Physiologic changes of pregnancy and considerations for screening and diagnosis of sepsis

Obstetric sepsis is a significant cause of morbidity and mortality in pregnant people worldwide. Initial evaluation and timely intervention are crucial to improving outcomes for birthing persons and their newborns. While many of the therapies and interventions for peripartum sepsis are consistent with the general population, there are considerations unique to pregnancy. Stabilization of the septic pregnant or immediately postpartum patient requires an understanding of the physiologic changes of pregnancy, hemodynamic changes during labor, and infections specific to pregnancy. We will review the interaction between pregnant physiology and sepsis pathophysiology, and how this can guide screening and diagnosis.

Thromboelastography as an early prediction method for hypofibrinogenemia in emergency department patients with primary postpartum hemorrhage

BACKGROUND

Timely and accurate assessment of coagulopathy is crucial for the management of primary postpartum hemorrhage (PPH). Thromboelastography (TEG) provides a comprehensive assessment of coagulation status and is useful for guiding the treatment of hemorrhagic events in various diseases. This study aimed to evaluate the role of TEG in predicting hypofibrinogenemia in emergency department (ED) patients with primary PPH.

METHODS

We conducted a retrospective observational study in the ED of a university-affiliated tertiary hospital between November 2015 and August 2023. TEG was performed upon admission. The cutoff value for hypofibrinogenemia was 200 mg/dL. The primary outcome was the presence of hypofibrinogenemia.

RESULTS

Among the 174 patients, 73 (42.0%) had hypofibrinogenemia. The need for massive transfusion was higher in the hypofibrinogenemia group (37.0% vs. 5.0%, p < 0.001). Among the TEG parameters, all values were significantly different between the groups, except for lysis after 30 min, suggesting a tendency toward hypocoagulability. Multivariable analysis revealed that the alpha angle (odds ratio (OR) 0.924, 95% confidence interval (CI) 0.876-0.978) and maximum amplitude (MA) (OR 0.867, 95% CI 0.801-0.938) were independently associated with hypofibrinogenemia. The optimal cutoff values for the alpha angle and maximum amplitude (MA) for hypofibrinogenemia were 63.8 degrees and 56.1 mm, respectively.

CONCLUSION

Point-of-care TEG could be a valuable tool for the early identification of hypofibrinogenemia in ED patients with primary PPH.

Early viscoelastometric guided fibrinogen replacement combined with escalation of clinical care reduces progression in postpartum haemorrhage: a comparison of outcomes from two prospective observational studies

BACKGROUND

Viscoelastometric haemostatic assays (VHA) give rapid information on coagulation status, allowing individualised resuscitation.

METHODS

This paper compares outcomes from two observational studies of postpartum haemorrhage (PPH) in the same institution, before and after practice changed from fixed ratio empirical transfusion of coagulation products with laboratory coagulation testing to VHA-guided fibrinogen replacement incorporated into an enhanced PPH care bundle. In both studies, all blood samples were taken near 1000 mL qualitative blood loss (QBL). In Study One, QBL started once PPH was identified, and resuscitation with coagulation blood products was empirical or based on laboratory tests of coagulation. In Study Two, QBL started at delivery and VHA was used to guide fibrinogen replacement if FIBTEM A5 was <12 mm (Claus fibrinogen ≤2 g/L) or to withhold coagulation products if FIBTEM A5 was >12 mm.

RESULTS

Improved PPH outcomes were observed in Study Two, with rates of measured blood loss ≥2500 mL, ≥4 units red blood cell (RBC) transfusion, fresh frozen plasma transfusion and ≥8 units of any blood product transfusion all reduced (P < 0.01). Clinically significant improvements occurred in women with fibrinogen ≤2 g/L at study entry, where the proportion of women who received ≥4 units RBC transfusion fell from 67% in Study One to 0% in Study Two (P = 0.0007).

CONCLUSIONS

These results suggest that use of VHA as part of an early bundle of PPH care targeting fibrinogen ≤2 g/L with fibrinogen concentrate reduces PPH progression. The greatest benefit was seen when fibrinogen levels were ≤2 g/L at first testing.

Implementation and early outcomes with Pathogen Reduced Cryoprecipitated Fibrinogen Complex

OBJECTIVES

Cryoprecipitated antihemophilic factor (cryo) has been used for fibrinogen replacement in actively bleeding patients, dysfibrinogenemia, and hypofibrinogenemia. Cryo has a shelf life of 4 to 6 hours after thawing and a long turnaround time in issuing the product, posing a major limitation of its use. Recently, the US Food and Drug Administration approved Pathogen Reduced Cryoprecipitated Fibrinogen Complex (INTERCEPT Fibrinogen Complex [IFC]) for the treatment of bleeding associated with fibrinogen deficiency, which can be stored at room temperature and has a shelf life of 5 days after thawing.

METHODS

We identified locations and specific end users with high cryoprecipitate utilization and waste. We partnered with our blood supplier to use IFC in these locations. We analyzed waste and turnaround time before and after implementation.

RESULTS

Operative locations had a waste rate that exceeded nonoperative locations (16.7% vs 3%) and were targeted for IFC implementation. IFC was added to our inventory to replace all cryo orders from adult operating rooms, and waste decreased to 2.2% in these locations. Overall waste of cryoprecipitated products across all locations was reduced from 8.8% to 2.4%. The turnaround time for cryoprecipitated products was reduced by 58% from 30.4 minutes to 14.6 minutes.

CONCLUSIONS

There has been a substantial decrease in waste with improved turnaround time after IFC implementation. This has improved blood bank logistics, improved efficiency of patient care, and reduced costly waste.

Thromboembolic events in severe postpartum hemorrhage treated with recombinant activated factor VII: a systematic literature review and meta-analysis

Postpartum hemorrhage (PPH) is an obstetric complication with high associated morbidity. Recombinant activated factor VII (rFVIIa) is used to treat severe PPH when uterotonics fail to stop bleeding. However, data on the safety of rFVIIa treatment of severe PPH from adequately powered trials are lacking. We systematically reviewed published data on the incidence of thromboembolic events (TEs) in women with PPH treated or not treated with rFVIIa (PROSPERO CRD42022360736). Databases (Embase, MEDLINE, BIOSIS, Current Contents, and the Cochrane Library) were searched for peer-reviewed publications published between January 1996 and August 2022 and conference abstracts published between January 2017 and August 2022 using search terms related to thromboembolism or infarction and PPH. Data were extracted from all publications reporting on a general population of women with PPH with information on TEs. Descriptive summary statistics and the estimated proportion of TEs were analyzed using a generalized linear mixed model based on the binomial distribution. Quality assessments were based on the checklist by Downs and Black. From 1637 potentially eligible studies, 55 publications were included reporting on 611 women treated and 32,488 women not treated with rFVIIa. The global estimated proportion of TEs was 1.82% (prediction interval [PI], 0.30-10.23) and 0.72% (PI, 0.03-16.47) in women with severe PPH treated and those not treated with rFVIIa, respectively. The estimated proportions of TEs were similarly small, with wide and largely overlapping PIs. Additional well-designed trials are needed to improve understanding of TE incidence in PPH.

Management and outcomes of women with low fibrinogen concentration during pregnancy or immediately postpartum: A UK national population-based cohort study

INTRODUCTION

Pregnant women with a fibrinogen level <2 g/L represent a high-risk group that is associated with severe postpartum hemorrhage and other complications. Women who would qualify for fibrinogen therapy are not yet identified.

MATERIAL AND METHODS

A population-based cross-sectional study was conducted using the UK Obstetric Surveillance System between November 2017 and October 2018 in any UK hospital with a consultant-led maternity unit. Any woman pregnant or immediately postpartum with a fibrinogen <2 g/L was included. Our aims were to determine the incidence of fibrinogen <2 g/L in pregnancy, and to describe its causes, management and outcomes.

RESULTS

Over the study period 124 women with fibrinogen <2 g/L were identified (1.7 per 10 000 maternities; 95% confidence interval 1.4-2.0 per 10 000 maternities). Less than 5% of cases of low fibrinogen were due to preexisting inherited dysfibrinogenemia or hypofibrinogenemia. Sixty percent of cases were due to postpartum hemorrhage caused by placental abruption, atony, or trauma. Amniotic fluid embolism and placental causes other than abruption (previa, accreta, retention) were associated with the highest estimated blood loss (median 4400 mL) and lowest levels of fibrinogen. Mortality was high with two maternal deaths due to massive postpartum hemorrhage, 27 stillbirths, and two neonatal deaths.

CONCLUSIONS

Fibrinogen <2 g/L often, but not exclusively, affected women with postpartum hemorrhage due to placental abruption, atony, or trauma. Other more rare and catastrophic obstetrical events such as amniotic fluid embolism and placenta accreta also led to low levels of fibrinogen. Maternal and perinatal mortality was extremely high in our cohort.

Deranged Balance of Hemostasis and Fibrinolysis in Disseminated Intravascular Coagulation: Assessment and Relevance in Different Clinical Settings

The disruption of hemostasis/fibrinolysis balance leads to disseminated intravascular coagulation, manifested clinically by bleeding or thrombosis, and multiorgan failure. This study reviews hemostatic assessment and therapeutic strategies that restore this balance in critically ill patients.

Rationale for the Potential Use of Recombinant Activated Factor VII in Severe Post-Partum Hemorrhage

Severe post-partum hemorrhage (PPH) is a major cause of maternal mortality worldwide. Recombinant activated factor VII (rFVIIa) has recently been approved by the European Medicines Agency for the treatment of severe PPH if uterotonics fail to achieve hemostasis. Although large randomized controlled trials are lacking, accumulated evidence from smaller studies and international registries supports the efficacy of rFVIIa alongside extended standard treatment to control severe PPH. Because rFVIIa neither substitutes the activity of a missing coagulation factor nor bypasses a coagulation defect in this population, it is not immediately evident how it exerts its beneficial effect. Here, we discuss possible mechanistic explanations for the efficacy of rFVIIa and the published evidence in patients with severe PPH. Recombinant FVIIa may not primarily increase systemic thrombin generation, but may promote local thrombin generation through binding to activated platelets at the site of vascular wall injury. This explanation may also address safety concerns that have been raised over the administration of a procoagulant molecule in a background of increased thromboembolic risk due to both pregnancy-related hemostatic changes and the hemorrhagic state. However, the available safety data for this and other indications are reassuring and the rates of thromboembolic events do not appear to be increased in women with severe PPH treated with rFVIIa. We recommend that the administration of rFVIIa be considered before dilutional coagulopathy develops and used to support the current standard treatment in certain patients with severe PPH.

Agnostic identification of plasma biomarkers for postpartum hemorrhage risk

BACKGROUND

Postpartum hemorrhage is difficult to predict, is associated with significant maternal morbidity, and is the leading cause of maternal mortality worldwide. The identification of maternal biomarkers that can predict increased postpartum hemorrhage risk would enhance clinical care and may uncover mechanisms that lead to postpartum hemorrhage.

OBJECTIVE

This retrospective case-control study employed agnostic proteomic profiling of maternal plasma samples to identify differentially abundant proteins in controls and postpartum hemorrhage cases.

STUDY DESIGN

Maternal plasma samples were procured from a cohort of >60,000 participants in a single institution's perinatal repository. Postpartum hemorrhage was defined as a decrease in hematocrit of ≥10% or receipt of transfusion within 24 hours after delivery. Postpartum hemorrhage cases (n=30) were matched by maternal age and delivery mode (vaginal or cesarean) with controls (n=56). Mass spectrometry was used to identify differentially abundant proteins using integrated peptide peak areas. Statistically significant differences between groups were defined as P<.05 after controlling for multiple comparisons.

RESULTS

By study design, cases and controls did not differ in race, ethnicity, gestational age at delivery, blood type, or predelivery platelet count. Cases had slightly but significantly lower predelivery and postdelivery hematocrit and hemoglobin. Mass spectrometry detected 1140 proteins, including 77 proteins for which relative abundance differed significantly between cases and controls (fold change >1.15, P<.05). Of these differentially abundant plasma proteins, most had likely liver or placental origins. Gene ontology term analysis mapped to protein clusters involved in responses to wound healing, stress response, and host immune defense. Significantly differentially abundant proteins with the highest fold change (prostaglandin D2 synthase, periostin, and several serine protease inhibitors) did not correlate with predelivery hematocrit or hemoglobin but identified postpartum hemorrhage cases with logistic regression modeling revealing good-to-excellent area under the operator receiver characteristic curves (0.802-0.874). Incorporating predelivery hemoglobin with these candidate proteins further improved the identification of postpartum hemorrhage cases.

CONCLUSION

Agnostic analysis of maternal plasma samples identified differentially abundant proteins in controls and postpartum hemorrhage cases. Several of these proteins are known to participate in biologically plausible pathways for postpartum hemorrhage risk and have potential value for predicting postpartum hemorrhage. These findings identify candidate protein biomarkers for future validation and mechanistic studies.

Changing hemostatic management in post-partum hemorrhage

Early and fast assessment of hemostasis during postpartum hemorrhage (PPH) is essential to allow early characterization of coagulopathy, estimate bleeding severity and improve outcome. During PPH, fibrinogen decrease occurs earlier than other coagulation factors deficiency and hypofibrinogenemia is an early marker of PPH severity of progression. With good evidence in the context of PPH, point-of-care viscoelastic (VET) hemostatic assays have been shown to provide rapid assessment of hemostatic disorders, low fibrinogen levels, and allow VET-guided fibrinogen replacement. Further studies are needed to define the thresholds for the other coagulation parameters.

CT-001, a novel fast-clearing factor VIIa, enhanced the hemostatic activity in postpartum samples

ABSTRACT

The hemostatic system is upregulated to protect pregnant mothers from hemorrhage during childbirth. Studies of the details just before and after delivery, however, are lacking. Recombinant factor VIIa (rFVIIa) has recently been granted approval by the European Medicines Agency for the treatment of postpartum hemorrhage (PPH). A next-generation molecule, CT-001, is being developed as a potentially safer and more efficacious rFVIIa-based therapy. We sought to evaluate the peripartum hemostatic status of pregnant women and assess the ex vivo hemostatic activity of rFVIIa and CT-001 in peripartum blood samples. Pregnant women from 2 study sites were enrolled in this prospective observational study. Baseline blood samples were collected up to 3 days before delivery. Postdelivery samples were collected 45 (±15) minutes after delivery. Between the 2 time points, soluble fibrin monomer and D-dimer increased whereas tissue factor, FVIII, FV, and fibrinogen decreased. Interestingly, the postdelivery lag time and time to peak in the thrombin generation assay were shortened, and the peak thrombin generation capacity was maintained despite the reduced levels of coagulation proteins after delivery. Furthermore, both rFVIIa and CT-001 were effective in enhancing clotting activity of postdelivery samples in activated partial thromboplastin time, prothrombin time, thrombin generation, and viscoelastic hemostatic assays, with CT-001 demonstrating greater activity. In conclusion, despite apparent ongoing consumption of coagulation factors at the time of delivery, thrombin output was maintained. Both rFVIIa and CT-001 enhanced the upregulated hemostatic activity in postdelivery samples, and consistent with previous studies comparing CT-001 and rFVIIa in vitro and in in vivo, CT-001 demonstrated greater activity than rFVIIa.

Long-Term Safety Analysis of a Fibrinogen Concentrate (RiaSTAP®/Haemocomplettan® P)

Fibrinogen concentrate treatment is recommended for acute bleeding episodes in adult and pediatric patients with congenital and acquired fibrinogen deficiency. Previous studies have reported a low risk of thromboembolic events (TEEs) with fibrinogen concentrate use; however, the post-treatment TEE risk remains a concern. A retrospective evaluation of RiaSTAP®/Haemocomplettan® P (CSL Behring, Marburg, Germany) post-marketing data was performed (January 1986-June 2022), complemented by a literature review of published studies. Approximately 7.45 million grams of fibrinogen concentrate was administered during the review period. Adverse drug reactions (ADRs) were reported in 337 patients, and 81 (24.0%) of these patients experienced possible TEEs, including 14/81 (17.3%) who experienced fatal outcomes. Risk factors and the administration of other coagulation products existed in most cases, providing alternative explanations. The literature review identified 52 high-ranking studies with fibrinogen concentrate across various clinical areas, including 26 randomized controlled trials. Overall, a higher number of comparative studies showed lower rates of ADRs and/or TEEs in the fibrinogen group versus the comparison group(s) compared with those that reported higher rates or no differences between groups. Post-marketing data and clinical studies demonstrate a low rate of ADRs, including TEEs, with fibrinogen concentrate treatment. These findings suggest a favorable safety profile of fibrinogen concentrate, placing it among the first-line treatments effective for managing intraoperative hemostatic bleeding.

Efficacy of prompt administration of cryoprecipitate in severe postpartum hemorrhage of preeclampsia patients

AIM

Cryoprecipitate (CRYO) is a concentrated preparation of coagulation factors formulated from fresh frozen plasma (FFP), which can replenish coagulation factors rapidly. Preeclampsia (PE) is frequently associated with postpartum hemorrhage (PPH), and the rapid replenishment of coagulation factors is vital in the management. We conducted a retrospective cohort study to determine the efficacy of administering CRYO irrespective of fibrinogen levels in patients with PE who experienced severe PPH.

METHODS

Patients with PPH accompanied by PE and those who required red blood cell (RBC) transfusion were included. Cases were divided into two groups: those treated with CRYO (N = 16) and those not treated with CRYO (N = 10). The total transfusion volume, blood loss before and after transfusion initiation, duration of hospitalization, presence of pulmonary edema, and performance of either interventional radiology or hysterectomy were compared.

RESULTS

The median fibrinogen levels before transfusion were 2.24 and 2.34 g/L in the CRYO group and the not using group, respectively. Although blood loss before transfusion was comparable between the two groups, blood loss after transfusion was significantly less in the CRYO group (median: 520 vs. 2352 mL, p = 0.015), as well as the total blood loss (median: 2285 vs. 3825 mL, p = 0.005) and total transfusion volume (median: RBC 6 vs. 16 U, p = 0.01, FFP 10 vs. 20 U, p = 0.017).

CONCLUSION

Prompt replenishment of coagulation factors using CRYO to patients with PE who experience severe PPH could decrease further bleeding.

Early and Empirical High-Dose Cryoprecipitate for Hemorrhage After Traumatic Injury: The CRYOSTAT-2 Randomized Clinical Trial

Importance

Critical bleeding is associated with a high mortality rate in patients with trauma. Hemorrhage is exacerbated by a complex derangement of coagulation, including an acute fibrinogen deficiency. Management is fibrinogen replacement with cryoprecipitate transfusions or fibrinogen concentrate, usually administered relatively late during hemorrhage.

Objective

To assess whether survival could be improved by administering an early and empirical high dose of cryoprecipitate to all patients with trauma and bleeding that required activation of a major hemorrhage protocol.

Design, Setting, and Participants

CRYOSTAT-2 was an interventional, randomized, open-label, parallel-group controlled, international, multicenter study. Patients were enrolled at 26 UK and US major trauma centers from August 2017 to November 2021. Eligible patients were injured adults requiring activation of the hospital's major hemorrhage protocol with evidence of active hemorrhage, systolic blood pressure less than 90 mm Hg at any time, and receiving at least 1 U of a blood component transfusion.

Intervention

Patients were randomly assigned (in a 1:1 ratio) to receive standard care, which was the local major hemorrhage protocol (reviewed for guideline adherence), or cryoprecipitate, in which 3 pools of cryoprecipitate (6-g fibrinogen equivalent) were to be administered in addition to standard care within 90 minutes of randomization and 3 hours of injury.

Main Outcomes and Measures

The primary outcome was all-cause mortality at 28 days in the intention-to-treat population.

Results

Among 1604 eligible patients, 799 were randomized to the cryoprecipitate group and 805 to the standard care group. Missing primary outcome data occurred in 73 patients (principally due to withdrawal of consent) and 1531 (95%) were included in the primary analysis population. The median (IQR) age of participants was 39 (26-55) years, 1251 (79%) were men, median (IQR) Injury Severity Score was 29 (18-43), 36% had penetrating injury, and 33% had systolic blood pressure less than 90 mm Hg at hospital arrival. All-cause 28-day mortality in the intention-to-treat population was 26.1% in the standard care group vs 25.3% in the cryoprecipitate group (odds ratio, 0.96 [95% CI, 0.75-1.23]; P = .74). There was no difference in safety outcomes or incidence of thrombotic events in the standard care vs cryoprecipitate group (12.9% vs 12.7%).

Conclusions and Relevance

Among patients with trauma and bleeding who required activation of a major hemorrhage protocol, the addition of early and empirical high-dose cryoprecipitate to standard care did not improve all cause 28-day mortality.

Trial Registration

ClinicalTrials.gov Identifier: NCT04704869; ISRCTN Identifier: ISRCTN14998314.

Viscoelastic Testing Methods

Viscoelastic testing methods examine the real-time formation of a clot in a whole blood sample, and include thromboelastography (TEG), rotational thromboelastometry (ROTEM), and several other testing platforms. They allow for concurrent assessment of multiple aspects of clotting, including plasmatic coagulation factors, platelets, fibrinogen, and the fibrinolytic pathway. This testing is rapid and may be performed at the point-of-care, allowing for prompt identification of coagulopathies to guide focused and rational administration of blood products as well as the identification of anticoagulant effect. With recent industry progression towards user-friendly, cartridge-based, portable instruments, viscoelastic testing has emerged in the 21st century as a powerful tool to guide blood transfusions in the bleeding patient, and to identify and treat both bleeding and thrombotic conditions in many operative settings, including trauma surgery, liver transplant surgery, cardiac surgery, and obstetrics. In these settings, the use of transfusion algorithms guided by viscoelastic testing data has resulted in widespread improvements in patient blood management as well as modest improvements in select patient outcomes. To address the increasingly wide adoption of viscoelastic methods and the growing number of medical and laboratory personnel tasked with implementing, performing, and interpreting these methods, this chapter provides an overview of the history, physiology, and technology behind viscoelastic testing, as well as a practical review of its clinical utility and current evidence supporting its use. Also included is a review of testing limitations and the contextual role played by viscoelastic methods among all coagulation laboratory testing.

Early treatment with Fibrinogen γ-chain peptide-coated, ADP-encapsulated Liposomes (H12-(ADP)-liposomes) ameliorates post-partum hemorrhage with coagulopathy caused by amniotic fluid embolism in rabbits

BACKGROUND

Amniotic fluid embolism is an unpredictable and sometimes lethal complication of childbirth. Fibrinogen γ-chain peptide-coated, ADP-encapsulated Liposomes (H12-(ADP)-liposomes), which were developed as a platelet substitute, may be useful to control postpartum hemorrhage with consumptive coagulopathy.

OBJECTIVE

This study aimed to establish a hemodynamically stable amniotic fluid embolism animal model and evaluate the efficacy of H12-ADP-liposome infusion in the initial management of postpartum hemorrhage complicated with amniotic fluid embolism-involved coagulopathy.

STUDY DESIGN

Pregnant New Zealand white rabbits (28th day of pregnancy or normal gestation period of 29-35 days) underwent cesarean delivery, followed by intravenous administration of amniotic fluid (a total of 3.0 mL administered in 4 doses over 9 minutes). Thereafter, uncontrolled postpartum hemorrhage was induced by transecting the right midartery and concomitant vein in the myometrium. After initial bleeding for 5 minutes, rabbits received isovolemic fluid resuscitation through the femoral vein with an equivalent volume of blood loss every 5 minutes for 60 minutes. The transfusion regimens included platelet-rich plasma, platelet-poor plasma, and a bolus administration of H12-ADP-liposomes followed by platelet-poor plasma transfusion (8 rabbits per group). Moreover, 60 minutes after initiation of bleeding, rabbits received surgical hemostasis by ligation of bleeding vessels, except in cases with spontaneous hemostasis.

RESULTS

The administration of amniotic fluid caused thrombocytopenia (56±3 × 103/μL) and prolonged both clotting time (before administration: 130.0±3.0 to 171.0±5.0 seconds) and prothrombin time (4.5±0.1 to 4.7±0.1 seconds). After the initial 5-minute bleeding in the rabbits, the mean arterial pressure fell to 43±2 mm Hg. Platelet-poor plasma transfusion alone further prolonged clotting time and prothrombin time at 60 minutes (192.0±10.0 and 5.2±0.1 seconds, respectively) with decreasing mean arterial pressure to <40 mm Hg. By contrast, the administration of H12-ADP-liposomes followed by platelet-poor plasma transfusion reduced the prolonged clotting time (153.0±5.0 seconds) and prothrombin time (4.9±0.1 seconds) similar to platelet-rich plasma transfusion (154.0±11.0 and 4.9±0.1 seconds, respectively) at 60 minutes. These rabbits maintained a mean arterial pressure of >45 mm Hg throughout the experiment. H12-ADP-liposome infusion and platelet-poor plasma transfusion and platelet-rich plasma transfusion yielded spontaneous hemostasis in 4 of 8 rabbits, whereas platelet-poor plasma transfusion did not stop bleeding in any of the rabbits. The total blood loss was 59±17 mL in the H12-ADP-liposomes and platelet-poor plasma group, which was half of that in the platelet-poor plasma group (124±10 mL).

CONCLUSION

H12-ADP-liposome infusion may be effective in the initial management of postpartum hemorrhage complicated with amniotic fluid embolism, resulting in mitigation of consumptive coagulopathy.

[Postpartum Hemorrhage]

Postpartum hemorrhage (PPH) affects about 4% of all deliveries in high-income countries and continues to rise, a trend attributable to the increase in caesarean section rates and maternal morbidity. Preventive measures such as the precautionary administration of uterotonics effectively reduce the risk of severe bleeding irrespective of birth mode. As a time-critical condition and a significant contributor to adverse maternal outcomes, PPH needs to be diagnosed early by measuring, not estimating, blood losses. Institutional treatment algorithms should be available to guide stage-based interdisciplinary management without delay. The main therapy goals are to identify the etiology and stop the bleeding by using uterotonics and mechanical and surgical interventions, to restore hemodynamic stability by volume and transfusion therapy and to optimize hemostasis by laboratory- and viscoelastic assay-guided factor replacement. This review highlights current recommendations for prevention, diagnosis and treatment of PPH.

Fibrinolytic potential as a risk factor for postpartum hemorrhage

Background

Postpartum hemorrhage (PPH) is still the leading cause of maternal morbidity and mortality worldwide. While impaired fibrin polymerization plays a crucial role in the development and progress of PPH, recent approaches using viscoelastic measurements have failed to sensitively detect early changes in fibrinolysis in PPH. This study aimed to evaluate whether women experiencing PPH show alterations in POC-VET fibrinolytic potential during childbirth and whether fibrinolytic potential offers benefits in the prediction and treatment of PPH.

Methods

Blood samples were collected at three different timepoints: T0 = hospital admission (19 h ± 18 h prepartum), T1 = 30-60 min after placental separation, and T2 = first day postpartum (19 h ± 6 h postpartum). In addition to standard laboratory tests, whole-blood impedance aggregometry (Multiplate) and viscoelastic testing (VET) were performed using the ClotPro system, which included the TPA-test lysis time, to assess the POC-VET fibrinolytic potential, and selected coagulation factors were measured. The results were correlated with blood loss and clinical outcome markers. Severe PPH was defined as a hemoglobin drop > 4g/dl and/or the occurrence of shock or the need for red blood cell transfusion.

Results

Blood samples of 217 parturient women were analyzed between June 2020 and December 2020 at Heidelberg University Women's Hospital, and 206 measurements were eligible for the final analysis. Women experiencing severe PPH showed increased fibrinolytic potential already at the time of hospital admission. When compared to non-PPH, the difference persisted 30-60 min after placental separation. A higher fibrinolytic potential was accompanied by a greater drop in fibrinogen and higher d-dimer values after placental separation. While 70% of women experiencing severe PPH showed fibrinolytic potential, 54% of those without PPH showed increased fibrinolytic potential as well.

Conclusion

We were able to show that antepartal and peripartal fibrinolytic potential was elevated in women experiencing severe PPH. However, several women showed high fibrinolytic potential but lacked clinical signs of PPH. The findings indicate that high fibrinolytic potential is a risk factor for the development of coagulopathy, but further conditions are required to cause PPH.

Coagulation management and transfusion in massive postpartum hemorrhage

PURPOSE OF REVIEW

Excessive bleeding during and following childbirth remains one of the leading causes of maternal mortality.

RECENT FINDINGS

Current guidelines differ in definitions and recommendations on managing transfusion and hemostasis in massive postpartum hemorrhage (PPH). Insights gained from trauma-induced coagulopathy are not directly transferable to the obstetric population due to gestational alterations and a differing pathophysiology.

SUMMARY

Factor deficiency is uncommon at the beginning of most etiologies of PPH but will eventually develop from consumption and depletion in the absence of bleeding control. The sensitivity of point-of-care tests for fibrinolysis is too low and may delay treatment, therefore tranexamic acid should be started early at diagnosis even without signs for hyperfibrinolysis. Transfusion management may be initiated empirically, but is best to be guided by laboratory and viscoelastic assay results as soon as possible. Hypofibrinogenemia is well detected by point-of-care tests, thus substitution may be tailored to individual needs, while reliable thresholds for fresh frozen plasma (FFP) and specific components are yet to be defined. In case of factor deficiency, prothrombin complex concentrate or lyophilized plasma allow for a more rapid restoration of coagulation than FFP. If bleeding and hemostasis are under control, a timely anticoagulation may be necessary.

Interventions of Postpartum Hemorrhage

Postpartum hemorrhage is a common and potentially life-threatening obstetric complication, with successful management relying heavily on early identification of hemorrhage and prompt intervention. This article will review the management of postpartum hemorrhage, including initial steps, exam-specific interventions, medical therapy, minimally invasive, and surgical interventions.

Blood Product Replacement for Postpartum Hemorrhage

Consideration for blood products replacement in postpartum hemorrhage should be given when blood loss exceeds 1.5 L or when an estimated 25% of blood has been lost. In cases of massive hemorrhage, standardized transfusion protocols have been shown to improve maternal morbidity and mortality. Most protocols recommend a balanced transfusion involving a 1:1:1 ratio of packed red blood cells, platelets, and fresh frozen plasma. Alternatives such as cryoprecipitate, fibrinogen concentrate, and prothrombin complex concentrates can be used in select clinical situations. Although transfusion of blood products can be lifesaving, it does have associated risks.

Placental abruption at near-term and term gestations: pathophysiology, epidemiology, diagnosis, and management

Placental abruption is the premature separation of the placenta from its uterine attachment before the delivery of a fetus. The clinical manifestations of abruption typically include vaginal bleeding and abdominal pain with a wide variety of abnormal fetal heart rate patterns. Clinical challenges arise when pregnant people with this condition present with profound vaginal bleeding, necessitating urgent delivery, especially when there is a concern for maternal and fetal compromise and coagulopathy. Abruption occurs in 0.6% to 1.2% of all pregnancies, with nearly half of abruption occurring at term gestations. An exposition of abruption at near-term (defined as the late preterm period from 34 0/7 to 36 6/7 weeks of gestation) and term (defined as ≥37 weeks of gestation) provides unique insights into its direct effects, as risks associated with preterm birth do not impact outcomes. Here, we explore the pathophysiology, epidemiology, and diagnosis of abruption. We discuss the interaction of chronic processes (decidual and uteroplacental vasculopathy) and acute processes (shearing forces applied to the abdomen) that underlie the pathophysiology. Risk factors for abruption and strengths of association are summarized. Sonographic findings of abruption and fetal heart rate tracings are presented. In addition, we propose a management algorithm for acute abruption that incorporates blood loss, vital signs, and urine output, among other factors. Lastly, we discuss blood component therapy, viscoelastic point-of-care testing, disseminated intravascular coagulopathy, and management of abruption complicated by fetal death. The review seeks to provide comprehensive, clinically focused guidance during a gestational age range when neonatal outcomes can often be favorable if rapid and evidence-based care is optimized.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Emergency administration of fibrinogen concentrate for haemorrhage: systematic review and meta-analysis

INTRODUCTION

The occurrence of massive haemorrhages in various emergency situations increases the need for blood transfusions and increases the risk of mortality. Fibrinogen concentrate (FC) use may increase plasma fibrinogen levels more rapidly than fresh-frozen product or cryoprecipitate use. Previous several systematic reviews and meta-analyses have not effectively demonstrated FC efficacy in significantly improving the risk of mortality and reducing transfusion requirements. In this study, we investigated the use of FC for haemorrhages in emergency situations.

METHODS AND ANALYSIS

In this systematic review and meta-analysis, we included controlled trials, but excluded randomized controlled trials (RCTs) in elective surgeries. The study population consisted of patients with haemorrhages in emergency situations, and the intervention was emergency supplementation of FC. The control group was administered with ordinal transfusion or placebo. The primary and secondary outcomes were in-hospital mortality and the amount of transfusion and thrombotic events, respectively. The electronic databases searched included MEDLINE (PubMed), Web of Science, and the Cochrane Central Register of Controlled Trials.

RESULTS

Nine RCTs in the qualitative synthesis with a total of 701 patients were included. Results showed a slight increase in in-hospital mortality with FC treatment (RR 1.24, 95% CI 0.64-2.39, p = 0.52) with very low certainty of the evidence. There was no reduction in the use of red blood cells (RBC) transfusion in the first 24 h after admission with FC treatment (mean difference [MD] 0.0 Unit in the FC group, 95% CI - 0.99-0.98, p = 0.99) with very low certainty of the evidence. However, the use of fresh-frozen plasma (FFP) transfusion significantly increased in the first 24 h after admission with FC treatment (MD 2.61 Unit higher in the FC group, 95% CI 0.07-5.16, p = 0.04). The occurrence of thrombotic events did not significantly differ with FC treatment.

CONCLUSIONS

The present study indicates that the use of FC may result in a slight increase in in-hospital mortality. While FC did not appear to reduce the use of RBC transfusion, it likely increased the use of FFP transfusion and may result in a large increase in platelet concentrate transfusion. However, the results should be interpreted cautiously due to the unbalanced severity in the patient population, high heterogeneity, and risk of bias.

The Role of Thromboelastography during the Management of Postpartum Hemorrhage: Background, Evidence, and Practical Application

Postpartum hemorrhage (PPH) is a common cause of significant maternal morbidity and mortality that can be associated with coagulopathy, especially hypofibrinogenemia. There is interest in point-of-care viscoelastic hemostatic assays (POC-VHA) in PPH because prompt knowledge of coagulation status can aid diagnosis, identify cases of severe coagulopathy, and allow ongoing monitoring during rapid bleeding. The incidence of coagulopathy in most cases of PPH is low because of the procoagulant state of pregnancy, including raised fibrinogen levels of around 4 to 6 g/L. A Clauss fibrinogen of >2 g/L or POC-VHA equivalent has been found to be adequate for hemostasis during PPH. POC-VHA has been used successfully to diagnose hypofibrinogenemia (Clauss fibrinogen of ≤2 g/L) and guide fibrinogen treatment which has reduced bleed size and complications of massive transfusion. There are uncertainties about the use of POC-VHA to direct fresh frozen plasma and platelet administration during PPH. Several POC-VHA algorithms have been used successfully incorporated in the management of many thousands of PPHs and clinicians report that they are easy to use, interpret, and aid decision making. Due to the relative cost of POC-VHA and lack of definitive data on improving outcomes, these devices have not been universally adopted during PPH.

Thromboelastometry-guided treatment algorithm in postpartum haemorrhage: a randomised, controlled pilot trial

BACKGROUND

Postpartum haemorrhage causes significant mortality among parturients. Early transfusion of blood products based on clinical judgement and conventional coagulation testing has been adapted to the treatment of postpartum haemorrhage, but rotational thromboelastometry (ROTEM) may provide clinicians means for a goal-directed therapy to control coagulation. We conducted a parallel design, randomised, controlled trial comparing these two approaches. We hypothesised that a ROTEM-guided protocol would decrease the need for red blood cell transfusion.

METHODS

We randomised 60 parturients with postpartum haemorrhage of more than 1500 ml to receive either ROTEM-guided or conventional treatment, with 54 patients included in the final analysis. The primary outcome was consumption of blood products, and secondarily we assessed for possible side-effects of managing blood loss such as thromboembolic complications, infections, and transfusion reactions.

RESULTS

The median (25th-75th percentile) number of RBC units transfused was 2 (1-4) in the ROTEM group and 3 (2-4) in the control group (P=0.399). The median number of OctaplasLG® units given was 0 in both groups (0-0 and 0-2) (P=0.030). The median total estimated blood loss was 2500 ml (2100-3000) in the ROTEM group and 3000 ml (2200-3100) in the control group (P=0.033). No differences were observed in secondary outcomes.

CONCLUSIONS

ROTEM-guided treatment of postpartum haemorrhage could have a plasma-sparing effect but possibly only a small reduction in total blood loss.

CLINICAL TRIAL REGISTRATION

NCT02461251.

Haemostatic support in postpartum haemorrhage: A review of the literature and expert opinion

Postpartum haemorrhage (PPH) remains the leading cause of pregnancy-related deaths worldwide. Typically, bleeding is controlled by timely obstetric measures in parallel with resuscitation and treatment of coagulopathy. Early recognition of abnormal coagulation is crucial and haemostatic support should be considered simultaneously with other strategies as coagulopathies contribute to the progression to massive haemorrhage. However, there is lack of agreement on important topics in the current guidelines for management of PPH. A clinical definition of PPH is paramount to understand the situation to which the treatment recommendations relate; however, reaching a consensus has previously proven difficult. Traditional definitions are based on volume of blood loss, which is difficult to monitor, can be misleading and leads to treatment delay. A multidisciplinary approach to define PPH considering vital signs, clinical symptoms, coagulation and haemodynamic changes is needed. Moreover, standardised algorithms or massive haemorrhage protocols should be developed to reduce the risk of morbidity and mortality and improve overall clinical outcomes in PPH. If available, point-of-care testing should be used to guide goal-directed haemostatic treatment. Tranexamic acid should be administered as soon as abnormal bleeding is recognised. Fibrinogen concentrate rather than fresh frozen plasma should be administered to restore haemostasis where there is elevated risk of fibrinogen deficiency (e.g., in catastrophic bleeding or in cases of abruption or amniotic fluid embolism) as it is a more concentrated source of fibrinogen. Lastly, organisational considerations are equally as important as clinical interventions in the management of PPH and have the potential to improve patient outcomes.

Laboratory Testing of Hemostasis in Pregnancy: A Brief Overview

Normal pregnancy is associated with significant physiological changes in the coagulation and fibrinolytic systems with an inclination toward a hypercoagulable state. This includes an increase in plasma levels of most clotting factors, a decrease in endogenous anticoagulants, and inhibition of fibrinolysis. Although these changes are critical in maintaining placental function and reducing postpartum hemorrhage, they may contribute to an increased risk of thromboembolism, particularly toward the end of pregnancy and during puerperium. Hemostasis parameters and the non-pregnant population reference ranges cannot be used in the assessment of bleeding or thrombotic complication risk during pregnancy, and pregnancy-specific information and reference ranges are not always available to support the interpretation of laboratory tests. This review aims to summarize the use of relevant hemostasis tests to promote evidence-based interpretation of laboratory test results as well as discuss challenges associated with testing during pregnancy.

The role of fibrinogen in postpartum hemorrhage

Postpartum hemorrhage (PPH) is the leading cause of maternal death worldwide (WHO), with almost 60000 deaths annually. Pregnancy is a prothrombotic state with increased levels of several coagulation factors to protect the parturient from bleeding problems during delivery. Fibrinogen has a significant role in coagulation and bleeding. Studies have pointed out that lower fibrinogen levels before delivery, but also at the initiation of PPH, are predictive of major hemorrhage. Early, the goal-directed fibrinogen concentrate therapy might be very useful in a subgroup of patients with serious PPH. This review aims to summarize the current literature on fibrinogen during PPH.

Epidemiology and definition of PPH worldwide

Postpartum/peripartum hemorrhage (PPH) is an obstetric emergency complicating 1-10% of all deliveries and is a leading cause of maternal mortality and morbidity worldwide. However, the incidence of PPH differs widely according to the definition and criteria used, the way of measuring postpartum blood loss, and the population being studied with the highest numbers in developing countries. Despite all the significant progress in healthcare, the incidence of PPH is rising due to an incomplete implementation of guidelines, resulting in treatment delays and suboptimal care. A consensus clinical definition of PPH is needed to enable awareness, early recognition, and initiation of appropriate intensive treatment. Unfortunately, the most used definition of PPH based on blood loss ≥500 ml after delivery suffers from inaccuracies in blood loss quantification and is not clinically relevant in most cases, as the amount of blood loss does not fully reflect the severity of bleeding.

Point-of-care coagulation testing for postpartum haemorrhage

The use of viscoelastic haemostatic assays (VHAs) to guide blood product replacement during postpartum haemorrhage is expanding. Rotem and TEG devices can be used to detect and treat clinically significant hypofibrinogenaemia, although evidence to support the role of VHAs for guiding fresh frozen plasma and platelet transfusion is less clear. If Rotem/TEG traces are normal, clinicians should investigate for another cause of bleeding, and haemostatic support is not required. Guidelines support the use of VHAs during postpartum haemorrhage as part of locally agreed algorithms. There is a wide consensus that fibrinogen replacement is needed if the Fibtem A5 is <12 mm and if there is ongoing bleeding. Guidelines recommend against using VHAs to guide tranexamic acid infusion, and this drug should be given as soon as bleeding is recognised, irrespective of the Rotem/TEG traces. The cost-effectiveness of VHAs during postpartum haemorrhage needs to be addressed.

Comparison of European recommendations about patient blood management in postpartum haemorrhage

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality and morbidity worldwide. Some documents with practical recommendations for the management of PPH do not include the most updated directives. This review offers a quality comparison of the recommendations stated in Europe since 2015. A literature search was conducted to identify the documents published in Europe from 2015 to 2020 containing recommendations about management of PPH. The search returned 10 publications. A narrative synthesis and a summary of the information about PPH definition and its management were performed. Differences in the definition of PPH were identified: some documents considered the delivery procedure, and many publications included severity criteria. The therapeutic goal for red blood cells transfusion ranged from 6 to 9 g/dl. There were divergences in the need for considering haemostatic results before fresh frozen plasma transfusion. The therapeutic goal of platelet transfusion ranged from 50 x 10⁹ to 100 x 10⁹  μ/L. There was a wide consensus about the therapeutic goal of fibrinogen replacement (>2 g/L), but not about its use in an unmonitored or pre-emptive manner. Most publications included therapeutic approaches such as tranexamic acid and recombinant factor VII activated, but not prothrombin complex concentrate or coagulation factor XIII. The recommendations about PPH management offered in European documents are heterogeneous and have changed over time. The standardisation of all them could be useful to make progress in PPH clinical management and research which, in turn, could strongly impact in patient outcomes.

Emergencies in obstetric anaesthesia: a narrative review

We conducted a narrative review in six areas of obstetric emergencies: category-1 caesarean section; difficult and failed airway; massive obstetric haemorrhage; hypertensive crisis; emergencies related to neuraxial anaesthesia; and maternal cardiac arrest. These areas represent significant research published within the last five years, with emphasis on large multicentre randomised trials, national or international practice guidelines and recommendations from major professional societies. Key topics discussed: prevention and management of failed neuraxial technique; role of high-flow nasal oxygenation and choice of neuromuscular drug in obstetric patients; prevention of accidental awareness during general anaesthesia; management of the difficult and failed obstetric airway; current perspectives on the use of tranexamic acid, fibrinogen concentrate and cell salvage; guidance on neuraxial placement in a thrombocytopenic obstetric patient; management of neuraxial drug errors, local anaesthetic systemic toxicity and unusually prolonged neuraxial block regression; and extracorporeal membrane oxygenation use in maternal cardiac arrest.

Plasental invazyon anomalisi olan hastalarda anestezi yönetimi: Tek merkez deneyimi

Aim: Postpartum hemorrhage is a life-threatening obstetric emergent clinical situation accompanied by blood loss of more than 500 ml after vaginal delivery and more than 1000 ml after cesarean section. This situation, frequently encountered in placental adhesion anomalies, is essential in terms of follow-up, treatment, and multidisciplinary management. We aimed to retrospectively evaluate the perioperative anesthesia management, transfusion requirement, and postoperative intensive care unit requirement of patients diagnosed with placental invasion anomaly who had an intraoperative hemorrhage Methods: In our single-center study, a total of 58 female patients diagnosed with of placental invasion anomaly with a cesarean section between 2017-2020 were examined. Patients under 18 years of age and missing data were excluded from the study. Demographic data of patients (age, American Society of Anesthesiologists score (ASA)), diagnosis, duration of operation, perioperative laboratory findings, anesthesia type, perioperative hemodynamics (highest heart rate, lowest mean arterial pressure, shock index), amount of bleeding, blood products, and fluids used, surgical interventions (B-Lynch, Bacri balloon application, uterine artery ligation, hysterectomy), intraoperative vasopressor/inotrope use, ICU stay, laboratory results in the first 24 hours postoperatively, and total hospital stay were recorded. Results: In the preoperative evaluation, 27 (46.5%) patients were diagnosed with placenta accreta, and placenta previa was diagnosed in 19 (32.7%) patients. Perioperatively mean of 3.08 ± 1.7 units of Red blood cell was used. In patients with postoperative intensive care unit hospitalization, the highest intraoperative lactate value was 3.5±1.8 mmol/L, shock index was 1.3±0.3 (0.6-1.8). In patients given intraoperative fibrinogen concentrate, the intraoperative shock index was 1.5±0.2 (0.9-1.8), the amount of intraoperative bleeding was 2575±302.2 ml, and the fibrinogen levels measured in the first 24 hours after surgery were 294.7±79.7 mg/dl. Conclusions: Anesthesia management of patients diagnosed with abnormal placental invasion is important because of significant hemorrhage. Due to unstable hemodynamics, preoperative blood product preparation with a multidisciplinary approach and a postoperative intensive care unit plan should be made for these patients.

Fibrinogen concentrate and maternal outcomes in severe postpartum hemorrhage: A population-based cohort study with a propensity score-matched analysis

STUDY OBJECTIVE

Fibrinogen concentrate is used to treat severe postpartum hemorrhage despite limited evidence of its effectiveness in obstetric settings. We aimed to explore the association between its administration and maternal outcomes in women with severe postpartum hemorrhage.

DESIGN, SETTING AND PATIENTS

This secondary analysis of the EPIMOMS prospective population-based study, exploring severe maternal morbidity, as defined by national expert consensus (2012-2013, 182,309 deliveries, France), included all women with severe postpartum hemorrhage and transfused with red blood cells during active bleeding.

MEASUREMENTS

The primary endpoint was maternal near-miss or death, and the secondary endpoint the total number of red blood cells units transfused.

INTERVENTIONS

We studied fibrinogen concentrate administration as a binary variable and then by the timing of its administration. We used multivariable analysis and propensity score matching to account for potential indication bias.

MAIN RESULTS

Among the 730 women with severe postpartum hemorrhage and transfused, 313 (42.9%) received fibrinogen concentrate, and 142 (19.5%) met near-miss criteria or died. The risk of near-miss or death was not significantly lower among the women treated with fibrinogen concentrate than among those not treated, in either the multivariable analysis (adjusted RR = 1.03; 95% CI, 0.72-1.49; P = 0.855) or the propensity score analysis (RR = 0.85; 95% CI, 0.55-1.32; P = 0.477). Among women treated with fibrinogen concentrate, administration more than three hours after red blood cell transfusion started was associated with a higher risk of near-miss or death than administration before or within 30 min after the transfusion began (adjusted RR = 2.07; 95% CI, 1.10-3.89; P = 0.024). Results were similar for the secondary endpoint.

CONCLUSIONS

The use of fibrinogen concentrate in severe postpartum hemorrhage needing red blood cell transfusion during active bleeding is not associated with improved maternal outcomes.

Latest advances in postpartum hemorrhage management

Hemorrhage is the leading cause of maternal mortality worldwide. A maternal health priority is improving how healthcare providers prevent and manage postpartum hemorrhage (PPH). Because anesthesiologists can help facilitate how hospitals develop approaches for PPH prevention and anticipatory planning, we review the potential utility of PPH risk-assessment tools, bundles, and protocols. Anesthesiologists rely on clinical and diagnostic information for initiating and evaluating medical management. Therefore, we review modalities for measuring blood loss after delivery, which includes visual, volumetric, gravimetric, and colorimetric approaches. Point-of-care technologies for assessing changes in central hemodynamics (ultrasonography) and coagulation profiles (rotational thromboelastometry and thromboelastography) are also discussed. Anesthesiologists play a critical role in the medical and transfusion management of PPH. Therefore, we review blood ordering and massive transfusion protocols, fixed-ratio vs. goal-directed transfusion approaches, coagulation changes during PPH, and the potential clinical utility of the pharmacological adjuncts, tranexamic acid, and fibrinogen concentrate.

Placebo and nocebo effects in transfusion medicine

BACKGROUND

Our own observations suggested that placebo and nocebo effects may occur with transfusions. However these effects seem to have been poorly studied.

OBJECTIVES

To examine published information on, and draw attention to the possibility of, placebo and nocebo effects with transfusion.

METHODS

Focused literature review.

RESULTS

There is some information on placebo effects with clotting factors and this effect appears modest at best. There is very little published information on this regarding other fresh blood components. Although unknown biologic effects cannot be ruled out, there are hints that placebo effects might operate - especially with red blood cell transfusions. There is practically no information on nocebo effects with transfusions.

CONCLUSIONS

There are ways of surmounting the practical and ethical difficulties involved, and obtaining better information on both types of effects. Individualised, contextualised, informed consenting of transfusion recipients may help to enhance placebo, and reduce nocebo, effects. This may be supportable ethically, and desirable clinically, and financially.

DIC in Pregnancy - Pathophysiology, Clinical Characteristics, Diagnostic Scores, and Treatments

Obstetrical hemorrhage and especially DIC (disseminated intravascular coagulation) is a leading cause for maternal mortality across the globe, often secondary to underlying maternal and/or fetal complications including placental abruption, amniotic fluid embolism, HELLP syndrome (hemolysis, elevated liver enzymes and low platelets), retained stillbirth and acute fatty liver of pregnancy. Various obstetrical disorders can present with DIC as a complication; thus, increased awareness is key to diagnosing the condition. DIC patients can present to clinicians who may not be experienced in a variety of aspects of thrombosis and hemostasis. Hence, DIC diagnosis is often only entertained when the patient already developed uncontrollable bleeding or multi-organ failure, all of which represent unsalvageable scenarios. Beyond the clinical presentations, the main issue with DIC diagnosis is in relation to coagulation test abnormalities. It is widely believed that in DIC, patients will have prolonged prothrombin time (PT) and partial thromboplastin time (PTT), thrombocytopenia, low fibrinogen, and raised D-dimers. Diagnosis of DIC can be elusive during pregnancy and requires vigilance and knowledge of the physiologic changes during pregnancy. It can be facilitated by using a pregnancy specific DIC score including three components: 1) fibrinogen concentrations; 2) the PT difference - relating to the difference in PT result between the patient's plasma and the laboratory control; and 3) platelet count. At a cutoff of ≥26 points, the pregnancy specific DIC score has 88% sensitivity, 96% specificity, a positive likelihood ratio (LR) of 22, and a negative LR of 0.125. Management of DIC during pregnancy requires a prompt attention to the underlying condition leading to this complication, including the delivery of the patient, and correction of the hemostatic problem that can be guided by point of care testing adjusted for pregnancy.

General or regional anaesthesia for postpartum haemorrhage-A national population-based cohort study

BACKGROUND

Anaesthesia is required to assist the treatment of postpartum haemorrhage (PPH) when manual removal of the placenta or emptying of the uterine cavity is required. The choice between general or regional anaesthesia may depend upon factors such as existing epidural, airway, hypovolaemia, and tradition.

METHODS

Data from a randomized controlled trial of PPH (FIB-PPH) was used to reveal differences between delivery centres. In addition, national data of 5,601 PPH procedures requiring anaesthesia during 2010-2015 was collected from the Danish Medical Birth Registry, the National Danish Patient Registry, and the Danish Anaesthesia Database. The aim is to describe the variation in choice of anaesthesia for treatment of PPH.

RESULTS

Data from the randomized trial showed large differences in practice between centres not explained by physiological factors. Using national Danish registry data, we show that large delivery centres as compared to small centres prefer regional anaesthesia for PPH procedures in opposed to general anaesthesia. Sevoflurane was used despite it causing uterine relaxation. The use of general anaesthesia was associated with younger parturients, larger blood loss, and larger Body-Mass Index. Aspiration was recorded in one case (0.02%). In the postoperative care-unit general anaesthesia was associated with a shorter stay, but also higher pain score at admission.

CONCLUSION

Practice varies immensely between delivery centres with large centres preferring regional anaesthesia. Difference in practice might be explained by level of experience, here large centres might be more confident using regional anaesthesia. Knowledge is being extrapolated from literature on caesarean sections. Future studies should address the optimal choice of anaesthesia for PPH procedures.

Early cryoprecipitate transfusion versus standard care in severe postpartum haemorrhage: a pilot cluster-randomised trial

There is a lack of evidence evaluating cryoprecipitate transfusion in severe postpartum haemorrhage. We performed a pilot cluster‐randomised controlled trial to evaluate the feasibility of a trial on early cryoprecipitate delivery in severe postpartum haemorrhage. Pregnant women (>24 weeks gestation), actively bleeding within 24 h of delivery and who required at least one unit of red blood cells were eligible. Women declining transfusion in advance or with inherited clotting deficiencies were not eligible. Four UK hospitals were randomly allocated to deliver either the intervention (administration of two pools of cryoprecipitate within 90 min of first red blood cell unit requested plus standard care), or the control group treatment (standard care, where cryoprecipitate is administered later or not at all). The primary outcome was the proportion of women who received early cryoprecipitate (intervention) vs. standard care (control). Secondary outcomes included consent rates, acceptability of the intervention, safety outcomes and preliminary clinical outcome data to inform a definitive trial. Between March 2019 and January 2020, 199 participants were recruited; 19 refused consent, leaving 180 for analysis (110 in the intervention and 70 in the control group). Adherence to assigned treatment was 32% (95%CI 23–41%) in the intervention group vs. 81% (95%CI 70–90%) in the control group. The proportion of women receiving cryoprecipitate at any time‐point was higher in the intervention (60%) vs. control (31%) groups; the former had fewer red blood cell transfusions at 24 h (mean difference −0.6 units, 95%CI −1.2 to 0); overall surgical procedures (odds ratio 0.6, 95%CI 0.3–1.1); and intensive care admissions (odds ratio 0.4, 95%CI 0.1–1.1). There was no increase in serious adverse or thrombotic events in the intervention group. Staff interviews showed that lack of awareness and uncertainty about study responsibilities contributed to lower adherence in the intervention group. We conclude that a full‐scale trial may be feasible, provided that protocol revisions are put in place to establish clear lines of communication for ordering early cryoprecipitate in order to improve adherence. Preliminary clinical outcomes associated with cryoprecipitate administration are encouraging and merit further investigation.

Fibrinogen Replacement in Haemostatic Resuscitation: Dose, Laboratory Targets and Product Choice

Fibrinogen is a key coagulation protein that is necessary for the formation of stable clots. Fibrinogen levels have been reported to be one of the first to fall during major haemorrhage reflecting consumption, dilution and fibrinogenolysis. Its role in acquired major haemorrhage, both in relation to the contribution it plays to the coagulopathy of major bleeding that can exacerbate bleeding and how effective fibrinogen supplementation can be at improving clinical outcomes, has received a great deal of attention over the last 10 - 15 years. This commentary focuses on just three of the more recent publications from the last 5 years that provide some of the evidence behind how we can think about fibrinogen as a haemostatic treatment for acquired major haemorrhage and how we can use the laboratory thresholds to guide therapy.

Clinical value of early viscoelastometric point-of-care testing during postpartum hemorrhage for the prediction of severity of bleeding: A multicenter prospective cohort study in the Netherlands

INTRODUCTION

To evaluate rotational fibrin-based thromboelastometry (ROTEM® FIBTEM) with amplitude of clot firmness at 5 min (A5) as an early point-of-care parameter for predicting progression to severe postpartum hemorrhage, and compare its predictive value with that of fibrinogen.

MATERIAL AND METHODS

Prospective cohort study in the Netherlands including women with 800-1500 ml of blood loss within 24 h following birth. Blood loss was quantitatively measured by weighing blood-soaked items and using a fluid collector bag in the operating room. Both FIBTEM A5 values and fibrinogen concentrations (Clauss method) were measured between 800 and 1500  ml of blood loss. Predictive accuracy of both biomarkers for the progression to severe postpartum hemorrhage was measured by area under the receiver operating curves (AUC). Severe postpartum hemorrhage was defined as a composite endpoint of (1) total blood loss >2000 ml, (2) transfusion of ≥4 packed cells, and/or (3) need for an invasive intervention to cease bleeding.

RESULTS

Of the 391 women included, 72 (18%) developed severe postpartum hemorrhage. Median (IQR) volume of blood loss at blood sampling was 1100 ml (1000-1300) with a median (interquartile range [IQR]) fibrinogen concentration of 3.9 g/L (3.4-4.6) and FIBTEM A5 value of 17 mm (13-20). The AUC for progression to severe postpartum hemorrhage was 0.53 (95% confidence interval [CI] 0.46-0.61) for FIBTEM A5 and 0.58 (95% CI 0.50-0.65) for fibrinogen. Positive predictive values for progression to severe postpartum hemorrhage for FIBTEM A5 ≤12 mm was 22.5% (95% CI 14-33) and 50% (95% CI 25-75) for fibrinogen ≤2 g/L.

CONCLUSIONS

The predictive value of FIBTEM A5 compared to fibrinogen concentrations measured between 800 and 1500 ml of blood loss following childbirth was poor to discriminate between women with and without progression towards severe postpartum hemorrhage.

Viscoelastic Hemostatic Assays for Postpartum Hemorrhage

This article discusses the importance and effectiveness of viscoelastic hemostatic assays (VHAs) in assessing hemostatic competence and guiding blood component therapy (BCT) in patients with postpartum hemorrhage (PPH). In recent years, VHAs such as thromboelastography and rotational thromboelastometry have increasingly been used to guide BCT, hemostatic adjunctive therapy and prohemostatic agents in PPH. The three pillars of identifying hemostatic competence include clinical observation, common coagulation tests, and VHAs. VHAs are advantageous because they assess the cumulative contribution of all components of the blood throughout the entire formation of a clot, have fast turnaround times, and are point-of-care tests that can be followed serially. Despite these advantages, VHAs are underused due to poor understanding of correct technique and result interpretation, a paucity of widespread standardization, and a lack of large clinical trials. These VHAs can also be used in cases of uterine atony, preeclampsia, acute fatty liver of pregnancy, amniotic fluid embolism, placental abruption, genital tract trauma, surgical trauma, and inherited and prepartum acquired coagulopathies. There exists an immediate need for a point-of-care test that can equip obstetricians with rapid results on developing coagulopathic states. The use of VHAs in predicting and treating PPH, although in an incipient state, can fulfill this need.

Effects of rotational thromboelastometry-guided transfusion management in patients undergoing surgical intervention for postpartum hemorrhage: An observational study

BACKGROUND

Postpartum hemorrhage (PPH) can be associated with coagulopathy, which may be difficult to rapidly assess and may exacerbate blood loss. Rotational thromboelastometry (ROTEM) at the point of care can guide clinician choice of blood products and has been shown in some settings to reduce transfusions and improve outcomes. This hospital-based observational study aims to measure effects of a ROTEM-guided transfusion protocol on transfusion practice and clinical outcomes in patients with PPH managed in the operating theater.

STUDY DESIGN AND METHODS

We compared a retrospective cohort of 450 consecutive patients with PPH treated in the operating theater before the introduction of a ROTEM-guided transfusion algorithm in June 2016, with 450 patients treated after its introduction. Multivariate regression was used to evaluate the effect of ROTEM introduction on the primary outcome, patients requiring a packed red blood cell (PRBC) transfusion and adjusting for demographic and obstetric confounders. Secondary outcomes included other blood product transfusions, hysterectomy, and intensive care unit admission.

RESULTS

A total of 90 (20%) of patients treated prior to ROTEM introduction received a PRBC transfusion, compared with 102 (22.7%) of those treated after ROTEM introduction (95% confidence interval [CI] 1.0-2.0, p = .04). There was no difference in PRBC transfusion in patients undergoing caesarean section (95% CI 0.5-1.8, p = .99). There was a trend toward increased use of cryoprecipitate and reduced use of platelets and fresh frozen plasma after ROTEM introduction.

CONCLUSION

In our institution, the introduction of ROTEM-guided transfusion did not reduce PRBC transfusion in patients with PPH treated in the operating theater.

Prophylactic fibrinogen concentrate administration in surgical correction of paediatric craniosynostosis: A double-blind placebo-controlled trial

BACKGROUND

Surgical craniosynostosis repair in children is associated with massive blood loss and significant transfusion of blood products. Fibrinogen concentrate is claimed to be useful in reducing blood loss and transfusion requirements.

OBJECTIVE

We investigated whether prophylactic administration of fibrinogen concentrate will reduce blood loss and transfusion requirements during paediatric craniofacial surgery.

DESIGN

Randomised, placebo-controlled, double-blind clinical trial.

SETTING

University medical centre.

PATIENTS

A total of 114 infants and children up to 25 months of age (median age 10 months).

INTERVENTION

Surgical craniosynostosis repair by calvarial remodelling was performed in each patient. Patients were randomised to receive prophylactic fibrinogen concentrate (Haemocomplettan P) at a mean dose of 79 mg kg-1 body weight or placebo.

MAIN OUTCOME MEASURES

Primary outcome was the volume of transfused blood products. Secondary outcomes were peri-operative blood loss, duration of surgery, length of stay in the paediatric ICU, length of hospital stay, postoperative complications and adverse effects of fibrinogen concentrate infusion.

RESULTS

No significant differences (P < 0.05) were found in the volume of transfused blood products (median 29 ml kg-1 body weight vs. 29 ml kg-1 body weight), intra-operative estimated blood loss (45 vs. 46 ml kg-1), calculated blood loss (57 vs. 53 ml kg-1), or postoperative blood loss (24 vs. 24 ml kg-1) between the intervention and placebo groups. In addition, duration of surgery, length of stay in the paediatric ICU, hospital stay and complications were not significantly different between the two groups.

CONCLUSION

During surgical craniosynostosis repair in young children, prophylactic administration of high-dose fibrinogen concentrate did not reduce the amount of transfused blood products or decrease peri-operative blood loss.

TRIAL REGISTRATION

National Trial Register (NTR2975) and EudraCT (2011-002287-24).

Anesthesia technique and postpartum hemorrhage: a prospective cohort study

Background and objective

During the past few years, an increased number of postpartum hemorrhages have been noticed, even in high-income countries. It has been suggested that this escalation could be associated with increased obstetric interventions. Among such interventions, anesthesia is one of the most prevalent. The present study aimed to investigate the influence of peripartum anesthesia on total blood loss during the 24 hours after delivery.

Methods

We performed a complementary analysis from a prospective cohort study that evaluated postpartum bleeding within 24 hours after birth. The study was performed between February 1^st, 2015 and March 31^st, 2016 at the Women’s Hospital at the Universidade Estadual de Campinas, Brazil. Postpartum bleeding was measured using a calibrated drape and summing the blood contained in the compresses and pads used for 24 hours. We calculated means, percentages, and standard deviation and performed Mann-Whitney analysis for the relation of anesthesia with Postpartum Hemorrhage (PPH) and logistic regression for drugs used in the anesthesia with PPH, using SAS 9.4 software.

Results

We included 270 women in the study; of these, 168 received anesthesia for delivery and almost 50% of them had spinal and epidural anesthesia. The mean blood loss within 24 hours after delivery did not show differences between those who did and those who did not receive obstetrical anesthesia (579.0 ± 361.6 vs. 556.6 ± 360.6; p = 0.57). Logistic regression showed that anesthesia, the type of anesthesia, and the drug used did not influence the PPH above 500 mL and above 1000 mL within 2 hours (p > 0.05).

Conclusion

Anesthesia did not influence postpartum bleeding after vaginal delivery.

Fibrinogen prophylaxis for reducing perioperative bleeding in patients undergoing radical cystectomy: A double-blind placebo-controlled randomized trial

OBJECTIVE

Excessive bleeding is an important complication of radical cystectomy. We aimed to assess whether preoperative administration of fibrinogen decreases perioperative bleeding and improves the outcome of radical cystectomy.

DESIGN

Double-blinded randomized trial with two parallel arms.

SETTING

The study was conducted in the department of surgery at a teaching hospital affiliated with a University of Medical Sciences.

PATIENTS

In total, 70 men undergoing radical cystectomy were randomized to fibrinogen (n = 35) and placebo-control groups. Mean (SD) age was 64.7 (7.4) years.

INTERVENTIONS

The intervention group received 2 g fibrinogen concentrate diluted in 100 ml distilled water, and the control group received 100 ml normal saline; both intravenously 15 ̶ 30 min before the start of the surgery.

OUTCOME MEASURES

The primary outcome was the amount of perioperative blood loss. The secondary outcomes were hemodynamic features and vital signs.

MAIN RESULTS

Fibrinogen significantly decreased the volume of blood loss (p < 0.001) and the total number of transfused packed-cell units per group (38 vs. 115 units); and compensated the decrease of HCO3 (p = 0.030), the mean arterial pressure (p < 0.001), hemoglobin O2 saturation (p = 0.001), heart rate (p < 0.001), and temperature (p < 0.001) throughout the surgery compared with the placebo. Patients in the fibrinogen group had shorter Intensive Care Unit (p = 0.001) and hospital (p < 0.001) stay. We did not find any adverse reaction in our patients receiving fibrinogen concentrate.

CONCLUSION

Fibrinogen concentrate reduces perioperative bleeding and the need for blood transfusion in radical cystectomy. It improves the outcomes of the surgery and decreases patients' length of stay in the healthcare system following radical cystectomy.

REGISTRATION

Iranian Registry of Clinical Trials (IRCT) http://www.irct.ir/, reference number: IRCT20191013045091N1.

ETHICS CODE

Shahid Beheshti University of Medical Sciences, reference number: IR.SBMU.RETECH.REC.1398.033.

Therapeutic Application of Fibrinogen in Spine Surgery: A Review Article

BACKGROUND

The aim of this review is to investigate current uses of fibrinogen as a tool to reduce operative and postoperative blood loss in different surgical fields especially orthopedic spine surgery. This is a systematic review.

METHODS

MEDLINE (via Ovid 1946 to June 1, 2020) and Embase (via Ovid 1947 to June 1, 2020) were searched using the keywords "fibrinogen", "surgery", and "spine" for relevant studies. The search strategy used text words and relevant indexing to identify articles discussing the use of fibrinogen to control surgical blood loss.

RESULTS

The original literature search yielded 407 articles from which 68 duplications were removed. Three hundred thirty-nine abstracts and titles were screened. Results were separated by surgical specialties.

CONCLUSIONS

Multiple studies have looked at the role of fibrinogen for acute bleeding in the operative setting. The current evidence regarding the use of fibrinogen concentrate in spine surgery is promising but limited, even though this is a field with the potential for severe hemorrhage. Further trials are required to understand the utility of fibrinogen concentrate as a first-line therapy in spine surgery and to understand the importance of target fibrinogen levels and subsequent dosing and administration to allow recommendations to be made in this field.