The Optimal Cell Salvage Settings to Maximize Hematocrit and Minimize Potassium Using the Cobe BRAT2 Autologous Blood Recovery Unit

Novel method for direct retransfusion reduces blood transfusions in descending and thoracoabdominal aneurysm repair

BACKGROUND

Allogenic blood product usage is associated with worse outcomes in open repair of descending and thoracoabdominal aortic aneurysms. This pilot study evaluated the safety and efficacy of a novel modification of the left heart bypass (LHB) circuit to reduce intraoperative blood transfusions.

METHODS

In modified LHB, pump suckers collected shed blood that was directly retransfused through a femoral vein cannula. In standard LHB, cellsavers were used to collect, wash, and retransfuse shed blood. Consecutive patients undergoing elective surgical descending or thoracoabdominal aneurysm repair using modified (N.=12) or standard (N.=21) LHB were compared. Intraoperative blood product use was the primary outcome. Hypotensive episodes, lactate levels, and adverse events (early mortality, spinal cord injury, renal and respiratory insufficiency) were secondary outcomes.

RESULTS

Groups were comparable regarding pre- and intraoperative variables. No perfusion-related adverse events occurred. With modified LHB, intraoperative blood product use was significantly reduced: packed red blood cells by 60% from 10 to 4 units (P=0.002), fresh frozen plasma by 70% from 17 to 5 units (P<0.001) as well as retransfused cellsaver volume by 75%, from 4500 mL to 1110 mL (P<0.001). Hemodynamic instability occurred in 1 (8.3%) vs. 6 (29%), P=0.22 and overall lactate levels were significantly reduced (P=0.045) with modified LHB. Adverse events combined occurred in 1/12 vs. (P=0.022).

CONCLUSIONS

The novel modified LHB with direct retransfusion was safe and associated with significantly reduced intraoperative blood product use, reduced lactate production and improved clinical outcomes as compared to standard LHB and could represent an important clinical improvement.

Patient blood management and patient safety

PURPOSE OF REVIEW

The particular fields within patient blood management (PBM) and patient safety reviewed here include novel insights into bleeding therapy, autologous cell salvage, and perioperative anemia therapy.

RECENT FINDING

World Health Organization has published that implementation of PBM is important but has not yet been performed in all hospitals. Two antibodies that mimic the function of FVIII, Emicizumab, and Mim8 have been developed. Tranexamic acid (TXA) has been investigated further in patients with hip surgery and shows reduction of bleeding. Thrombocytopenia in patients undergoing cardiac surgery is a particular concern that has been investigated in another trial. The use of autologous cell salvage was updated in form of a review and meta-analysis. And last but not least, intravenous iron in preoperative anemia therapy can reduce the number of transfusions, but especially iron carboxymaltose can cause hypophosphatemia.

SUMMARY

PBM should be further implemented in more hospitals. Emicizumab and Mim8 are indicated in acquired hemophilia or hemophilia A with inhibitors. TXA was confirmed to reduce bleeding. Autologous cell salvage is state of the art to reduce transfusion requirements in major cardiac and noncardiac surgery. Serum phosphate concentrations should be monitored after administration of intravenous iron compounds.