A recent webinar on cell salvage and the ROTEM system hosted by the TPE team at the Blood Service was a great opportunity to come up to speed on new patient blood management techniques.
This joint presentation was given by Peter Frantzis, Head Perfusionist at the Royal Adelaide Hospital and Associate Professor David Roxby, Head of SA Pathology Transfusion Services at Flinders Medical Centre.
Here’s some of the key information from the session:
What is cell salvage?
Intraoperative cell salvage (ICS) is performed as a blood conservation technique and is frequently used in cardiothoracic and vascular surgery as these areas traditionally have high levels of blood usage. It has been gaining more attention lately as transfusion risks have become more fully appreciated, patient blood management (PBM) guidelines have been released and the National Blood Authority of Australia has recently implemented guidelines for intraoperative cell salvage (March 2014).
What happens during the cell salvage process?
During the process, the surgeon aspirates any bleeding into a collection reservoir, the blood is filtered and anticoagulant is added in order to remove debris and prevent clotting. The blood is then centrifuged and washed to produce separated red blood cells (RBC) with a high Hct, suspended in 0.9% normal saline for re-infusion to the patient (autotransfusion).
What are the benefits of cell salvage?
Cell salvage helps to reduce the requirement for allogenic blood transfusion during cardiothoracic and vascular surgery and when combined with improved bypass circuitry/techniques and haemofiltration, patients can even have elevated Hb levels post-surgery. ICS is also very useful for Jehovah witness patients who refuse blood transfusions as a circuit is set up between the patient, heart lung machine and the autotransfusion device providing continuity and ensuring all their red blood cells are returned.
What is the ROTEM system?
The ROTEM (rotational thromboelastometry) system is actually a modified version of thromboelastography [TEG], probably a more familiar term to many of us. The ROTEM system provides real-time measurement of the interactions of coagulation factors, inhibitors and cellular components during the phases of clotting and subsequent lysis over time. The aim of this method is to mimic the sluggish flow of blood in veins.
What are the benefits of ROTEM?
The ROTEM system provides a point of care (POC) test and is proving to be an extremely useful source of information. Clinicians are able to assess their patients before surgery (to determine if coagulopathies are present), during surgery (to determine if coagulopathies are developing) and after surgery (when trying to establish the cause of bleeding). It can also be located in either the operating theatre, transfusion laboratory or networked between these areas. ROTEM results are also available much quicker than traditional coagulation tests like INR, APTT, Fibrinogen and platelet count and enable the treating clinician to discriminate between coagulation related conditions in a more efficient manner.
The benefits of coagulation POC testing have also been highlighted in an article in Anesthesiology, where the randomised clinical trial was terminated 6 months early as initial results demonstrated that haemostatic therapy based on POC testing significantly reduced patient exposure to allogenic blood products and provided significant benefits with respect to clinical outcomes.
Additional information and extra reading
The Blood Service clinical website transfusion.com.au contains excellent information about PBM, blood conservation and the PBM guidelines. In fact, the PBM guidelines: Module 2 Perioperative actually state that ICS is recommended for adult patients undergoing surgery in which substantial blood loss is anticipated and also mentions that TEG and TEG-based POC tests should be considered in adult patients undergoing cardiac surgery.
If you would like more information on these topics, this joint webinar was recorded for educational purposes and can be accessed in Transfusion online learning.
– Tanya Raison, Project Officer, TPE