Clinical and Chemical Outcomes Following Cardiac Surgery: The Post-Operative Effects of MUF (MUF)

May 22, 2013 updated by: University of Saskatchewan

Clinical and Chemical Outcomes Following Cardiac Surgery: The Post-Operative Effects of Modified Ultrafiltration (On-line MUF) and Off-line (MUF)

It is hypothesized that on-line modified ultrafiltration (MUFF) post-cardiopulmonary bypass will result in improved patient outcomes over the 12-hour post-operative period as compared to control and off-line MUFF.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Current practice in cardiac surgery requiring cardiopulmonary bypass (CPB) dictates the salvage of the residual circuit volume at the end of the procedure into an autologous recovery system. This system uses the centrifugation method (CF) to separate whole blood into red blood cells (RBCs) and plasma components (Sutton et al, 1993). The RBCs are then washed with normal saline and re-infused into the patient as needed while the plasma components are discarded.

While this technique produces a product with a high haemoglobin (Hb), the main disadvantage of this process is the loss of plasma protein and clotting factors (Samolyk et al, 2005).

The Modified Ultrafitration (MUF) is a standard of care technique that was originally used on pediatric patients undergoing cardiac surgery with CPB. Following CPB while the aorta is still cannulated, MUF uses an inline hemofilter to concentrate the patients total blood volume thereby increasing Hb, plasma proteins, systemic blood pressure, and cardiac index while decreasing cytokines and post-operative bleeding (Kiziltepe et al. 2001).

According to a task-force on evidence based surgery (the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesia) the use of modified ultrafiltration (online-MUF) is indicated for blood conservation and reduction of post-operative blood loss in adult cardiac operations using cardiopulmonary bypass (CPB) (Ferraris et al 2011). Moreover, Luciani et al. 2001, showed significantly lower levels of GI, neurologic and cardiac complications in patients who underwent on-line MUF following cardiac surgery as compared to those who did not. They also demonstrated a significantly lower mortality at 30 days follow-up in patients receiving online MUF as compared to control. Boodhwani et al. (2006) demonstrated that the use of online MUF was associated with a 0.72 unit reduction in blood transfused and a reduction of post-operative loss. The disadvantages to this technique are the time required (10-15 min), delays protamine administration, and the requirement of anaesthesia cooperation for pressure management. According to the Proceedings of the American Society of Extracorporeal Technology International Conf. March 9, 2013, online MUF works best and is recommended for smaller patients 75 kg or less because the effect of concentration of the blood volume is greater in smaller patients as compared to larger patients. In house data collected by our Department of Clinical Perfusion at the Royal University Hospital has demonstrated that 70% of the smaller patients undergoing cardiac surgery (mainly women) receive allogeneic transfusion peri- and post-operatively.

Off-line MUFF, another standard of care technique, is used after separation from CPB and decannulation. This technique uses a hemofilter to concentrate the residual CPB volume to produce a product which is more analogous to whole blood as compared to that processed by the CF method. Recently, our research group has shown that after 12-hours post-operatively patients' biochemical (total protein and albumin) and clinical parameters (vasoactive inotrope score and fluid balance) were significantly improved when patients' residual CPB volume underwent multiple-pass hemofiltration as compared to the CF (McNair et al. (2013), Journal of Cardiothoracic and Vascular Anaesthesia, In Press). Recently, it has been demonstrated that following cardiac surgery, the post-operative use of vasoactive inotropes is decreased when the residual CPB volume is processed by the offline MUF method as compared to the CF method (Coli et al 2012; McNair et al. (2013), Journal of Cardiothoracic and Vascular Anaesthesia, In Press). The disadvantages of on-line MUFF are the possible entrainment of air into the arterial line and prolonged time for protamine administration. The disadvantages of off-line MUFF are inadequate clearance of heparin by the hemofilter and prolonged processing time.

There is a need for the proposed study because it will help to determine whether there is any difference in patient outcomes between the use of on-line MUF and off-line MUF. Our study will also demonstrate which method is better at enhancing clinical (volume of allogeneic transfusion, chest tube loss, fluid balance length of stay and ventilation time) and biochemical (Hb, total protein, albumin and markers of inflammation) outcomes during the 12-hour post-operative period.

The data gathered from this study may save smaller patients from exposure to allogeneic transfusions during the 12-hour postoperative period. This study will also determine which method our institution will use to better serve our patients, allowing them to have a safer, shorter, transfusion-free recovery during the post-operative period.

Study Type

Interventional

Enrollment (Anticipated)

90

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Saskatchewan
      • Saskatoon, Saskatchewan, Canada, S7N 0W8
        • Royal University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

36 years to 76 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • male and female
  • patient weighs 75 kg or smaller
  • 40-80 years of age
  • elective or urgent cardiac surgery

Exclusion Criteria:

  • emergent surgery
  • severe anemia
  • severe kidney dysfunction
  • ejection fraction of less than 30%

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Control (CF)
Centrifugation Method (CF): currently used to separate whole blood into red blood cells (RBCs) and plasma components. The RBCs are washed with normal saline and re-infused into the patient, while the plasma portion is discarded.
Procedure: Centrifugation Method
Currently used to separate whole blood into red blood cells (RBCs) and plasma components. The RBCs are washed with normal saline and re-infused into the patient, while the plasma portion is discarded.
Experimental: Online MUF
Online MUF: hemofilter is used online while the heart-lung machine is connected to the patient.
Procedure: Online MUF
Hemofilter is used online while the heart-lung machine is connected to the patient.
Experimental: Offline MUF
Offline MUF: hemofilter is used offline when the heart-lung machine is not connected to the patient.
Procedure: Offline MUF
Hemofilter is used offline when the heart-lung machine is not connected to the patient.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Post-Operative Volume of Chest Tube Drainage
Time Frame: 12 hours
Our primary outcome variable is the post-operative volume of chest tube drainage.
12 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Biochemical Variables
Time Frame: 12 hours
Biochemical variables include Hb, albumin fibrinogen, and total protein.
12 hours
Clinical Variables
Time Frame: 12 hours
Clinical variables include volume of allogeneic transfusion, length of stay in ICU, intubation time, and vasoactive inotrope score.
12 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Saskatchewan

Investigators

  • Principal Investigator: Erick D McNair, PhD, Clinical Assistant Professor, Department of Surgery, Cardiovascular Surgery

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2013

Primary Completion (Anticipated)

July 1, 2014

Study Completion (Anticipated)

October 1, 2014

Study Registration Dates

First Submitted

May 14, 2013

First Submitted That Met QC Criteria

May 22, 2013

First Posted (Estimate)

May 29, 2013

Study Record Updates

Last Update Posted (Estimate)

May 29, 2013

Last Update Submitted That Met QC Criteria

May 22, 2013

Last Verified

May 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 13-143

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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