Dexmedetomidine's Cardiac and Cognitive Influence on Patients Undergoing Off-pump Coronary Artery Bypass Graft Surgery

The investigators hypothesized that dexmedetomidine as an anesthetic adjunct can be used in the setting of off-pump coronary bypass procedure and can provide benefits to cardiac function and cognitive performance on the ground of the dexmedetomidine's characteristics.

Study Overview

• Status: Unknown
• Conditions: Coronary Artery Disease
• Intervention / Treatment: Drug: Dexmedetomidine

Detailed Description

The emergence of off-pump coronary artery bypass grafting (OPCAB) procedure brings up new challenges to anesthesiologists and urges us to contemplate the choice of anesthetics. In face of these challenges Dexmedetomdine with multiple unique traits can readily fit into this situation.

Off-pump coronary artery bypass (OPCAB) procedure is an emerging procedure which might bring benefit to patients in comparison with conventional CABGs although final words about outcomes haven't been reached on the basis of recent literature. However, OPCAB technique definitely requires more involvement of anesthesiologists especially in cases where hemodynamic compromise is usually inevitable during anastomosis of Lcx or PDA and early extubation in the OR is expected1. Thus, the investigators are encountered with more intraoperative challenges caused by OPCAB than routine CABGs. Concerning about challenges the investigators might take on, the investigators shall not only pay more attention to surgeons' manipulation but also review anesthetics that the investigators have selected to find an optimal plan to minimize adverse effects on heart and other important organs. With this perspective, dexmedetomidine come into our sight with its peculiar traits of hemodynamic effects and assumed cardiac protective effects.

Dexmedetomidine as a more selective α2-adrenoreceptor agonist than clonidine has gradually gain popularity in anesthetic and ICU settings for its unique pharmacologic characteristics. Dexmedetomidine provides sufficient sedative effects with minimal respiratory effect and then reduces the consumption of other sedative and antinociceptive drugs.Given specific requirements of OPCAB surgery, dexmedetomidine's may be more suitable in varying aspects. Firstly, dexmedetomine can dramatically diminish the level of serum catecholamine (CA). As the investigators know, the diminished level of catecholamine indicates less stress response to surgical stimuli and lower incidence of cardiac events. Secondly, the relatively slower HR by dexmedetomidine can decrease oxygen consumption of myocardium and consequently improve the perfusion of endangered ischemic area. In addition, the decreased HR which is assumably analogous to effects of esmolol or other β-blockers can reduce the occurrence of tachycardia and minimize the motion of heart when "bypass" procedure is performed on the target vessels. Thirdly, it has been reported that dexmedetomidine can alleviate sufferings of renal function during major thoracic surgery .Thus, it is implied that dexmedetomidine might in the similar way ameliorate the damage to renal system caused by hours of stress response and havoc of SIRS ,and then improve clinical prognosis . In view of assumptions the investigators have proposed on the ground of dexmedetomidine's characteristics and specific requirements of OPCAB surgery, the investigators are expecting that dexmdetomidine can fit the situation where patients' limited capacity of coronary artery and sophisticated pathophysiological courses have to be taken into account.

• Study Type: Observational
• Enrollment (Anticipated): 90

Contacts and Locations

Study Locations

• China
  • Hubei
    • Wuhan, Hubei, China, 430030
      • Recruiting
      • Department of Anesthesiology ,Tongji Hospital, Tongji Medical College,Huazhong University of Science and Technology
      • Principal Investigator: Xin Chen, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients who are planned to undergo off-pump coronary bypass surgery

Description

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) scores are between classⅡand Ⅲ
• undergo off-pump coronary artery bypass grafting (OPCAB)

Exclusion Criteria:

• left ventricular ejection fraction <40%
• left ventricular aneurysm
• acute myocardial infarction in latest two weeks
• atrial fibrillation
• associated vascular diseases
• severe systemic diseases involving the renal and hepatic systems
• respiratory disease( forced vital capacity less than 50% of predicted values ) preoperative left bundle branch block .

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Group High-dose; Dexmedetomidine loading dose 1μg/kg Dexmedetomidine maintenance dose 0.6μg/kg/h	Drug: Dexmedetomidine
Group Low-dose; Dexmedetomidine loading dose 0.6μg/kg Dexmedetomidine maintenance dose 0.3μg/kg/h	Drug: Dexmedetomidine
Group Control; Dexmedetomidine loading dose and Dexmedetomidine maintenance dose were placed with the same amount of 0.9% saline as placebo	Drug: Dexmedetomidine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
cardioprective results represented by serial determination of troponin I (cTnI) cardioprective results represented by serial determination of troponin I (cTnI)	The parameter measured is dynamic so that it is needed to detect the level at different time points	up to 3 days after the surgery
Hemodynamic values	On the basis of our experience, the period from baseline to the end of the surgery is five hours on average and would depend on the complexity of the surgical procedure	from baseline to the end of the surgery
Serum level of β-amyloid protein	The study is going to reflect the degree of central nerve system damage by detecting the level of S100 protein in serum. The serum level of S100 is preferred rather than the CSF sample because the approach of CSF sample obtaining is invasive and costly.	up to 3 days after the surgery
Serum level of S100 protein	The study is going to reflect the degree of central nerve system damage by detecting the level of S100 protein in serum. The serum level of S100 is preferred rather than the CSF sample because the approach of CSF sample obtaining is invasive and costly.	up to 3 days after the surgical procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
intraoperative and postoperative urine output (UO), extubation time (ET), length of stay in ICU(LOSICU ) and length of hospital stay (LOS)	The intraoperative and postoperative urine output (UO), extubation time (ET), length of stay in ICU(LOSICU ) are measured in ICU while the length of hospital stay is recorded at the discharge of every patient.	participants will be followed for the duration of hospital stay, an expected average of4 weeks
Mini-mental state examination(MMSE) scoring	The study is planned to detect the cognitive performance with this commonly used cognitive evaluation scoring	up to patients' discharge from hospital

Collaborators and Investigators

• Sponsor: Huazhong University of Science and Technology

Study record dates

Study Major Dates

• Study Start: May 1, 2012
• Primary Completion (Anticipated): December 1, 2012
• Study Completion (Anticipated): March 1, 2013

Study Registration Dates

• First Submitted: October 1, 2012
• First Submitted That Met QC Criteria: October 9, 2012
• First Posted (Estimate): October 11, 2012

Study Record Updates

• Last Update Posted (Estimate): October 30, 2012
• Last Update Submitted That Met QC Criteria: October 26, 2012
• Last Verified: October 1, 2012

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Coronary Disease; Coronary Artery Disease; Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Non-Narcotic; Adrenergic alpha-2 Receptor Agonists; Adrenergic alpha-Agonists; Adrenergic Agonists; Hypnotics and Sedatives; Dexmedetomidine
• Other Study ID Numbers: 2012001