[Alternative mechanical autotransfusion. Hemofiltration vs. hemoseparation].

Area of Science:

• Cardiovascular Surgery
• Blood Transfusion
• Biomedical Engineering

Background:

• Intraoperative blood loss during vascular surgery necessitates effective blood management strategies.
• Autotransfusion techniques aim to reinfuse the patient's own blood, reducing the need for allogeneic transfusions.
• Concentrating shed blood requires methods that maintain blood product quality.

Purpose of the Study:

• To investigate the effects of haemoconcentration on shed blood quality using centrifugation (cell separation) versus haemofiltration.
• To compare the efficiency and blood product quality resulting from these two haemoconcentration techniques.
• To evaluate the potential of haemofiltration as an alternative for intraoperative autotransfusion.

Main Methods:

• An in-vitro study comparing centrifugation and haemofiltration for concentrating shed blood from vascular surgery patients (n=10 each).
• Measurement of various blood parameters in patients, shed blood, and post-concentration samples.
• Assessment of coagulation activation, free hemoglobin, elastase, thrombocytes, plasma proteins, and hematocrit.

Main Results:

• Haemofiltration was faster (1.2 minutes) than cell separation (3.0 minutes).
• Cell separation removed thrombocytes, elastase, free hemoglobin, and plasma proteins (including antithrombin III and fibrinogen), with higher red cell concentration (hct 55% vs 35%).
• Haemofiltration preserved plasma proteins and resulted in tolerable heparin levels, showing potential for autotransfusion without needing fresh frozen plasma.

Conclusions:

• Haemofiltration is a promising alternative for intraoperative autotransfusion due to its speed and preservation of essential plasma proteins.
• This method avoids the need for additional fresh frozen plasma, particularly beneficial in cases of significant blood loss.
• Both procedures were safe, with no activated clotting factors observed post-procedure.