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

Esmolol is the first intravenous, short-acting, titratable beta-blocker available for use in critical care and surgical settings. The predominant pharmacodynamic actions of the drug include a reduction in HR, BP, rate-pressure product, LVEF, and cardiac index. A desirable pharmacokinetic feature of esmolol is its esterase-induced rapid metabolic inactivation, which results in a return of all hemodynamic parameters to pretreatment levels within 30 minutes after discontinuation of the infusion. Control over the magnitude and duration of beta-blockade and the relative cardioselectivity of esmolol make it an ideal agent for use in critically ill patients, including those who, because of other conditions, are at risk if treated with beta-blockers. The clinical indications for esmolol therapy include SVT and perioperative tachycardia and hypertension. In patients with myocardial ischemic conditions (acute myocardial infarction and unstable angina), esmolol was safe and produced clinically significant reductions in HR and rate-pressure product. In general, untoward reactions to esmolol have been minimal, mild, and transient. Although attention must be given to the possibility of systolic hypotension during esmolol administration, this complication often occurs at doses beyond those which provide optimal therapeutic response and may be avoided by titrating to the minimal effective dose. If systolic hypotension occurs, it is reversible by either reducing the dose or discontinuing the esmolol infusion. A nursing plan of care should be developed for patients receiving esmolol therapy. Dosage and administration must be individualized. Careful titration of the esmolol infusion and monitoring of therapeutic and safety parameters by nursing professionals will promote the achievement of maximum beta-blocker effect while avoiding persistent and unnecessary adverse reactions.
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PMID:Esmolol, the first ultra-short-acting intravenous beta blocker for use in critically ill patients. 327 51

Hypertensive emergencies are uncommon and physiologically diverse. Consequently, it is difficult for most physicians to develop a familiarity with all the different hypertensive crises and with all drugs available for treating them (Table 4). Clinicians should not agonize over which is the perfect therapeutic agent for a particular emergency, but instead, they should focus on scrupulous monitoring and familiarize themselves with a few agents that will serve in most situations. Generally, these agents will be sodium nitroprusside and nitroglycerin. Vigilant neurologic monitoring is mandatory in all hypertensive emergencies. The early symptoms and signs of cerebral hypoperfusion can be vague and subtle, but if recognized, serious complications of therapy can be avoided. Remember, the patient may still be hypertensive. Avoid acute (during the first hour) reductions in MAP of more than 20% whenever possible; subsequent reductions should be gradual. In patients known to have markedly elevated ICP and who need acute reductions in their BP, serious consideration should be given to direct monitoring of the ICP so that CPP can be maintained within safe limits. In general, oral agents should not be used for the treatment of hypertensive emergencies. Intravenous Labetalol and intravenous nicardipine are not suitable for general use in hypertensive emergencies. In special situations (e.g., perioperative hypertension and subarachnoid hemorrhage), however, they may be employed. Their role may expand with further study. Trimethaphan may be superior to nitroprusside for hypertension complicated by elevated ICP or cerebral dysfunction. Realistically, most physicians will continue to use nitroprusside. Intense neurologic monitoring is more important than the specific agent used. Nitroglycerin is the agent of choice for acute ischemic heart disease complicated by severe hypertension; if it fails, use nitroprusside. For aortic dissection, the combination of nitroprusside and IV propranolol is the therapy of choice; beta-blockade must be achieved rapidly or the dissection may worsen. Trimethaphan is also an agent for first-line therapy. Esmolol is an alternative to IV propranolol for the treatment of aortic dissection, if prolonged beta-blockade might seriously jeopardize the patient. For eclampsia, unless an expert in hypertension during pregnancy has established an alternative, the therapy of choice is hydralazine and magnesium. The treatment of subarachnoid hemorrhage is in flux; calcium channel blockers are used to prevent spasm, not to lower BP. If the BP must be lowered immediately, use nitroprusside.
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PMID:Hypertensive emergencies. 758 98

Esmolol is a unique cardioselective, intravenous, ultra-short acting, beta-adrenergic blocking agent. A 9-minute half-life with rapid clinical onset and offset of action and the ability to titrate the drug to changing circumstances makes esmolol a useful addition to our treatment armamentarium. The efficacy and safety of esmolol have been shown in specific clinical settings, i.e. in patients with unstable angina, myocardial infarction, atrial fibrillation or flutter and supraventricular tachycardia. In the emergency management of hypertension, tachycardia or arrhythmia in critical care units, emergency room and surgery, esmolol is effective by attenuating hemodynamic responses from sympathetic activation or endogenous catecholamine release. With careful titration and monitoring of the patient, esmolol is relatively safe in the management of hypertension or tachyarrhythmias associated with congestive heart failure or chronic obstructive lung disease where beta-blockers are otherwise contraindicated. Different dosage schedules have been employed as per the clinical setting and the diagnosis. Generally, esmolol is infused intravenously in doses ranging from 25-300 micrograms/kg/min, along with a loading dose or bolus. The most frequently reported adverse effect associated with esmolol infusion was hypotension. Adverse effects due to beta-blockade can be corrected by down-titrating or discontinuing the infusion with complete disappearance of clinical effects in 20-30 minutes. Therefore, as an ultra-short acting beta-blocker, esmolol is an important therapeutic option in the acute clinical setting.
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PMID:Clinical rationale for the use of an ultra-short acting beta-blocker: esmolol. 762 Jun 91

Esmolol is an ultra short-acting intravenous cardioselective beta-antagonist. It has an extremely short elimination half-life (mean: 9 minutes; range: 4 to 16 minutes) and a total body clearance [285 ml/min/kg (17.1 L/h/kg)] approaching 3 times cardiac output and 14 times hepatic blood flow. The alpha-distribution half-life is approximately 2 minutes. When esmolol is administered as a bolus followed by a continuous infusion, onset of activity occurs within 2 minutes, with 90% of steady-state beta-blockade occurring within 5 minutes. Full recovery from beta-blockade is observed 18 to 30 minutes after terminating the infusion. Esmolol blood concentrations are undetectable 20 to 30 minutes postinfusion. The elimination of esmolol is independent of renal or hepatic function as it is metabolised by red blood cell cytosol esterases to an acid metabolite and methanol. The acid metabolite, which is renally eliminated, has 1500-fold less activity than esmolol. Methanol concentrations remain within the range of normal endogenous levels. Clinically, esmolol is used for the following: (i) situations where a brief duration of adrenergic blockade is required, such as tracheal intubation and stressful surgical stimuli; and (ii) critically ill or unstable patients in whom the dosage of esmolol is easily titrated to response and adverse effects are rapidly managed by termination of the infusion. In adults, bolus doses of 100 to 200mg are effective in attenuating the adrenergic responses associated with tracheal intubation and surgical stimuli. For the control of supraventricular arrhythmias, acute postoperative hypertension and acute ischaemic heart disease, doses of < 300 micrograms/kg/min, administered by continuous intravenous infusion, are used. The principal adverse effect of esmolol is hypotension (incidence of 0 to 50%), which is frequently accompanied with diaphoresis. The incidence of hypotension appears to increase with doses exceeding 150 micrograms/kg/min and in patients with low baseline blood pressure. Hypotension infrequently requires any intervention other than decreasing the dose or discontinuing the infusion. Symptoms generally resolve within 30 minutes after discontinuing the drug. In surgical and critical care settings where clinical conditions are rapidly changing, the pharmacokinetic profile of esmolol allows the drug to provide rapid pharmacological control and minimises the potential for serious adverse effects.
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PMID:Esmolol. A review of its therapeutic efficacy and pharmacokinetic characteristics. 775 50

In addition to laryngoscopy, endotracheal intubation, and other stressful intraoperative phases, hypertension occurs during recovery from anaesthesia, provoking post-operative complications like bleeding and increased intracranial or intraocular pressure. Furthermore, these hypertensive reactions result in life-threatening complications, especially in patients with pre-existing cardiovascular diseases. In this study, the effect of the new, short-acting beta-blocker esmolol given as a single bolus for preventing the increases in blood pressure and heart rate during recovery from anaesthesia and extubation in patients with hypertension was investigated. PATIENTS AND METHODS. Sixty-three patients with a history of hypertension over a period of more than 6 months and blood pressure (BP) more than 150/90 mm Hg undergoing intervertebral-disc, otolaryngologic, or eye surgery were included in the study. The operations were performed during thiopentone-induced isoflurane anaesthesia with relaxation by atracurium. The patients were assigned to three groups after giving witnessed oral informed consent. During the study period they received the study drug twice: (A) 30-90 s before turning off the nitrous oxide; and (B) 20-90 s before extubation. Group I (placebo) received placebo each time, group II (100 mg esmolol) placebo at A and 100 mg esmolol i.v. at B, and group III (200 mg esmolol) 100 mg esmolol i.v. each time. After each medication the cardiovascular parameters were measured noninvasively over a period of 10 min every minute and in the following 2 h every 15 min. RESULTS. After the first medication systolic and diastolic BP, heart rate (HR), and rate-pressure product (RPP) were lower in patients receiving 100 mg esmolol (Group III) than in groups I and II. After the second injection the blood pressure was lower in the two groups receiving 100 mg esmolol, than the placebo group (I: 180.1 +/- 7.4/100.7 +/- 3.6; II: 152.8 +/- 5.8/87.9 +/- 3.4; III: 157.9 +/- 5.3/91.5 +/- 3.6 mm Hg [mean 2 min +/- SEM]). The changes in HR (I: 88.2 +/- 3.8; II: 75.6 +/- 2.6; III: 72 +/- 3.1 min-1) and RPP (I: 15,800 +/- 900; II: 11,700 +/- 700; III: 11,400 +/- 600) were similar. In 8 of the 20 patients in group III the HR dropped below 60.min-1, but in none of these patients did the BP become instable. CONCLUSIONS. The sympathoadrenergic reaction during recovery from anaesthesia and extubation can be treated by beta-blocking agents, but such therapy is not without risk because of the long half-life and effects of the therapy on other factors such as postoperative loss of intravascular volume. Esmolol is a new, short-acting, cardioselective beta-blocker with a very short plasma distribution time and a elimination half-life of 9.2 min. Thus, the potential risks of beta-blockers due to half-life are minimised. The results of this study show that a dangerous increase in BP and HR with increased myocardial oxygen consumption can be prevented by a single bolus, and better by a double bolus of 100 mg esmolol. Although bradycardia with HR below 50.min-1 in 8 patients might indicate a risk of cardiac instability, the systolic BP did not fall below 100 mm Hg, and the episode of bradycardia was so short that there was no risk to the patients.
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PMID:[Esmolol as a bolus for prevention of sympathetic adrenergic reactions following induction of anesthesia]. 784 Apr

Esmolol is an ultra-short-acting beta-blocker that is widely used to lower blood pressure in acute settings intraoperatively and in patients with hypertension. Other beta-blockers have not been used in this way because of the belief that beta-blockers do not acutely lower blood pressure. The purpose of this study was to determine if esmolol has a hypotensive effect that is greater than other beta-blockers at similar degrees of beta-blockade. Esmolol, metoprolol, and propranolol were administered intravenously at three doses chosen to produce comparable degrees of beta-blockade. In spite of achieving comparable beta-blockade, esmolol produced a greater reduction in blood pressure than the other beta-blockers, implying that the hypotensive effect of esmolol cannot be accounted for simply by beta-blockade. There was no evidence to support a direct vasodilatory action of esmolol, and esmolol did not lower plasma norepinephrine concentrations.
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PMID:Beta-receptor antagonism does not fully explain esmolol-induced hypotension. 791 45

Tachycardia and hypertension usually accompany laryngoscopy and tracheal intubation. This response is undesirable, especially in patients with cardiovascular or intracranial diseases. Esmolol is a cardioselective, ultrashort-acting beta adrenergic blocking agent with a very short half-life. The efficacy of bolus dose of esmolol in blunting hemodynamic responses during laryngoscopy and tracheal intubation was evaluated. 45 patients (15 in each group) of ASA physical status I and II scheduled for elective non-cardiac surgery were included in this randomized, placebo-controlled study. At time zero, the study preparation (placebo, 100 or 200 mg of esmolol) was administered intravenously, followed by thiopentone 5 mg/kg and succinylcholine 1.5 mg/kg for induction. Tracheal intubation was performed 2 minutes after time zero. Anesthesia was maintained with 50% nitrous oxide and 1.0 MAC halothane in oxygen, and vecuronium 0.08 mg/kg. Heart rate (HR) and systolic blood pressure (SBP) were recorded every minute for 10 minutes. To compare with the placebo group, there was a significant decrease in either HR or SBP in 200 mg group in the 8 minutes course after intubation (p < 0.05). There was a significant decrease in HR in the 100 mg group at the 3rd, 4th, and 5th minutes when compared with the placebo group (p < 0.05). The differences in SBP between the 100 mg group and placebo group were significant at the 3rd and 4th minutes (p < 0.05). Both bolus dosages of esmolol could effectively attenuate the tachycardia and hypertension produced by laryngoscopy and tracheal intubation. Furthermore, esmolol 200 mg presented a better hemodynamic stability than esmolol 100 mg during induction of anesthesia.
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PMID:The effect of single bolus dose of esmolol for controlling the tachycardia and hypertension during laryngoscopy and tracheal intubation. 792 58

Hypertensive emergency is a condition in which there is elevation of both systolic and diastolic blood pressure with the presence of acute target organ disease. Hypertensive urgency is a condition where the blood pressure is elevated (diastolic > 120 mmHg) with the absence of acute target organ disease. Hypertensive emergencies are best managed with parenteral drugs and careful intraarterial blood pressure monitoring. Hydralazine has been widely used in treatment of hypertension in eclampsia and preeclampsia, and its safety has been demonstrated in these patients. Sodium nitroprusside (SNP) has the most reliable antihypertensive activity, which begins immediately after its administration and ends when the infusion is stopped. As with diazoxide, it should be used with caution in patients with impaired cerebral flow. SNP is the preferred drug in obtaining controlled hypotension in patients undergoing neurovascular surgery. Intravenous nitroglycerin is useful in patients prone to myocardial ischemia, but should be avoided in patients with increased intracranial pressure. Esmolol is effective in controlling both supraventricular tachyarrhythmias and severe hypertension. Its short onset of duration of action make it useful in the emergent setting, but because of its negative inotropic effect its use should be avoided in patients with low cardiac output. Verapamil should not be used in patients with preexisting conduction abnormalities. Nicardipine is a potent arteriolar vasodilator without a significant direct depressant effect on myocardium. As with other afterload reducing agents, it should not be used in patients with severe aortic stenosis. Because angiotensin-converting enzyme (ACE) inhibitors generally cause cerebral vasodilatation, enalaprilat may be particularly beneficial for patients who are at high risk of developing cerebral hypotensive episodes secondary to impaired cerebral circulation. Fenoldopam, a selective post-synaptic dopaminergic receptor (DA1) has been shown to be effective in treating severe hypertension with a lower incidence of side effects than SNP. Hypertensive urgencies can usually be managed with oral agents. Oral nifedipine, captopril, clonidine, labetalol, prazosin, and nimodipine have all been shown to be effective in these situations.
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PMID:Management of hypertensive urgencies and emergencies. 852 30

A study was conducted on 100 middle-aged to elderly patients (n = 52, healthy; n = 48, suffering from either diabetes, hypertension, ischaemic heart disease or a combination of these diseases) undergoing cataract extraction to assess the effects of laryngoscopy and tracheal intubation, anaesthesia and surgery, eye bandaging and tracheal extubation, saline (control), magnesium sulphate 40 mg kg-1, esmolol 4.0 mg kg-1, lignocaine 1.5 mg kg-1 and glyceryl trinitrate 7.5 micrograms kg-1 given i.v. at induction of anaesthesia on heart rate (HR), blood pressure (BP), rate-pressure product (RPP) and pressure-rate quotient (PRQ). Anaesthesia was standardized. Haemodynamic responses and requirements for atropine, ephedrine and labetalol to maintain HR and BP during surgery were similar in healthy and diseased patients, and in the test drug groups. Differences produced by the test drugs were evident until 5 min following intubation. Esmolol prevented rises in HR and RPP. Glyceryl trinitrate prevented a rise in BP, but was associated with tachycardia and a fall in PRQ to < 1.0. Magnesium sulphate and lignocaine did not prevent responses to laryngoscopy and tracheal intubation, and were associated with rises in RPP. Application of the eye dressing and tracheal extubation at the end of surgery each caused significant increases in HR, BP and RPP in all groups.
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PMID:Attenuation of the haemodynamic responses to noxious stimuli in patients undergoing cataract surgery. A comparison of magnesium sulphate, esmolol, lignocaine, nitroglycerine and placebo given i.v. with induction of anaesthesia. 908 11

Jimson weed (Datura stramonium, a member of the Belladonna alkyloid family) is a plant growing naturally in West Virginia and has been used as a home remedy since colonial times. Due to its easy availability and strong anticholinergic properties, teens are using Jimson weed as a drug. Plant parts can be brewed as a tea or chewed, and seed pods, commonly known as "pods" or "thorn apples," can be eaten. Side effects from ingesting jimson weed include tachycardia, dry mouth, dilated pupils, blurred vision, hallucinations, confusion, combative behavior, and difficulty urinating. Severe toxicity has been associated with coma and seizures, although death is rare. Treatment consists of activated charcoal and gastric lavage. Esmolol or other beta-blocker may be indicated to reduce severe sinus tachycardia. Seizures, severe hypertension, severe hallucinations, and life-threatening arrhythmias are indicators for the use of the anticholinesterase inhibitor, Physostigmine. This article reviews the cases of nine teenagers who were treated in hospitals in the Kanawha Valley after ingesting jimson weed. We hope this article will help alert primary care physicians about the abuse of jimson weed and inform health officials about the need to educate teens about the dangers of this plant.
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PMID:The dangers of jimson weed and its abuse by teenagers in the Kanawha Valley of West Virginia. 927 42


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