Hemorrhage or even massive hemorrhage in PPP patients with placenta accrete during cesarean section is common in clinical practice, which may lead to serious outcomes such as hysterectomy and maternal death . PRBCs transfusion as a routine intraoperative treatment for cesarean section can effectively improve the decreased oxygen saturation capacity and tissue perfusion caused by intraoperative blood loss, saving the patient's life at a critical moment . However, blood transfusion can also result in increased risk of infection and alloimmunization, transfusion-related lung injury, hemolytic reactions, fever and allergic reactions. In addition, massive PRBC infusion is strongly associated with poor short- and long-term clinical prognosis of patients . Therefore, preoperative identification of PPP patients with placenta accrete requiring blood transfusion provides great assistance to clinicians in patient management and blood bank resource deployment. In this study, after performing a comprehensive analysis of the preoperative and intraoperative clinical data collected from 428 PPP patients with placenta accrete, we constructed a prediction model based on blood routine and coagulation parameters by LASSO regression model, and finally developed a clinically applicable nomogram that can accurately predict intraoperative PRBCs infusion. Subsequently, we performed an internal validation of the performance of this nomogram, and the results revealed that this nomogram had good discrimination and calibration and was able to accurately predict the PRBCs infusion risk during delivery.
During pregnancy, previous studies have proved that pregnant women undergo significant physiological anemia, increase in coagulation factors, decrease in anticoagulation factors and decrease in fibrinolytic activity and other changes in hemodilution and hemostatic coagulation . What’s more, obstetric bleeding accompanied by coagulation imbalances such as massive depletion of coagulation factors and dilutive coagulation disorders can aggravate bleeding . Thus, it is clear that preoperative blood routine and hemagglutination indexes are key factors influencing intraoperative PRBCs transfusion in PPP patients with placenta accrete. Most of the blood routine and hemagglutination parameters have been demonstrated to correlate significantly with blood transfusion. For example, Hb and HCT levels were excellent predictors of PRBCs transfusion and could be used for transfusion management during delivery . Jeffrey and colleagues also identified specific thresholds for Hb and HCT in their study that can be used to guide PRBCs infusion . RDW served as an important variable in the perioperative transfusion risk of patients undergoing cardiac surgery . In Australia and New Zealand, platelet counts, INR and fibrinogen concentrations are included into the guidelines to direct PRBCs transfusion in intensive care units . The level of aPTT in septicemic patients treated with modern extracorporeal membrane oxygenation (ECMO) was significantly and positively correlated with the need for transfusion at the time of treatment . However, the results of these studies were independent of each other. Our study is a comprehensive analysis that incorporates blood routine and coagulation parameters as well as the clinical characteristics of the patients to develop a nomogram to stratify patients according to the risk of PRBCs transfusion during delivery. This study is unique in that it identified and internally validated a predictive model for intraoperative PRBCs transfusion in PPP patients with placenta accrete including a wide range of preoperative variables using retrospective data from a large cohort, which was not available in previous studies.
EBO has become an increasingly widely used procedure that provides rapid and effective hemostasis to reduce bleeding during delivery in PPP patients and has a significant benefit in preserving the uterus [18, 19]. However, there are some shortcomings to EBO. For example, the application of EBO has some chance of arterial thrombosis and acute renal impairment and can also bring the fetus a dose of x-ray radiation [20, 21]. Interestingly, zhu found that ultrasound could be used instead of digital subtraction angiography (DSA) to guide the installation of the intra-arterial balloon , which could reduce X-ray radiation to the fetus. Therefore, the judicious application of EBO can largely reduce the amount of intraoperative hemorrhage and the occurrence of balloon catheter-related complications. In our study, although no difference in the application rate of EBO was observed between the transfused and non-transfused group, the reduction in intraoperative PRBCs requirement for the application of EBO could be seen in the nomogram, which was consistent with previous study .
Admittedly, our study has some limitations. The study was limited by its retrospective design and may have suffered from selection bias. In addition, transfusion rates by different obstetricians, duration of surgery, intraoperative blood loss and choice of intraoperative hemostasis methods are important factors affecting transfusion rates in PPP patients with placenta accrete undergoing cesarean section. Finally, our study was a single-center cohort. Future data from well-designed studies involving multiple centers and a large number of patients are needed to robustly assess and validate the validity of our findings.