In this large retrospective cohort study, our results showed that the hospital stay of patients who received a blood transfusion was significantly longer, the incidence of postoperative vomiting and wound complications was higher than that of patients without a blood transfusion, and the postoperative inflammatory index fluctuated more drastically in patients who received a blood transfusion.
The main bleeding site in postpartum hemorrhage is the uterus(10). When postpartum hemorrhage occurs, the uterine muscle tissue is hypoxic and does not contract well, and the sensitivity of oxytocin receptors decreases. Repeated hemostasis operations increase further damage to the uterine muscles(10). At the same time, the sinusoids on the dissected surface of the placenta cannot be closed, and fibrinogen deposition and thrombosis do not play a role(10). Therefore, obstetric hemorrhage has the characteristics of a fast speed, large volume, difficult evaluation, and difficulty of stopping bleeding quickly.
Blood transfusion is the most common method for the clinical treatment of patients with obstetric hemorrhage. It effectively solve the patient’s anemia caused by excessive blood loss, helps maintain blood volume and blood pressure, exerts a certain preventive effect on patients with shock, and improves the prognosis of patients(11, 12). However, a large number of clinical practices have found that after patients with obstetric hemorrhage receive a large transfusion of blood, although their life and safety are guaranteed, they also experience certain side effects, mainly manifested as abnormal blood coagulation(13). Due to the long-term storage of blood, platelets and coagulation factors are destroyed to a certain extent. After entering the patient’s body, the active coagulation factors will be reduced, which will lead to coagulation dysfunction.
In terms of postoperative complications, a large number of allogeneic blood transfusions will significantly increase the incidence of postoperative complications, such as blood transfusion-related lung injury (14) and surgical site infections (15). In the present study, the incidence of postoperative complications in patients receiving blood transfusion increased significantly during the perioperative period. Zhang et al reported that a perioperative blood transfusion potentially increases the risk of postoperative complications and is associated with a prolonged LOS(9). Furthermore, another study reported that perioperative blood transfusion may be associated with worse outcome in patients undergoing surgery(16). After blood transfusion, the immune system changes significantly. These changes have been shown to be potential mechanisms that increase the risk of infection, graft-versus-host disease and postoperative complications after blood transfusion(17). According to recent studies, the suppression of perioperative immune function may promote postoperative metastasis and recurrence in patients with cancer(18). A large number of studies have also shown that certain markers of blood components, such as NLR, LMR and SII, comprehensively indicate the balance of the host immune system and have been considered indicators related to the prognosis(19, 20). An increased NLR or SII and decreased LMR are associated with a poor prognosis in patients undergoing surgery(21, 22). Based on our results, patients undergoing a blood transfusion exhibit greater fluctuations in these systemic inflammatory markers after surgery. Thus, blood transfusion is related to the strong suppression of immune function and/or inflammatory response disorders, such as a higher complication rate and longer hospital stay, in patients receiving a blood transfusion. (23)
Our research has limitations.The limitations include the following: the study was a retrospective study rather than a random controlled trial, and the data were obtained from a single center. Second, even if we perform a propensity score matching analysis, considering the various factors related to postpartum hemorrhage, we still cannot avoid the possibility of biased results due to unmeasured confounding factors.