A Comparison of the Effects of Intraoperative Administration of Metoprolol or Esmolol on General Anesthetic Requirement
We will compare three study groups receiving metoprolol, esmolol, or placebo. Level of anesthesia will be titrated to achieve the same range of BIS value in all groups. Our hypothesis is that the metoprolol and esmolol groups will require a lower level of anesthetic agent to achieve the targeted BIS range, compared to the placebo group.
Our objective is to clarify if metoprolol, in a dose range used for perioperative cardiac protection, decreases anesthetic requirement.
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Other
|Official Title:||A Comparison of the Effect of Intraoperative Administration of Metoprolol or Esmolol on General Anesthetic Requirement|
- Area Under the Curve of etSEV Over the First Hour [ Time Frame: Every 5 minutes for 2 hours ]We will measure the amount of Sevoflurane used to achieve the same level Bispectral Index. Each patient will have their percentage of sevoflurane in expired breath measured every 5 minutes for 2 hours, resulting in 24 data points per person. The primary endpoint will be area under the curve (AUC) for each subject for the first hour.
|Study Start Date:||October 2008|
|Study Completion Date:||September 2, 2015|
|Primary Completion Date:||September 2, 2015 (Final data collection date for primary outcome measure)|
Patients were randomly assigned to Metoprolol Group. The drug was dispensed in 60ml & 5ml syringes of 0.9% NaCl and 1mg/ml Metoprolol. Investigators and patients were blinded to the group assignment.
60ml syringes of 0.9% NaCl, 5ml syringes of metoprolol at 1mg/ml concentration
Other Name: M-Group
Patients were randomly assigned to Esmolol Group. The drug was dispensed in 60ml & 5ml syringes of 0.9% NaCl and 10mg/ml Esmolol. Investigators and patients were blinded to the group assignment.
60ml syringes of esmolol at 10 mg/ml concentration, 5ml syringes of 0.9% of NaCl
Other Name: E-Group
Placebo Comparator: P-Group
Patients were randomly assigned to this group. Patients received 0.9% NaCl only. To maintain the blind, 0.9% NaCl was also dispensed in 60ml & 5ml syringes.
0.9%NaCl dispensed in 60ml & 5ml syringes
Other Name: Placebo Comparator
Beta-receptor antagonists are commonly used in the perioperative setting. These agents have been shown to decrease the incidence of perioperative myocardial ischemia and are recommended by a recent practice guideline in certain patient groups.1 Besides protection from ischemia, there are other situations where beta-receptor antagonists are used intraoperatively such as control of the sympathetic response to tracheal intubation and certain types of surgical stimuli.
There is new evidence suggesting that administration of esmolol, a short-acting beta-receptor antagonist, might reduce the actual anesthetic requirement. This was initially shown by studies in which esmolol decreased the amount of anesthetic required to prevent movement after skin incision.2;3 Subsequent studies used bispectral index (BIS) as an endpoint and demonstrated decreased BIS values in subjects receiving esmolol during general anesthesia. 4;5
This anesthetic-sparing effect observed with esmolol has not been prospectively studied with other beta-receptor antagonists. Since perioperative beta-blockade is commonly achieved using longer acting agents such as metoprolol or atenolol, it is clinically relevant to understand the effects of these medications on anesthetic requirement. We aim to conduct a prospective, randomized, controlled, double-blind study to compare the anesthetic-sparing effect of metoprolol and esmolol administered intraoperatively.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00756236
|United States, Oklahoma|
|Univeristy of Oklahoma Health Sciences Center Dept. Anesthesiology|
|Oklahoma City, Oklahoma, United States, 73104|
|Principal Investigator:||Pramod Chetty, MD||Faculty, Anesthesiology|