The Effects of High Spinal Anesthesia on Heart Function, Stress Response and Pain Control in Aortic Valve Surgery

This study has been completed.
Sponsor:
Collaborators:
St. Boniface General Hospital Research Centre
Health Sciences Centre Foundation, Manitoba
Information provided by (Responsible Party):
Trevor William R. Lee, University of Manitoba
ClinicalTrials.gov Identifier:
NCT00348920
First received: July 5, 2006
Last updated: July 22, 2013
Last verified: July 2013
  Purpose

This study is looking at the effects of high spinal anesthesia (also known as total spinal anesthesia) combined with general anesthesia versus general anesthesia alone on the following:

Stress response: Patients undergoing aortic valve replacement surgery have a large incision and a complex operation where they must be placed on the heart-lung machine. The body reacts to the heart-lung machine, increasing the stress response.

High spinal anesthesia using local anesthetics when combined with general anesthesia has been shown to block some of the stress response to surgery and the response to the heart-lung machine. This study will examine if blood levels of stress hormones and also inflammatory mediators can be lowered with the use of high spinal anesthesia.

Heart function: High spinal anesthesia in combination with general anesthesia may help the heart work better when there is a narrowed valve (aortic stenosis). The heart may also have improved ability to pump blood with this anesthetic technique.

Lung function and post-operative pain control: After surgery, patients often have pain which prevents them from taking deep breaths and coughing. This can lead to pneumonia. This study will also examine if the post-operative pain relief provided by spinal morphine (given together with the spinal anesthetic) can provide any better pain control following surgery. By doing this, we want to see if patients can take bigger breaths after their surgery when spinal morphine is used, and try to prevent the complications that occur if patients are not able to breath deeply after surgery.


Condition Intervention
Aortic Stenosis
Procedure: High Spinal and General Anesthesia

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
Official Title: The Effects of High Spinal Anesthesia on Hemodynamics, Stress Response, Renal Function and Post-operative Pain Control in Patients Undergoing Aortic Valve Replacement for Aortic Stenosis

Resource links provided by NLM:


Further study details as provided by University of Manitoba:

Primary Outcome Measures:
  • Stress response as measured by levels of circulating epinephrine, norepinephrine, and cortisol. [ Time Frame: Multiple time points ] [ Designated as safety issue: No ]
  • Inflammatory response as measured by levels of circulating inflammatory mediators (e.g. interleukin-6, interleukin-8, interleukin-10, C-reactive protein, TNF-alpha). [ Time Frame: Multiple time points ] [ Designated as safety issue: No ]
  • Blood glucose control (amount of insulin required to keep blood glucose 5-8 mmol/L). Renal function as measured by serum creatinine. [ Time Frame: Multiple time points ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Vasopressor requirements to keep mean blood pressure between 60-80 mm Hg. [ Time Frame: Multiple time points ] [ Designated as safety issue: No ]
  • Left ventricular wall motion score index as measured by TTE and TEE. [ Time Frame: Multiple time points ] [ Designated as safety issue: No ]
  • Hemodynamics including cardiac output and cardiac index, heart rate, systemic arterial and pulmonary arterial blood pressures, central venous pressure, and systemic and pulmonary vascular resistance. [ Time Frame: Multiple time points ] [ Designated as safety issue: No ]
  • Time to extubation. [ Time Frame: Time of extubation ] [ Designated as safety issue: No ]

Enrollment: 14
Study Start Date: February 2007
Study Completion Date: July 2013
Primary Completion Date: July 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
No Intervention: 1- General Anesthesia
General Anesthesia includes administration of a routine cardiac anesthetic as per institutional norms.
Experimental: 2- High Spinal and General Anesthesia
High Spinal and General Anesthesia includes a high dose intrathecal anesthetic administered prior to the induction of a standardized cardiac general anesthetic.
Procedure: High Spinal and General Anesthesia
Spinal bupivacaine 0.75% in dextrose, 6 mls (45mg) and preservative free morphine 3 mcg/kg (to a maximum of 300 mcg).
Other Names:
  • Bupivacaine
  • Epimorph

Detailed Description:

It is hypothesized that high spinal anesthesia combined with general anesthesia decreases the intraoperative stress and inflammatory response and improve post-operative pain control and respiratory function in this patient population. It is also hypothesized that the technique will provide stable intraoperative hemodynamics during aortic valve replacement surgery.

Stress response: Levels of hormones such as epinephrine, norepinephrine and cortisol are elevated during cardiac surgery and on the initiation of cardiopulmonary bypass. This stress response has previously been shown to be blunted with the use of high spinal anesthesia when combined with general anesthesia in coronary artery bypass surgery patients (Lee, Grocott, et al).

Inflammatory response: In addition to the stress response there is also an accentuated inflammatory response. With contact of the patient's blood to the artificial bypass circuit, there is activation of various plasma protease pathways that generate multiple proinflammatory mediators. Complement levels and cytokine levels also rise. Clinical organ dysfunction involving the cardiovascular, pulmonary, renal and neurological systems can ultimately result. The effects of high spinal anesthesia on the inflammatory response that occurs with bypass have not been studied.

Hemodynamics: It has previously been shown that high-spinal anesthesia for coronary artery bypass surgery provides stable intra-operative hemodynamics (Kowalewski, MacAdams, et al; Lee, Grocott, et al.). Although the use of spinal anesthesia in patients with aortic stenosis has been considered to be relatively contra-indicated, total spinal anesthesia may actually improve cardiac function by decreasing systemic afterload and increasing myocardial contractility.

Post-operative analgesia and pulmonary function: The spinal administration of opioids, such as morphine, has been shown to improve post-operative pain management in patients having both cardiac and non-cardiac surgery (Jacobsohn, Lee, et al). Total spinal anesthesia with bupivacaine and spinal morphine combined with general anesthesia may also improve post-operative pain management and facilitate improved post-operative lung function.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Undergoing surgery for aortic valve replacement due to aortic stenosis with or without CABG.

Exclusion Criteria:

  • INR > 1.4, PTT > 40 seconds
  • platelet count < 80, 000 per microlitre
  • local infection or deformity at the site of administration of the spinal anesthetic
  • raised intracranial pressure or evolving neurological deficit at the time of surgery
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00348920

Locations
Canada, Manitoba
St. Boniface General Hospital
Winnipeg, Manitoba, Canada, R2H 2A6
Sponsors and Collaborators
University of Manitoba
St. Boniface General Hospital Research Centre
Health Sciences Centre Foundation, Manitoba
Investigators
Principal Investigator: Trevor WR Lee, MD Department of Anesthesia and Perioperative Medicine, St. Boniface General Hospital, University of Manitoba
Principal Investigator: Stephen E Kowalski, MD Department of Anesthesia, Health Sciences Centre, University of Manitoba
  More Information

Publications:
Responsible Party: Trevor William R. Lee, Site Leader, Dept. of Anesth, St. Boniface Hospital, University of Manitoba
ClinicalTrials.gov Identifier: NCT00348920     History of Changes
Other Study ID Numbers: AOTSA1
Study First Received: July 5, 2006
Last Updated: July 22, 2013
Health Authority: Canada: Ethics Review Committee

Keywords provided by University of Manitoba:
Aortic Valve
Aortic Stenosis
High Spinal Anesthesia
Total Spinal Anesthesia
Stress Response
Inflammatory Mediators
Renal Function
Hemodynamic Stability

Additional relevant MeSH terms:
Aortic Valve Stenosis
Constriction, Pathologic
Heart Valve Diseases
Heart Diseases
Cardiovascular Diseases
Ventricular Outflow Obstruction
Pathological Conditions, Anatomical
Anesthetics
Bupivacaine
Central Nervous System Depressants
Physiological Effects of Drugs
Pharmacologic Actions
Central Nervous System Agents
Therapeutic Uses
Anesthetics, Local
Sensory System Agents
Peripheral Nervous System Agents

ClinicalTrials.gov processed this record on August 27, 2014