Double-Blind Comparison of Combined General-Spinal Anesthesia to General Anesthesia for Coronary Artery Surgery

A Randomized Double-Blind Comparison of Combined General-Spinal Anesthesia to General Anesthesia for Coronary Artery Surgery

Use of neuraxial agents in anesthesia for cardiac surgery is expanding. We have used combined general-spinal anesthesia for cardiac surgery for 12 years. We hypothesized that compared to general anesthesia, the combined techniques would provide comparable intraoperative hemodynamics and improved postoperative analgesia. This study subjected these techniques to a double-blind randomized trial.

Study Overview

• Status: Completed
• Conditions: Coronary Artery Disease; Coronary Artery Bypass Surgery
• Intervention / Treatment: Procedure: spinal analgesia and anesthesia for coronary artery surgery

Detailed Description

Use of neuraxial agents in anesthesia for cardiac surgery is expanding. We have used combined general-spinal anesthesia for cardiac surgery for 12 years. We performed a trial in order to determine if our clinical impressions of the techniques would be confirmed. We hypothesized that compared to general anesthesia, the combined techniques would provide comparable intraoperative hemodynamics and improved postoperative analgesia. This study subjected these techniques to a double-blind randomized trial.

METHODS

After IRB approval, 63 consenting patients undergoing non-emergent coronary artery bypass grafting (CABG) entered a randomized, double-blind trial. Patients received lorazepam 0.03 mg/kg preoperatively, and midazolam 0.03 mg/kg during line insertion and induction. Spinal procedures, performed by an unblinded study anesthesiologist, preceded general anesthesia, which was induced with propofol and rocuronium, and maintained with isoflurane through CPB, and propofol thereafter. All caregivers were blinded to group assignment. Opioid and spinal management defined 3 groups:

GA: Sufentanil IV: 3 μg/kg induction, 1 μg/kg x 2 prn; mock spinal SO: Sufentanil IV: 0.2 μg/kg induction, 0.1 μg/kg x 2 prn; Spinal: sufentanil 50 μg, morphine 0.5 mg, hyperbaric SL: Sufentanil IV: 0.2 μg/kg induction, 0.1 μg/kg x 2 prn; Spinal: sufentanil 25 μg, morphine 0.5 mg, bupivacaine 9.75 mg, hyperbaric

When patients were stable in ICU, propofol was stopped and an extubation protocol begun. Patients received scheduled NSAID and prn opioid, IV or PO. The chi-square test and ANOVA using the Scheffe method for multiple comparisons were applied appropriately.

The primary end points of the study were analgesic requirements, visual analogue pain scores, and duration of endotracheal intubation in the intensive care unit. Secondary endpoints were intraoperative hemodynamic variables, blood catecholamine and lactate levels, anesthetic supplementation, and vasoactive drug support.

• Study Type: Interventional
• Enrollment: 63
• Phase: Phase 3

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada, T2N 2T9
      • Foothills Medical Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 25 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• patients undergoing non-emergent primary coronary artery bypass grafting using cardiopulmonary bypass

Exclusion Criteria:

• < 25 or > 80 years of age
• left ventricular ejection fraction < 35%
• receiving inotropic or intraaortic balloon therapy at time of surgery
• receiving intravenous heparin therapy at time of surgery
• pre-existing back problems in the lumbar area
• clinical or laboratory evidence of coagulopathy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
analgesic requirement in the intensive care unit
visual analogue pain scores in the intensive care unit
duration of endotracheal intubation in the intensive care unit

Secondary Outcome Measures

Outcome Measure
intraoperative hemodynamic variables
intraoperative blood catecholamine and lactate levels
intraoperative anesthetic supplementation
intraoperative vasoactive drug therapy

Collaborators and Investigators

• Sponsor: University of Calgary
• Collaborators: Canadian Institutes of Health Research (CIHR)
• Investigators: Principal Investigator: Charles L MacAdams, MD FRCPC, Department of Anesthesia, Foothills Medical Centre, University of Calgary

Publications and helpful links

General Publications

• MacAdams, CL et al. Combined general-spinal vs spinal anesthesia for coronary artery bypass grafting. Can J Anesth 73(Suppl I):A73,2003.

Study record dates

Study Major Dates

• Study Start: April 1, 2002
• Study Completion: July 1, 2003

Study Registration Dates

• First Submitted: October 19, 2005
• First Submitted That Met QC Criteria: October 19, 2005
• First Posted (Estimate): October 20, 2005

Study Record Updates

• Last Update Posted (Estimate): October 20, 2005
• Last Update Submitted That Met QC Criteria: October 19, 2005
• Last Verified: October 1, 2005

More Information

Terms related to this study

• Keywords: coronary artery bypass surgery; heart-lung machine; anesthesia, spinal; anesthesia, general
• 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; Central Nervous System Depressants; Anesthetics
• Other Study ID Numbers: CARF1