Is cell salvaged vaginal blood loss suitable for re-infusion?

Routine use of cell salvage during cesarean section: A practice evaluation

INTRODUCTION

Intraoperative cell salvage is a well-documented alternative to donor blood transfusion given the scarcity of donor blood pools and the incumbent risk of allogenic blood transfusion. Its use in obstetrics has been limited by concern over fetal alloimmunization due to the risk of fetomaternal hemorrhage. However, there are a paucity of studies reporting on outcome. The aim of this study was to report on a four-year experience of routine use of intraoperative cell salvage and the impact on subsequent pregnancy outcomes.

MATERIAL AND METHODS

This was a tertiary center retrospective service evaluation cohort study and included all women undergoing cesarean section between December 2014 and November 2018 in a tertiary obstetric unit, identifying women who had reinfusion of intraoperative cell salvage. Data regarding index pregnancy as well as subsequent pregnancies at the hospital were extracted from hospital electronic records. Subsequent pregnancy outcome and maternal antibody status in that pregnancy were collected up until November 2022.

RESULTS

During the study period, 6656 cesarean sections were performed, with 436 (6.6%) receiving reinfusion of salvaged blood. The mean volume of reinfused blood was 396 mL. A total of 49 (0.7%) women received donor blood transfusion. Of those who received reinfusion of salvaged blood, 79 (18.1%) women had subsequent pregnancies over the eight-year follow-up period. There was one case (0.23%) of fetal cell alloimmunization demonstrated by the presence of anti-D antibodies on the subsequent pregnancy booking bloods.

CONCLUSIONS

Routine intraoperative cell salvage may be used to reduce the need for blood transfusion during cesarean section. The risk of fetal cell alloimmunization in a future pregnancy following reinfusion of intraoperative cell salvage is one in 436. Given an apparent small risk of fetal cell alloimmunization, further work is required to establish the safety profile of intraoperative cell salvage in pregnancy.

Maternal outcomes following postpartum autotransfusion of blood lost during vaginal obstetric hemorrhage

BACKGROUND

Autotransfusion following vaginal delivery has not been as widely adopted and existing data on this topic are limited to small case series.

METHODS

This is a single-center retrospective matched cohort study. Deliveries exposed to autotransfusion during obstetric hemorrhage were matched to unexposed controls with obstetric hemorrhage who did not receive autotransfusion. The primary outcome was allogeneic transfusion of packed red blood cells. Planned secondary analyses included change in hemoglobin following delivery, composite maternal safety outcomes, and unplanned postpartum health care utilization.

RESULTS

Thirty-six deliveries exposed to autotransfusion were matched to 144 unexposed controls. There was no significant difference in allogenic transfusion of packed red blood cells in the patients exposed to autotransfusion red with unexposed controls (adjusted OR 1.1; 95% CI 0.5-2.4). Deliveries that received autotransfusion had a less severe pre- to post-delivery decline in hemoglobin compared with unexposed controls across all values of QBL (p = .003). There were no significant differences in maternal morbidity outcomes evaluated in exposed versus unexposed deliveries.

CONCLUSION

Autotransfusion in cases of vaginal obstetric hemorrhage did not attenuate rates of allogenic packed red blood cell transfusion but did result in a less severe pre- to postdelivery decline in hemoglobin at discharge. Autotransfusion cases did not have any markers of increased maternal morbidity when compared with a control group. These findings support emerging evidence indicating that autotransfusion of blood lost during vaginal obstetric hemorrhage is a safe and potentially effective tool for use in the management of obstetric hemorrhage.

How do I perform cell salvage during vaginal obstetric hemorrhage?

BACKGROUND

Obstetric hemorrhage is a leading cause of preventable maternal mortality. To combat this, obstetric organizations worldwide recommend consideration of autotransfusion during severe peripartum bleeding to minimize allogenic transfusion. Current guidelines for autotransfusion in obstetrics are limited to patients undergoing cesarean birth. At present, women experiencing vaginal obstetric hemorrhage are excluded from many obstetric autotransfusion protocols. However, emerging data suggest that autotransfusion of vaginally shed blood is both safe and feasible in the obstetric patient population.

METHODS AND MATERIALS

In this review, we will provide an overview of the current literature surrounding cell salvage of vaginally send blood and a detailed outline of our institution's blood collection protocol.

RESULTS

Recent data suggests autotransfusion of vaginally shed blood is both safe and effective.

DISCUSSION

Implementation of autotransfusion technology into the delivery room is a critical next step for the advancement of transfusion medicine in obstetrics. This review provides an overview of the data surrounding autotransfusion of vaginally shed blood during maternal hemorrhage and describes practical suggestions for how it can be effectively implemented into routine practice.

Autotransfusion of vaginally shed blood as a novel therapy in obstetric hemorrhage: A case series

OBJECTIVE

To report maternal outcomes in a cohort of women who received autotransfusion of vaginally shed blood and to describe the feasibility of blood collection and cell salvage processing at the time of vaginal hemorrhage.

STUDY DESIGN AND METHODS

We conducted a retrospective case series of patients who received autotransfusion of vaginally shed blood at the time of obstetric hemorrhage from January 2014 to August 2020. Maternal data and cell salvage utilization characteristics were abstracted from the electronic medical record.

RESULTS

Sixty-four cases were identified in which autotransfusion of vaginally shed blood occurred during an obstetric hemorrhage. Median quantitative blood loss was 2175 ml (interquartile range 1500-2250 ml) with 89% of cases having a blood loss greater than 1000 ml. Patients on average received approximately 1.3 units of autologous blood product (384 ml, interquartile range 244-520 ml) and no direct adverse events were observed during transfusion. We observed heterogeneity in autologous blood volume across all values of quantitative blood loss. The need for allogenic blood transfusion was common and occurred in 72% of all cases (N = 46). There were no documented cases of maternal sepsis or severe infectious morbidity.

CONCLUSION

In 64 cases where autotransfusion of vaginally shed blood occurred, autotransfusion was well tolerated. Heterogeneity in autologous blood volume collection likely represents the lack of standardized protocols for blood collection in the delivery room. Autotransfusion of vaginally shed blood is a feasible and reasonable technique to employ during severe obstetric hemorrhage.

Comparison of cell salvage with one and two suction devices during cesarean section in patients with placenta previa and/or accrete: a randomized controlled trial

Background

Cell salvage has recently been recommended for obstetric use in cases with a high risk of massive hemorrhage during cesarean section (CS). However, limited data are available to support the use of one suction device to collect lost blood. This study aimed to investigate the volume of red blood cells (RBCs) salvaged and the components of amniotic fluid (AF) in blood salvaged by one suction device or two devices during CS in patients with placenta previa and/or accrete.

Methods

Thirty patients with placenta previa and/or accrete undergoing elective CS in the Women's Hospital of Zhejiang University School of Medicine were recruited for the present study from November 1, 2017 to December 1, 2018. The patients were randomly assigned to one of the two groups according to an Excel-generated random number sheet: Group 1 (n = 15), in which only one suction device was used to aspirate all blood and AF, and Group 2 (n = 15), in which a second suction device was mainly used to aspirate AF before the delivery of the placenta. Three samples of blood per patient (pre-wash, post-wash, and post-filtration) were collected to measure AF components. The salvaged RBC volumes were recorded. Continuous data of pre-wash, post-wash, and post-filtration samples were analyzed by using one-way analysis of variance with Tukey's test for multiple comparisons, or Kruskal-Wallis test with Dunn test for multiple comparisons. Comparisons of continuous data between Group 1 and Group 2 were conducted using Student's t test or Mann-Whitney U test.

Results

The salvaged RBC volume was significantly higher in Group 1 than that in Group 2 (401.6 ± 77.2 mL vs. 330.1 ± 53.3 mL, t = 4.175, P < 0.001). In both groups, squamous cells, lamellar bodies, and fat were significantly reduced by washing (all P<0.001) and squamous cells were further reduced by filtering (P < 0.001). Squamous cells were found in six post-filtration samples (three from each group). Lamellar bodies and fat were completely removed by filtering. Insulin-like growth factor binding protein 1, alpha-fetoprotein, albumin, lactate dehydrogenase, and potassium were significantly reduced post-wash (all P < 0.05), with no further significant reduction after filtration in either group (all P > 0.05). The mean percentage of fetal RBCs post-filtration was (1.8 ± 0.8)% with a range of 1.0% to 3.5% and (1.9 ± 0.9)% with a range of 0.7% to 4.0% in Groups 1 and 2, respectively, showing no significant difference between the two groups (U = 188.5, P = 0.651).

Conclusion

Cell salvage performed by one suction device could result in higher volume of salvaged RBCs and can be used safely for CS in patients with placenta previa and/or accrete when massive hemorrhage occurs.

Trial registration number

ChiCTR-INR-17012926, http://www.chictr.org.cn/ Chinese Clinical Trial Registry.

Obstetric intra-operative cell salvage: a review of an established cell salvage service with 1170 re-infused cases

The use of cell salvage during caesarean section has been increasing steadily, although there are concerns relating to cost, a perceived risk of amniotic fluid embolism, and fetal red cell sensitisation. We present observational data from almost a decade of use of intra-operative cell salvage in obstetrics. By the end of this period, we set up cell salvage collection for > 98% of all caesarean sections. From 2008 to 2017, 1170 women have had a re-infusion of cell salvaged blood with no clinical safety concerns; the median (IQR [range]) volume was 231 (154-306 [80-1690]) ml. During this time there has been a marked reduction in the number of women who were transfused allogeneic blood, as well as the amount of blood transfused. In total, 647 (55%) women have had alloimmunisation testing, with two positive cases. Quality control data indicate that the quality of blood processed from partial first bowls is no worse than that from full bowls. We discuss the costs of providing this service with regard to: staffing costs; single suction; leucodepletion filters; selectivity in the processing of collected blood; and the use of partial first bowls.

Obstetric intra-operative cell salvage and maternal fetal red cell contamination

BACKGROUND

The significance of fetal red blood cell (RBC) contamination in obstetric intra-operative cell salvage is not fully known. It is unclear if we re-infuse a larger volume of fetal RBCs into the maternal circulation than the amount that occurs secondary to transplacental haemorrhages is unclear. We also do not know if there is a critical volume required to cause alloimmunisation or if larger volumes increase the risk.

OBJECTIVES

The aim of this study is to provide data on the level of fetal RBC contamination in the maternal circulation prior to delivery and immediately post-partum and to compare these levels to those found in processed cell-salvaged blood.

METHODS

In the first part of this study, we quantified the levels of fetal RBCs circulating in women immediately prior to delivery. This was then repeated with a separate group measuring the levels of fetal RBCs pre- and post-delivery.

RESULTS

We found that 37% of women had fetal cells detected in their circulation, median 0·00 mL (IQR 0-0·24; average 0·3 mL, maximum 4·56 mL). Fetal RBCs were present pre-delivery (maximum 0·66 mL) in 16% of women, increasing to 53% post-delivery (median 0·66 mL; IQR 0·22-2·20, maximum 21·20 mL).

CONCLUSIONS

We have shown that fetal RBCs are present in the maternal circulation throughout pregnancy and that the volumes are comparable to that obtained from intra-operative salvage, with contamination amounts of up to 19 mL. At the Royal Cornwall Hospital, our experience and evidence supports offering intra-operative salvage to all women, and we have not noted an increase in antibody formation, compared to allogeneic transfusion.

Cell salvage for postpartum haemorrhage during vaginal delivery: a case series

BACKGROUND

The safety and effectiveness of cell salvage for vaginal delivery is unknown. This case series aimed to assess the utility and adverse events related to the use of cell salvage for maternal haemorrhage during vaginal delivery.

MATERIALS AND METHODS

A cohort study design was chosen, focused on postpartum haemorrhages that occurred after vaginal delivery for which cell salvage equipment was requested to be set up in the labour and delivery room outside of a sterile operating room environment. Variables recorded included duration of stay in hospital, occurrence of wound infections, sepsis, thromboembolic events, and amniotic fluid embolism.

RESULTS

Of 28 cases of postpartum haemorrhage during vaginal deliveries involving the setup or use of cell salvage equipment, ten were associated with successful re-infusion of salvaged shed blood. These ten cases were compared to the 18 cases in which cell salvage equipment was set up, but insufficient shed blood was salvaged for re-infusion. There were no instances of postpartum sepsis, wound infection, or thromboembolism associated with the use of cell salvage for vaginal delivery. Although one case of suspected amniotic fluid embolism occurred, severe symptoms began prior to the infusion of salvaged blood.

DISCUSSION

Infusion of salvaged shed blood collected from a vaginal delivery field is feasible. The outcomes of these cases do not exclude an unacceptably high risk of infection or embolic events. Trials evaluating the safety and effectiveness associated with the use of cell salvage in vaginal deliveries are justified.

Autologous Blood Transfusion for Postpartum Hemorrhage

Postpartum hemorrhage (PPH) is a leading contributor to maternal morbidity and mortality in the United States and globally. Although the rate of PPH is generally decreasing nationally, severity of PPH appears to be increasing, potentially related to the various comorbidities associated with women of childbearing age. There is increasing evidence of risks associated with allogeneic blood transfusion, which has historically been the classic therapeutic approach for treatment to PPH. Pregnant women are particularly susceptible to the implications of sensitization to red cell antigens, a common sequela to allogenic blood transfusion. Autologous blood transfusion eliminates the potential of communicable disease transmission as well as the conceivable threat of a blood transfusion reaction. Recent technological advances allow cell salvage coupled with the use of a leukocyte filter to be used as an alternative approach for improving the outcome for women experiencing a PPH. Modest changes in standard operating procedure and continued training in use and application of cell salvaged blood may assist in minimizing negative outcomes from PPH. Salvaged blood has been demonstrated to be at least equal and often superior to banked blood. We discuss nursing implications for application of this technology for women with PPH. Continued research is warranted to evaluate the impact that application of cell salvage with filtration has on the patient experiencing a PPH.