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Completed

NCT Number: NCT02465125

The Transfusion Triggers in Vascular Surgery Trial

BACKGROUND

* Vascular surgical patients often receive red blood cell (RBC) transfusions in the peri-operative period * RBC transfusion may lead to improved outcome but on the other hand the intervention may be harmful * Danish Health and Medicines Authority recommends transfusion of RBC at hemoglobin below 5 mmol/L while local clinical guidelines recommend transfusion of RBC to maintain hemoglobin levels above 6 mmol/L * A large randomized clinical trial is needed to evaluate the efficacy and safety of RBC transfusion in patients undergoing vascular surgery. * A trial examining the effect of RBC transfusion on tissue oxygenation is used to test the trial-design and feasibility for a trial evaluating post-operative mortality and morbidity.

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Key information

Conditions

Atherosclerosis Anemia Aneurysm Aortic Aneurysm Aortic Aneurysm, Abdominal Aortic Diseases Arterial Occlusive Diseases Arteriosclerosis Cardiovascular Diseases Hematologic Diseases Hemic and Lymphatic Diseases Vascular Diseases

Age range

40 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Slagelse Hospital

Slagelse, Region Sjælland, 4200, Denmark

About this study

DESIGN Single-center, randomized, open-label trial including vascular surgical patients for peri-operative red blood cell (RBC) transfusion.

If the patient drops out of the trial, either at his/her own request or due to withdrawal from active therapy, the patient will be followed up in the intention-to-treat analyses.

PROTOCOL SUSPENSION

The patient can temporarily be suspended from the protocol in the following circumstances, if the clinician in charge finds indication for blood transfusions not adhering to the planned transfusion threshold:

  • Uncontrollable bleeding, defined as loss of surgical hemostasis resulting in overt or imminent hemodynamic instability with insufficient tissue oxygenation and increasing lactate production OR
  • Hypotension unresponsive to fluid replacement OR
  • Decompensated heart failure OR
  • Stroke, extremity- and intestinal ischaemia

SAMPLE SIZE With a total of 50 randomised patients, the trial is powered to

  • Show difference in mean postoperative hemoglobin of 1.0 mmol/L. With a power of 95%, 5% significance and a standard deviation of 0.9 mmol/L.
  • Show a difference in 2 units (600 mL) of RBC transfused based on a standard deviation of RBC transfusion volume of 717 mL, with a power of 80 % and 5% significance
  • Produce a 97.5% confidence interval (CI) equal to the sample adherence prevalence plus or minus 8% when the true prevalence of adherence is hypothesized to be 90%
  • Detect a difference in near infrared spectroscopy-determined tissue oxygenation (ScO2) of 6 % during surgery. With a power of 80%, 5% significance and a ScO2-standard deviation of 7%

TIME-LINE The first patient is expected to be randomized June 8th 2015, the last will be randomized March 31st 2016 and the trial database is expected to be closed ultimo June 2016. The main manuscript will be submitted shortly thereafter.

PROTOCOL AMENDMENTS

  • The Ethical Committee of Region Zealand has approved a protocol amendment of March 29th 2016 for permission of extending the trial period to the end of 2016.
  • On September 20th 2016 The Ethical Committee of Region Zealand approved a protocol amendment of September 16th 2016 for permission of extending the sample size to 58 patients and extending the trial period to June 31st 2017.

The 2nd amendment was submitted to compensate for an unexpected high rate of patients randomised postoperatively and thus to secure a sufficient sample size (n=44) for the primary outcome measure, postoperative Hb, and the secondary outcome measures NIRS and ROTEM.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients for planned open repair of the abdominal aorta or infrainguinal arterial bypass
  • Hemoglobin < 6 mmol/L

Exclusion criteria

  • Documented wish against transfusion
  • Previous serious adverse reaction with blood products
  • Unable to understand the benefits and risks of testing
  • Previous participation in trial

Treatment and study plan

red blood cell transfusion

Biological

Other names: erythrocyte transfusion

Primary outcomes

  1. Mean Post-operative hemoglobin (longitudinal outcome)

    Time frame: Day 0 - 15

    Day 0 is the hemoglobin measured upon arrival at the recovery room or at the intensive care unit depending on what level of care the patient needs after surgery.

Secondary outcomes

  1. Units of red blood cells transfused (count data)

    Time frame: 30 days after operation

    During 30 day trial period

  2. Recruitment rate with 95% confidence interval

    Time frame: Day -1 (day before operation)

    Defined as the ratio of: number of patients included divided by the number of patients eligible (fulfilling the inclusion criteria)

  3. Protocol suspension

    Time frame: 30 days after operation

    Number of patients having their protocol suspended after primary inclusion due to hemodynamic instability

  4. Protocol adherence

    Time frame: 30 days after operation

    Adherence to hemoglobin concentrations used for transfusion triggers

  5. Intraoperative tissue oxygenation

    Time frame: Participants will be monitored during their stay at the operation theatre, an expected average of 3 hours

    The outcome measure is defined as lowest values and area-under-baseline calculations. Baseline is defined as the average saturation value over a 1-min period after the patient has been fluid optimized after induction of anesthesia, before start of surgery.

  6. Changes in coagulation competence measured by rotational thromboelastometry (ROTEM)

    Time frame: An expected average time frame of 3 hours

    Changes in coagulation competence will be the baseline ROTEM level (before induction of anesthesia) compared to the end of surgery ROTEM level.

  7. Severe adverse events

    Time frame: 30 days after operation

    myocardial injury, acute kidney injury, 30-days mortality, ischemic stroke, severe adverse transfusion reactions

  8. Explorative Outcomes

    Time frame: 90 days after operation

    • Major cardiovascular events (acute myocardial infarction, stroke, renal replacement therapy, vascular reoperation and amputation) (dichotomous outcome) AND
    • Days alive outside hospital within 90 days (count data)

Sponsors and collaborators

Lead sponsor

Naestved Hospital

Other

Collaborators

  • Copenhagen Trial Unit, Center for Clinical Intervention Research
  • Research Unit, Naestved, Region Zealand, Denmark.

Registry information

Official study title

The Transfusion Triggers in Vascular Surgery Trial: Two Different Transfusion Triggers for Postoperative Haemoglobin Separation and Adherence to Transfusion Strategies in Vascular Surgery: a Randomised Clinical Feasibility Trial

Acronym: TV

Important dates

Study start
2015
Primary completion
2016
Study completion
2017
First posted
Jun 8, 2015
Registry last updated
Jul 25, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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