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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This is an open randomized study comparing the efficacy and safety of i.v. esmolol and labetalol in the treatment of perioperative hypertension in ambulatory surgery. Twenty-two elderly patients undergoing cataract surgery under local anaesthesia were studied. The main inclusion criteria were development of systolic blood pressure greater than 200 mmHg or diastolic greater than 100 mmHg. Esmolol was given as a bolus 500 micrograms.kg-1 i.v. followed by a maintenance infusion (150-300 micrograms.kg-1.min-1). Labetalol was given as a bolus of 5 mg i.v. followed by 5 mg increments as needed up to a maximum of 1 mg.kg-1. Esmolol and labetalol both produced reductions in systolic and diastolic blood pressure (P less than 0.05) within ten minutes of administration which lasted for at least two hours. Reduction of blood pressure by esmolol was accompanied by a decrease in HR (P less than 0.05). Two patients developed extreme bradycardia (HR less than 50 beats.min-1) and esmolol had to be discontinued. Labetalol, in contrast, induced only a moderate decrease in HR. None of the patients treated with labetalol experienced any prolonged side effects such as orthostatic hypotension. In conclusion, esmolol may produce considerable bradycardia in elderly patients when hypertension is not accompanied by tachycardia. Labetalol was easier to administer in the ambulatory setting and one-tenth the cost of esmolol.
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PMID:A comparison of esmolol and labetalol for the treatment of perioperative hypertension in geriatric ambulatory surgical patients. 135 8

Laryngoscopy and intubation cause an adrenergic response manifested by tachycardia and hypertension. Various pharmacological agents, including fentanyl, have been administered prior to induction in an attempt to attenuate the adrenergic response but they all have limitations. Esmolol, an ultrashort-acting cardioselective beta blocker, has been administered by infusion to successfully protect surgical patients from the stresses of intubation. The objective of our study was to determine if esmolol would be equally effective when administered in a bolus with and without fentanyl. Forty-four ASA I and II females undergoing elective surgery were randomly divided into four groups and received the following agents prior to intubation: Group 1-esmolol 1 mg/kg and fentanyl 2 micrograms/kg, Group 2-placebo (normal saline), Group 3-esmolol 1 mg/kg and Group 4-fentanyl 3.5 micrograms/kg. Groups 1 and 4, which received fentanyl, demonstrated significantly less elevation in blood pressure. Esmolol appeared to attenuate increases in heart rate. Esmolol has a tissue distribution time of 2 minutes and an elimination half-life of 9 minutes. The window of its availability to the tissues is narrow, and timing of bolus administration is more critical than in administration by infusion. Doses in excess of 1 mg/kg appear to be necessary for effective control of heart rate. However, when used with fentanyl, esmolol provides effective protection against the adrenergic response to laryngoscopy and intubation.
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PMID:Evaluation of esmolol and fentanyl in controlling increases in heart rate and blood pressure during endotracheal intubation. 167 49

The pharmacokinetics and concentration-response relationships of intravenous esmolol were investigated in 20 children undergoing indicated cardiac electrophysiologic testing. A loading dose of 600 micrograms/kg was infused for 2 minutes. An infusion of esmolol was initiated and dosage was titrated until beta-blockade occurred. Serial esmolol blood samples were obtained for pharmacokinetic analysis. Non-compartmental pharmacokinetic analysis of the data revealed the following parameter estimates (mean +/- SD): volume of distribution at steady state, 2.0 +/- 1.4 L/kg; total body clearance, 321.2 +/- 238.8 ml/kg/min; and terminal elimination half-life, 4.5 +/- 2.1 minutes. There was a significant correlation between mean esmolol concentrations and mean percentage of reductions of mean arterial pressures and heart rates at each sample time (p less than 0.001). The doses of esmolol required for beta-blockade (mean +/- SD, 535 +/- 180 micrograms/kg/min) in children were considerably higher than those typically used in adults. Esmolol should prove useful in children in the acute management of cardiac arrhythmias and hypertension.
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PMID:Pharmacokinetics of esmolol in children. 167 57

Electroconvulsive therapy (ECT) under anesthesia is associated with hypertension and tachycardia. The cardiovascular effects of ECT were studied after pre-treatment of 10 patients with esmolol (1.0 mg/kg), fentanyl (1.5 micrograms/kg), labetalol (0.3 mg/kg), lidocaine (1.0 mg/kg), and saline solution (control), using a double-blind, randomized block-design. Each patient received all five pretreatment regimens over the course of five ECT sessions. During control studies, arterial blood pressure and heart rate increased significantly in all patients after ECT (P less than 0.05 and P less than 0.01, respectively). The rate-pressure product increased by an average of 336% +/- 14% (P less than 0.01). There were appreciable individual differences in the cardiovascular response to ECT, independent of pretreatment (P less than 0.01). Pretreatment with esmolol and labetalol significantly reduced the hemodynamic response to ECT, compared with fentanyl, lidocaine, or saline solution (P less than 0.05). Esmolol attenuated arterial blood pressure to a larger extent than did labetalol (P less than 0.05). Compared with saline solution (control), pretreatment with labetalol, fentanyl, or lidocaine significantly reduced seizure duration (P less than 0.05) and increased the frequency with which a second electrical stimulus was required. In contrast, esmolol pretreatment did not significantly affect seizure duration. Esmolol (1 mg/kg), administered 1 min before induction of anesthesia, produced significant amelioration of the cardiovascular response to ECT with minimal effect on seizure duration.
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PMID:Prevention of the cardiovascular and neuroendocrine response to electroconvulsive therapy: I. Effectiveness of pretreatment regimens on hemodynamics. 195 35

Beta-adrenoceptor antagonists (BB) demonstrate a competitive antagonism with endogenous catecholamines. Beta-1 receptor blockade mediates the depressive action on contractility, heart rate and atrio-ventricular conduction. Beta-2 receptor blockade mediates vascular, bronchial and uterine smooth muscle constriction. BB with beta-1 selective and intrinsec sympathomimetic activity do not increase systemic vascular resistance. BB are mostly used to treat ischaemic heart disease, hypertension and arrhythmias. Bradycardia, hypotension and bronchospasm are the main hazards in BB treated patients undergoing anaesthesia. However giving BB with premedication to patients taking usely this treatment allows better perioperative haemodynamic stability and avoids rebound effect. Experimentally, oxprenolol reverses regional dysfunction in ischaemic myocardium under halothane anaesthesia. During and after anaesthesia, intravenous (i.v.) BB must be used with caution to treat hypertension associated with tachycardia. In controlled hypotension, i.v. BB potentialise other agents. In phaechromocytoma surgery, alpha-blocking drugs are essential but additional BB can control tachycardia successfully. In coronary artery bypass surgery, giving BB prior to induction decreases cardiac enzymes serum levels. Esmolol, a new ultra-short-acting BB, would control perioperative tachycardia and hypertension without risk of prolonged cardiac depression.
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PMID:[Beta blockers and anesthesia]. 197 29

Esmolol, administered as a bolus followed by continuous infusion, was used to treat the occurrence of transient tachycardia and hypertension or tachycardia alone before cardiopulmonary bypass in 45 patients. The study was conducted in two phases. Phase I (15 patients) was a dose-finding study and phase II (30 patients) was a randomized, double-blind, placebo-controlled efficacy study. All patients received the last dose of their usual beta-adrenergic blocker the night before the operation and were anesthetized with midazolam, vecuronium, and enflurane in oxygen. Treatment criteria were either a systolic blood pressure greater than 140 mm Hg and a heart rate greater than 70 or a heart rate greater than 80 beats/min. In phase I, graduated doses of esmolol were given to successive patients. A dose of 80 mg followed by a 12 mg/min infusion was declared effective. Phase II patients were randomized to receive esmolol (n = 16) or placebo (n = 14). Hemodynamic data were collected at baseline and 1, 3, 5, and 10 minutes after the administration of esmolol. Plasma norepinephrine was measured at baseline, 1, and 10 minutes. Esmolol significantly (p less than 0.05) reduced heart rate at 1, 3, 5, and 10 minutes but did not change blood pressure, pulmonary artery diastolic pressure, right atrial pressure, cardiac output, or systemic vascular resistance. Our results show that a bolus loading dose of esmolol is safe and effective in the treatment of tachycardia in patients with ischemic heart disease and that esmolol rapidly blocks the beta-adrenergic effects of norepinephrine associated with surgical stress.
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PMID:Esmolol for treatment of intraoperative tachycardia and/or hypertension in patients having cardiac operations. Bolus loading technique. 197 64

The efficacy of a single bolus dose of esmolol in the prevention of intubation-induced tachycardia and hypertension was studied in a double-blind manner. Thirty patients from the Ambulatory Surgery Unit at Rush-Presbyterian-St. Luke's Medical Center were prospectively randomized to receive a placebo, 100 mg of esmolol, or 200 mg of esmolol immediately prior to induction (2.5 to 3.0 minutes before intubation). The groups were similar in demographic characteristics and with regard to preoperative blood pressure (BP) and heart rate (HR). Anesthetic management was standardized for all patients. Esmolol 100 mg (1.4 +/- 0.3 mg/kg) and 200 mg (2.6 +/- 0.7 mg/kg) significantly (p less than 0.05) blunted the maximum increases in HR and BP following intubation. The average maximum HR increase in the placebo group was 40% as opposed to 16% in the esmolol 100 mg group and 14% in the esmolol 200 mg group. Both esmolol groups blunted the tachycardic response over a 4-minute postintubation time period. The average maximum BP increase was 47% in the placebo group versus 22% and 19% in the esmolol 100 mg and esmolol 200 mg groups, respectively. There were no significant differences between the two esmolol groups. This study demonstrates the efficacy of a single bolus dose of esmolol in blunting the tachycardic and hypertensive responses to laryngoscopy and intubation in an ambulatory surgery setting.
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PMID:A single bolus dose of esmolol in the prevention of intubation-induced tachycardia and hypertension in an ambulatory surgery unit. 197 86

We report the successful treatment with esmolol of intraoperative myocardial ischaemia associated with concurrent hypertension and tachycardia, in a patient with risk factors for coronary artery disease undergoing peripheral vascular surgery. The pathophysiology of myocardial ischaemia, and the therapeutic role of beta blocking drugs are briefly reviewed. Esmolol, a short-acting cardioselective beta blocking drug, was administered in a bolus of 1.5 mg.kg-1, and resulted in prompt resolution of the haemodynamic abnormalities, with concomitant restitution of the ST segments to isoelectric baseline. We conclude that bolus administration of esmolol is practical and can be effective for the treatment of intraoperative myocardial ischaemia.
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PMID:Bolus administration of esmolol for the treatment of intraoperative myocardial ischaemia. 232 81

The pharmacological properties of centrally acting alpha2-receptor agonists such as clonidine suggest a potentially important role as ideal adjuvants for anesthesia since they produce sedation, analgesia anxiolysis, xerostomia and cardiovascular stability without respiratory depression, development of tolerance or addiction liability. Further clinical experience with this exciting development will undoubtedly establish the ultimate role and optimal use of alpha2 -receptor agonists in anesthetic practice. Beta-blockage can result in significant bradycardia, atrial ventricular conduction problems, bronchospasm and left ventricular contractile dysfunction. Thus, the use of long-acting beta-blockers is of limited value in the perioperative period. Esmolol, because of its ultrashort action, cardioselective properties and titratability, has been shown to be safe and effective for the treatment of tachycardia and hypertension. Doses from 50 to 300 micrograms/kg/min for up to 7 hours in the perioperative period have been shown to cause no apparent cumulative effect. It has been used in the treatment of asthmatic patients with tachycardia and hypertension without significant increases in airway resistance. Studies using esmolol during general anesthesia have demonstrated no significant interaction with several anesthetic regimens.
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PMID:Clinical pharmacology of alpha2-agonist and beta-adrenergic blocker. 257 80

Stressful surgical stimuli, such as endotracheal intubation, surgical incision, organ manipulation and emergence from anesthesia, elicit adrenergic responses that precipitate transient but intense increases in heart rate and blood pressure. Although this response is well tolerated in healthy patients, patients with ischemic heart disease are at significant risk of myocardial ischemia and infarction owing to the sudden increase in myocardial oxygen demand. Parenteral beta blockers are effective in blunting this adrenergic response, but the duration of action of these agents is long-lasting and the degree of beta blockade is often difficult to predict. Further, long-acting parenteral beta blockers may cause adverse effects, the reversal of which presents a difficult clinical problem in patients with ischemic heart disease. The availability of esmolol, an ultrashort-acting parenteral beta-adrenergic antagonist with a half-life of 9 minutes, brings obvious advantages to the perioperative management of hypertension and tachycardia. With esmolol treatment, the difficulties of therapy with long-lasting beta blockers are avoided. Also, to blunt the adrenergic response, the anesthesiologist will have an alternative to increasing the depth of anesthesia, which can accentuate cardiovascular depression and prolong awakening and postoperative respiratory depression. Clinical studies performed during the perioperative period reveal that esmolol is safe and effective in this setting. Esmolol has been shown to be safe and efficacious in patients in ASA classifications I through IV and patients undergoing carotid endarterectomy and coronary artery bypass surgery. The pharmacokinetic profile, rapid onset and elimination half-life make this agent particularly well suited to treat the very intense but transient adrenergic responses to surgical stress in patients undergoing cardiac and noncardiac surgery.
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PMID:Perioperative use of esmolol. 286 50


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