[Analysis of cardiopulmonary bypass diluted autologous blood transfusion: a report of 5000 cases].

Objective: To explore the clinical application and experience of cardiopulmonary bypass (CPB) diluted autologous transfusion so as to provide clinical rationales for blood conservation.

Methods: At Department of Cardiothoracic Surgery, First Affiliated Hospital, Zhengzhou University, the clinical data were reviewed for 5000 CPB surgical patients without banked blood from September 1996 to March 2012 to analyze the clinical application of autologous blood transfusion and summarize the experience of depth hemodilution. No significant changes occurred in blood pressure, central venous pressure or heart rate after blood collection. The values of blood gases stayed within the normal perioperative range. The collected blood and all the remaining blood in CPB machine were reinfused to bring the postoperative level of Hb to over 90 g/L. Only 129 cases on a second thoracotomy for hemostasis required banked blood transfusion because of hemogloblin (Hb) under 70 g/L.

Results: Hb, hematocrit (Hct), pH, base excess (BE), lactate (Lac), cerebral oxygen saturation (rSO2) and arterial oxygen saturation (SaO2) indicated a statistically significant during CPB compared with pre-anesthetic (P < 0.05). The remaining indicators stayed within the normal perioperative range except for Hb and Hct. There were 146 cases of deaths. And the causes were postoperative low cardiac output (n = 34), cerebrovascular accident (n = 48), malignant arrhythmias (n = 28) and lung infection and multiple organ dysfunction (n = 36). The case fatality rate was merely 2.92%. All survivors recovered well and no heart, brain, kidney or other complications occurred.

Conclusion: Hct 15%-19% depth of hemodilution with proper cooling and anesthetic management during cardiopulmonary bypass is both safe and feasible. And neutralization heparinemia in stored blood before CPB by protamine is one of the effective methods of blood conservation.