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

Current concepts in the use of cell salvage in obstetrics

PURPOSE OF REVIEW

The worldwide leading cause of maternal death is severe maternal hemorrhage. Maternal hemorrhage can be profound leading to an entire loss of blood volume. In the past two decades, Patient Blood Management has evolved to improve patient's care and safety. In surgeries with increased blood loss exceeding 500 ml, the use of cell salvage is strongly recommended in order to preserve the patient's own blood volume and to minimize the need for allogeneic red blood cell (RBC) transfusion. In this review, recent evidence and controversies of the use of cell salvage in obstetrics are discussed.

RECENT FINDINGS

Numerous medical societies as well as national and international guidelines recommend the use of cell salvage during maternal hemorrhage.

SUMMARY

Intraoperative cell salvage is a strategy to maintain the patient's own blood volume and decrease the need for allogeneic RBC transfusion. Historically, cell salvage has been avoided in the obstetric population due to concerns of iatrogenic amniotic fluid embolism (AFE) or induction of maternal alloimmunization. However, no definite case of AFE has been reported so far. Cell salvage is strongly recommended and cost-effective in patients with predictably high rates of blood loss and RBC transfusion, such as women with placenta accreta spectrum disorder. However, in order to ensure sufficient practical experience in a multiprofessional obstetric setting, liberal use of cell salvage appears advisable.

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.

Patient Blood Management programs for post-partum hemorrhage

Patient blood management (PBM) strategies aim to maintain hemoglobin concentration, optimize hemostasis, and minimize blood loss to improve patient outcomes. Because postpartum hemorrhage (PPH) is a leading cause of maternal mortality and blood product utilization, PBM principles can be applied in its therapeutic approach. First, pre-operative identification of risk factors for PPH and identification of peri-delivery anemia should be conducted. Iron supplementation should be used to optimize hemoglobin concentration before delivery; it can also be used to treat anemia in the postpartum period after severe PPH. Both acute normovolemic hemodilution and intraoperative cell salvage can be effective techniques to reduce allogeneic blood transfusion during or after surgical procedures. Furthermore, these strategies appear to be safe when used in the pregnant population.

Effect of intraoperative cell rescue on bleeding related indexes after cesarean section

BACKGROUND

Obstetric hemorrhage is the leading cause of maternal mortality globally, especially in China. The key to a successful rescue is immediate and rapid blood transfusion. Autotransfusion has become an integral part of clinical blood transfusion, with intraoperative cell salvage (IOCS) being the most widely used.

AIM

To investigate the application of IOCS in cesarean section.

METHODS

A total of 87 patients who underwent cesarean section and blood transfusion in our hospital from March 2015 to June 2020 were included in this prospective controlled study. They were divided into the observation (43 cases) and control (44 cases) groups using the random number table method. The patients in both groups underwent lower-segment cesarean section. The patients in the control group were treated with traditional allogeneic blood transfusion, whereas those in the observation group were treated with IOCS. Hemorheology [Red blood cell count, platelet volume, and fibrinogen (FIB)] and coagulation function (partial prothrombin time, prothrombin time (PT), platelet count, and activated coagula-tion time) were measured before and 24 h after transfusion. In the two groups, adverse reactions, such as choking and dyspnea, within 2 h after cesarean section were observed.

RESULTS

Before and after transfusion, no significant differences in hemorheology and coagulation function indices between the two groups were observed (P > 0.05). About 24 h after transfusion, the erythrocyte count, platelet ratio, and FIB value significantly decreased in the two groups (P < 0.05); the PLT value significantly decreased in the two groups; the activated partial thromboplastin time, PT, and activated clotting time significantly increased in the two groups (P < 0.05); and no statistical differences were observed in hemorheology and coagulation function indices between the two groups (P > 0.05). Furthermore, there was no significant difference in the incidence of adverse reactions between the two groups (P > 0.05).

CONCLUSION

In patients undergoing cesarean section, intraoperative cell salvage has a minimum effect on hemorheology and coagulation function and does not increase the risk of amniotic fluid embolism.

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.

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.

Comparative changes of pre-operative autologous transfusions and peri-operative cell salvage in the United States

BACKGROUND

With improved safety of allogeneic blood supply, the use of preoperative autologous donations (PADs) and perioperative autologous cell salvage (PACS) has evolved. This study evaluated temporal trends in PAD and PACS use in the United States.

METHODS

The National Inpatient Sample database, a stratified probability sample of 20% of hospitalizations in the United States, was used to compare temporal trends in hospitalizations reporting use of PADs and PACS from 1995 to 2015. Factors associated with their use were examined between 2012 and 2015 with use of multivariable Poisson regression. Sampling weights were applied to generate nationally representative estimates.

RESULTS

There was a steady decrease in hospitalizations reporting PAD transfusions from 27.90 per 100 000 in 1995 to 1.48 per 100 000 hospitalizations in 2015 (P-trend <.001). In contrast, PACS increased from a rate of 1.16 per 100 000 in 1995 to peak of 20.51 per 100 000 hospitalizations in 2008 and then steadily declined (P-trend<.001). Higher odds of PACS and PADs were observed in older patients, elective procedures (vs urgent), and urban teaching/nonteaching hospitals (vs rural hospitals) (P < .001). PACS was more common in hospitalizations in patients with higher levels of severity of illness as compared to those with minor severity (adjusted prevalence ratio [adjPR], 2.39; 95% confidence interval [CI], 2.08-2.73; P<.001), while PADs were performed less often in patients with higher underlying severity of illness (All Patient Refined Diagnosis Related Groups, 4 vs 1, adjPR, 0.61; 95% CI, [0.39-0.95]; P = .028).

CONCLUSIONS

There was a significant decrease in PAD red blood cell transfusions, while PACS has increased and subsequently decreased; PACS plays an important role in surgical blood conservation. The subsequent decline in PACS likely reflects further optimization of transfusion practice through patient blood management programs and improvement of surgical interventions.