Fibrinogen concentrate versus placebo for treatment of postpartum haemorrhage: study protocol for a randomised controlled trial

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.

Next Generation Medical Management of Postpartum Hemorrhage

BACKGROUND

Postpartum hemorrhage remains a significant contributor to morbidity and mortality of women of childbearing age worldwide. Trends in both incidence and severity of postpartum hemorrhage are increasing which makes it imperative to identify drugs that could target prevention and/or treatment of these postpartum hemorrhages for women living in high, middle and low-income countries.

METHODS

We have reviewed current advances in the medical management of postpartum hemorrhage focusing on non-uterotonic therapy. We specifically describe the use and mechanism of action of tranexamic acid (TXA) and fibrinogen concentrate. Furthermore, we address the existing data for using these medications in postpartum hemorrhage, highlighting both strengths and limitations.

RESULTS

This review describes a new generation of medications that are promising for the prevention and/or treatment of postpartum hemorrhage. For patients at risk for significant hemorrhage, TXA has been shown to reduce intraoperative blood loss and can be given as a prophylactic agent. For the treatment of postpartum hemorrhage, early use of TXA has the potential to reduce mortality. In addition, some data exists supporting the use of fibrinogen concentrate, though more studies are required to help formulate guidelines for its use.

CONCLUSION

A promising new approach for the management of severe postpartum hemorrhage is using medications that alter coagulation. More data are needed to describe ideal patient populations, dosing, the time of administration, and infusion rate.

The Effect of Fibrinogen on Blood Loss After Lumbar Surgery: A Double-Blind Randomized Clinical Trial

Background

Spinal surgeries often have a high risk of hemorrhage during and after surgery, thus most patients require blood transfusions and blood products. Fibrinogen is used in different forms to control hemorrhage.

Objectives

The present study aimed to evaluate the outcomes of prophylactic fibrinogen administration in reducing hemorrhage after lumbar surgery.

Methods

This was a randomized clinical trial conducted on 30 patients undergoing lumbar surgery. The levels of fibrinogen, as well as hemoglobin (HB), hematocrit (HCT), prothrombin time (PT), partial thromboplastin time (PTT), and INR, were assessed preoperatively as the baseline values. The patients were divided into two groups: intervention (N = 15) and control (N = 15) groups. The intervention group received 1 g fibrinogen dissolved in 50 cc distilled water with surgical incision and the control group received 50 cc distilled water with the surgical incision. At the end of the operation, the volume of hemorrhage transfused blood products (fresh frozen plasma, packed cell, and platelet) was measured. In addition, at 0, 6, and 24 hours after the end of surgery and transfer to recovery, serum levels of fibrinogen, HB, HCT, INR, PT, PTT, and hemovac drain volume were measured.

Results

The hemorrhage during and after the operation in the control group was significantly higher than that of the intervention group (P < 0.05). There were no significant differences between hemoglobin and serum level of fibrinogen before and after surgery between the two groups. The postoperative hypotension showed no significant difference between the two groups.

Conclusions

The findings showed the effectiveness of fibrinogen in reducing acute hemorrhage. Considering the adverse consequences of hemorrhage and coagulopathy in patients undergoing surgery, using fibrinogen as prophylaxis is recommended in surgeries with high risks of hemorrhage.

Patient blood management in obstetrics: prevention and treatment of postpartum haemorrhage. A NATA consensus statement

Patient blood management (PBM) is the timely application of evidence-informed medical and surgical concepts designed to maintain haemoglobin concentration, optimise haemostasis, and minimise blood loss in an effort to improve patient outcomes. The aim of this consensus statement is to provide recommendations on the prevention and treatment of postpartum haemorrhage as part of PBM in obstetrics. A multidisciplinary panel of physicians with expertise in obstetrics, anaesthesia, haematology, and transfusion medicine was convened by the Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis (NATA) in collaboration with the International Federation of Gynaecology and Obstetrics (FIGO), the European Board and College of Obstetrics and Gynaecology (EBCOG), and the European Society of Anaesthesiology (ESA). Members of the task force assessed the quantity, quality and consistency of the published evidence, and formulated recommendations using the system developed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) working group. The recommendations in this consensus statement are intended for use by clinical practitioners managing perinatal care of women in all settings, and by policy-makers in charge of decision making for the update of clinical practice in health care establishments.

Massive hemorrhage protocol activation in obstetrics: a 5-year quality performance review

BACKGROUND

A structured approach to hemorrhagic emergencies in obstetrics has gained popularity with the implementation of massive hemorrhage protocols. The trauma literature suggests that routine quality reviews should be in place to improve patient outcomes. The aim of this study was to develop quality indicators and assess compliance by the clinical team.

METHODS

A multidisciplinary team set the institutional quality indicators for the massive hemorrhage protocol review. A retrospective review of all obstetrical massive hemorrhage protocol activation events from September 2010 to January 2015 was performed. All protocol events occurred before the creation of the quality indicators. Data were retrieved from patient records.

RESULTS

There were 17 (0.09%) protocol activations for 19 790 deliveries during the study period. All 17 (100%) patients received at least one unit of red blood cells. Overactivation, defined as the transfusion of <2 units of red blood cells, occurred in two cases (12%). Common causes of non-compliance were: 24% (4/17) temperature monitoring, 18% (3/17) lactate measurement, 41% (7/17) arterial blood gas sampling, and 18% (3/17) hemoglobin maintenance within the target range of 55-95 g/L. Admission to intensive care and peripartum hysterectomy occurred in 12 and 5 cases (71% and 29%), respectively.

CONCLUSIONS

Suboptimal compliance was found in multiple areas, which may be attributable to the low frequency of activation of our massive haemorrhage protocol in obstetrics. The quality targets identified in this report can act as a basis for other institutions developing quality indicators to evaluate performance.

Antifibrinolytic drugs for treating primary postpartum haemorrhage

BACKGROUND

Postpartum haemorrhage (PPH) - heaving bleeding within the first 24 hours after giving birth - is one of the main causes of death of women after childbirth. Antifibrinolytics, primarily tranexamic acid (TXA), have been shown to reduce bleeding in surgery and safely reduces mortality in trauma patients with bleeding without increasing the risk of adverse events.An earlier Cochrane review on treatments for primary PPH covered all the various available treatments - that review has now been split by types of treatment. This new review concentrates only on the use of antifibrinolytic drugs for treating primary PPH.

OBJECTIVES

To determine the effectiveness and safety of antifibrinolytic drugs for treating primary PPH.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (28 May 2017) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs), including cluster-randomised trials of antifibrinolytic drugs (aprotinin, TXA, epsilon-aminocaproic acid (EACA) and aminomethylbenzoic acid, administered by whatever route) for primary PPH in women.Participants in the trials were women after birth following a pregnancy of at least 24 weeks' gestation with a diagnosis of PPH, regardless of mode of birth (vaginal or caesarean section) or other aspects of third stage management.We have not included quasi-randomised trials, or cross-over studies. Studies reported as abstracts have not been included if there was insufficient information to allow assessment of risk of bias.In this review we only identified studies looking at TXA.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from each study using an agreed form. We entered data into Review Manager software and checked for accuracy.For key review outcomes, we rated the quality of the evidence as 'high', 'moderate', 'low' or 'very low' according to the GRADE approach.

MAIN RESULTS

Three trials (20,412 women) met our inclusion criteria. Two trials (20,212 women) compared intravenous (IV) TXA with placebo or standard care and were conducted in acute hospital settings (labour ward, emergency department) (in high-, middle- and low-income countries).One other trial (involving 200 women) was conducted in Iran and compared IV TXA with rectal misoprostol, but did not report on any of this review's primary or GRADE outcomes. There were no trials that assessed EACA, aprotinin or aminomethylbenzoic acid.Standard care plus IV TXA for the treatment of primary PPH compared with placebo or standard care aloneTwo trials (20,212 women) assessed the effect of TXA for the treatment of primary PPH compared with placebo or standard care alone. The larger of these (The WOMAN trial) contributed over 99% of the data and was assessed as being at low risk of bias. The quality of the evidence varied for different outcomes, Overall, evidence was mainly graded as moderate to high quality.The data show that IV TXA reduces the risk of maternal death due to bleeding (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.65 to 1.00; two trials, 20,172 women; quality of evidence: moderate). The quality of evidence was rated as moderate due to imprecision of effect estimate. The effect was more evident in women given treatment between one and three hours after giving birth with no apparent reduction when given after three hours (< one hour = RR 0.80, 95% CI 0.55 to 1.16; one to three hours = RR 0.60, 95% CI 0.41 to 0.88; > three hours = RR 1.07, 95% 0.76 to 1.51; test for subgroup differences: Chi² = 4.90, df = 2 (P = 0.09), I² = 59.2%). There was no heterogeneity in the effect by mode of birth (test for subgroup differences: Chi² = 0.01, df = 1 (P = 0.91), I² = 0%). There were fewer deaths from all causes in women receiving TXA, although the 95% CI for the effect estimate crosses the line of no effect (RR 0.88, 95% CI 0.74 to 1.05; two trials, 20,172 women, quality of evidence: moderate). Results from one trial with 151 women suggest that blood loss of ≥ 500 mL after randomisation may be reduced (RR 0.50, 95% CI 0.27 to 0.93; one trial, 151 women; quality of evidence: low). TXA did not reduce the risk of serious maternal morbidity (RR 0.99, 95% CI 0.83 to 1.19; one trial, 20,015 women; quality of evidence: high), hysterectomy to control bleeding (RR 0.95, 95% CI 0.81 to 1.12; one trial, 20,017 women; quality of evidence: high) receipt of blood transfusion (any) (RR 1.00, 95% CI 0.97 to 1.03; two trials, 20,167 women; quality of evidence: moderate) or maternal vascular occlusive events (any), although results were imprecise for this latter outcome (RR 0.88, 95% CI 0.54 to 1.43; one trial, 20,018 women; quality of evidence: moderate). There was an increase in the use of brace sutures in the TXA group (RR 1.19, 95% CI 1.01, 1.41) and a reduction in the need for laparotomy for bleeding (RR 0.64, 95% CI 0.49, 0.85).

AUTHORS' CONCLUSIONS

TXA when administered intravenously reduces mortality due to bleeding in women with primary PPH, irrespective of mode of birth, and without increasing the risk of thromboembolic events. Taken together with the reliable evidence of the effect of TXA in trauma patients, the evidence suggests that TXA is effective if given as early as possible.Facilities for IV administration may not be available in non-hospital settings therefore, alternative routes to IV administration need to be investigated.

National and International Guidelines for Patient Blood Management in Obstetrics: A Qualitative Review

In developed countries, rates of postpartum hemorrhage (PPH) requiring transfusion have been increasing. As a result, anesthesiologists are being increasingly called upon to assist with the management of patients with severe PPH. First responders, including anesthesiologists, may adopt Patient Blood Management (PBM) recommendations of national societies or other agencies. However, it is unclear whether national and international obstetric societies' PPH guidelines account for contemporary PBM practices. We performed a qualitative review of PBM recommendations published by the following national obstetric societies and international groups: the American College of Obstetricians and Gynecologists; The Royal College of Obstetricians and Gynecologists, United Kingdom; The Royal Australian and New Zealand College of Obstetricians and Gynecologists; The Society of Obstetricians and Gynecologists of Canada; an interdisciplinary group of experts from Austria, Germany, and Switzerland, an international multidisciplinary consensus group, and the French College of Gynaecologists and Obstetricians. We also reviewed a PPH bundle, published by The National Partnership for Maternal Safety. On the basis of our review, we identified important differences in national and international societies' recommendations for transfusion and PBM. In the light of PBM advances in the nonobstetric setting, obstetric societies should determine the applicability of these recommendations in the obstetric setting. Partnerships among medical, obstetric, and anesthetic societies may also help standardize transfusion and PBM guidelines in obstetrics.

Massive obstetric hemorrhage: Current approach to management

Massive obstetric hemorrhage is a major cause of maternal mortality and morbidity worldwide. It is defined (among others) as the loss of>2,500ml of blood, and is associated to a need for admission to critical care and/or hysterectomy. The relative hemodilution and high cardiac output found in normal pregnancy allows substantial bleeding before a drop in hemoglobin and/or hematocrit can be identified. Some comorbidities associated with pregnancy can contribute to the occurrence of catastrophic bleeding with consumption coagulopathy, which makes the situation even worse. Optimization, preparation, rational use of resources and protocolization of actions are often useful to improve outcomes in patients with postpartum hemorrhage. Using massive obstetric hemorrhage protocols is useful for facilitating rapid transfusion if needed, and can also be cost-effective. If hypofibrinogenemia during the bleeding episode is identified, early fibrinogen administration can be very useful. Other coagulation factors in addition to fibrinogen may be necessary during postpartum hemorrhage replacement measures in order to effectively correct coagulopathy. A hysterectomy is recommended if the medical and surgical measures prove ineffective.

Commentary on Reconstituting Fibrinogen Concentrate to Maintain Blinding in a Double-blind, Randomized Trial in an Emergency Setting

BACKGROUND

The gold standard of trial design is the double-blind, placebo-controlled, randomized trial. Intravenous medication, which needs reconstitution by the attending clinician in an emergency situation, can be challenging to incorporate into a suitably blinded study.

DISCUSSION

We have developed a method of blindly reconstituting and administering fibrinogen concentrate (presented as a lyophilized powder), where the placebo is normal saline. Fibrinogen concentrate is increasingly being used early in the treatment of major hemorrhage. Our methodology was designed for a multicenter study investigating the role of fibrinogen concentrate in the treatment of the coagulopathy associated with major obstetric hemorrhage. The method has been verified by a stand-alone pharmaceutical manufacturing unit with an investigational medicinal products license, and to date has successfully been applied 45 times in four study centers. There have been no difficulties in reconstitution and no related adverse events reported.

CONCLUSION

We feel our method is simple to perform and maintains blinding throughout, making it potentially suitable for use in other trials conducted in psychologically high-pressure environments. Although fibrinogen concentrate was the focus of our study, it is likely that the method is applicable to other lyophilized medication with limited shelf life (e.g., antibiotics).

Postpartum hemorrhage: a continuing challenge

Obstetric hemorrhage remains a leading cause of maternal morbidity and mortality worldwide. Many postpartum hemorrhages (PPHs) do not have identifiable risk factors; maternity units should therefore have obstetric hemorrhageprotocols in place for all parturients as every pregnancy has the potential to be complicated by hemorrhage. This review will examine the epidemiology of PPH as well as current recommendations for key elements in obstetric hemorrhage protocols. Recent advances in hematologic management of PPH will be also be reviewed, including: (1) recognition of hypofibrinogenemia as a risk factor for severe PPH, (2) use of antifibrinolytic therapy, and (3) strategies for fibrinogen replacement therapy.