F. XIII in perioperative coagulation management

Novel Insights into Heterozygous Factor XIII Deficiency

The prevalence and clinical significance of heterozygous factor XIII (FXIII) deficiency has long been debated, with controversial reports emerging since 1988. In the absence of large epidemiologic studies, but based on a few studies, a prevalence of 1 per 1,000 to 5,000 is estimated. In southeastern Iran, a hotspot area for the disorder, a study of more than 3,500 individuals found an incidence of 3.5%. Between 1988 and 2023, a total of 308 individuals were found with heterozygous FXIII deficiency, of which molecular, laboratory, and clinical presentations were available for 207 individuals. A total of 49 variants were found in the F13A gene, most of which were missense (61.2%), followed by nonsense (12.2%) and small deletions (12.2%), most occurring in the catalytic domain (52.1%) of the FXIII-A protein and most frequently in exon 4 (17%) of the F13A gene. This pattern is relatively similar to homozygous (severe) FXIII deficiency. In general, heterozygous FXIII deficiency is an asymptomatic condition without spontaneous bleeding tendency, but it can lead to hemorrhagic complications in hemostatic challenges such as trauma, surgery, childbirth, and pregnancy. Postoperative bleeding, postpartum hemorrhage, and miscarriage are the most common clinical manifestations, while impaired wound healing has been rarely reported. Although some of these clinical manifestations can also be observed in the general population, they are more common in heterozygous FXIII deficiency. While studies of heterozygous FXIII deficiency conducted over the past 35 years have shed light on some of the ambiguities of this condition, further studies on a large number of heterozygotes are needed to answer the major questions related to heterozygous FXIII deficiency.

Heterozygosity in factor XIII genes and the manifestation of mild inherited factor XIII deficiency

BACKGROUND

The characterization of inherited mild factor XIII deficiency is more imprecise than its rare, inherited severe forms. It is known that heterozygosity at FXIII genetic loci results in mild FXIII deficiency, characterized by circulating FXIII activity levels ranging from 20% to 60%. There exists a gap in information on 1) how genetic heterozygosity renders clinical bleeding manifestations among these individuals and 2) the reversal of unexplained bleeding upon FXIII administration in mild FXIII-deficient individuals.

OBJECTIVES

To assess the prevalence and burden of mild FXIII deficiency among the apparently healthy German-Caucasian population and correlate it with genetic heterozygosity at FXIII and fibrinogen gene loci.

METHODS

Peripheral blood was collected from 752 donors selected from the general population with essentially no bleeding complications to ensure asymptomatic predisposition. These were assessed for FXIII and fibrinogen activity, and FXIII and fibrinogen genes were resequenced using next-generation sequencing. For comparison, a retrospective analysis was performed on a cohort of mild inherited FXIII deficiency patients referred to us.

RESULTS

The prevalence of mild FXIII deficiency was high (∼0.8%) among the screened German-Caucasian population compared with its rare-severe forms. Although no new heterozygous missense variants were found, certain combinations were relatively dominant/prevalent among the mild FXIII-deficient individuals.

CONCLUSION

This extensive, population-based quasi-experimental approach revealed that the burden of heterozygosity in FXIII and fibrinogen gene loci causes the clinical manifestation of inherited mild FXIII deficiency, resulting in ''unexplained bleeding'' upon provocation.

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.

Genetic landscape in coagulation factor XIII associated defects – Advances in coagulation and beyond

Coagulation factor XIII (FXIII) acts as a fine fulcrum in blood plasma that maintains the balance between bleeding and thrombosis by covalently crosslinking the pre-formed fibrin clot into an insoluble one that is resistant to premature fibrinolysis. In plasma, FXIII circulates as a pro-transglutaminase complex composed of the dimeric catalytic FXIII-A encoded by the F13A1 gene and dimeric carrier/regulatory FXIII-B subunits encoded by the F13B gene. Growing evidence accumulated over decades of exhaustive research shows that not only does FXIII play major roles in both pathological extremes of hemostasis i.e. bleeding and thrombosis, but that it is, in fact, a pleiotropic protein with physiological roles beyond coagulation. However, the current FXIII genetic-epidemiological literature is overwhelmingly derived from the bleeding pathology associated with its deficiency. In this article we review the current clinical, functional, and molecular understanding of this fascinating multifaceted protein, especially putting into the same perspective its genetic landscape.

The impact of acquired coagulation factor XIII deficiency in traumatic bleeding and wound healing

Factor XIII (FXIII) is a protein involved in blood clot stabilisation which also plays an important role in processes including trauma, wound healing, tissue repair, pregnancy, and even bone metabolism. Following surgery, low FXIII levels have been observed in patients with peri-operative blood loss and FXIII administration in those patients was associated with reduced blood transfusions. Furthermore, in patients with low FXIII levels, FXIII supplementation reduced the incidence of post-operative complications including disturbed wound healing. Increasing awareness of potentially low FXIII levels in specific patient populations could help identify patients with acquired FXIII deficiency; although opinions and protocols vary, a cut-off for FXIII activity of ~ 60–70% may be appropriate to diagnose acquired FXIII deficiency and guide supplementation. This narrative review discusses altered FXIII levels in trauma, surgery and wound healing, diagnostic approaches to detect FXIII deficiency and clinical guidance for the treatment of acquired FXIII deficiency.

Mild Acquired Factor XIII Deficiency and Clinical Relevance at the ICU-A Retrospective Analysis

Acquired FXIII deficiency is a relevant complication in the perioperative setting; however, we still have little evidence about the incidence and management of this rarely isolated coagulopathy. This study aims to help find the right value for the substitution of patients with an acquired mild FXIII deficiency. In this retrospective single-center cohort study, we enrolled critically ill patients with mild acquired FXIII deficiency (>5% and ≤70%) and compared clinical and laboratory parameters, as well as pro-coagulatory treatments. The results of the present analysis of 104 patients support the clinical relevance of FXIII activity out of the normal range. Patients with lower FXIII levels, beginning at <60%, had lower minimum and maximum hemoglobin values, corresponding to the finding that patients with a minimum FXIII activity of <50% needed significantly more packed red blood cells. FXIII activity correlated significantly with general coagulation markers such as prothrombin time, activated partial thromboplastin time, and fibrinogen. Nevertheless, comparing the groups with a cut-off of 50%, the amount of fresh frozen plasma, thrombocytes, PPSB, AT-III, and fibrinogen given did not differ. These results indicate that a mild FXIII deficiency occurring at any point of intensive care unit stay is also probably relevant for the total need of packed red blood cells, independent of pro-coagulatory management. In alignment with the ESAIC guidelines, the measurement of FXIII in critically ill patients with the risk of bleeding and early management, with the substitution of FXIII at levels <50%-60%, could be suggested.

Factor XIII activity at onset of labour and association with postpartum haemorrhage: an exploratory post-hoc study

BACKGROUND

Platelets, fibrinogen and factor XIII (FXIII) are required to form a stable clot in case of haemorrhage. The aims of this study were to evaluate a possible association between FXIII activity at the onset of labour and postpartum haemorrhage (PPH), and to ascertain whether FXIII activity at labour onset differs from after delivery.

METHODS

FXIII activity in 239 women with PPH (blood loss >1 L) and in 76 women without PPH was compared, as was activity before and after delivery in a third group of 80 women.

RESULTS

FXIII activity at onset of labour was significantly lower in the PPH group compared with the control group (mean ± SD 0.98 ± 0.20 vs 1.05 ± 0.17 kIU/L; P=0.0006). The difference was significantly greater in subgroups having vaginal delivery with no oxytocin stimulation or uterine exploration (absolute difference 0.131; 95% CI 0.055 to 0.206), compared with a subgroup experiencing any complication (0.04; 95% CI -0.023 to 0.104; interaction P-value 0.098). There was a weak but statistically significant inverse correlation between FXIII and estimated blood loss (r=-0.25; P=0.030) in the control group but not the PPH group. There was no significant difference between FXIII activity at onset of labour and after delivery (mean ± SD 1.03 ± 0.17 vs 1.04 ± 0.19 kIU/L; P=0.093).

CONCLUSIONS

At the onset of labour women with a subsequent PPH had significantly lower mean FXIII activity than that of women without PPH. This difference was small and within normal limits. FXIII activity did not change during normal delivery. The importance of FXIII during PPH requires study.

Complete hemostasis achieved by factor XIII concentrate administration in a patient with bleeding after teeth extraction as a complication of aplastic anemia and chronic disseminated intravascular coagulation

: Hemostatic treatment of disseminated intravascular coagulation (DIC) due to aortic aneurysm involves numerous difficulties. An 89-year-old man with aplastic anemia and chronic DIC developed periodontitis and loose teeth requiring extraction, after which hemostasis was difficult. Platelet concentrates and fresh-frozen plasma transfusions were ineffective, and there was a risk of hemorrhage; therefore, administration of anticoagulant agents for DIC was inappropriate. A decrease in factor XIII (FXIII) was discovered, and FXIII concentrate was administered, resulting in hemostasis together with wound healing. No complications were seen, but the following coagulation markers were found to decrease: fibrin degradation products, D-dimer, thrombin-antithrombin complex, and plasmin-α2 plasmin inhibitor complex. By 1 month after FXIII administration, FXIII had returned to the preadministration level, thus, the FXIII decrease was deduced to be have been due to DIC. These findings suggest that FXIII concentrate is useful for treating hemorrhage associated with DIC due to aortic aneurysm.

Acquired factor XIII deficiency in patients under therapeutic plasma exchange: A poorly explored etiology

INTRODUCTION

Factor XIII (FXIII) deficiency may cause bleeding under certain clinical circumstances. Therapeutic plasma exchange (TPE) may lead to a transient deficiency.

OBJECTIVES

To describe the clinical evolution of patients with acquired FXIII deficiency secondary to TPE.

METHODS

We respectively studied a cohort of consecutive patients from 2014 to 2019 who were treated with TPE with FXIII levels <50%. The FXIII was measured after the start of the TPE course, on days between the TPE sessions, due to suspected acquired deficiency. All TPE were performed using continuous flow cell separator. In all cases, the initial replacement fluid applied was albumin. Apheresis procedures were held at 24to 48 hours intervals.

RESULTS

Eighteen patients were included, 13 of them were recipients of kidney transplants. The main TPE prescription was humoral rejection. Median FXIII at diagnosis (measured on days between sessions of the TPE course) was 19%(IQR17-25). The median of apheresis procedures before measurement of FXIII was 3(IQR2-4). Among the total cohort, 10 patients suffered hemorrhages. None of the patients without history of kidney transplants had bleeding (n = 5), however, 10/13 with kidney transplants did. Five kidney transplant patients received therapy with FXIII concentrate because of life-threatening bleeding. In all cases, the bleeding stopped within the first 24 hours. All patients had their FXIII levels measured again after finishing the TPE course, with normal results.

CONCLUSIONS

TPE is an under-diagnosed cause of acquired FXIII deficiency since routine coagulation tests remain unaltered. It might cause major bleeding, particularly in patients with a recent history of surgery like kidney transplants.

Nonimmune-acquired factor XIII deficiency: a cause of high volume and delayed postoperative hemorrhage

: Factor XIII (FXIII) levels may decrease because of surgical consumption. Acquired FXIII deficiency could be a cause of postoperative hemorrhage usually underdiagnosed in clinical practice. To determine the diagnosis confirmation rate of acquired FXIII deficiency in postsurgical patients with clinical suspicion and to compare the characteristics and evolution of patients with or without FXIII deficiency. We performed a retrospective cohort study, which included 49 inpatients who were attended at our university hospital from 2014 to 2018 with suspicion of acquired FXIII deficiency because of disproportionate postoperative hemorrhage. FXIIIA levels less than 50% was considered a deficiency. Persistence of bleeding for more than 48 h, drop in hematocrit points, red blood cells transfused units, hemoglobin levels 12-36 h after bleeding, and time elapsed from the procedure to the bleeding were assessed as outcome variables. Logistic regression was employed for both univariate and multivariate analyses. Of the 49 patients included, 27(55%) had FXIII deficiency, with a median level of 34% [interquartile range (IQR) 19-42]. Abdominal surgery was the most common [n = 21 (43%)]. All patients had routine coagulation tests within the hemostatic range. FXIII deficiency was associated with a drop of more than 4 points in hematocrit [OR 59.69 (95% CI 4.71-755.30)], red blood transfused units >2 [OR 45.38 (95% CI 3.48-590.65)], and delayed bleeding >36 h after surgery [OR 100.90 (95% CI 3.78-2695.40)]. Plasma-derived FXIII concentrate was administered to eight patients with life-threatening bleeding with resolution within 24 h. Only one deficient patient died from bleeding. FXIII levels were measured 15 days after diagnosis or more in 20 out of 27 deficient patients, with normal results. Acquired FXIII deficiency may be a frequent underdiagnosed entity that should be considered when high-volume and delayed postoperative hemorrhage is present in patients with hemostatic routine coagulation test results.

The impact of prepartum factor XIII activity on postpartum blood loss

BACKGROUND

Postpartum hemorrhage (PPH), a major cause of maternal mortality, has several known risk factors but frequently occurs unexpectedly. PPH incidence and related maternal morbidity and mortality are rising worldwide.

OBJECTIVE

To evaluate the impact of defined prepartum blood coagulation parameters on postpartum blood loss.

METHODS

This single-center, prospective cohort study analyzed prepartum activities of coagulation factors II and XIII and fibrinogen levels in 1300 women. Blood samples were obtained at labor onset and analyzed only after the last patient had delivered, to prevent a potential treatment bias. Blood loss was quantified using a validated technique. The influence of coagulation factors on measured blood loss was assessed by continuous outcome logistic regression.

RESULTS

Prepartum factor XIII activity strongly influenced measured blood loss: every one unit (%) increase in prepartum factor XIII was associated with an odds ratio of 1.011 (95% confidence interval, 1.006-1.015; P < .001) to keep blood loss below any given cut-off level. For illustration, this suggests that a 30% increase in factor XIII activity increases the odds of not suffering PPH (defined as blood loss ≥500 mL) by 38.9%. This effect remained significant after stratification for the delivery mode, when correcting for other risk factors, and was independent of the statistical model used. Factor II but not fibrinogen had a partially comparable, but much less pronounced, effect.

CONCLUSION

In the largest population analyzed for the influence of prepartum coagulation factors on PPH to date, prepartum factor XIII activity had a strong impact on postpartum blood loss across every statistical model and clinical subgroup. Our hypothesis that early replenishment of factor XIII levels might constitute a new tool in the prevention and effective early treatment of PPH should be evaluated in future trials.

Recurrent Hematomas following a Revision Total Hip Arthroplasty in Acquired Coagulation Factor XIII Deficiency

Coagulation factor XIII (FXIII) is the final enzyme in the coagulation cascade and plays an important role in catalyzing the intermolecular cross-linking of fibrin polymers. FXIII deficiency is a rare disorder that presents with recurrent soft tissue bleeding. In this case report, we describe a patient with recurrent hematomas, following a revision total hip arthroplasty (THA). A 50-year-old female patient with no past history of bleeding and with a normal perioperative coagulation profile presented with recurrent hip joint hematomas. Her plasma FXIII activity showed a slight decrease (69%). Therefore, the patient was diagnosed with an acquired deficiency and was administered FXIII to correct it. The bleeding did not recur once the FXIII activity had returned to a normal level (76%). At 2 months after the second evacuation procedure, the patient was discharged from the hospital in an ambulatory state. There has been no recurrence of a hematoma since. We managed a rare case of acquired FXIII deficiency, which highlighted that a patient can present with an acquired bleeding disorder despite having a normal coagulation profile. An acquired FXIII deficiency should be suspected in patients with inexplicable, sudden-onset bleeding, as early diagnosis and treatment are important to prevent life-threatening complications.

Efficacy of a new pathogen-reduced cryoprecipitate stored 5 days after thawing to correct dilutional coagulopathy in vitro

BACKGROUND

Fibrinogen supplementation during bleeding restores clot strength and hemostasis. Cryoprecipitate, a concentrated source of fibrinogen, has prolonged preparation time for thawing, a short shelf life resulting in frequent wastage, and infectious disease risk. This in vitro study investigated the efficacy of a new pathogen-reduced cryoprecipitate thawed and stored at room temperature for 5 days (PR Cryo) to treat dilutional hypofibrinogenemia, compared to immediately thawed standard cryoprecipitate (Cryo) or fibrinogen concentrate (FC).

STUDY DESIGN AND METHODS

Ten phlebotomy specimens from healthy volunteers were diluted 1:1 with crystalloid and supplemented with PR Cryo and Cryo (at a dose replicating transfusion of two pooled doses [10 units]) and FC at a dose replicating 50 mg/kg. Changes in clot firmness (thromboelastometry) and in coagulation factor activity were assessed at baseline, after dilution, and after supplementation.

RESULTS

Clinical dosing was used, as described above, and consequently the FC dose contained 24% and 36% more fibrinogen versus PR Cryo and Cryo, respectively. At baseline, subjects had a median FIBTEM maximum clot firmness of 13.5 mm, versus 6.5 mm after 50% dilution (p = 0.005). After supplementation with PR Cryo, a median FIBTEM maximum clot firmness of 13 mm was observed versus 9.0 mm for Cryo (p = 0.005) or 16.5 mm for FC (p = 0.005). Median factor XIII was higher after PR Cryo (64.8%) versus Cryo (48.3%) (p = 0.005). Fibrinogen activity was higher after FC (269.0 mg/dL) versus PR Cryo (187.0 mg/dL; p = 0.005) or Cryo (193.5 mg/dL; p = 0.005); the difference between PR Cryo and Cryo supplementation (p = 0.445) was not significant.

CONCLUSION

PR Cryo used 5 days after thawing effectively restores clot strength after in vitro dilution.

Stellenwert der Thrombelastometrie für das Monitoring von Faktor XIII

Recently published studies give evidence, that an increased maximum lysis in the APTEM® – test (ML60 > 12%) of the ROTEM® (Tem International GmbH, Munich, Germany) might indicate a factor XIII deficiency (FXIII < 70%). It was the aim of this study to investigate the feasibility of thrombelastometric measurements with the ROTEM device to reflect the isolated influence of FXIII on clot stability and therefore to indicate potential factor XIII deficiencies. Patients, method: After approval by the local Scientific and Ethic Review Board, 26 consecutive patients, scheduled for elective craniotomy for tumour resection, were prospectively enrolled into this study. Blood samples were taken for conventional laboratory coagulation analyses, FXIII analyses and thrombelastometric measurements (EXTEM, FIBTEM and APTEM tests) after induction of general anaesthesia (T1), before skin incision (T2) as well as at (T3) and 24 hours after (T4) postoperative admission to ICU, respectively. Statistical analyses included Spearman rank order correlations and multiple linear regressions. Results: FXIII concentrations did not correlate with the ML60 in the APTEM test at any measuring point. Neither platelet count nor fibrinogen nor FXIII concentrations were of predictive value for ML60 of the APTEM test. Conclusion: The results lead to the assumption that thrombelastometric measurements may not be appropriate for the perioperative monitoring of FXIII concentration.

The role of fibrinogen in trauma-induced coagulopathy

Fibrinogen plays an essential role in clot formation and stability. Importantly it seems to be the most vulnerable coagulation factor, reaching critical levels earlier than the others during the course of severe injury. A variety of causes of fibrinogen depletion in major trauma have been identified, such as blood loss, dilution, consumption, hyperfibrinolysis, hypothermia and acidosis. Low concentrations of fibrinogen are associated with an increased risk of diffuse microvascular bleeding. Therefore, repeated measurements of plasma fibrinogen concentration are strongly recommended in trauma patients with major bleeding. Recent guidelines recommend maintaining plasma fibrinogen concentration at 1.5–2 g/l in coagulopathic patients. It has been shown that early fibrinogen substitution is associated with improved outcome.

Clinical influence of preoperative factor XIII activity in patients undergoing pancreatoduodenectomy

BACKGROUND

The influence of decreased factor XIII (FXIII) activity on perioperative bleeding has been reported in some surgical procedures. The purposes of this study were to investigate the perioperative dynamics of FXIII in patients undergoing pancreatoduodenectomy and to clarify the effects of low preoperative FXIII activity on intraoperative bleeding and postoperative complications.

METHODS

Total of 43 patients who underwent a pancreatoduodenectomy were enrolled. The perioperative FXIII activities were measured, and their associations with intraoperative bleeding and postoperative outcomes were analyzed.

RESULTS

Fifteen patients (35%) had low FXIII activities (<70%, lower than the institutional normal range). The patients with preoperative FXIII activities <70% experienced significantly greater blood loss (median, 1309 mL) during surgery compared to those with FXIII levels of ≥70% (median, 710 mL) (p = 0.001). The postoperative morbidity rates, including pancreatic fistula, were comparable between the patients with FXIII activities <70% and those with FXIII activities ≥70%. The FXIII levels substantially decreased on postoperative day 1 and remained at low levels until postoperative day 7.

CONCLUSION

Unexpectedly high proportions of patients undergoing pancreatoduodenectomy had low preoperative FXIII activities. Preoperative FXIII deficiency may increase intraoperative bleeding but had no influence on the postoperative outcomes.

Blood coagulation factor XIII and factor XIII deficiency

Factor XIII (FXIII) is a multifunctional pro-γ-transglutaminase that, in addition to its well-known role in hemostasis, has a crucial role in angiogenesis, maintenance of pregnancy, wound healing, bone metabolism, and even cardio protection. FXIII deficiency (FXIIID) is a rare bleeding disorder (RBD) with an estimated incidence of one per two million that is accompanied by life-threatening bleeding such as umbilical cord bleeding, recurrent spontaneous miscarriage, and intracranial hemorrhage (ICH). Today, the disease is successfully managed by FXIII concentrate and recombinant FXIII for prophylaxis, management of minor and major bleeding, treatment of ICH, and successful delivery in women with recurrent pregnancy loss. Molecular analysis of patients with FXIIID revealed a wide spectrum of mutations, most frequently missense mutations in the FXIII-A subunit, with a few recurrent mutations observed worldwide. In vitro expression studies revealed that most of the missense mutations cause intracellular instability of the FXIII protein and, subsequently, FXIIID.

Identification of acquired coagulation disorders and effects of target-controlled coagulation factor substitution on the incidence and severity of spontaneous intracranial bleeding during veno-venous ECMO therapy

Introduction:

Intracranial haemorrhage is a redoubtable complication during extracorporeal membrane oxygenation (ECMO) therapy. The underlying mechanisms of haemorrhagic diathesis are still not completely understood. This study was performed to evaluate a coagulation protocol for the regular analysis of acquired coagulation disorders and the systematic substitution of coagulation factors to reach predefined target values. We hypothesised that using this strategy would lead to the identification of acquired bleeding disorders which cannot be monitored with standard coagulation tests and that substitution of the respective factors in a target-controlled approach could have an impact on the incidence and severity of intracranial haemorrhage.

Methods:

A protocol for the analysis of acquired coagulation disorders and the subsequent administration of associated factor concentrates was introduced. Previously, coagulation management was mainly based on clinical bleeding signs as the trigger for the administration of blood products. In this investigation, nineteen consecutive patients before (control group) and twenty consecutive patients after the implementation of the protocol (intervention group) have been included in the study.

Results:

Eighty-eight percent of the patients developed factor XIII deficiency, 79% acquired von Willebrand syndrome, 40% fibrinogen deficiency and 54% of the patients showed a decline in platelet count >20% within the first 24 hours of ECMO therapy. In 6 out of 19 (31%) patients in the control group and in 2 patients out of 20 (10%) in the intervention group, intracranial haemorrhage was detected. Whilst 5 of 6 patients in the control group died because of fatal bleeding, both of the patients in the intervention group recovered with a favourable neurologic outcome.

Conclusions:

Veno-venous ECMO therapy leads to thrombocytopenia, factor XIII and fibrinogen deficiency as well as acquired von Willebrand syndrome. The implementation of a coagulation protocol including a standardized determination and target-controlled substitution of coagulation factors may have a beneficial impact on the incidence and severity of intracranial haemorrhage.

Catridecacog: a breakthrough in the treatment of congenital factor XIII A-subunit deficiency?

Circulating factor XIII (FXIII) consists of two active (A) and two carrier (B) subunits in tetrameric form. Congenital FXIII deficiency is a rare autosomal-recessive trait that mostly results from an FXIII A-subunit deficiency. Classic coagulation assays, such as prothrombin time or activated partial thromboplastin time, are not sensitive to FXIII; therefore, specific FXIII assays are necessary to detect the deficiency. The clinical picture of congenital FXIII deficiency comprises abortions, umbilical cord bleeding, increased surgical bleeding, intracerebral hemorrhage (which can, unfortunately, be the very first sign of severe FXIII deficiency), menorrhagia, and wound-healing disorders. Given the risk of intracranial hemorrhage, continued prophylaxis is to be recommended in severe deficiency, even in the actual absence of bleeding symptoms. Functional FXIII half-life decreases in consumptive processes (eg, surgery), explaining why increased dosing is needed in such situations. A recombinant FXIII (rFXIII) subunit-A molecule, which is expressed in Saccharomyces cerevisiae, has been evaluated for replacement therapy in congenital FXIII deficiency. The bleeding frequency under continued rFXIII prophylaxis during a year-long treatment period was significantly lower compared to on-demand treatment. Importantly, no severe spontaneous bleedings occurred, and bleeding requiring additional intervention only occurred after relevant trauma. Treatment with rFXIII proved to be safe: antibodies against rFXIII detected in four patients were not considered clinically relevant. No allergic reactions were observed. These data show that rFXIII can be used safely and effectively for continued prophylaxis in congenital FXIII deficiency; it is conceivable that this also holds true for treatment of acute bleeding, but clinical proof of this is pending.

Management of hemorrhage in cardiothoracic surgery

Bleeding is an important issue in cardiothoracic surgery, and about 20% of all blood products are transfused in this clinical setting worldwide. Transfusion practices, however, are highly variable among different hospitals and more than 25% of allogeneic blood transfusions have been considered inappropriate. Furthermore, both bleeding and allogeneic blood transfusion are associated with increased morbidity, mortality, and hospital costs. In the past decades, several attempts have been made to find a universal hemostatic agent to ensure hemostasis during and after cardiothoracic surgery. Most drugs studied in this context have either failed to reduce bleeding and transfusion requirements or were associated with severe adverse events, such as acute renal failure or thrombotic/thromboembolic events and, in some cases, increased mortality. Therefore, an individualized goal-directed hemostatic therapy ("theranostic" approach) seems to be more appropriate to stop bleeding in this complex clinical setting. The use of point-of-care (POC) transfusion and coagulation management algorithms guided by viscoelastic tests such as thromboelastometry/thromboelastography in combination with POC platelet function tests such as whole blood impedance aggregometry, and based on first-line therapy with fibrinogen and prothrombin complex concentrate have been associated with reduced allogeneic blood transfusion requirements, reduced incidence of thrombotic/thromboembolic and transfusion-related adverse events, and improved outcomes in cardiac surgery. This article reviews the current literature dealing with the management of hemorrhage in cardiothoracic surgery based on POC diagnostics and with specific coagulation factor concentrates and its impact on transfusion requirements and patients' outcomes.

The perioperative course of factor XIII and associated chest tube drainage in newborn and infants undergoing cardiac surgery

BACKGROUND

Perioperative acquired factor XIII deficiency has been looked upon as a potential cause of postoperative bleeding in adult cardiac surgery.

METHODS

Forty-four infants were prospectively studied for the time course of factor XIII in plasma and the effect on chest tube drainage (CTD) and transfusion requirements in the first 24 h after surgery. A reconstituted blood prime (RBP) with fresh-frozen plasma (FFP) and packed red blood cells (PRBC) was used. Samples were taken at baseline, after cardiopulmonary bypass and upon arrival in the ICU. Differences in blood loss and transfusion requirements based on a cutoff value of 70% factor XIII activity at the time of ICU admission were also calculated.

RESULTS

Baseline factor XIII activity was 79%, decreased to 71% after CPB (P = 0.102) and increased back up to 77% at ICU arrival (P = 0.708). There was no significant correlation between factor XIII, CTD, age, cyanosis, platelet count, and transfusion requirements at any time point. Only preoperative fibrinogen levels correlated significantly with factor XIII activity. Perioperative blood transfusions (PRBC P = 0.712, FFP P = 0.909, platelets P = 0.807) and chest tube losses (P = 0.424 at 6 h and P = 0.215 at 24 h) were not significantly different above or below a 70% factor XIII activity at ICU arrival.

CONCLUSION

Factor XIII activity in infants with congenital heart defects is within the lower range of normal adults, independent of patient's age and the presence of cyanosis. Reconstituted blood prime maintains factor XIII activity at sufficient levels during pediatric cardiac surgery. We could not detect a correlation between FXIII and CTD.

The Massive Bleeding after the Operation of Hip Joint Surgery with the Acquired Haemorrhagic Coagulation Factor XIII(13) Deficiency: Two Case Reports

Two women, aged 81 and 61, became haemorrhagic after surgery. Their previous surgeries were uneventful with no unexpected bleeding observed. Blood tests prior to the current surgeries indicated normal values including those related to coagulation. There were no problems with the current surgeries prior to leaving the operating room. At 3 hours after the surgery, the 81-year-old patient had an outflow of the drain at 1290 grams and her blood pressure decreased. She had disseminated intravascular coagulation (DIC). The 61-year-old woman had repeated haemorrhages after her current surgery for a long time. Their abnormal haemorrhages were caused by a deficiency of coagulation factor XIII(13). The mechanism of haemorrhagic coagulation factor XIII(13) deficiency is not understood, and it is a rare disorder. The only diagnostic method to detect this disorder is to measure factor XIII(13) activity in the blood. In this paper, we used Arabic and Roman numerals at the same time to avoid confusion of coagulation factor XIII(13) with coagulation factor VIII(8) that causes hemophilia A.

New developments in the area of factor XIII

Coagulation factor (F)XIII is best known for its role in fibrin stabilization and cross-linking of antifibrinolytic proteins to the fibrin clot. From patients with congenital FXIII deficiency, it is known that FXIII also has important functions in wound healing and maintaining pregnancy. Over the last decade more and more research groups with different backgrounds have studied FXIII and have unveiled putative novel functions for FXIII. FXIII, with its unique role as a transglutaminase among the other serine protease coagulation factors, is now recognized as a multifunctional protein involved in regulatory mechanisms and construction and repair processes beyond hemostasis with possible implications in many areas of medicine. The aim of this review was to give an overview of exciting novel findings and to highlight the remarkable diversity of functions attributed to FXIII. Of course, more research into the underlying mechanisms and (patho-)physiological relevance of the many described functions of FXIII is needed. It will be exciting to observe future developments in this area and to see if and how these interesting findings may be translated into clinical practice in the future.

Coagulation management in patients undergoing mechanical circulatory support

The incidence of bleeding and thrombo-embolic complications in patients undergoing mechanical circulatory support therapy remains high and is associated with bad outcomes and increased costs. The need for anticoagulation and anti-platelet therapy varies widely between different pulsatile and non-pulsatile ventricular-assist devices (VADs) and extracorporeal membrane oxygenation (ECMO) systems. Therefore, a unique anticoagulation protocol cannot be recommended. Notably, most thrombo-embolic complications occur despite values of conventional coagulation tests being within the targeted range. This is due to the fact that conventional coagulation tests such as international normalised ratio (INR), activated partial thromboplastin time (aPTT) and platelet count cannot detect hyper- or hypofibrinolysis, hypercoagulability due to tissue factor expression on circulating cells or increased clot firmness, and platelet aggregation as well as response to anti-platelet drugs. By contrast, point-of-care (POC) whole blood viscoelastic tests (thromboelastometry/-graphy) and platelet function tests (impedance or turbidimetric aggregometry) reflect in detail the haemostatic status of patients undergoing mechanical circulatory support therapy and the efficacy of their anticoagulation and antiaggregation therapy. Therefore, monitoring of haemostasis using POC thromboelastometry/-graphy and platelet function analysis is recommended during mechanical circulatory support therapy to reduce the risk of bleeding and thrombo-embolic complications. Notably, these haemostatic tests should be performed repeatedly during mechanical circulatory support therapy since thrombin generation, clot firmness and platelet response may change significantly over time with a high inter- and intra-individual variability. Furthermore, coagulation management can be hampered in non-pulsatile VADs by acquired von Willebrand syndrome, and in general by acquired factor XIII deficiency as well as by heparin-induced thrombocytopenia. In addition, POC testing can be used in bleeding patients to guide calculated goal-directed therapy with allogeneic blood products, haemostatic drugs and coagulation factor concentrates to optimise the haemostasis and to minimise transfusion requirements, transfusion-associated adverse events and to avoid thrombo-embolic complications, as well. However, coagulation management in patients undergoing mechanical circulatory support therapy is somehow like navigating between Scylla and Charybdis, and development of protocols based on POC testing seems to be beneficial.

Postoperatives Management der Gerinnung

<b><i>Hintergrund: </i></b>Das Gerinnungsmanagement in der postoperativen Phase stellt eine komplexe Herausforderung dar. Einerseits führt eine bereits präoperativ vorbestehende oder intraoperativ erworbene Beeinträchtigung der Blutgerinnung zu einem erhöhten Risiko für Nachblutungen. Andererseits sind Patienten in der postoperativen Phase einem erhöhten Risiko für thromboembolische Komplikationen ausgesetzt. Zudem drängen vermehrt neue orale Antikoagulanzien und Thrombozytenaggregationshemmer auf den Markt, für deren perioperativen Einsatz noch wenig Erfahrung besteht. <b><i>Methode: </i></b>Literaturübersicht. <b><i>Ergebnisse: </i></b>Das postoperative Gerinnungsmanagement sollte individualisiert nach einer Diagnostik mit klassischen Gerinnungstests und Point-of-Care(POC)-Diagnoseverfahren erfolgen. Verglichen mit dem intraoperativen Gerinnungsmanagement bestehen Unterschiede. <b><i>Schlussfolgerungen: </i></b>Das Ziel des postoperativen Gerinnungsmanagements ist eine Gerinnungsaktivität, die eine suffiziente Wundheilung zulässt, ohne thromboembolische Ereignisse zu begünstigen. Im Falle einer postoperativen Blutung sollte zur Diagnostik neben den klassischen Gerinnungstests auf viskoelastische POC-Verfahren zurückgegriffen werden. Neben der bedarfsadaptierten Substitution von Gerinnungsfaktoren ist die Aufrechterhaltung der Rahmenbedingungen der Gerinnung von entscheidender Bedeutung (Normothermie, physiologischer pH-Wert, Normokalziämie). Die Fortführung einer bestehenden Antikoagulation mit neuen oralen Antikoagulanzien ist eine Einzelfallentscheidung. Für ihren perioperativen Einsatz gib es noch keine Leitlinien.

Intraoperatives Gerinnungsmanagement

<b><i>Hintergrund: </i></b>Intraoperative Gerinnungsstörungen kommen bei großen Operationen häufig vor und können verschiedene, oft parallel auftretende Ursachen haben. Die Blutungsdynamik unter laufender Operation erfordert eine gute interdisziplinäre Zusammenarbeit sowie ein effektives Team- und Kontextmanagement. Geeignete diagnostische Methoden sind für ein rasches und zielgerichtetes Gerinnungsmanagement notwendig. <b><i>Methode: </i></b>Die Literatur bis April 2013 wurde selektiv, inklusive der neuen europäischen und deutschen anästhesiologischen Handlungsempfehlungen zum perioperativen Blutungsmanagement, berücksichtigt. <b><i>Ergebnisse: </i></b>Dilutionskoagulopathien zählen zu den häufigsten intraoperativen Gerinnungsstörungen, da bei Blutverlust zur Aufrechterhaltung der Makrozirkulation kolloidale oder kristalloide Lösungen infundiert bzw. Erythrozytenkonzentrate zur Oxygenierung transfundiert werden. Hypothermien, Azidosen, Hypocalciämien, Anämien, Hyperfibrinolysen, Medikamenteneinnahmen und Vorerkrankungen können die Koagulopathien verstärken. Fibrinogen ist der erste Faktor, der bei massiven Blutungen kritisch abfällt und substituiert werden muss. <b><i>Schlussfolgerungen: </i></b>Patientennahe diagnostische Verfahren eignen sich besonders zur Differenzierung von intraoperativen Gerinnungsstörungen und einer zielgerichteten Therapie. Faktorenkonzentrate stehen schneller als Gefrierplasmen (fresh frozen plasma, FFP) zur Verfügung und bilden häufig die Basis einer zielgerichteten Therapie. FFP enthalten alle Faktoren in einem physiologischen Verhältnis, allerdings unkonzentriert. Zu den Limitationen zählen neben geringerer Wirksamkeit die zeitaufwendige Vorbereitung und die nicht unerheblichen unerwünschten Wirkungen. Die Evidenzlage ist noch nicht ausreichend für eindeutige Empfehlungen.

The effect of fibrinogen concentrate and factor XIII on thromboelastometry in 33% diluted blood with albumin, gelatine, hydroxyethyl starch or saline in vitro

BACKGROUND

Fluid replacement results in dilutional coagulopathy. We investigated the potential role of fibrinogen, factor XIII and a combination of both to reverse dilutional coagulopathy, assessed by thromboelastometry (ROTEM(®)).

MATERIAL AND METHODS

Blood samples from healthy volunteers were analysed undiluted and after 33% dilution in vitro with albumin, gelatine, 130/0.4 hydroxyethyl starch or saline. Diluted samples were incubated with fibrinogen (3 g/70 kg bodyweight equivalent), factor XIII (10,000 IU/70 kg bodyweight equivalent), or a combination of both. Measurements were performed using an extrinsic activated assay (EXTEM(®)) and a functional fibrin polymerisation test (FIBTEM(®)).

RESULTS

Compared with baseline, EXTEM clotting time increased with hydroxyethyl starch, exceeding the upper limit of the reference value. Albumin prolonged clotting time within normal limits. Gelatine did not change clotting time, and saline reduced clotting time. Clot formation time increased in colloids only. Maximum clot firmness of both EXTEM and FIBTEM decreased with all fluids, but was less pronounced in saline. Incubation with fibrinogen had no effect on EXTEM maximum clot firmness but improved FIBTEM maximum clot firmness in saline (P <0.001) and albumin (P <0.05), but not gelatine and hydroxyethyl starch). Factor XIII had no effect on any EXTEM and FIBTEM maximum clot firmness results. Fibrinogen and factor XIII combined did not improve EXTEM maximum clot firmness. Fibrinogen and factor XIII did not change FIBTEM maximum clot firmness in hydroxyethyl starch but improved FIBTEM maximum clot firmness in albumin (P <0.001), gelatine (P <0.01) and saline (P <0.001).

DISCUSSION

ROTEM parameters in dilutional coagulopathy in vitro cannot be improved with factor XIII alone in any tested diluent. The combination of fibrinogen and factor XIII is highly effective in raising FIBTEM maximum clot firmness after dilution with albumin, gelatine and saline back to normal values, but is ineffective in 130/0.4 hydroxyethyl starch.

Knee hemarthrosis after arthroscopic surgery in an athlete with low factor XIII activity

We report a thirteen-year-old tennis player with knee hemarthrosis caused by low factor XIII activity. She visited our hospital because of medial peripatellar pain for two years. Although there was no abnormal sign in X-ray or MRI, diagnostic arthroscopy was performed. It revealed some cartilage debris, medial plica and complete septum of suprapatellar plica. Removing the debris by washing out and resecting the medial plica, she could return to play tennis without perioperative symptom. Two months after the first operation, her knee got swelling without any apparent cause. Since 20 ml blood was aspirated twice and MRI revealed suprapatellar mass, we performed arthroscopy again. Suprapatellar mass was old blood clot covered with complete suprapatellar plica. Resection of suprapatellar plica and washing out blood clot were performed, and severe postoperative hemarthrosis was progressively occurred. As factor XIII level was 54% preoperatively, we diagnosed that this condition was caused by low activity level of the factor and administered factor XIII concentrates. The level got improved to 129% and then hemarthrosis gradually relieved. She had no signs of recurrence. We should keep in mind of low factor XIII activity case in case of unexplained postoperative hemarthrosis after arthroscopy because consumption of the factor might promote this condition.

[Principles of perioperative coagulation management]

The coagulation system is a complex network of interacting proteins and cells with extensive sensitivity, amplification and control pathways. The system represents a delicate balance between procoagulant and anticoagulant as well as profibrinolytic and antifibrinolytic activities. Clinically relevant phenotypes, e.g. bleeding and thrombosis, occur immediately when this balance is no longer in equilibrium. A correct understanding of the complex coagulation pathophysiology in the perioperative setting is essential for an effective treatment. In a bleeding patient, patient's history, clinical findings, routine and advanced laboratory coagulation testing as well as point-of-care coagulation monitoring help to reliably and readily identify the underlying coagulation disorder. Modern coagulation management is proactive, individualized, balanced and follows clearly defined algorithms. Coagulopathic bleeding can be successfully controlled with specific interventions in the coagulation system.

Massive Bleeding and Massive Transfusion

Massive bleeding in trauma patients is a serious challenge for all clinicians, and an interdisciplinary diagnostic and therapeutic approach is warranted within a limited time frame. Massive transfusion usually is defined as the transfusion of more than 10 units of packed red blood cells (RBCs) within 24 h or a corresponding blood loss of more than 1- to 1.5-fold of the body's entire blood volume. Especially male trauma patients experience this life-threatening condition within their productive years of life. An important parameter for clinical outcome is to succeed in stopping the bleeding preferentially within the first 12 h of hospital admission. Additional coagulopathy in the initial phase is induced by trauma itself and aggravated by consumption and dilution of clotting factors. Although different aspects have to be taken into consideration when viewing at bleedings induced by trauma compared to those caused by major surgery, the basic strategy is similar. Here, we will focus on trauma-induced massive hemorrhage. Currently there are no definite, worldwide accepted algorithms for blood transfusion and strategies for optimal coagulation management. There is increasing evidence that a higher ratio of plasma and RBCs (e.g. 1:1) endorsed by platelet transfusion might result in a superior survival of patients at risk for trauma-induced coagulopathy. Several strategies have been evolved in the military environment, although not all strategies should be transferred unproven to civilian practice, e.g. the transfusion of whole blood. Several agents have been proposed to support the restoration of coagulation. Some have been used for years without any doubt on their benefit-to-risk profile, whereas great enthusiasm of other products has been discouraged by inefficacy in terms of blood transfusion requirements and mortality or significant severe side effects. This review surveys current literature on fluid resuscitation, blood transfusion, and hemostatic agents currently used during massive hemorrhage in order to optimize patients' blood and coagulation management in emergency medical aid.

Management of Dilutional Coagulopathy during Pediatric Major Surgery

Perioperative dilutional coagulopathy is a major coagulation disorder during adult and pediatric surgery. Although the main underlying mechanisms are comparable, data of the development and management of dilutional coagulopathy in children are scarce. Observational data showed that intraoperative coagulation disorders mainly based on complex disturbances of clot firmness including acquired fibrinogen as well as factor XIII deficiencies, while clotting time and platelet counts remained fairly stable. A fast and reliable monitoring of the entire coagulation process (e.g. thrombelastometry) might be of extreme value for detection and guidance of effective coagulation management. Although the transfusion of fresh frozen plasma was recommended in several guidelines, the use of coagulation factors might offer an alternative and potentially superior approach in managing perioperative coagulation disorders. Further studies are urgently needed to determine the efficacy of modern coagulation management.

Reduction of Fresh Frozen Plasma Requirements by Perioperative Point-of-Care Coagulation Management with Early Calculated Goal-Directed Therapy

BACKGROUND: Massive bleeding and transfusion of packed red blood cells (PRBC), fresh frozen plasma (FFP) and platelets are associated with increased morbidity, mortality and costs. PATIENTS AND METHODS: We analysed the transfusion requirements after implementation of point-of-care (POC) coagulation management algorithms based on early, calculated, goal-directed therapy with fibrinogen concentrate and prothrombin complex concentrate (PCC) in different perioperative settings (trauma surgery, visceral and transplant surgery (VTS), cardiovascular surgery (CVS) and general and surgical intensive care medicine) at 3 different hospitals (AUVA Trauma Centre Salzburg, University Hospital Innsbruck and University Hospital Essen) in 2 different countries (Austria and Germany). RESULTS: In all institutions, the implementation of POC coagulation management algorithms was associated with a reduction in the transfusion requirements for FFP by about 90% (Salzburg 94%, Innsbruck 88% and Essen 93%). Furthermore, PRBC transfusion was reduced by 8.4-62%. The incidence of intraoperative massive transfusion (≥10 U PRBC) could be more than halved in VTS and CVS (2.56 vs. 0.88%; p < 0.0001 and 2.50 vs. 1.06%; p = 0.0007, respectively). Platelet transfusion could be reduced by 21-72%, except in CVS where it increased by 115% due to a 5-fold increase in patients with dual antiplatelet therapy (2.7 vs. 13.7%; p < 0.0001). CONCLUSIONS: The implementation of perioperative POC coagulation management algorithms based on early, calculated, goal-directed therapy with fibrinogen concentrate and PCC is associated with a reduction in the transfusion requirements for FFP, PRBC and platelets as well as with a reduced incidence of massive transfusion. Thus, the limited blood resources can be used more efficiently.

[Principles of perioperative coagulation management]

The coagulation system is a complex network of interacting proteins and cells with extensive sensitivity, amplification and control pathways. The system represents a delicate balance between procoagulant and anticoagulant as well as profibrinolytic and antifibrinolytic activities. Clinically relevant phenotypes, e.g. bleeding and thrombosis, occur immediately when this balance is no longer in equilibrium. A correct understanding of the complex coagulation pathophysiology in the perioperative setting is essential for an effective treatment. In a bleeding patient, patient's history, clinical findings, routine and advanced laboratory coagulation testing as well as point-of-care coagulation monitoring help to reliably and readily identify the underlying coagulation disorder. Modern coagulation management is proactive, individualized, balanced and follows clearly defined algorithms. Coagulopathic bleeding can be successfully controlled with specific interventions in the coagulation system.