Blood loss and blood transfusion at caesarean section: a prospective observational study covering 30 years

Construction and effect evaluation of prediction model for red blood cell transfusion requirement in cesarean section based on artificial intelligence

OBJECTIVES

This study intends to build an artificial intelligence model for obstetric cesarean section surgery to evaluate the intraoperative blood transfusion volume before operation, and compare the model prediction results with the actual results to evaluate the accuracy of the artificial intelligence prediction model for intraoperative red blood cell transfusion in obstetrics. The advantages and disadvantages of intraoperative blood demand and identification of high-risk groups for blood transfusion provide data support and improvement suggestions for the realization of accurate blood management of obstetric cesarean section patients during the perioperative period.

METHODS

Using a machine learning algorithm, an intraoperative blood transfusion prediction model was trained. The differences between the predicted results and the actual results were compared by means of blood transfusion or not, blood transfusion volume, and blood transfusion volume targeting postoperative hemoglobin (Hb).

RESULTS

Area under curve of the model is 0.89. The accuracy of the model for blood transfusion was 96.85%. The statistical standard for the accuracy of the model blood transfusion volume is the calculation of 1U absolute error, the accuracy rate is 86.56%, and the accuracy rate of the blood transfusion population is 45.00%. In the simulation prediction results, 93.67% of the predicted and actual cases in no blood transfusion surgery; 63.45% of the same predicted blood transfusion in blood transfusion surgery, and only 20.00% of the blood transfusion volume is the same.

CONCLUSIONS

In conclusion, this study used machine learning algorithm to process, analyze and predict the results of a large sample of cesarean section clinical data, and found that the important predictors of blood transfusion during cesarean section included preoperative RBC, surgical method, the site of surgery, coagulation-related indicators, and other factors. At the same time, it was found that the overall accuracy of the AI model was higher than actual blood using. Although the prediction of blood transfusion volume was not well matched with the actual blood using, the model provided a perspective of preoperative identification of high blood transfusion risks. The results can provide good auxiliary decision support for preoperative evaluation of obstetric cesarean section, and then promote the realization of accurate perioperative blood management for obstetric cesarean section patients.

Effect of blood transfusion during cesarean section on postpartum hemorrhage in a tertiary hospital over a 4-year period

Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and death worldwide. The history of cesarean section and the occurrence of placenta previa were significantly associated with the increase in blood transfusion. Therefore, to prevent PPH, it is important to understand the effect of blood transfusion during cesarean section on postpartum hemorrhage. The purpose of this study is to determine the cause of blood transfusion during cesarean section, especially large amounts of blood transfusion, and to take measures to reduce the blood demand caused by PPH with limited blood supply.This study was a retrospective study of patients who underwent blood transfusion during cesarean section in Qilu Hospital of Shandong University (China) from January 2013 to December 2016. Red blood cell infusion ≥10 U during cesarean section was defined as massive blood transfusion. The study collected the demographics of pregnant women, obstetric characteristics and reasons for blood transfusions, as well as blood components and blood transfusion results. Multivariate regression analysis was performed for evaluating the risk factors of PPN.From 2013 to 2016, a total of 587 patients received blood transfusions during cesarean section. The proportion of women receiving blood transfusion during cesarean section increased (from 3.21% to 7.40%, P < .001). The history of cesarean section (P = .005) and the occurrence of placenta previa were positively correlated with the increase in blood transfusion (P = .016). There were 72 cases of massive blood transfusion, accounting for 12.27% of blood transfusion patients. Among mass blood transfusions, 93.1% of cases had prior cesarean delivery, and placenta previa accounted for 95.8%. 19.4% of patients receiving massive blood transfusions underwent hysterectomy. There was no significant difference in maternal BMI and gestational age between the mass blood transfusion group and the non-mass blood transfusion group.From 2013 to 2016, the demand for blood transfusion, especially the demand for massive blood transfusion, increased. Repeated cesarean section and placental previa combined with uterine scar are positively correlated with increased blood transfusion. Reducing the initial cesarean section should help reduce the massive blood transfusion caused by placenta previa with a history of cesarean section.

The Health Impact of Surgical Techniques and Assistive Methods Used in Cesarean Deliveries: A Systemic Review

Cesarean delivery is one of the most frequently performed surgeries in women throughout the world. However, the most optimal technique to minimize maternal and fetal morbidities is still being debated due to various clinical situations and surgeons' preferences. The contentious topics are the use of vacuum devices other than traditional fundal pressure to assist in the delivery of the fetal head and the techniques of uterine repair used during cesarean deliveries. There are two well-described techniques for suturing the uterus: The uterus can be repaired either temporarily exteriorized (out of abdominal cavity) or in situ (within the peritoneal cavity). Numerous studies have attempted to compare these two techniques in different aspects, including operative time, blood loss, and maternal and fetal outcomes. This review provides an overview of the assistive method of vacuum devices compared with fundal pressure, and the two surgical techniques for uterine repair following cesarean delivery. This descriptive literature review was performed to address important issues for clinical practitioners. It aims to compare the advantages and disadvantages of the assistive methods and surgical techniques used in cesarean deliveries. All of the articles were retrieved from the databases Medline and PubMed using the search terms cesarean delivery, vacuum, and exteriorization. The searching results revealed that after exclusion, there were 9 and 13 eligible articles for vacuum assisted cesarean delivery and uterine exteriorization, respectively. Although several studies have concluded vacuum assistance for fetal extraction as a simple, effective, and beneficial method during fetal head delivery during cesarean delivery, further research is still required to clarify the safety of vacuum assistance. In general, compared to the use of in situ uterine repairs during cesarean delivery, uterine exteriorization for repairs may have benefits of less blood loss and shorter operative time. However, it may also carry a higher risk of intraoperative complications such as nausea and vomiting, uterine atony, and a longer time to the return of bowel function. Clinicians should consider these factors during shared decision-making with their pregnant patients to determine the most suitable techniques for cesarean deliveries.

Preoperative moderate thrombocytopenia is not associated with increased blood loss for low-risk cesarean section: a retrospective cohort study

BACKGROUND

The occurrence of thrombocytopenia is as high as 7-12% in pregnancy, yet minimum platelet count safe for cesarean section remains unknown.

METHODS

In this retrospective noninferior cohort study, we consecutively included patients undergoing cesarean section for a period of 6 years in a tertiary hospital and excluded patients at very high risk for excessive hemorrhage. The included patients with preoperative platelet count of 50-100 × 10⁹/L were defined as the thrombocytopenic group. The control group were eligible patients with preoperative platelet count>150 × 10⁹/L, matched to the thrombocytopenic group by age and operation timing in a 1:2 ratio. Mixed effect model was used to analyze the effect of thrombocytopenia based on a noninferiority assumption. The predefined noninferiority delta of bleeding was 50 mL.

RESULTS

There was no significant difference of the calculated blood loss between the thrombocytopenic and the control group (mean difference = 8.94, 95% CI - 28.34 mL to 46.09 mL). No statistical difference was observed in the requirement for blood transfusion, visually estimated blood loss, or the incidence of adverse events between groups. Although there were more patients admitted to intensive care unit (odds ratio = 12, 95% CI 2.69-53.62, p = 0.001) in the thrombocytopenic group, most of them required critical care for reasons other than hemorrhage. The thrombocytopenic group had longer length of hospital stay (mean difference = 0.40 days, 95% CI 0.09-0.71, p = 0.011), but the difference was considered as clinically insignificant.

CONCLUSIONS

Preoperative moderate thrombocytopenia is not associated with increased blood loss, blood transfusion, or occurrence of adverse events in patients undergoing cesarean section in absence of additional bleeding risk.