Whole blood transfusion reduces overall component transfusion in cases of placenta accreta spectrum: a pilot program

What's new in whole blood resuscitation? In the trauma bay and beyond

PURPOSE OF REVIEW

Transfusion therapy commonly supports patient care during life-threatening injury and critical illness. Herein we examine the recent resurgence of whole blood (WB) resuscitation for patients in hemorrhagic shock following trauma and other causes of severe bleeding.

RECENT FINDINGS

A growing body of literature supports the use of various forms of WB for hemostatic resuscitation in military and civilian trauma practice. Different types of WB include warm fresh whole blood (FWB) principally used in the military and low titer O cold stored whole blood (LTOWB) used in a variety of military and civilian settings. Incorporating WB initial resuscitation alongside subsequent component therapy reduces aggregate blood product utilization and improves early mortality without adversely impacting intensive care unit length of stay or infection rate. Applications outside the trauma bay include prehospital WB and use in patients with nontraumatic hemorrhagic shock.

SUMMARY

Whole blood may be transfused as FWB or LTOWB to support a hemostatic approach to hemorrhagic shock management. Although the bulk of WB resuscitation literature has appropriately focused on hemorrhagic shock following injury, extension to other etiologies of severe hemorrhage will benefit from focused inquiry to address cost, efficacy, approach, and patient-centered outcomes.

Risk factors for intensive care unit admission after cesarean hysterectomy for placenta accreta spectrum

OBJECTIVE

Placenta accreta spectrum (PAS) is a complex disorder of uterine wall disruption with significant morbidity and mortality, particularly at time of delivery. Both physician and physical hospital resource allocation/utilization remains a challenge in PAS cases including intensive care unit (ICU) beds. The primary objective of the present study was to identify preoperative risk factors for ICU admission and create an ICU admission prediction model for patient counseling and resource utilization decision making in an evidence-based manner.

METHODS

This was a case-control study of 145 patients at our PAS referral center undergoing cesarean hysterectomy for PAS. Final confirmation by histopathology was required for inclusion. Patient disposition after surgery (ICU vs post-anesthesia care unit) was our primary outcome and pre-/intra-/postoperative variables were obtained via electronic medical records with an emphasis on the predictive capabilities of the preoperative variables. Uni- and multivariate analysis was performed to identify independent predictive factors for ICU admission.

RESULTS

In this large cohort of 145 patients who underwent cesarean hysterectomy for PAS, with histopathologic confirmation, 63 (43%) were admitted to the ICU following delivery. These patients were more likely to be delivered at an earlier gestational age (34 vs 35 weeks, P < 0.001), have had >2 episodes of vaginal bleeding and emergent delivery compared to patients admitted to patients with routine recovery care (44% vs 18.3%, P = 0.009). Uni- and multivariate logistic regression showed an area under the curve of 0.73 (95% CI: [0.63, 0.81], P < 0.001) for prediction of ICU admission with these three variables. Patients with all three predictors had 100% ICU admission rate.

CONCLUSION

Resource prediction, utilization and allocation remains a challenge in PAS management. By identifying patients with preoperative risk factors for ICU admission, not only can patients be counseled but this resource can be requested preoperatively for staffing and utilization purposes.

Survey of policies at US hospitals on the selection of RhD type of low-titer O whole blood for use in trauma resuscitation

BACKGROUND

Low-titer group O whole blood (LTOWB) use is increasing due to data suggesting improved outcomes and safety. One barrier to use is low availability of RhD-negative LTOWB. This survey examined US hospital policies regarding the selection of RhD type of blood products in bleeding emergencies.

STUDY DESIGN AND METHODS

A web-based survey of blood bank directors was conducted to determine their hospital's RhD-type selection policies for blood issued for massive bleeding.

RESULTS

There was a 61% response rate (101/157) and of those responses, 95 were complete. Respondents indicated that 40% (38/95) use only red blood cells (RBCs) and 60% (57/95) use LTOWB. For hospitals that issue LTOWB (N = 57), 67% are supplied only with RhD-positive, 2% only with RhD-negative, and 32% with both RhD-positive and RhD-negative LTOWB. At sites using LTOWB, RhD-negative LTOWB is used exclusively or preferentially more commonly in adult females of childbearing potential (FCP) (46%) and pediatric FCP (55%) than in men (4%) and boys (24%). RhD-positive LTOWB is used exclusively or preferentially more commonly in men (94%) and boys (54%) than in adult FCP (40%) or pediatric FCP (21%). At sites using LTOWB, it is not permitted for adult FCPs at 12%, pediatric FCP at 21.4%, and boys at 17.1%.

CONCLUSION

Hospitals prefer issuing RhD-negative LTOWB for females although they are often ineligible to receive RhD-negative LTOWB due to supply constraints. The risk and benefits of LTOWB compared to the rare occurrence of hemolytic disease of the fetus/newborn (HDFN) need further examination in the context of withholding a therapy for females that has the potential for improved outcomes.

Use of Low-Titer O-Positive Whole Blood in Female Trauma Patients: A Literature Review, Qualitative Multidisciplinary Analysis of Risk/Benefit, and Guidelines for Its Use as a Universal Product in Hemorrhagic Shock

BACKGROUND

Whole blood transfusion is associated with benefits including improved survival, coagulopathy, and decreased transfusion requirements. The majority of whole blood transfusion is in the form of low-titer O-positive whole blood (LTOWB). Practice at many trauma centers withholds the use of LTOWB in women of childbearing potential due to concerns of alloimmunization. The purpose of this article is to review the evidence for LTOWB transfusion in female trauma patients and generate guidelines for its application.

STUDY DESIGN

Literature and evidence for LTOWB transfusion in hemorrhagic shock are reviewed. The rates of alloimmunization and subsequent obstetrical outcomes are compared to the reported outcomes of LTOWB vs other resuscitation media. Literature regarding patient experiences and preferences in regards to the risk of alloimmunization is compared to current trauma practices.

RESULTS

LTOWB has shown improved outcomes in both military and civilian settings. The overall risk of alloimmunization for Rhesus factor (Rh) - female patients in hemorrhagic shock exposed to Rh + blood is low (3% to 20%). Fetal outcomes in Rh-sensitized patients are excellent compared to historical standards, and treatment options continue to expand. The majority of female patients surveyed on the risk of alloimmunization favor receiving Rh + blood products to improve trauma outcomes. Obstetrical transfusion practices have incorporated LTOWB with excellent results.

CONCLUSIONS

The use of whole blood resuscitation in trauma is associated with benefits in the resuscitation of severely injured patients. The rate at which severely injured, Rh-negative patients develop anti-D antibodies is low. Treatments for alloimmunized pregnancies have advanced, with excellent results. Fears of alloimmunization in female patients are likely overstated and may not warrant the withholding of whole blood resuscitation. The benefits of whole blood resuscitation likely outweigh the risks of alloimmunization.

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.

Implementation and outcomes of a uterine artery embolization and tranexamic acid protocol for placenta accreta spectrum

BACKGROUND

Placenta accreta spectrum disorders are a continuum of placental pathologies with significant maternal morbidity and mortality. Morbidity is related to the overall degree of placental adherence, and thus patients with placenta increta or percreta represent a high-risk category of patients. Hemorrhage and transfusion of blood products represent 90% of placenta accreta spectrum morbidity. Both tranexamic acid and uterine artery embolization independently decrease obstetrical hemorrhage.

OBJECTIVE

This study aimed to provide an evidence-based intraoperative protocol for placenta accreta spectrum management.

STUDY DESIGN

This study was a pre- and postimplementation analysis of concomitant uterine artery embolization and tranexamic acid in cases of patients with antenatally suspected placenta increta and percreta over a 5-year period (2018-2022). For comparison, a 5-year (2013-2017) preimplementation group was used to assess the impact of the uterine artery embolization and tranexamic acid protocol for placenta accreta spectrum. Patient demographics and clinically relevant outcomes were obtained from electronic medical records.

RESULTS

A total of 126 cases were managed by the placenta accreta spectrum team, of which 66 had suspected placenta increta/percreta over the 10-year time period. Two patients were excluded from the postimplementation cohort because they did not undergo both interventions. Thus, 30 (30/64; 47%) were treated after implementation of the uterine artery embolization and tranexamic acid protocol for placenta accreta spectrum, and 34 (34/64; 53%) preimplementation patients did not undergo uterine artery embolization or tranexamic acid infusion. With the uterine artery embolization and tranexamic acid protocol, operative times were longer (416 vs 187 minutes; P<.01), and patients were more likely to receive general anesthesia (80% vs 47%; P<.01). However, blood loss was reduced by 33% (2000 vs 3000 cc; P=.03), overall blood transfusion rates decreased by 51% (odds ratio, 0.05 [95% confidence interval, 0.001-0.20]; P<.01), and massive blood transfusion (>10 units transfused) was reduced 5-fold (odds ratio, 0.17 [95% confidence interval, 0.02-0.17]; P=.02). Postoperative complication rates remained unchanged (4 vs 10 events; P=.14). Neonatal outcomes were equivalent.

CONCLUSION

The uterine artery embolization and tranexamic acid protocol for placenta accreta spectrum is an effective approach to the standardization of complex placenta accreta spectrum cases that results in optimal perioperative outcomes and reduced maternal morbidity.

Impact of placenta accreta spectrum (PAS) pathology on neonatal respiratory outcomes in cesarean hysterectomies

OBJECTIVE

Placenta accreta spectrum (PAS) is a continuum of disorders characterized by the pathologically adherent placenta to the uterine myometrium. Delivery by cesarean hysterectomy at 34-36 weeks is recommended to mitigate the risks of maternal morbidity. Iatrogenic preterm delivery, has potential neonatal implications; late preterm infants are at risk for significant respiratory morbidity. Neonatal outcomes in PAS neonates are not well described in the literature, we aimed to investigate these outcomes.

METHODS

A case-control study was performed with 107 cases of pathology-confirmed PAS patients with singleton, non-anomalous, viable pregnancies, compared to 76 cases of placenta previa with prior cesarean section who underwent repeat cesarean section. All patients were delivered through our institution's Placenta Accreta Program from 2005 to 2020. Rates of neonatal respiratory morbidity and related outcomes were analyzed.

RESULTS

Maternal characteristics and antenatal complications were similar between groups, as were gestational age, steroid exposure, and emergent delivery. PAS was associated with increased use of general anesthesia (20 vs. 54%, p = .001), larger estimated blood loss (1875 vs. 6077 ml, p = .008), and longer post-operative stays (4.8 vs. 7.3 days, p = .01). PAS was also associated with neonatal increased rates of high flow nasal cannula (HFNC) (41 vs. 58%, p = .02), intubation (17 vs. 37%, p = .008), and duration of respiratory support (0 vs. 2 days, p = .03). There were no differences in rates of continuous positive airway pressure (CPAP)/positive pressure ventilation (PPV) (21 vs. 22%, p = .85), anemia, hyperbilirubinemia, or NICU length of stay. Multivariate analysis adjusting for general anesthesia demonstrated this variable confounded the impact of PAS pathology in respiratory outcomes the risk of the respiratory composite (adjusted odds ratio (aOR) 0.57, 95% CI [0.11, 2.82]), use of HFNC (aOR 0.33, 95% CI [0.08-1.48]), and intubation (aOR 1.29, 95% CI [0.25-6.75]), were no longer significant.

CONCLUSIONS

Based on these results, we conclude that PAS neonates have higher rates of respiratory morbidity and that general anesthesia is a significant contributor to these respiratory outcomes. This is important for the antenatal counseling of cases of PAS, especially if general anesthesia is anticipated or requested. Furthermore, it supports efforts to limit general anesthesia exposure of neonates when necessary.

Effect of anesthesia selection on neonatal outcomes in cesarean hysterectomies for placenta accreta spectrum (PAS)

OBJECTIVES

Optimal treatment for placenta accreta spectrum (PAS) is late-preterm cesarean hysterectomy to minimize maternal morbidity. This study aims to assess the impact of surgical planning during this gestational age on neonates as a key part of the pregnancy dyad.

METHODS

A retrospective cohort analysis was performed of 115 singleton, non-anomalous pregnancies complicated by PAS at the University of Texas Health San Antonio Placenta Accreta program from 2005 to 2020. Univariate and multivariate analyses were performed to identify the individual impact of variables such as anesthesia selection, advancing gestational age and operative characteristics.

RESULTS

With regards to neonatal intubation, on multivariate analysis, neuraxial anesthesia (OR=0.09, [95% CI 0.02, 0.37]) and advancing gestational age (OR=0.49 [95% CI 0.34, 0.71]) were independent protective factors. In addition, NICU length of stay was directly impacted by neuraxial anesthesia (IRR=0.73, [95% CI 0.55, 0.97]) and advancing gestational age (IRR=0.80 [95% CI 0.76, 0.84]), resulting in shorter NICU admissions.

CONCLUSIONS

As gestational age at delivery may not be modifiable in cases of PAS, the utilization of neuraxial anesthesia (as oppose to general anesthesia) presents a modifiable intervention which may optimize neonatal outcomes from cesarean hysterectomy.

The regional whole blood program in San Antonio, TX: A 3-year update on prehospital and in-hospital transfusion practices for traumatic and non-traumatic hemorrhage

Low titer type O Rh-D + whole blood (LTO + WB) has become a first-line resuscitation medium for hemorrhagic shock in many centers around the World. Showing early effectiveness on the battlefield, LTO + WB is used in both the pre-hospital and in-hospital settings for traumatic and non-traumatic hemorrhage resuscitation. Starting in 2018, the San Antonio Whole Blood Collaborative has worked to provide LTO + WB across Southwest Texas, initially in the form of remote damage control resuscitation followed by in-hospital trauma resuscitation. This program has since expanded to include pediatric trauma resuscitation, obstetric hemorrhage, females of childbearing potential, and non-traumatic hemorrhage. The objective of this manuscript is to provide a three-year update on the successes and expansion of this system and outline resuscitation challenges in special populations.

The Role of Whole Blood Transfusions in Civilian Trauma: A Review of Literature in Military and Civilian Trauma

Resuscitation techniques for the management of adult trauma patients have evolved over the 20th century. Whole blood transfusions were previously used as the standard of care, whereas blood component therapy is the current method employed across most trauma centers across the United States. Prior to the transition, no studies were conducted to show improved efficacy of hemostatic potential in trauma patients. Recent conflicts in Iraq and Afghanistan have challenged the dogma that whole blood transfusions are not the standard of care and have shown potential as the superior transfusion product for adult trauma patients. The purpose of this review is to provide a comprehensive review and elucidate if whole blood transfusions have a role in civilian trauma patients based upon recent military medical literature and civilian pilot studies using whole blood transfusions.

Short interval pregnancy is associated with pathology severity in placenta accreta spectrum (PAS)

OBJECTIVE

Placenta accreta spectrum (PAS) is a continuum of invasive pathologies associated with significant maternal morbidity and mortality. Pregnancies with short intervals present additional complications which may result from suboptimal wound healing. The impact of short interval pregnancy on placental invasion is unknown our primary objective was to characterize the impact of short interval pregnancy in the subsequent invasive degree of PAS.

METHODS

Here we present a retrospective case-control analysis of 133 patients with pathology-confirmed PAS who presented to our Placenta Accreta program and assessed for the impact of short interval pregnancy (<18 months) as an independent risk factor for the development of advanced pathology.

RESULTS

33.8% (45/133) of patients with PAS had pregnancies complicated by short intervals between gestations. Short interval pregnancies were significantly associated with placenta percreta/increta pathology (p = .006). Ordinal logistic regression showed an inversely proportional relationship between short-interval pregnancy and the degree of placental invasion (OR 2.91 [95% CI 1.02, 4.05]).

CONCLUSION

Short interval pregnancies are at increased risk for greater degrees of placenta invasion seen in placenta increta and percreta when compared to interpregnancy interval >18 months. This relationship is inversely proportional and consistent at shorter intervals. Thus, when counseling patients on their overall risk of placental invasive pathology, short interval pregnancy may be considered a significant risk factor.

Neuraxial to general anesthesia conversion has equitable intraoperative and improved post-operative outcomes compared to general anesthesia in cesarean hysterectomy for placenta accreta spectrum (PAS)

OBJECTIVE

Placenta Accreta Spectrum (PAS) represents a series of placental disorders with an estimated incidence of 1:1000. Delivery and subsequent cesarean hysterectomy for PAS is associated with significant maternal morbidity and mortality. Neuraxial anesthesia may be utilized initially with subsequent conversion to general anesthesia after delivery of the fetus as an alternative to initiating with general anesthesia.

METHODS

We performed a case-control study and analyzed 85 cases of pathology-confirmed PAS patients who underwent a cesarean hysterectomy in singleton, non-anomalous, viable pregnancies. All patients were delivered at our institution's established Placenta Accreta Program from 2005 to 2020.

RESULTS

Fifty-two (61%) patients underwent general anesthesia and 33 (39%) patients underwent neuraxial anesthesia (collectively spinal, epidural, and combined spinal-epidural) converted to general anesthesia after cesarean delivery. Baseline demographics between groups were similar. Pre-operative ASA airway assessment of III/IV was equivalent between groups (94 and 82%, p = .08). Intraoperatively, neuraxial conversion and general anesthesia were equal with respect to operative time (241 vs. 261 min, p = .47), estimated blood loss (6039 vs. 8134 mL, p = .51), and composite maternal morbidity (84.6 vs. 75.8%, p = .40). Post-operatively, ICU admission (47 vs. 46%, p = 1.0) and intensive care length of stay was equivalent (p = .07), yet the total post-operative length of stay was significantly reduced in patients who underwent neuraxial anesthesia (3.76 vs. 6.35 days, p = .02). In addition, while general anesthesia was associated with a greater sonographic suspicion for placenta percreta (40 vs. 12%, p = .007), final pathology was equivalent (52 vs. 60%, p = .5).

CONCLUSIONS

Taken together, our data show neuraxial conversion to general anesthesia has equivalent intra-operative parameters with improved post-operative outcomes when compared to general anesthesia alone in the case of cesarean hysterectomy for Placenta Accreta Spectrum disorders.