Beyond the operating room: preservation of blood quality and erythrocyte function in postoperative salvaged mediastinal blood

Abstract

Background - Postoperative hemorrhage is a major complication in cardiovascular surgery, and whether to salvage and reinfuse postoperative shed blood remains controversial. The quality and erythrocyte function of this blood have not been well defined, making clinical decision-making challenging. This study compared postoperative autologous cell-salvaged blood (Postop-ACS) with intraoperative salvaged blood (ICS) and stored packed red blood cells (PRBC).

Materials and methods - This in vitro observational study analyzed 60 blood samples (20 per group): Postop-ACS, ICS, and mid-storage (stored for 15-20 days) PRBC. The salvaged samples were processed using a cell saver. Assessed parameters included hemoglobin, hematocrit, pH, potassium, glucose, lactate, hemolysis rate, erythrocyte deformability, morphology, 2,3-diphosphoglycerate (2,3-DPG) and ATP levels.

Results - All groups met international hemolysis standards (<0.8%). Regarding blood quality, the median [interquartile range] Postop-ACS hemoglobin (19.4 [16.0-19.7] g/dL) and hematocrit (56.3 [46.5-59.0]%) levels were comparable to those of PRBC (18 [17-19] days), with near physiological pH (7.34 [7.31-7.40]); potassium (1.10 [0.91-1.25] mmol/L), glucose (0.88 [0.84-0.98] mmol/L), and lactate
(0.45 [0.20-0.90] mmol/L) levels were significantly lower than those of mid-storage PRBC (all p<0.001) and similar to ICS (all p>0.05). Regarding erythrocyte function, Postop-ACS had significantly higher 2,3-DPG (12.00 [9.24-13.32] μmol/gHb), ATP (5.59 [5.27-5.93] μmol/gHb), and deformability (0.88 [0.77-0.93]) than PRBC (all p<0.05), but comparable to those of ICS (all p>0.05). Erythrocyte morphology remained biconcave, discoid in all groups.

Discussion - Postop-ACS showed comparable quality and more physiological metabolic and erythrocyte functional profiles relative to mid-storage PRBC, with results similar to ICS. These findings support postoperative autologous cell salvage as a physiologically favorable strategy to enhance patient blood management in cardiovascular surgery.