How about "The effect of intraoperative cell salvage on allogeneic blood transfusion for patients with placenta accreta"?: An observational study

[Cell salvage in obstetrics-Background and practical implementation]

Postpartum hemorrhage (PPH) remains a leading cause of maternal mortality worldwide, with an increasing incidence in western countries over the past decades. During this period the numbers of PPH-related allogeneic red blood cell (RBC) transfusions have also significantly increased. Given the increasing scarcity and risks of allogeneic RBC transfusions, which are also associated with adverse maternal outcomes, optimized blood management strategies are urgently needed in obstetrics. In recent years, patient blood management (PBM) has been increasingly integrated into medical care, resulting in a significant improvement in patient outcomes. Cell salvage (CS) is one of the PBM blood-sparing techniques that enables the collection, processing and retransfusion of the patient's own blood during major bleeding events. Although recent evidence indicates that CS can significantly reduce the demand for allogeneic RBC transfusions and improve patient outcomes, the utilization in obstetrics in German hospitals remains low, with a usage rate of only 0.07% of births with peripartum hemorrhage. It must be assumed that concerns about patient-related complications, such as amniotic fluid embolism and maternal alloimmunization contribute to this hesitancy, alongside a lack of familiarity with the technique. This article provides an overview of the current evidence on the use and safety of CS in obstetrics. To facilitate a practical implementation, fundamental considerations and organizational precautions were prepared based on the experiences of the University Hospitals in Würzburg and Frankfurt and presented in the form of graphics and checklists for the perioperative use of CS during cesarean sections.

Intraoperative cell salvage as an effective intervention for postpartum hemorrhage—Evidence from a prospective randomized controlled trial

Background

Postpartum hemorrhage (PPH) is one of the leading causes of maternal mortality. Promptly recovering blood loss is critical for PPH. Intraoperative cell salvage (ICS) is a method to collect and process red blood cells (RBCs) from the blood lost during surgery and transfuse them to the patient’s circulation during or immediately after surgery. Its effectiveness in reducing the demand for allogeneic blood transfusion has been proven, but its effectiveness and safety as a sole treatment for PPH during Cesarean sections are unclear. This is particularly important for patients who cannot or do not want to accept allogeneic blood transfusion.

Materials and methods

In this prospective randomized controlled study, patients with high risks of PPH were randomized into the ICS group or the control group, receiving ICS or allogeneic RBC transfusion if their hemoglobin level was less than 80 g/L during operation. Data collected include clinical examination, blood cell count, hemoglobin level, coagulation function, and plasma levels of fetal hemoglobin, tissue factor, and alpha-fetoprotein before and after fetal delivery and 0, 2, and 12 h after treatment. Adverse events were recorded.

Results

A total of 130 patients were enrolled, aged 33 ± 1 years with a mean gestation period of 37 ± 1 week. The most common cause of Cesarean section was placenta previa, followed by twin pregnancy, scarred uterus, preeclampsia, placental abruption, fetal distress, and placenta accreta spectrum. Bleeding amount was similar between the two groups. The ICS group, compared to controls, had more efficient increases in levels of hemoglobin, RBC, and hematocrit (all p < 0.05). Coagulation function was maintained in the ICS group but reduced in controls 24 h after transfusion, indicated by significantly reduced fibrinogen level and prolonged prothrombin time (PT), thrombin time (TT), and activated partial thromboplastin time (aPTT) (all p < 0.05). There was a transient but significant decrease in plasma tissue factor and alpha-fetoprotein levels and an increase in plasma fetal hemoglobin level with ICS treatment in the postpartum period. No adverse event occurred with ICS intervention.

Conclusion

ICS is an effective and safe intervention for patients with a high risk of PPH during elective or emergency Cesarean section. It can effectively clear tissue factors and alpha-fetoprotein but not fetal hemoglobin.

Cell Salvage in Oncological Surgery, Peripartum Haemorrhage and Trauma

Oncological surgery, obstetric haemorrhage and severe trauma are the most challenging conditions for establishing clinical recommendations for the use of cell salvage. When the likelihood of allogeneic transfusion is high, the intraoperative use of this blood-saving technique would be justified, but specific patient selection criteria are needed. The main concerns in the case of oncological surgery are the reinfusion of tumour cells, thereby increasing the risk of metastasis. This threat could be minimized, which may help to rationalize its indication. In severe peripartum haemorrhage, cell salvage has not proven cost-effective, damage control techniques have been developed, and, given the risk of fetomaternal alloimmunization and amniotic fluid embolism, it is increasingly out of use. In trauma, bleeding may originate from multiple sites, coagulopathy may develop, and it should be evaluated whether re-transfusion of autologous blood collected from uncontaminated organ cavities would be feasible. General safety measures include washing recovered blood and its passage through leukocyte depletion filters. To date, no well-defined indications for cell salvage have been established for these pathologies, but with accurate case selection and selective implementation, it could become safe and effective. Randomized clinical trials are urgently needed.

Intraoperative Cell Salvage for Women at High Risk of Postpartum Hemorrhage During Cesarean Section: a Systematic Review and Meta-analysis

Postpartum hemorrhage (PPH) can lead to substantial blood loss that compromises maternal hemodynamic stability and consequently cause severe maternal complications such as organ dysfunction or death. Intraoperative cell salvage (IOCS), an effective method of blood conservation used in other surgical specialties, can be an alternative intervention for managing PPH. Thus, our aim was to evaluate the efficacy and safety of IOCS for women at high risk of PPH undergoing cesarean sections. We conducted a systematic search of electronic databases from inception to February 25, 2021 for randomized controlled studies and observational studies published in English or Mandarin about IOCS use in cesarean sections. Primary outcomes of interest were changes in postoperative hematologic parameters and any adverse events reported among patients that had IOCS and controls that had an allogeneic blood transfusion. The certainty of the evidence of the outcomes was evaluated using the GRADE approach. A total of 24 studies with 5872 patients were included in the meta-analysis. Eleven randomized controlled trials (RCTs), and 13 observational studies were analyzed. Postoperative hemoglobin levels were higher among patients with IOCS SMD 0.39 (95% CI; 0.20, 0.60; P < 0.001, high certainty). Allogeneic blood transfusion increased adverse events RR = 1.81(95% CI; 1.24, 2.62; P = 0.002, low certainty). IOCS shortened hospital stay SMD - 0.59 (95% CI: - 0.98, - 0.19; P = 0.004, low certainty) and shortened prothrombin time SMD - 0.67 (95% CI; - 1.31, - 0.04), P = 0.037, low certainty). The lower incidence of transfusion-related adverse events and shorter hospital stay among other findings demonstrate that IOCS use in obstetrics is an effective and safe alternative for the management of PPH; however, high-quality randomized control studies are required to confirm this evidence.

Balancing the Blood Component Transfusion Ratio for High- and Ultra High-Dose Cell Salvage Cases

OBJECTIVE

To assess the ratio of non-red blood cell to red blood cell components required to avoid coagulopathy when transfusing large amounts of salvaged blood using laboratory test-guided therapy.

DESIGN

Retrospective cohort study.

SETTING

Single-center, academic hospital.

PARTICIPANTS

Thoracoabdominal and abdominal open aortic surgery patients.

MEASUREMENT AND MAIN RESULTS

Thirty-eight patients in whom at least 1,000 mL of salvaged red blood cells were transfused were identified and divided into the following 2 cohorts: 1,000-to-2,000 mL of salvaged red blood cells (high dose) (n = 20) and >2,000 mL of salvaged red blood cells (ultra-high dose) (n = 18). Compared with the high-dose cohort, the ultra high-dose cohort received ∼4 times more salvaged red blood cells (1,240 ± 279 mL v 5,550 ± 3,801 mL). With transfusion therapy guided by intraoperative coagulation tests and thromboelastography, the adjusted ratio of non-red blood cell to red blood cell components (plasma + platelets + cryoprecipitate:allogeneic + salvaged red blood cells) was 0.59 ± 0.66 in the high-dose and 0.93 ± 0.27 in the ultra high-dose cohorts. Multiple coagulation parameters were normal and similar between cohorts at the end of surgery, as determined by the mean, median, and 95% confidence intervals.

CONCLUSIONS

When transfusing large volumes of salvaged blood, it is important to balance the ratio between non-red blood cell and red blood cell components. Through a laboratory test-guided approach, coagulopathy was not detected when transfusing blood in ratios of approximately 1:2 for patients receiving 1,000-to-2,000 mL of salvaged blood and 1:1 for patients receiving >2,000 mL of salvaged blood.

Intraoperative cell salvage is associated with reduced allogeneic blood requirements and has no significant impairment on coagulation function in patients undergoing cesarean delivery: a retrospective study

OBJECTIVE

The aim of the study is to examine the association between Intraoperative cell salvage (ICS), allogeneic blood transfusion (ABT) and coagulation function in obstetrics.

METHODS

A total of 486 pregnant women undergoing cesarean delivery, of whom 157 were enrolled in this retrospective study. Patients were divided into ICS group (n = 101, ICS used during operation) and control group (n = 56, ICS not used during operation). Clinical data, including plasma prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib) and thrombin time (TT) levels, were collected from all patients preoperatively (within 12-24 h) and postoperatively (within 6-12 h) and analyzed by t test, two-way repeated-measures ANOVA and Spearman's correlation.

RESULTS

The use of ICS is associated with lower requirement rate for ABT (P < .001), while the blood loss was similar between the two groups (P = .990). Mean volume of ICS transfusion was 432.65 mL. Compared to preoperative values, the postoperative PT and APTT levels were significantly increased, while Fib was decreased in the two groups (all P < .01). No significant difference in coagulation function was observed between groups in preoperative and postoperative phase (P > .05). Furthermore, PT, APTT and TT after surgery were not correlated with the transfused volume of salvaged blood (P > .05) while the levels of Fib were negatively correlated with the volume (P < .01). In addition, there were no transfusion reactions in both two groups.

CONCLUSIONS

Intraoperative cell salvage is correlated with reduced allogeneic blood requirements but did not impair blood coagulation significantly in patients undergoing cesarean delivery.

Successful resuscitation of a patient with pernicious placenta previa and placenta accreta who had massive life-threatening bleeding during cesarean section: A case report

RATIONALE

Pernicious placenta accrete (PPP) is an obstetrical complication associated with severe life-threatening hemorrhage, which is one of the leading causes of maternal mortality worldwide. Caesarean hysterectomy is the effective method to control intraoperative bleeding for this unscheduled high-risk patient. But a challenge for clinicians in this case is to determine the optimal timing of hysterectomy, because it will directly determine maternal outcome.

PATIENT CONCERNS

We here report a case diagnosed with PPP who suffered from a severe life-threatening hemorrhage during cesarean section but was successfully resuscitated and subsequently discharged from hospital after a smooth recovery.

DIAGNOSES

Although binding the lower uterine segment with a tourniquet markedly reduced bleeding in the surgical field after delivery, massive concealed vaginal life-threatening bleeding occurred immediately, and the amount of vaginal blood loss within 10 minutes was as much as 3000 mL.

INTERVENTIONS

An experienced multidisciplinary team was immediately established, and an unscheduled caesarean hysterectomy was performed immediately, and cell salvage was used.

OUTCOME

The patient was successfully resuscitated and both the parturient and neonate were well and discharged.

LESSON

If binding the lower uterine segment with a tourniquet markedly reduces bleeding in the surgical field after cesarean delivery in high-risk patients with PPP, and persistence of hypotension after active resuscitation of the circulation is detected, anesthesiologist should be vigilant enough to detect the possibility of concealed vaginal life-threatening bleeding. If this is confirmed, it should be quickly identified whether bleeding can be quickly controlled within a short period of time. If not, the preferred strategy is that the earlier the unscheduled hysterectomy, the better the outcome. A well-established multidisciplinary team and autologous blood recovery and transfusion techniques are also important in ensuring successful resuscitation of patients.

Abnormal placentation

The term "morbidly adherent placenta" has recently been introduced to describe the spectrum of disorders including placenta accreta, increta and percreta. Due to excessive invasion of the placenta into the uterus there is associated significant maternal morbidity and mortality. Most significant risk factors for morbidly adherent placenta include history of prior cesarean delivery as well as placenta previa in the current pregnancy. Ultrasound remains the gold standard for antenatal diagnosis, however, in recent years MRI has assisted in identifying complex parametrial involvement. Optimizing maternal and neonatal outcomes involves early prenatal diagnosis, a multi-disciplinary team-based approach, and referral to an experienced center.