110mm Hg. A reasonable approach for most patients with hypertensive emergencies is to lower the mean arterial pressure by 25% over the initial 2 to 4 hours with the most specific antihypertensive regimen.
Ehud Grossman - One of the best experts on this subject based on the ideXlab platform.
-
Comparative Tolerability Profile of Hypertensive Crisis Treatments
Drug Safety, 1998Co-Authors: Ehud Grossman, Avi N. Ironi, Franz H. MesserliAbstract:Hypertensive crisis is defined as a severe elevation in BP and is classified as either urgency or emergency. In hypertensive urgency there is no end-organ injury and no evidence that acute BP lowering is beneficial. Indeed, rapid uncontrolled pressure reduction may be harmful. Therefore, in hypertensive urgencies BP should be lowered gradually over 24 to 48 hours using oral antihypertensives. When the cause of transient BP elevations is easily identified, appropriate treatment should be given. When the cause is unknown, an oral antihypertensive should be given. The efficacy of available treatments appear similar; however, the underlying pathophysiological and clinical findings, mechanism of action and potential for adverse effects should guide choice. Captopril should be avoided in patients with bilateral renal artery stenosis or unilateral renal artery stenosis in patients with a solitary kidney. Nifedipine and other dihydropyridines increase heart rate whereas Clonidine, β-blockers and labetalol tend to decrease it. This is particularly important in patients with ischaemic heart disease. Labetalol and β-blockers are contraindicated in patients with bronchospasm and bradycardia or heart blocks. Clonidine should be avoided if mental acuity is desired. In hypertensive emergency there is an immediate threat to the integrity of the cardiovascular system. BP should be immediately reduced to avoid further end organ damage. Sodium nitroprusside is the most popular agent. Nitroglycerin (glyceryl trinitrate) is preferred when there is acute coronary insufficiency. A β-blocker may be added in some patients. Loop diuretics, nitroglycerin and sodium nitroprusside are effective in patients with concomitant pulmonary oedema. Enalaprilat is also theoretically helpful, especially when the renin system might be activated. Initial treatment of aortic dissection involves rapid, controlled titration of arterial pressure to normal levels using intravenous sodium nitroprusside and a β-blocker. If β-blockers are contraindicated, Urapidil or Trimetaphan Camsilate are alternatives. Hydralazine is the drug of choice for patients with eclampsia. Labetalol, Urapidil or calcium antagonists are possible alternatives if hydralazine fails or is contraindicated. For patients with catecholamine-induced crises, an α-blocker such as phentolamine should be given; labetalol or sodium nitroprusside with β-blockers are alternatives. There are few, if any, comparative or randomised trials providing definitive conclusions about the efficacy and safety of comparative agents. Some investigators recommend decreasing the diastolic BP to no less than 100 to 110mm Hg. A reasonable approach for most patients with hypertensive emergencies is to lower the mean arterial pressure by 25% over the initial 2 to 4 hours with the most specific antihypertensive regimen.
Avi N. Ironi - One of the best experts on this subject based on the ideXlab platform.
-
Comparative Tolerability Profile of Hypertensive Crisis Treatments
Drug Safety, 1998Co-Authors: Ehud Grossman, Avi N. Ironi, Franz H. MesserliAbstract:Hypertensive crisis is defined as a severe elevation in BP and is classified as either urgency or emergency. In hypertensive urgency there is no end-organ injury and no evidence that acute BP lowering is beneficial. Indeed, rapid uncontrolled pressure reduction may be harmful. Therefore, in hypertensive urgencies BP should be lowered gradually over 24 to 48 hours using oral antihypertensives. When the cause of transient BP elevations is easily identified, appropriate treatment should be given. When the cause is unknown, an oral antihypertensive should be given. The efficacy of available treatments appear similar; however, the underlying pathophysiological and clinical findings, mechanism of action and potential for adverse effects should guide choice. Captopril should be avoided in patients with bilateral renal artery stenosis or unilateral renal artery stenosis in patients with a solitary kidney. Nifedipine and other dihydropyridines increase heart rate whereas Clonidine, β-blockers and labetalol tend to decrease it. This is particularly important in patients with ischaemic heart disease. Labetalol and β-blockers are contraindicated in patients with bronchospasm and bradycardia or heart blocks. Clonidine should be avoided if mental acuity is desired. In hypertensive emergency there is an immediate threat to the integrity of the cardiovascular system. BP should be immediately reduced to avoid further end organ damage. Sodium nitroprusside is the most popular agent. Nitroglycerin (glyceryl trinitrate) is preferred when there is acute coronary insufficiency. A β-blocker may be added in some patients. Loop diuretics, nitroglycerin and sodium nitroprusside are effective in patients with concomitant pulmonary oedema. Enalaprilat is also theoretically helpful, especially when the renin system might be activated. Initial treatment of aortic dissection involves rapid, controlled titration of arterial pressure to normal levels using intravenous sodium nitroprusside and a β-blocker. If β-blockers are contraindicated, Urapidil or Trimetaphan Camsilate are alternatives. Hydralazine is the drug of choice for patients with eclampsia. Labetalol, Urapidil or calcium antagonists are possible alternatives if hydralazine fails or is contraindicated. For patients with catecholamine-induced crises, an α-blocker such as phentolamine should be given; labetalol or sodium nitroprusside with β-blockers are alternatives. There are few, if any, comparative or randomised trials providing definitive conclusions about the efficacy and safety of comparative agents. Some investigators recommend decreasing the diastolic BP to no less than 100 to 110mm Hg. A reasonable approach for most patients with hypertensive emergencies is to lower the mean arterial pressure by 25% over the initial 2 to 4 hours with the most specific antihypertensive regimen.
Hiroaki Takahashi - One of the best experts on this subject based on the ideXlab platform.
-
Effects of a depressor on cochlear blood flow and perilymphatic oxygen tension.
Acta oto-laryngologica, 1991Co-Authors: Michiro Kawakami, Kazuo Makimoto, Shinya Fukuse, Hiroaki TakahashiAbstract:To clarify the characteristics of the blood circulation in the cochlea, we investigated the relationship between cochlear blood flow and perilymphatic oxygen tension in guinea pigs with Trimetaphan Camsilate induced hypotension. Cochlear blood flow was measured by laser Doppler flowmetry, and perilymphatic oxygen tension by a polarographic method. Cochlear blood flow generally paralleled systemic blood pressure, while perilymphatic oxygen tension showed a slower response to the decrease of systemic blood pressure. Although there were individual differences in the changes of systemic blood pressure, cochlear blood flow and perilymphatic oxygen tension, they were found to be dose dependent. Since hypotension induced by Trimetaphan Camsilate is fairly reproducible in the dose range of this experiment, this drug can be used as a ganglion blocking agent in experiments on cochlear blood flow and perilymphatic oxygen tension during systemic hypotension. The change of perilymphatic oxygen tension with a slower response could be considered to be a factor in the homeostasis in the inner ear fluid.
Michiro Kawakami - One of the best experts on this subject based on the ideXlab platform.
-
Effects of a depressor on cochlear blood flow and perilymphatic oxygen tension.
Acta oto-laryngologica, 1991Co-Authors: Michiro Kawakami, Kazuo Makimoto, Shinya Fukuse, Hiroaki TakahashiAbstract:To clarify the characteristics of the blood circulation in the cochlea, we investigated the relationship between cochlear blood flow and perilymphatic oxygen tension in guinea pigs with Trimetaphan Camsilate induced hypotension. Cochlear blood flow was measured by laser Doppler flowmetry, and perilymphatic oxygen tension by a polarographic method. Cochlear blood flow generally paralleled systemic blood pressure, while perilymphatic oxygen tension showed a slower response to the decrease of systemic blood pressure. Although there were individual differences in the changes of systemic blood pressure, cochlear blood flow and perilymphatic oxygen tension, they were found to be dose dependent. Since hypotension induced by Trimetaphan Camsilate is fairly reproducible in the dose range of this experiment, this drug can be used as a ganglion blocking agent in experiments on cochlear blood flow and perilymphatic oxygen tension during systemic hypotension. The change of perilymphatic oxygen tension with a slower response could be considered to be a factor in the homeostasis in the inner ear fluid.
