Autologous blood in obstetrics: where are we going now?

Association between routine cell salvage use for lower segment caesarean section and post-operative iron infusion and anemia

PURPOSE

Intraoperative cell salvage is central to Patient Blood Management including for lower segment caesarean section. Prior to April 2020, we initiated intraoperative cell salvage during caesarean section based on risk assessment for hemorrhage and patient factors. As the pandemic broadened, we mandated intraoperative cell salvage to prevent peri-partum anemia and potentially reduce blood product usage. We examined the association of routine intraoperative cell salvage on maternal outcomes.

METHODS

We conducted a single-center non-overlapping before-after study of obstetric patients undergoing lower segment caesarean section in the 2 months prior to a change in practice ('usual care = selective intraoperative cell salvage', n = 203) and the 2 months following ('mandated intraoperative cell salvage', n = 228). Recovered blood was processed when a minimal autologous reinfusion volume of 100 ml was expected. Post-operative iron infusion and length of stay were modelled using logistic or linear regression, using inverse probability weighting to account for confounding.

RESULTS

More emergency lower-segment caesarean sections occurred in the Usual Care group. Compared to the Usual Care group, post-operative hemoglobin was higher and anemia cases fewer in the Mandated intraoperative cell salvage group. Rates of post-partum iron infusion were significantly lower in the Mandated intraoperative cell salvage group (OR = 0.31, 95% CI = 0.12 to 0.80, P = 0.016). No difference was found for length of stay.

CONCLUSION

Routine cell salvage provision during lower segment caesarean section was associated with a significant reduction in post-partum iron infusions, increased post-operative hemoglobin and reduced anemia prevalence.

Role of Acute Normovolemic Hemodilution in Pregnancy for Emergency Cesarean Section in a Patient With Bombay Blood Group

Postpartum hemorrhage (PPH) is among the leading causes of maternal morbidity and mortality, and various blood conservation strategies can be implemented to minimize blood loss. Acute normovolemic hemodilution (ANH) is a simple yet effective blood management tool in the armamentarium of an anesthesiologist, the use of which can be considered for patients undergoing surgical procedures with inherent bleeding risks, procedures where more than 50% of the patient's circulating blood volume is lost, patients with multiple antibodies and rare blood groups, and those unwilling to undergo an allogenic blood transfusion. We hereby describe the performance of ANH in a pregnant woman with a Bombay blood group during an emergency cesarean section. Existing literature on ANH in obstetric patients does not report adverse fetal or maternal outcomes due to preoperative blood donation and advocates its selected use in situations where the benefits outweigh the risks.

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 as part of a blood conservation strategy in an obstetric population with abnormal placentation at a large Irish tertiary referral centre: an observational study

BACKGROUND

Haemorrhagic morbidity is more common in women with abnormal placentation, that is placenta praevia or morbidly adherent placenta. The incidence of abnormal placentation is increasing due to rising caesarean section rates. Concerns regarding blood safety, blood shortages and soaring costs of blood processing have generated growing enthusiasm for blood conservation strategies. The aim of our study was to look at intraoperative cell salvage (IOCS) use and allogeneic transfusion patterns in patients with abnormal placentation.

METHODS

Patients with abnormal placentation were identified from the hospital database over a 2-year period between 2015 and 2016. Information collected for those that had IOCS setup included estimated blood loss, volume of blood collected and returned, pre- and postoperative haemoglobin levels and use of allogeneic blood.

RESULTS

A total of 139 cases of abnormal placentation were identified. Abnormal placentation accounted for 62% of all cases of IOCS usage and was established for 53 patients with abnormal placentation. The re-transfusion rate was 18.5%. Five patients received IOCS blood only. The allogeneic transfusion rate was 7.5% in patients who had IOCS setup compared with 6.9% in those who did not (p = 1.00). Median blood loss was greater for patients who had IOCS blood returned compared with patients who had not (p = 0.004). The median volume of blood returned was 520 (114-608) mL. Preoperative haemoglobin levels were lower for patients who received a combination of cell salvage and allogeneic blood (p = 0.006).

CONCLUSIONS

IOCS contributed to a reduction or elimination of allogeneic transfusion for a proportion of this high-risk cohort and should be an integral component of a hospitals' blood conservation strategy.

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

Intraoperative cell salvage (IOCS) for high-risk obstetric hemorrhage is now endorsed by a number of obstetric organizations. Most previous studies have focused on the safety of IOCS from case series and small controlled studies. Here, we describe the effect of IOCS on rates of allogeneic blood transfusion (ABT) under different degrees of bleeding during cesarean section in women with placenta accreta, which has seldom been reported in the literature.We conducted a retrospective analysis on the introduction of routine application of IOCS for the management of hemorrhage during cesarean section in women with placenta accreta. We identified 115 women, with prenatally diagnosed placenta accreta/increta/percreta before this change in practice, who served as controls, and 108 women who had IOCS applied during cesarean section.Compared with the control treatment, IOCS was significantly associated with a lower incidence of ABT (odds ratio, 0.179; 95% confidence interval, 0.098-0.328). Among the women with ≤3000 mL of bleeding, ABT was avoided in 80 (93.0%) of the 86 patients in the IOCS group, while 49 (50.0%) of the 98 controls required ABT. For women with an estimated blood loss >3000 mL, the reinfused IOCS blood may have helped prevent the need for ABT in 6 (28.6%) of the 21 patients, while all of the 17 controls required ABT. Subgroup analysis of coagulation function and the need for coagulation components showed no significant difference between the 2 groups (P > .05). Compared with the control treatment, IOCS was associated with a lower intraoperative volume of crystalloid (P < .01) and colloid infusion (P < .01) and a shorter length of postoperative hospital stay (P < .01) in patients with placenta accreta. In addition, there were no complications or adverse reactions in patients with placenta accreta who underwent IOCS.IOCS helped reduce the need for ABT and fluid transfusion in patients with placenta accreta and may be safe for use in obstetrics.

Does current evidence support the use of intraoperative cell salvage in reducing the need for blood transfusion in caesarean section?

PURPOSE OF REVIEW

An important cause of maternal morbidity and direct maternal death is obstetric haemorrhage at caesarean section. Concerns regarding allogeneic blood safety, limited blood supplies and rising health costs have collectively generated enthusiasm for the utility of methods intended to reduce the use of allogeneic blood transfusion in cases of haemorrhage at caesarean section. This can be achieved by intraoperative cell salvage (IOCS). The aim of this review is to summarize and examine the evidence for the efficacy of IOCS during caesarean section, in women at risk of haemorrhage, in reducing the need for allogeneic blood transfusion.

RECENT FINDINGS

The majority of the evidence currently available is from case reports and case series. Although this evidence appears to support the use of IOCS in obstetrics, strong clinical evidence or economic effectiveness from clinical trials are essential to support the routine practice of IOCS in obstetrics.

SUMMARY

Current evidence is limited to reported case series and two small controlled studies. Overall, IOCS may reduce the need for allogeneic blood transfusions during caesarean section. Future large randomized trials are required to assess effectiveness, cost effectiveness and safety. The results of the current ongoing SALVO (A randomised controlled trial of intra-operative cell salvage during caesarean section in women at risk of haemorrhage) trial will shed light on these aspects.

Indications and organisational methods for autologous blood transfusion procedures in Italy: results of a national survey

INTRODUCTION

Pre-operative donation of autologous blood is a practice that is now being abandoned. Alternative methods of transfusing autologous blood, other than predeposited blood, do however play a role in limiting the need for transfusion of allogeneic blood. This survey of autologous blood transfusion practices, promoted by the Italian Society of Transfusion Medicine and Immunohaematology more than 2 years after the publication of national recommendations on the subject, was intended to acquire information on the indications for predeposit in Italy and on some organisational aspects of the alternative techniques of autotransfusion.

MATERIALS AND METHODS

A structured questionnaire consisting of 22 questions on the indications and organisational methods of autologous blood transfusion was made available on a web platform from 15 January to 15 March, 2013. The 232 Transfusion Services in Italy were invited by e-mail to complete the online survey.

RESULTS

Of the 232 transfusion structures contacted, 160 (69%) responded to the survey, with the response rate decreasing from the North towards the South and the Islands. The use of predeposit has decreased considerably in Italy and about 50% of the units collected are discarded because of lack of use. Alternative techniques (acute isovolaemic haemodilution and peri-operative blood salvage) are used at different frequencies across the country.

DISCUSSION

The data collected in this survey can be considered representative of national practice; they show that the already very limited indications for predeposit autologous blood transfusion must be adhered to even more scrupulously, also to avoid the notable waste of resources due to unused units.Users of alternative autotransfusion techniques must be involved in order to gain a full picture of the degree of use of such techniques; multidisciplinary agreement on the indications for their use is essential in order for these indications to have an effective role in "patient blood management" programmes.

Blood transfusion practices in obstetric anaesthesia

Blood transfusion is an essential component of emergency obstetric care and appropriate blood transfusion significantly reduces maternal mortality. Obstetric haemorrhage, especially postpartum haemorrhage, remains one of the major causes of massive haemorrhage and a prime cause of maternal mortality. Blood loss and assessment of its correct requirement are difficult in pregnancy due to physiological changes and comorbid conditions. Many guidelines have been used to assess the requirement and transfusion of blood and its components. Infrastructural, economic, social and religious constraints in blood banking and donation are key issues to formulate practice guidelines. Available current guidelines for transfusion are mostly from the developed world; however, they can be used by developing countries keeping available resources in perspective.

Perioperative management of undiagnosed placenta percreta: case report and management strategies

Placenta percreta is a rare pregnancy disorder in which the placenta penetrates the uterine myometrium and can invade surrounding organs. Because the rate of cesarean sections is increasing in developed countries, the incidence of placenta percreta is also rising. This condition significantly increases the risk of maternal and fetal morbidity and mortality, and is currently the most common indication for peripartum hysterectomy. Multidisciplinary management in a specialized center capable of providing massive transfusions can improve outcomes for the mother and baby. This team should include a surgeon specialized in pelvic surgery, an anesthesiologist experienced in obstetrics, a skilled urologist, a neonatologist, a blood bank team capable of administering multiple blood products, and an intensive care facility where the patient can be monitored. In this report, we present the case of a patient with preoperatively undiagnosed placenta percreta and discuss the relevant management methods. We also discuss the relevant obstetric and anesthetic management methods, as well as diagnostic and transfusion protocols.