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David J Chambers - One of the best experts on this subject based on the ideXlab platform.

  • Cardioprotection with Esmolol cardioplegia: efficacy as a blood-based solution
    European Journal of Cardio-Thoracic Surgery, 2012
    Co-Authors: Masahiro Fujii, David J Chambers
    Abstract:

    OBJECTIVES: Current cardiac surgery patients are older, sicker, with more diffuse disease and hence a reduced tolerance to ischaemiareperfusion injury. We previously demonstrated that Esmolol, an ultra-short-acting β-blocker, can be used as an arresting agent at high (millimolar) concentrations, and that a crystalloid-based Esmolol cardioplegia afforded cardioprotection at least equivalent to hyperkalaemic (St Thomas’ Hospital) cardioplegia. Esmolol is rapidly metabolized by blood esterases, so it was important to determine the feasibility of its use in blood-based solutions. This study compared the efficacy of blood-based Esmolol cardioplegia with hyperkalaemic cardioplegia in a novel blood-perfused rat heart preparation. METHODS: Isolated rat hearts were Langendorff blood-perfused with a rat blood/buffer perfusate mixture (flow rate, 3.0 ml/min) and pre-ischaemic baseline function (left ventricular developed pressure) assessed. All values are expressed as mean ± SEM. Three studies were conducted: (i) the efficacy of blood-based vs crystalloid-based Esmolol or hyperkalaemic cardioplegia (40 min ischaemia) was evaluated (five groups; six hearts/group); (ii) the effect of the mode of cardioplegia delivery (constant flow/pressure), Esmolol concentration and extended delivery interval (45 min ischaemia) was evaluated (four groups; six hearts/group); (iii) the efficacy of blood-based Esmolol compared with hyperkalaemic cardioplegia over extended (60 min) ischaemia duration was evaluated (two groups; six hearts/ group). Hearts were reperfused (60 min) and recovery (percent of pre-ischaemic baseline function) measured at the end of reperfusion. RESULTS: Hearts subjected to blood-based Esmolol or hyperkalaemia cardioplegia recovered to 78 ± 4% and 68 ± 6%, whereas crystalloid-based Esmolol or hyperkalaemic cardioplegia recovered to 84 ± 1% and 77 ± 2%, respectively [all P< 0.05 vs control (2 ± 2%)]; there were no differences between cardioplegia groups. When infusion duration was extended, a lower (2 mmol/l) Esmolol concentration improved recovery compared with the higher (3 mmol/l) concentration (66 ± 4% vs 29 ± 12%, P< 0.05). Extending the ischaemic duration demonstrated enhanced efficacy for blood-based Esmolol cardioplegia (70 ± 4%; P< 0.05) compared with hyperkalaemic cardioplegia (47 ± 10%). CONCLUSIONS: Blood-based Esmolol cardioplegia improved cardioprotective efficacy compared with hyperkalaemic cardioplegia; the metabolic effects of blood esterase did not appear to influence this efficacy. An Esmolol-based cardioplegic solution may be a beneficial alternative to hyperkalaemic solutions.

  • Esmolol cardioplegia the cellular mechanism of diastolic arrest
    Cardiovascular Research, 2010
    Co-Authors: Hazem B Fallouh, David J Chambers, Sonya C Bardswell, Linda M Mclatchie, Michael J Shattock, Jonathan C Kentish
    Abstract:

    Aims Esmolol, an ultra-short-acting β-blocker, acts as a cardioplegic agent at millimolar concentrations. We investigated the mechanism by which Esmolol induces diastolic ventricular arrest. Methods and results In unpaced Langendorff-perfused rat hearts, Esmolol (0.03–3 mmol/L) had a profound negative inotropic effect resulting in diastolic arrest at 1 mmol/L and above. This inhibition of contraction was maintained during ventricular pacing. At 3 mmol/L, Esmolol also abolished action potential conduction. To determine the cellular mechanism for the negative inotropism, we measured contraction (sarcomere shortening) and the calcium transient (fura-2 fluorescence ratio; Catr) in electrically-stimulated rat ventricular myocytes at 23 and 34°C. The decrease in contraction (by 72% at 23°C, from 0.16 ± 0.01 to 0.04 ± 0.01 µm, P < 0.001) was similar to that of isolated hearts and was caused by a large decrease in Catr (from 0.13 ± 0.02 to 0.07 ± 0.02, P < 0.001). There was no additional effect on myofilament Ca2+ sensitivity. Esmolol's effects on contraction and Catr were not shared or altered by the β-blocker, atenolol (1 mmol/L). Sarcoplasmic reticulum inhibition with thapsigargin did not alter the inhibitory effects of Esmolol. Whole-cell voltage-clamp experiments revealed that Esmolol inhibited the L-type calcium current ( I Ca,L) and the fast sodium current ( I Na), with IC50 values of 0.45 ± 0.05 and 0.17 ± 0.025 mmol/L, respectively. Conclusion Esmolol at millimolar concentrations causes diastolic ventricular arrest by two mechanisms: at 1 mmol/L (and below), the pronounced negative inotropic effect is due largely to inhibition of L-type Ca2+ channels; additionally, higher concentrations prevent action potential conduction, probably due to the inhibition of fast Na+ channels.

  • myocardial protection the efficacy of an ultra short acting β blocker Esmolol as a cardioplegic agent
    The Journal of Thoracic and Cardiovascular Surgery, 2001
    Co-Authors: Ryuzo Bessho, David J Chambers
    Abstract:

    Abstract Objective: During myocardial revascularization, some surgeons (particularly in the United Kingdom) use intermittent crossclamping with fibrillation as an alternative to cardioplegia. We recently showed that intermittent crossclamping with fibrillation has an intrinsic protection equivalent to that of cardioplegia. In this study we hypothesized that arrest, rather than fibrillation, during intermittent crossclamping may be beneficial. Because Esmolol, an ultra-short-acting β-blocker, is known to attenuate myocardial ischemia-reperfusion injury, we compared the protective effect of Esmolol arrest with that of intermittent crossclamping with fibrillation and conventional cardioplegia (St Thomas' Hospital solution). Methods: Isolated rat hearts were Langendorff perfused at either constant flow (14 mL/min) or constant pressure (75 mm Hg) with oxygenated Krebs-Henseleit bicarbonate buffer (37°C), and left ventricular developed pressure was assessed. In study 1 (constant flow perfusion) 8 groups (n = 6 hearts per group) were studied: (1) 40 minutes of global ischemia; (2) 2 minutes of St Thomas' Hospital infusion and 40 minutes of ischemia; (3) multidose (every 10 minutes) infusions of St Thomas' Hospital solution during 40 minutes of ischemia; (4) 2 minutes of Esmolol infusion and 40 minutes of ischemia; (5) multidose (every 10 minutes) Esmolol infusions during 40 minutes of ischemia; (6) continuous infusion of Esmolol for 40 minutes during coronary perfusion; (7) intermittent (4 × 10 minutes) ischemia with ventricular fibrillation; and (8) intermittent (4 × 10 minutes) ischemia preceded by intermittent Esmolol administration. All protocols were followed by 60 minutes of reperfusion. Further experiments (study 2) examined the Esmolol administration method in hearts perfused by constant pressure. Results: An optimal arresting dose of 1.0 mmol/L Esmolol was established. In study 1 recovery of left ventricular developed pressure (expressed as percentage of preischemic value) was 7% ± 4%, 28% ± 8%, 70% ± 5%, 8% ± 1%, 90% ± 4%, 65% ± 3%, 71% ± 5%, and 76% ± 5% in groups 1 to 8, respectively. Intermittent Esmolol arrest with global ischemia provided equivalent myocardial protection to intermittent crossclamping with fibrillation, continuous Esmolol perfusion, and multidose St Thomas' Hospital solution. Surprisingly, multidose Esmolol infusion was more protective than all other treatments. In further experiments (study 2) optimal recovery was obtained with multiple Esmolol infusions (by constant flow or constant pressure), but continuous Esmolol infusion (at constant flow) was less effective than constant pressure infusion. Conclusions: Intermittent arrest with Esmolol did not enhance protection of intermittent crossclamping with fibrillation; however, multiple Esmolol infusions during global ischemia provided improved protection. Administration (constant flow or constant pressure) of arresting solutions influenced outcome only during continuous infusion. Multidose Esmolol arrest may be a beneficial alternative to intermittent crossclamping with fibrillation or conventional cardioplegia. J Thorac Cardiovasc Surg 2001;122:993-1003

Eunmi Choi - One of the best experts on this subject based on the ideXlab platform.

  • comparison of effects of intraoperative Esmolol and ketamine infusion on acute postoperative pain after remifentanil based anesthesia in patients undergoing laparoscopic cholecystectomy
    Korean Journal of Anesthesiology, 2014
    Co-Authors: Mi Hwa Chung, Young Ryong Choi, Eunmi Choi
    Abstract:

    ment for morphine and provides more effective analgesia than the administration of remifentanil and ketamine. Hence, this study was conducted to determine whether Esmolol reduces early postoperative pain in patients who are continuously infused with remifentanil for anesthesia during laparoscopic cholecystectomy. Methods: Sixty patients scheduled to undergo laparoscopic cholecystectomy were randomly divided into three groups. Anesthesia was maintained with sevoflurane and 4 ng/ml (target-controlled infusion) of remifentanil in all patients. Esmolol (0.5 mg/kg) was injected and followed with a continuous dosage of 10 μg/kg/min in the Esmolol group (n = 20). Ketamine (0.3 mg/kg) was injected and followed with a continuous dosage of 3 μg/kg/min in the ketamine group (n = 20), while the control group was injected and infused with an equal amount of normal saline. Postoperative pain score (visual analog scale [VAS]) and analgesic requirements were compared for the first 6 hours of the postoperative period. Results: The pain score (VAS) and fentanyl requirement for 15 minutes after surgery were lower in the Esmolol and ket amine groups compared with the control group (P < 0.05). There were no differences between the Esmolol and ketamine groups. Conclusions: Intraoperative Esmolol infusion during laparoscopic cholecystectomy reduced opioid requirement and pain score (VAS) during the early postoperative period after remifentanil-based anesthesia. (Korean J Anesthesiol 2014; 66: 222-229)

  • effect of a single dose of Esmolol on the bispectral index to endotracheal intubation during desflurane anesthesia
    Korean Journal of Anesthesiology, 2013
    Co-Authors: Eunmi Choi, Seung Ho Choi
    Abstract:

    Background: In this prospective, randomized, double-blind, placebo-controlled trial, we investigated the effect of a single dose of Esmolol on the bispectral index (BIS) to endotracheal intubation during desflurane anesthesia. Methods: After induction of anesthesia, 60 patients were mask-ventilated with desflurane (end-tidal 1 minimum alveolar concentration) for 5 min and then received either normal saline, Esmolol 0.5 or 1 mg/kg, 1 min prior to intubation (control, Esmolol-0.5 and Esmolol-1 groups, n = 20/group). BIS, mean arterial pressure, and heart rate were measured prior to anesthesia induction and Esmolol administration, immediately preceding intubation (time point 0), and every minute for 5 min after intubation (time point 1 to 5). At time point 0, 1 and 5, 5 ml of arterial blood was taken to measure plasma concentrations of norepinephrine and epinephrine. Results: BIS increased significantly at 1 min after intubation when compared with pre-intubation values in all groups. Both mean arterial pressure and heart rate increased significantly 1 min after intubation when compared with preintubation values for all groups. Plasma epinephrine concentrations did not increase significantly after tracheal intubation in any of the groups. Norepinephrine increased at 1 min after intubation when compared with the preintubation values in the Esmolol groups (P < 0.05). Conclusions: A single bolus of Esmolol was unable to blunt the increase in BIS to endotracheal intubation during desflurane anesthesia. (Korean J Anesthesiol 2013; 64: 420-425)

S Savaci - One of the best experts on this subject based on the ideXlab platform.

  • postoperative beneficial effects of Esmolol in treated hypertensive patients undergoing laparoscopic cholecystectomy
    BJA: British Journal of Anaesthesia, 2008
    Co-Authors: Tulin Ozturk, H Kaya, Gulcin Aran, Murat Aksun, S Savaci
    Abstract:

    Background. In an attempt to decrease haemodynamic instability and early postoperative complications such as nausea, vomiting, and pain, Esmolol was added to the routine alfentanil infusion of patients with treated hypertension undergoing laparoscopic cholecystectomy. Methods. Forty consecutive ASA class II patients with controlled hypertension about to undergo laparoscopic cholecystectomy were randomized into two groups: an Esmolol group (Group E, n¼20) was given a 1 mg kg 21 bolus of Esmolol and a placebo group (Group P, n¼20) was given an identical volume of Ringer’s lactate. The rate of Esmolol infusion was adjusted to keep the heart rate between 65 and 75 beats min 21 and was 5–10 m gk g 21 min 21 throughout the procedure. After operation, patients reported their nausea using a four-point scale. Results. Esmolol had an opioid-sparing effect intraoperatively (P¼0.001). Postoperative requirements for antiemetics were significantly less in the Esmolol group, with no antiemetics given to eight patients. In the placebo group, however, all patients required at least one dose of antiemetic (P¼0.007). The frequency of PONV did not correlate to the amounts of alfentanil, propofol, postoperative antiemetics consumed, or to female gender, non-smoking status, and history of PONV or motion sickness. Postoperative analgesic consumption in Group E was significantly lower than in Group P (P¼0.012). Conclusions. Esmolol had an opioid-sparing effect in the intraoperative and immediate postoperative period in hypertensive patients undergoing laparoscopy. When combined with alfentanil, it was more effective than placebo in decreasing early PONV.

Antoine Kimmoun - One of the best experts on this subject based on the ideXlab platform.

  • effects of low doses of Esmolol on cardiac and vascular function in experimental septic shock
    Critical Care, 2016
    Co-Authors: Huguette Louis, Margaux Schmitt, Eliane Albuisson, Sophie Orlowski, Bruno Levy, Antoine Kimmoun
    Abstract:

    Administration of a selective β1-blocker, such as Esmolol, in human septic shock has demonstrated cardiovascular protective effects related to heart rate reduction. Certain experimental data also indicate that Esmolol exerts systemic anti-inflammatory and beneficial effects on vascular tone. Thus, the present study aimed to determine whether a non-chronotropic dose of Esmolol maintains its protective cardiovascular and anti-inflammatory effects in experimental septic shock. Four hours after cecal ligation and puncture (CLP), Wistar male rats were randomly allocated to the following groups (n = 8): CLP, CLP + E-1 (Esmolol: 1 mg.kg−1.h−1), CLP + E-5 (Esmolol: 5 mg.kg−1.h−1), CLP + E-18 (Esmolol: 18 mg.kg−1.h−1). An additional eight rats underwent sham operation. All rats received a continuous infusion of saline, analgesic and antibiotics 4 hours after the surgery. Assessment at 18 hours included in vivo cardiac function assessed by echocardiography and ex vivo vasoreactivity assessed by myography. Circulating cytokine levels (IL-6 and IL-10) were measured by ELISA. Cardiac and vascular protein expressions of p-NF-κB, IκBα, iNOS, p-AKT/AKT and p-eNOS/eNOS were assessed by western blotting. CLP induced tachycardia, hypotension, cardiac output reduction, hyperlactatemia and vascular hypo-responsiveness to vasopressors. Compared to CLP animals, heart rate was unchanged in CLP + E-1 and CLP + E-5 but was reduced in CLP + E-18. Stroke volume, cardiac output, mean arterial pressure and lactatemia were improved in CLP + E-1 and CLP + E-5, while vascular responsiveness to phenylephrine was only improved in CLP + E-5 and CLP + E-18. Plasma IL-6 levels were decreased in all Esmolol groups. p-NF-κB was decreased in both cardiac and vascular tissues in CLP + E-5 and CLP + E-18. In experimental septic shock, low doses of Esmolol still improved cardiac function and vasoreactivity. These benefits appear to be associated with a modulation of inflammatory pathways.

Donald B. Wiest - One of the best experts on this subject based on the ideXlab platform.

  • clinical pharmacokinetics and therapeutic efficacy of Esmolol
    Clinical Pharmacokinectics, 2012
    Co-Authors: Donald B. Wiest, Jason S Haney
    Abstract:

    Esmolol is a unique cardioselective β1-receptor blocking agent with a rapid onset and short duration of action. Since our previous review in 1995, the pharmacokinetics and efficacy of Esmolol have been investigated in a number of acute care settings. Three studies investigated the pharmacokinetics and safety of Esmolol in the paediatric population. The disposition of Esmolol in children was found to be linear with plasma concentrations increasing in proportion to dose over the ranges studied. The pharmacokinetic estimates for Esmolol showed a shorter elimination half-life (t1/2) [2.7–4.8 minutes] and a higher clearance (281 mL/kg/min) in newborns and infants than that found in children (>2 years old) and adults. Dosing requirements to achieve targeted blood pressure in post-coarctectomy patients were substantially higher (mean 700 μg/kg/min) than that used in adults. Esmolol was effective in controlling hypertension following cardiac surgery and terminating supraventricular arrhythmias in children.

  • Clinical Pharmacokinetics and Therapeutic Efficacy of Esmolol
    Clinical Pharmacokinetics, 2012
    Co-Authors: Donald B. Wiest, Jason S Haney
    Abstract:

    Esmolol is a unique cardioselective β_1-receptor blocking agent with a rapid onset and short duration of action. Since our previous review in 1995, the pharmacokinetics and efficacy of Esmolol have been investigated in a number of acute care settings. Three studies investigated the pharmacokinetics and safety of Esmolol in the paediatric population. The disposition of Esmolol in children was found to be linear with plasma concentrations increasing in proportion to dose over the ranges studied. The pharmacokinetic estimates for Esmolol showed a shorter elimination half-life (t_1/2) [2.7–4.8 minutes] and a higher clearance (281 mL/kg/min) in newborns and infants than that found in children (>2 years old) and adults. Dosing requirements to achieve targeted blood pressure in post-coarctectomy patients were substantially higher (mean 700 μg/kg/min) than that used in adults. Esmolol was effective in controlling hypertension following cardiac surgery and terminating supraventricular arrhythmias in children. The efficacy of Esmolol has been established in a variety of patients, including those with unstable angina, myocardial ischaemia, supraventricular arrhythmias, peri- and postoperative tachycardia and hypertension, and electroconvulsive therapy. With careful titration and monitoring, Esmolol can be used effectively in patients with congestive heart failure and chronic obstructive lung disease because of its unique short t_1/2 and β_1-selectivity. Different dosage schedules have been developed depending on clinical setting and diagnosis. Generally, a loading dose of ≤500 μg/kg/min over 1 minute is administered followed by a continuous infusion of 25–300 μg/kg/min. Hypotension, being the primary adverse effect, can be minimized by careful dosage titration and patient monitoring. In the perioperative setting involving tracheal intubation and extubation, a number of recent studies have suggested that titration of Esmolol to a haemodynamic endpoint can be safe and effective, resulting in a decreased incidence of myocardial ischaemia. The most effective regimen in attenuating the response to heart rate and blood pressure after laryngeal tracheal intubation was a loading dose of 500 μg/kg/min for 4 minutes followed by a continuous infusion of 200–300 μg/kg/min. In cardiac and non-cardiac surgical patients Esmolol has been shown to decrease episodes of myocardial ischaemia and arrhythmias. In the perioperative period for non-cardiac surgery routine use of β-blockers (β-adrenoceptor antagonists) is no longer recommended. However, in patients at high risk for myocardial ischaemia or undergoing high-risk surgery where a β-blocker is indicated, Esmolol is the ideal perioperative agent to minimize the risk of hypotension and bradycardia based on its pharmacodynamic and pharmacokinetic characteristics. For postoperative patients in atrial fibrillation, Esmolol achieves rapid ventricular rate control. However, for the prevention of postoperative atrial fibrillation Esmolol provides no advantage over oral β-blockers. In other situations where emergent β-blockade is required, such as electroconvulsive therapy, Esmolol has been shown to effectively control haemodynamic response. After more than 2 decades of use Esmolol continues to provide an important therapeutic option in the acute care setting.

  • Esmolol for the management of pediatric hypertension after cardiac operations
    The Journal of Thoracic and Cardiovascular Surgery, 1998
    Co-Authors: Donald B. Wiest, Sandra S. Garner, Walter E. Uber, Robert M. Sade
    Abstract:

    Abstract Objective: Hypertension frequently occurs during the immediate postoperative period in children after repair of aortic coarctation but may also occur after repair of other congenital heart defects. Nitroprusside has often been used to control blood pressure in this setting. Because hypertension after coarctation repair is frequently associated with elevations in catecholamines, Esmolol, a short-acting β-blocking agent, may be an effective alternative. Therefore we undertook the first systematic investigation to determine the efficacy and disposition of Esmolol in pediatric patients with acute hypertension after cardiac operations. Methods: Twenty patients aged 1 month to 12 years (median 25.6 months) with acute hypertension after cardiac operations received Esmolol in an opened-labeled trial. Esmolol was titrated to a blood pressure less than or equal to the 90th percentile for age. Results: Ten patients had coarctation repair and the remaining patients underwent repair of other congenital heart defects. On final Esmolol dose (mea n  ± standard deviation dosage 700 ± 232 μg/kg/min) there was a significant percent decrease in heart rate and systolic and diastolic blood pressures from postoperative values. Esmolol dose was significantly associated with percent reduction in systolic blood pressure. Final Esmolol dose and total body clearance were significantly higher in patients after coarctation repair. There were significant associations between Esmolol dose and Esmolol blood concentrations at steady state. Conclusions: The dosage required to control hypertension in patients after repair of aortic coarctation was higher than patients who underwent repair of other congenital heart defects. Esmolol was effective in controlling blood pressure in 19 of 20 patients without adverse effects. (J Thorac Cardiovasc Surg 1998;115:890-7)

  • Esmolol. A review of its therapeutic efficacy and pharmacokinetic characteristics.
    Clinical Pharmacokinectics, 1995
    Co-Authors: Donald B. Wiest
    Abstract:

    Esmolol is an ultra short-acting intravenous cardioselective Q-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 α-distribution halflife 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 β-blockade occurring within 5 minutes. Full recovery from β-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 doses of

  • Esmolol a review of its therapeutic efficacy and pharmacokinetic characteristics
    Clinical Pharmacokinectics, 1995
    Co-Authors: Donald B. Wiest
    Abstract:

    Esmolol is an ultra short-acting intravenous cardioselective Q-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 α-distribution halflife 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 β-blockade occurring within 5 minutes. Full recovery from β-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 doses of <300 μg/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 μg/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