Continuous Infusion Of Esmolol Research Articles

Esmolol as an adjunct to general balanced anaesthesia in neurosurgery

Background/Aim: In surgery, and especially in the neurosurgical operations, maintenance of cardiovascular stability during and in the phase of the immediate postoperative recovery is of vital importance. The aim of this study was to investigate the effects of continuous esmolol infusion on the values of cardiovascular parameters and quality of the emergence from anaesthesia in neurosurgical patients. Methods: A total of 40 patients of both sexes scheduled for elective supratentorial surgery were randomly assigned to two groups. Esmolol group received intravenous (iv) infusion of esmolol dissolved in 5 % glucose solution (during the first 5 min at a rate of 0.3 mg/kg/min and thereafter at a rate of 0.1 mg/kg/min), while the ones from the control group received a 5 % glucose solution without esmolol at the same volume and rate. Cardiovascular parameters were registered at critical phases of anaesthesia and operation (induction, intubation, placement of Mayfield frame, craniotomy, skull closure, extubation). Recovery after anaesthesia was assessed based on times of eye opening on command, spontaneous eye opening and regaining of full orientation. Results: Values of systolic blood pressure and heart rate were significantly lower in the esmolol than in the control group of patients. Although the durations of anaesthesia did not differ, patients from the esmolol group required significantly less opioids and isoflurane and recovered after the anaesthesia significantly faster than the patients in the control group. Conclusion: Ultrashort-acting beta-adrenergic receptor antagonist esmolol, administered as a continuous iv infusion, assures better cardiovascular stability and smoother emergence from the balanced inhalation general anaesthesia than the control glucose infusion in elective neurosurgical patients.

Effect of esmolol infusion on myocardial oxygen consumption during extubation and quality of recovery in elderly patients undergoing general anesthesia: randomized, double blinded, clinical trial

BackgroundUpon recovery from anesthesia and during extubation, there will be mechanical stimulation of receptors in the respiratory tract that results in both respiratory and cardiovascular reflex responses. Heart rate plays a major determinant of myocardial oxygen consumption and cardiac workload, so decreasing the heart rate will increase the ischemic threshold and improve the cardiac performance.ObjectiveTo evaluate the effect of esmolol infusion on myocardial oxygen consumption during extubation and quality of recovery in elderly patients undergoing general anesthesia.MethodsHundred adult patients ASA I & II scheduled for elective open unilateral inguinal hernia were randomized, double-blindly into one of two parallel groups, esmolol group (E) (n = 50) and control group (C) (n = 50). In the esmolol group, 1 mg/kg esmolol was given as bolus over 30 s then followed by a continuous esmolol infusion of 100 μg/kg/min starting 10 min before end of surgery till 5 min after extubation. While patients in group C received normal saline bolus of the same volume followed by a continuous normal saline infusion of the same volume per hour as group E. Mean heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), rate pressure product (RPP), anesthesia time, recovery time, postoperative nausea & vomiting, number of doses of antiemetic agent and quality of extubation were recorded.ResultsThe results showed that patients in the esmolol group had lower values of (RPP) after esmolol infusion with statistically significant difference when compared with patients in the control group using unpaired t-test (P < 0.05), this will decrease oxygen consumption in esmolol group. Also, there was statistically significant difference between both groups regarding values of HR (beat/min), SBP (mmHg), DBP (mmHg) and MBP (mmHg) starting 2 min after esmolol infusion and continued till 10 min after extubation using unpaired t-test (p < 0.05). As regards PONV, there was lower incidence in esmolol group when compared to control group using unpaired t-test with statistically significant difference (P < 0.05).ConclusionsEsmolol is a safe, effective and well-tolerated drug that can be used in elderly patients undergoing general anesthesia to reduce the myocardial oxygen consumption and improve the quality of recovery.

Comparison of bolus and continuous infusion of esmolol on hemodynamic response to laryngoscopy, endotracheal intubation and sternotomy in coronary artery bypass graft

Background and objectiveThe aim of this randomized, prospective and double blinded study is to investigate effects of different esmolol use on hemodynamic response of laryngoscopy, endotracheal intubation and sternotomy in coronary artery bypass graft surgery. MethodsAfter approval of local ethics committee and patients’ written informed consent, 45 patients were randomized into three groups equally. In Infusion Group; from 10min before intubation up to 5th minute after sternotomy, 0.5mg/kg/min esmolol infusion, in Bolus Group; 2min before intubation and sternotomy 1.5mg/kg esmolol IV bolus and in Control Group; %0.9 NaCl was administered. All demographic parameters were recorded. Heart rate and blood pressure were recorded before infusion up to anesthesia induction in every minute, during endotracheal intubation, every minute for 10minutes after endotracheal intubation and before, during and after sternotomy at first and fifth minutes. ResultsWhile area under curve (AUC) (SAP×time) was being found more in Group B and C than Group I, AUC (SAP×Tint and Tst) and AUC (SAP×T2) was found more in Group B and C than Group I (p<0.05). Moreover AUC (HR×Tst) was found less in Group B than Group C but no significant difference was found between Group B and Group I. ConclusionThis study highlights that esmolol infusion is more effective than esmolol bolus administration on controlling systolic arterial pressure during endotracheal intubation and sternotomy in CABG surgery.

β-Blockers to Optimize Peripheral Oxygenation During Extracorporeal Membrane Oxygenation: A Case Series

Veno-venous extracorporeal membrane oxygenation (ECMO) is a well-established therapy in patients affected by respiratory failure and unresponsive to conventional therapy. Despite technical innovations, some limitations still exist, the most important one being refractory hypoxemia. This problem is linked partially to the mixture between patients' blood and ECMO fully oxygenated blood. In the present work, the reduction of cardiac output was proposed for the treatment of refractory hypoxemia in patients with high-flow ECMO and high endogenous cardiac output. An observational study. A university hospital. Three consecutive patients suffering from persisting severe hypoxemia despite high-flow ECMO and with concomitant high cardiac output (>7 L/min). A bolus dose of 500 μg/kg and a continuous infusion of esmolol was used and titrated to an SpO(2) >92%. Esmolol administration was safe and highly beneficial in terms of peripheral oxygenation. PaO(2) increased from 54 to 90 mmHg, from 50 to 94 mmHg, and from 49 to 66 mmHg during the first 12 hours of esmolol treatment in the 3 patients. In selected septic, tachycardic patients with a high cardiac output, veno-venous ECMO, led to improvement of peripheral oxygenation with the addition of a short-acting β-blocker infusion.

Effects of esmolol on systemic and pulmonary hemodynamics and on oxygenation in pigs with hypodynamic endotoxin shock

The aim of this experimental study is to investigate cardiovascular tolerance of blockade of beta-adrenergic receptors in an endotoxin model. Prospective, randomized, controlled study. Animal laboratory in a university medical center. Ten anesthetized, mechanically ventilated pigs were challenged with intravenous lipopolysaccharide (LPS) to achieve a status of profound hypodynamic shock. Systemic and pulmonary hemodynamics and cardiac output were continuously monitored throughout the 5-h study period, and blood samples were taken at baseline (T - 30 min), 1 h from the beginning of LPS infusion (T + 60 min), and every 2 h (T + 180 min and T + 300 min). Animals were randomly assigned to continuous intravenous esmolol infusion titrated to decrease heart rate by 20% or isotonic saline. Esmolol decreased heart rate by 20%, while in the saline group, heart rate increased by 7% and 22% at T + 180 min and T + 300 min, respectively (p < 0.001). In esmolol-treated animals, cardiac index decreased by 9% at T + 180 min and by 2% at T + 300 min, and in controls by 14% at T + 180 min and by 27% at T + 300 min (p = 0.870). In esmolol-treated animals, median (interquartile range, IQR) stroke index was 31 (6) and 47 (11) ml/min/m(2) at T + 180 min and T + 300 min, respectively, and decreased steadily from 45 (20) to 18 (13) ml/min/m(2) in controls (p = 0.030). There were no significant differences between groups for any other hemodynamics variables, except for systemic vascular resistance (SVR) (p = 0.017). In large animals with endotoxemic shock, continuous infusion of esmolol, a selective beta-1 adrenergic blocker, titrated to decrease heart rate by 20%, was well tolerated and may offset LPS-induced cardiac dysfunction by a preload positive effect.

Atrial Fibrillation Developed during Recovery from General Anesthesia: A case report

Laparoscopic cholecystectomy was performed in a 69-year old woman due to perforated acute gangrenous cholecystitis. After completion of the surgery, we administered 10 mg pyridostigmine for the reversal of neuromuscular block and 4 mg ondansetron for the prevention of nausea and vomiting. Twenty minute after arrival in the recovery room, atrial fibrillation and tachycardia occurred. Even with the continuous infusion of esmolol and then administration of digoxin, atrial fibrillation and tachycardia continued in the recovery room. After transfer to the general ward, the heart rate was gradually decreased, and next morning, we could find the atrial fibrillation disappeared.

Beta Blocker Sensitive Idiopathic Ventricular Tachycardia

A 31-year-old female patient suffering from hemoptysis was scheduled for a lobectomy. Her preoperative electrocardiogram was normal sinus rhythm and electrolytes were within normal range. During mask ventilaton a short run of ventricular tachycardia appeared, but she returned to normal sinus rhythm after lidocaine 60 mg was injected. However, after intubation, sustained ventricular tachycardia developed and did not respond to additional lidocaine immediately. Blood gases and electrolytes were in acceptable range and severe hypotension did not occur during the attack. Several minutes later, the rhythm changed spontaneously to sinus rhythm with intermittent premature ventricular contractions. However, stimuli such as position change and endotracheal suctioning caused another paroxysmal ventricular tachycardia. Idiopathic ventricular tachycardia was suspected and esmolol 30 mg was injected. Ventricular tachycardia terminated abruptly and changed to sinus rhythm so that the lobectomy was done successfully with a continuous infusion of esmolol. Weare going to report this clinical experience with review of its mechanism, treatment, and long term prognosis.

Difference of Jugular Bulb Oxygen Saturation under Propofol, Enflurane and Isoflurane Anesthesia with Hydralazine-induced Deliberate Hypotension

Background: Hydralazine produces cerebral vasodilation, which could appear differently according to which kind of anesthetics was used. SjO, CBF and AJDO2 have been studied during general anesthesia with enflurane, isoflurane or propofol in 42 patients undergoing spinal surgery. Methods: Forty-two healthy adult patients were divided into Group P (Propofol-N2O, n = 15), Group E (Enflurane-N2O, n = 15) and Group I (Isoflurane-N2O, n = 12). During the course of the study, the anesthetic concentration was constant. Induced hypotension was provided with hydralazine 20 mg in combination with a continuous infusion of esmolol within 50-100g/kg/min. Arterial blood and jugular bulb blood were obtained and analyzed at normotensive and hypotensive period, respectively. SjO2, was compared within and between groups. Results: SjO values of Group P were 66.2 7.7%, and 81.5 ﾒ 6.1%, those of Group E were 79.5 5.6%, and 78.9 X 4.9% and those of Group I were 82.0 ･ 6.2%, and 84.4 ﾝ 3.7% at normotension and hypotension, respectively (P 0.05 between Group P and Group E, P 0.05 between Group P and Group I, P 0.05 within Group P). Conclusions: When the changes of CBF is assumed with that of SjO, it may be concluded that CBF increased with hydralazine-induced hypotension in propofol-N2O anesthesia. It may be suggested that hydralazine reverses propofol induced cerebral vasoconstriction.

Myocardial protection: The efficacy of an ultra-short-acting β-blocker, esmolol, as a cardioplegic agent

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

Use of intravenous esmolol to predict efficacy of oral beta-adrenergic blocker therapy in patients with neurocardiogenic syncope

The usefulness of esmolol in predicting the efficacy of treatment with an oral beta-adrenergic blocking agent was evaluated in 27 consecutive patients with neurocardiogenic syncope. Seventeen patients had a positive head-up tilt test response at baseline and 10 patients required intravenous isoproterenol for provocation of hypotension. All patients were then given a continuous esmolol infusion (500 μg/kg per min loading dose for 3 min followed by 300 μg/kg per min maintenance dose) and rechallenged with a head-up tilt test at baseline or with isoproterenol.Of the 17 patients with a positive baseline tilt test response, 11 continued to have a positive response to esmolol challenge. Sixteen patients (including all 10 patients with a positive tilt test response with isoproterenol) exhibited a negative response to upright tilt during esmolol infusion.Irrespective of their response to esmolol infusion, all patients had a follow-up tilt test with oral metoprolol after an interval of ≥5 half-lives of the drug. All 16 patients (100%) with a negative tilt test response during esmolol infusion had a negative tilt test response with oral metoprolol. Of the 11 patients with a positive tilt test response during esmolol infusion, 10 (90%) continued to have a positive response with oral metoprolol.It is concluded that in the electrophysiology laboratory, esmolol can accurately predict the outcome of a head-up tilt response to oral metoprolol. This information may be helpful in formulating a therapeutic strategy at the initial head-up tilt test in patients with neurocardiogenic syncope.

Evaluation of an extraaortic counterpulsation device in severe cardiac failure

A valveless, single-orifice polyurethane ventricle with a maximum stroke volume of 60 mL was implanted on the brachiocephalic artery just above the aortic arch in sheep (n = 14) to act as an extraaortic counterpulsation device. In parallel, an intraaortic balloon was placed in the descending thoracic aorta. Both devices were pneumatically driven with an intraaortic balloon pump console that was gated by the electrocardiogram to provide aortic diastolic augmentation at a stroke volume of 40 mL. To compare the efficacy of counterpulsation for each device during severe cardiac failure, biventricular block was induced by continuous infusion of esmolol (100 to 600 μg · kg −1 · min −1), titrated to reduce aortic flow and pressure to less than 75% of baseline. Pulsatile coronary and aortic flows were recorded with ultrasonic flow probes placed around their respective vessels. Aortic root and left ventricular pressures were recorded using micromanometers. The enhancement of hemodynamic variables for both devices were compared for optimal timing conditions, which were defined as inflation set just before the dicrotic notch and deflation bordering on isovolumetric systole. The extraaortic counterpulsation device was able to significantly augment aortic and coronary flows while simultaneously decreasing left ventricular tension time index and aortic end-diastolic pressure ( p < 0.02). The intraarotic balloon pump was able to significantly reduce only tension time index ( p < 0.002) to a lesser extent that the extraaortic counterpulsation device. All analysis was performed with the pairedsamples t test. The extraaortic counterpulsation device greatly improves the myocardial oxygen supply-consumption ratio of the left ventricle by increasing diastolic coronary flow and reducing left ventricular wall tension during systole. The salutary effects of the extraaortic counterpulsation device greatly exceed those of the intraaortic balloon pump, and it may, therefore, provide a viable alternative for patients in pump failure after cardiopulmonary bypass.

Use of esmolol to control autonomic instability of tetanus

Tetanus is often accompanied by autonomic instability, rendering hemodynamic management difficult. Death is frequently secondary to an inability to control this instability. A variety of modalities have been used to stabilize the cardiovascular system, but all are not ideal. Esmolol offers theoretical advantages over other modalities. We report a case of severe tetanus in which a continuous infusion of esmolol was effective in controlling the autonomic instability.