Purpose: Patients undergoing cardiac surgery with extracorporeal circulation (ECC) frequently
present haemorrhages as a complication associated with high morbidity and mortality. One of
the factors that influences this risk is the volume of blood infused during surgery. The objective of this
study was to determine the optimal volume of autologous blood that can be processed during cardiac
surgery with ECC. We also determined the number of salvaged red blood cells to be reinfused into the
patient in order to minimize the risk of haemorrhage in the postoperative period.
Methods: This was an observational retrospective cross-sectional study performed in 162 ECC cardiac
surgery patients. Data regarding the sociodemographic profiles of the patients, their pathologies and
surgical treatments, and the blood volume recovered, processed, and reinfused after cell salvage were
collected. We also evaluated the occurrence of postoperative haemorrhage.
Results: The volume of blood infused after cell salvage had a statistically significant effect (p < 0.01) on
the risk of post-operative haemorrhage; the receiver operating characteristic sensitivity was 0.813 and
the optimal blood volume cut-off was 1800 ml. The best clinical outcome (16.7% of patients presenting
haemorrhages) was in patients that had received less than 1800 ml of recovered and processed autologous
blood, which represented a volume of up to 580 ml reinfused red blood cells.
Conclusion: The optimum thresholds for autologous processed blood and red blood cells reinfused into
the patient were 1800 and 580 ml, respectively. Increasing these thresholds augmented the risk of haemorrhage
as an immediate postoperative period complication.