Low vs. high haemoglobin trigger for transfusion in vascular surgery: protocol for a randomised trial

Area of Science:

• Cardiovascular Surgery
• Transfusion Medicine
• Vascular Surgery

Background:

• Current red blood cell (RBC) transfusion guidelines for cardiovascular disease patients are often based on non-vascular surgery studies.
• Lower hemoglobin (hb) trigger levels may compromise blood oxygen transport, risking tissue ischemia and postoperative complications.

Purpose of the Study:

• To compare the effects of two different perioperative RBC transfusion trigger levels (hb < 8 g/dl vs. hb < 9.7 g/dl) in vascular surgery patients.
• To assess the impact of transfusion triggers on postoperative hemoglobin levels, RBC unit transfusion, and tissue oxygenation.

Main Methods:

• A single-center, open-label, blinded-assessor trial involving 58 patients over 40 years old undergoing aortic or arterial bypass surgery.
• Randomization to perioperative RBC transfusion triggered by hb < 8 g/dl or hb < 9.7 g/dl.
• Individualized fluid administration strategy optimizing cardiac stroke volume and near-infrared spectroscopy for tissue oxygenation monitoring.

Main Results:

• The trial is designed to determine if a higher hb trigger level (9.7 g/dl) leads to adequate separation of postoperative hb levels compared to a lower trigger (8 g/dl).
• It is expected to show whether the higher trigger results in transfusion of more RBC units.
• The study aims to ascertain if a higher trigger maintains better tissue oxygenation.

Conclusions:

• This trial is anticipated to provide crucial data on the optimal hemoglobin trigger for RBC transfusion in vascular surgery.
• Results will guide the design of a larger multicenter trial to evaluate significant postoperative outcomes.