Sequestration of Platelets Prior to Bypass Reduces Bleeding After Cardiac Surgery

Post-operative Administration of Platelet Rich Plasma Sequestered Prior to Cardiopulmonary Bypass Reduces the Coagulopathy Associated With Complex Cardiac Surgery

Excessive bleeding is common after cardiac surgery. This may result in patients receiving a blood transfusion or suffering the life-threatening complication of cardiac tamponade. Tamponade is when excessive bleeding compresses the heart and prevents it from pumping properly. A major reason for the bleeding is the damage done to platelets by the cardiopulmonary bypass (CPB) machine. Often patients receive platelets and plasma from blood donors to try to reduce the bleeding post-operatively. The investigators plan to take platelets and plasma from patients before they are damaged. They would then return these 'undamaged' sequestered platelets to the patients after the bypass machine is no longer needed. Therefore, the investigators' primary question is whether platelet sequestration would reduce the bleeding problems that occur following cardiac surgery. They will evaluate bleeding problems using thromboelastography, which provides a comprehensive assessment of both how blood clots form and their strength. If sequestration reduces bleeding problems following cardiac surgery then it may reduce the chance of patients receiving blood products from donors. Although donated blood is thoroughly tested, its use does expose patients to the risk of transfusion errors, blood borne infections and reactions. Avoiding its use would be very desirable.

Study Overview

• Status: Terminated
• Conditions: Blood Coagulation Disorders; Blood Platelet Disorders; Cardiopulmonary Bypass; Cardiac Surgical Procedures
• Intervention / Treatment: Procedure: Platelet rich plasma sequestration

Detailed Description

Hypothesis:

Patients undergoing repeat median sternotomy or requiring prolonged cardiopulmonary bypass (CPB) often develop a coagulopathy at the end of surgery. We propose sequestering plasma and platelets from these patients prior to CPB and thus prior to the dilution and platelet damage that occurs with CPB. We hypothesise that if these plasma and platelets are stored properly during CPB, and administered at the end of the operation, they will reduce any coagulopathy and the associated bleeding.

Study population:

Patients undergoing repeat median sternotomy, mitral valve repair, double valve operations, aortic surgery, or combined valve and coronary artery surgery.

Exclusion criteria will include those with anaemia, thrombocytopenia, unstable angina, anti-platelet therapy within the previous seven days, known or symptomatic cerebrovascular disease, known disorders of haemostasis, aprotinin sensitivity and pregnancy.

Intervention:

Patients will be randomised by a closed envelope technique to receive platelet/plasma sequestration or not. Patients randomised to undergo sequestration will have 14 mL/Kg blood taken. The blood will be separated into red cells and platelets/plasma. Anaemia would be prevented by returning the processed red blood cells to the patient. We will store platelets at 20-24°C/room temperature on a platelet rocker according to guidelines from the National Blood Service.

Assessment of coagulation:

Patients' coagulation status will be evaluated before and after surgery. Four methods will be employed to comprehensively assess the coagulation system: platelet counts and conventional clotting studies; heparin levels; thromboelastography; and platelet function analyser.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Phase 2

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, SW3 6LY
    • Royal Brompton Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

Adult patients undergoing cardiac surgery that involves:

• Repeat median sternotomy
• Mitral valve repair
• Double valve operations
• Combined valve and coronary surgery
• Anticipated prolonged cardiopulmonary bypass

Exclusion Criteria:

• Pre-operative anaemia
• Pre-operative thrombocytopenia
• Unstable angina
• Anti-platelet therapy (e.g. aspirin, clopidogrel) within the previous 7 days
• Known or symptomatic cerebrovascular disease
• Known disorders of haemostasis
• Aprotinin sensitivity
• Pregnancy.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Platelet sequestration; Sequestration of platelet rich plasma before cardiopulmonary bypass	Procedure: Platelet rich plasma sequestration; Venesection of blood (14 ml/kg) and separation to red cells and platelet rich plasma.; Other Names: Haemonetics cell salavage system
No Intervention: Standard care; No platelet rich plasma sequestration undertaken before cardiopulmonary bypass (usual practice)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Incidence of coagulation abnormalities as assessed by thromboelastography and platelet function analyser	At end of surgery (usually <1 day)

Secondary Outcome Measures

Outcome Measure	Time Frame
Volume of blood lost into chest drains during first 24 post-operative hours	24 hours
Volume of blood product administered during first 24 post-operative hours	24 hours
Length of stay in the intensive care unit (ICU)	Usually < 30 days
ICU mortality	Usually < 30 days
Incidence of surgical re-exploration	Hospital admission (usually < 30 days)

Collaborators and Investigators

• Sponsor: Royal Brompton & Harefield NHS Foundation Trust
• Investigators: Principal Investigator: Simon J Finney, MBChB, PhD, Royal Brompton & Harefield NHS Foundation Trust; Principal Investigator: Andrea Kelleher, MBBS, Royal Brompton & Harefield NHS Foundation Trust; Principal Investigator: Judith Hall, Royal Brompton & Harefield NHS Foundation Trust; Principal Investigator: Simon Davidson, PhD, Royal Brompton & Harefield NHS Foundation Trust

Study record dates

Study Major Dates

• Study Start: August 1, 2006
• Primary Completion (Actual): July 1, 2009
• Study Completion (Actual): July 1, 2009

Study Registration Dates

• First Submitted: August 1, 2006
• First Submitted That Met QC Criteria: August 1, 2006
• First Posted (Estimate): August 2, 2006

Study Record Updates

• Last Update Posted (Estimate): April 14, 2016
• Last Update Submitted That Met QC Criteria: April 13, 2016
• Last Verified: April 1, 2016

More Information

Terms related to this study

• Keywords: Cardiopulmonary bypass; Blood component removal
• Additional Relevant MeSH Terms: Pathologic Processes; Cardiovascular Diseases; Vascular Diseases; Hematologic Diseases; Hemorrhagic Disorders; Hemostatic Disorders; Blood Coagulation Disorders; Disease; Blood Platelet Disorders
• Other Study ID Numbers: 2006IC003B