Utilization and outcomes of massive transfusion protocols in women with and without invasive placentation

Risk factors of massive blood transfusion (MTP) in cesarean hysterectomy for placenta accreta spectrum

BACKGROUND

Placenta Accreta Spectrum (PAS) represents a particularly morbid condition for which blood transfusion is the leading cause. Delivery by cesarean hysterectomy is recommended for the management of PAS. Massive Transfusion Protocols (MTP) in obstetrics vary in definition and implementation. Given the significant blood loss during PAS cesarean hysterectomy, this is particularly important for surgeons and blood banks. Our objective was to identify risk factors for MTP in patients with antenatally suspected PAS.

METHODS

We performed a case-control study over a 11-year period from 2012 to 2022 at our center for Placenta Accreta Spectrum. MTP was defined by two methods, >4 units or > 10 units of red blood cells/whole blood transfused over 24 h. Antenatal, operative and post-operative outcomes were obtained from electronic medical records of these cases.

RESULTS

During the study time frame, 142 cases were managed by our PAS team and met all criteria. 85 % (120/142) of patients were transfused at least 1 unit of blood, 64 patients (45 %) received 0-3 units of blood, 50 patients (35 %) received 4-9 units of blood and 28 patients (19.7 %) were transfused > 10 units of blood. Pre-delivery vaginal bleeding, preterm labor and delivery < 34 weeks were independently significant in transfused patients. ROC analysis revealed an area under the curve (AUC) of 0.79 (p < 0.0001) in patients transfused > 10 units, showing predictive capability for this subgroup.

DISCUSSION

We here report pre-operative risk factors for MTP in patients undergoing cesarean hysterectomy for PAS. This allows for both resource utilization and patient counseling for this morbid maternal condition.

Periostin promotes extensive neovascularization in placenta accreta spectrum disorders via Notch signaling

OBJECTIVE

Extensive neovascularization, closely linked to massive intraoperative blood loss, is a pathological hallmark of placenta accreta spectrum (PAS) cases. This study aims to explore proteins related to neovascularization and elucidate their regulatory roles in PAS, enhancing our understanding of this condition.

METHODS

The isobaric tags for relative and absolute quantitation technique were used to identify and quantify the differentially expressed proteins in placentas from PAS and healthy pregnant women. Immunofluorescence staining and western blot analysis were conducted to determine the protein expression and localization. Gain-of-function experiments were used to conduct cell proliferation and migration assays. In addition, the tube formation assay was performed to evaluate angiogenesis in vitro. The Notch inhibitor DAPT was used to determine the involvement of Notch signaling in angiogenesis in PAS.

RESULTS

Periostin (POSTN) exhibited higher expression in PAS placentas than in normal placentas. Moreover, the overexpression of POSTN in endothelial cells promoted cell proliferation, mobility, and endothelial angiogenesis via the Notch signaling pathway in vitro.

CONCLUSION

Elevated POSTN expression in PAS is associated with increased angiogenesis, indicating its potential as a molecular marker for significant intraoperative blood loss.

Red Blood Cell Transfusion in Patients With Placenta Accreta Spectrum: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate red blood cell use during delivery in patients with placenta accreta spectrum.

DATA SOURCES

We searched MEDLINE, EMBASE, CINAHL, Cochrane Central, ClinicalTrials.gov, and Scopus for clinical trials and observational studies published between 2000 and 2021 in countries with developed economies.

METHODS OF STUDY SELECTION

Abstracts (n=4,275) and full-text studies (n=599) were identified and reviewed by two independent reviewers. Data on transfused red blood cells were included from studies reporting means and SDs, medians with interquartile ranges, or individual patient data. The primary outcome was the weighted mean number of units of red blood cells transfused per patient. Between-study heterogeneity was assessed with an I2 statistic. Secondary analyses included red blood cell usage by placenta accreta subtype.

TABULATION, INTEGRATION, AND RESULTS

Of the 599 full-text studies identified, 20 met criteria for inclusion in the systematic review, comprising 1,091 cases of placenta accreta spectrum. The number of units of red blood cells transfused was inconsistently described across studies, with five studies (25.0%) reporting means, 11 (55.0%) reporting medians, and four (20.0%) reporting individual patient data. The weighted mean number of units transfused was 5.19 (95% CI 4.12-6.26) per patient. Heterogeneity was high across studies (I2=91%). In a sensitivity analysis of five studies reporting mean data, the mean number of units transfused was 6.61 (95% CI 4.73-8.48; n=220 patients). Further quantification of units transfused by placenta accreta subtype was limited due to methodologic inconsistencies between studies and small cohort sizes.

CONCLUSION

Based on the upper limit of the CI in our main analysis and the high study heterogeneity, we recommend that a minimum of 6 units of red blood cells be available before delivery for patients with placenta accreta spectrum. These findings may inform future guidelines for predelivery blood ordering and transfusion support.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021240993.

Incidence, trends and risk factors for obstetric massive blood transfusion in China from 2012 to 2019: an observational study

OBJECTIVES

This study aims to use the high-quality national monitoring data from the China's National Maternal Near Miss Surveillance System (NMNMSS) to ascertain the incidence, trends and risk factors of obstetric massive blood transfusion (MBT) from 2012 to 2019 in China and determine its clinical outcomes.

SETTINGS

Observational study of hospitalised pregnancies who had given birth or ended their pregnancy among member hospitals of NMNMSS.

PARTICIPANTS

11 667 406 women were included in this study.

PRIMARY AND SECONDARY OUTCOME MEASURES

We screened for the incidence, trends, risk factors and main reasons for obstetric MBT, and the outcomes after obstetric MBT. MBT was defined as the transfusion of ≥5 units of red blood cells or ≥1000 mL of whole blood. The incidence of MBT was defined as the MBT cases per 10 000 pregnancies.

RESULTS

Obstetric MBT occurred in 27 626 cases, corresponding to an incidence of 23.68 per 10 000 maternities, which exhibited an increasing trend in China during 2012-2019 (14.03-29.59 per 10 000 maternities, p for trend <0.001). Obstetric MBT was mainly associated with amniotic fluid embolism, uterine atony, abnormal placenta, severe anaemia, ectopic pregnancy, abortion, caesarean section, advanced maternal age and multiparous from biological effect. While from sociological effects, uterine atony, severe anaemia and placenta previa are the top three complications which more likely to undergo obstetric MBT in the Chinese population. Overall, the secular trends of hysterectomy incidence (25.07%-9.92%) and MMR during hospitalisation (21.41‰-7.48‰) among women who underwent MBT showed decreasing trends (p for trend <0.001).

CONCLUSION

To minimise the incidence of obstetric MBT, more attention should be paid to education on the importance of the antenatal visit, evidence-based transfusion practice and females who are multiparous and have an advanced age, amniotic fluid embolism, uterine atony, severe anaemia and placenta previa.

Advances in anesthetic and obstetric management of patients with placenta accreta spectrum

PURPOSE OF REVIEW

The incidence of placenta accreta spectrum is increasing and it is a leading cause of peripartum hysterectomy and massive postpartum hemorrhage. The purpose of the present article is to provide a contemporary overview of placenta accreta spectrum pertinent to the obstetric anesthesiologist.

RECENT FINDINGS

Recent changes in the terminology used to report invasive placentation were proposed to clarify diagnostic criteria and guidelines for use in clinical practice. Reduced morbidity is associated with scheduled preterm delivery in a center of excellence using a multidisciplinary team approach. Neuraxial anesthesia as a primary technique is increasingly being used despite the known risk of major bleeding. The use of viscoelastic testing and endovascular interventions may aid hemostatic resuscitation and improve outcomes.

SUMMARY

Accurate diagnosis and early antenatal planning among team members are essential. Obstetric anesthesiologists should be prepared to manage a massive hemorrhage, transfusion, and associated coagulopathy. Increasingly, viscoelastic tests are being used to assess coagulation status and the ability to interpret these results is required to guide the transfusion regimen. Balloon occlusion of the abdominal aorta has been proposed as an intervention that could improve outcomes in women with placenta accreta spectrum, but high-quality safety and efficacy data are lacking.

How do I manage severe postpartum hemorrhage?

In the United States, postpartum hemorrhage (PPH) accounts for 4.6% of all maternal deaths and is responsible for major peripartum medical and surgical morbidity. Therefore, a national health priority is to ensure that women who experience severe PPH receive timely, appropriate, and effective treatment. In this article, we describe our system-wide approach for the planning and delivery of women with suspected placenta accreta spectrum disorder, a condition associated with life-threatening blood loss at the time of delivery. We also highlight current evidence related to transfusion decision making and hemostatic monitoring during active postpartum bleeding. Specifically, we describe how we activate and use the massive transfusion protocol to obtain sufficient volumes and types of blood products. We also describe how we use viscoelastic monitoring (thromboelastography) and standard laboratory tests to assess the maternal coagulation profile. Finally, we review the findings of recent studies examining the potential efficacy of tranexamic acid and fibrinogen concentrate as adjuncts for PPH prevention and treatment. We describe how we have incorporated these drugs into PPH treatment protocols at our institution.