Stellenwert der Thrombelastometrie für das Monitoring von Faktor XIII

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.

Rotational Thromboelastometry for Assessing Bleeding Complications and Factor XIII Deficiency in Cardiac Surgery Patients

We aimed to detect alterations and deficits in hemostasis during cardiac surgery with cardiopulmonary bypass (CPB) using point-of-care-supported coagulation analysis (rotational thromboelastometry, impedance aggregometry), in addition to single factor assays for the measurement of fibrinogen (FI) and factor XIII (FXIII) levels. Forty-one patients scheduled for elective cardiac surgery with CPB were enrolled in this observational study. Perioperative measurement (pre-, postheparin, 30-minutes before the end of bypass, 1-hourpostoperatively) of standard laboratory variables, additional rotational thromboelastometry (ROTEM; International GmbH, Munich, Germany), Multiplate analysis (Roche, Switzerland), and an assay of FXIII activity were performed as well as the collection of epidemiological data and blood loss. The FI and FXIII levels as well as the measured ROTEM and Multiplate parameters correlated weakly with the blood loss. Clotting time and maximum clot firmness (MCF) of the intrinsically activated ROTEM showed a good correlation (r_CT-INTEM = 0.378; P < .05, r_MCF-INTEM = 0.305; P < .05) with postoperative drainage loss, suggesting a dependence of blood loss on the initial intrinsic activity. Additionally, perioperative FI or FIBTEM levels and the FXIII levels correlated with each other. Intrinsically activated ROTEM showed a good correlation with postoperative drainage loss, thus suggesting a dependence of blood loss on the initial intrinsic activity and therefore facilitating clinicians to assess postoperative bleeding complications. Based on the FI level or the MCF_FIBTEM measured by ROTEM, it may also be possible to assess the FXIII concentration. Especially in chronically ill and massive bleeding cardiac surgery patients with significantly decreased FXIII levels, the knowledge of FXIII deficiency may help clinicians to treat coagulation disorders more adequately.

[Modern coagulation management in bleeding trauma patients : Point-of-care guided administration of coagulation factor concentrates and hemostatic agents]

BACKGROUND

Uncontrolled bleeding with trauma-induced coagulopathy (TIC) is still the leading cause of preventable death following severe multiple injury. Rapid diagnosis and treatment are associated with improved outcome. Early individualized goal-directed therapy and the use of point-of-care technology may be superior to empiric and ratio-based therapies with conventional blood products.

MATERIALS AND METHODS

Selective review of the literature considering current recommendations/expert opinion for coagulation management in bleeding trauma patients via individualized goal-directed therapy and the use of viscoelastic point-of-care (ROTEM®)-guided substitution of coagulation factor concentrates and hemostatic agents.

RESULTS

The administration of fibrinogen concentrate in bleeding trauma patients may be considered if ROTEM®-FIBTEM A10 < 10 mm (FIBTEM A5 < 9 mm; FIBTEM MCF < 12 mm) and EXTEM A10 < 45 mm (EXTEM A5 < 35 mm; EXTEM MCF < 55 mm); the administration of prothrombin complex concentrate (PCC) may be considered if signs of delayed coagulation initiation (ROTEM®-EXTEM CT > 80 s). At this stage, no concluding statement can be made for monitoring or treatment guidance with factor XIII by using point-of-care technology. Viscoelastic assays display high sensitivity and specificity for the detection of hyperfibrinolysis with subsequent administration of an antifibrinolytic.

CONCLUSIONS

Individualized therapeutic concepts based upon viscoelastic point-of-care (ROTEM®) assays present an alternative to empiric and ratio-based therapies with conventional blood products in bleeding trauma patients and may be associated with reduced need for allogenic blood products and morbidity.

Rotational thromboelastometry can detect factor XIII deficiency and bleeding diathesis in patients with cirrhosis

BACKGROUND & AIMS

Patients with progressive liver disease exhibit complex coagulation disorders. Factor XIII plays a crucial role in the last steps of haemostasis, and its deficiency is associated with an increased incidence of bleeding diathesis. However, current conventional coagulation tests cannot detect factor XIII deficiency. In this study, we examined factor XIII activity and the ability of rotational thromboelastometry to detect factor XIII deficiency and bleeding diathesis in patients with cirrhosis.

METHODS

We retrospectively studied 74 patients with cirrhosis, comparing the results of conventional coagulation tests (international normalized ratio, activated partial thromboplastin time, platelet count, fibrinogen level), rotational thromboelastometry, factor XIII activity and clinical scores.

RESULTS

Patients with cirrhosis exhibited reduced factor XIII activity. Factor XIII activity was positively correlated with conventional coagulation parameters and rotational thromboelastometry values, such as maximum clot formation (MCF)_extem (r=.48, P<.0001) and MCF_fibtem (r=.60, P<.0001). However, maximum lysis (ML)_extem and ML_aptem were not correlated with factor XIII activity. Three-month mortality rates (P=.0469) and bleeding complications (P<.0001) were significantly associated with lower factor XIII activity. Patients with haemorrhage exhibited significantly altered rotational thromboelastometry values.

CONCLUSIONS

Reduced levels of MCF_extem and MCF_fibtem but not high levels of ML_extem and ML_aptem are associated with factor XIII deficiency in patients with liver disease. Therefore, substituting factor XIII should be considered for such patients to strengthen clot formation in patients experiencing haemorrhage or those who have undergone interventions.

Effects of Factor XIII Deficiency on Thromboelastography. Thromboelastography with Calcium and Streptokinase Addition is more Sensitive than Solubility Tests

Background

Homozygous or double heterozygous factor XIII (FXIII) deficiency is characterized by soft tissue hematomas, intracranial and delayed spontaneous bleeding. Alterations of thromboelastography (TEG) parameters in these patients have been reported. The aim of the study was to show results of TEG, TEG Lysis (Lys 60) induced by subthreshold concentrations of streptokinase (SK), and to compare them to the clot solubility studies results in samples of a 1-year-old girl with homozygous or double heterozygous FXIII deficiency.

Case

A year one girl with a history of bleeding from the umbilical cord. During her first year of life, several hematomas appeared in soft upper limb tissue after punctures for vaccination and a gluteal hematoma. One additional sample of a heterozygous patient and three samples of acquired FXIII deficiency were also evaluated.

Materials and Methods

Clotting tests, von Willebrand factor (vWF) antigen and activity, plasma FXIII-A subunit (pFXIII-A) were measured by an immunoturbidimetric assay in a photo-optical coagulometer. Solubility tests were performed with Ca²⁺-5 M urea and thrombin-2% acetic acid. Basal and post-FXIII concentrate infusion samples were studied. TEG was performed with CaCl₂ or CaCl₂ + SK (3.2 U/mL) in a Thromboelastograph.

Results

Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, fibrinogen, factor VIIIc, vWF, and platelet aggregation were normal. Antigenic pFXIII-A subunit was < 2%. TEG, evaluated at diagnosis and post FXIII concentrate infusion (pFXIII-A= 37%), presented a normal reaction time (R), 8 min, prolonged k (14 and 11min respectively), a low Maximum-Amplitude (MA) ( 39 and 52 mm respectively), and Clot Lysis (Lys60) slightly increased (23 and 30% respectively). In the sample at diagnosis, clot solubility was abnormal, 50 and 45 min with Ca-Urea and thrombin-acetic acid, respectively, but normal (>16 hours) 1-day post-FXIII infusion. Analysis of FXIII deficient and normal plasma mixtures (< 2–102% of pFXIII-A), showed that Ca-urea solubility was abnormal at pFXIII-A < 9%, thrombin-acetic acid at pFXIII-A<18%, but TEG MA and elasticity at 23% and Lys60 with SK at pFXIII-A< 40%.

Conclusions

TEG parameters MA and elasticity, and Lys 60 in TEG either with Ca²⁺ or Ca²⁺ and SK are more sensitive to low levels of pFXIII than solubility tests. The increased Lys60 induced by a subthreshold concentration of SK could probably reflect the clot characteristics “in vivo” in many patients with pFXIII levels between 5–40% and could be potentially considered as screening test.

[Rotational thromboelastometry for the diagnosis of coagulation disorders]

BACKGROUND

Compared to conventional coagulation assays, as prothrombin time (PT) or activated partial thromboplastin time (aPTT), viscoelastic methods of coagulation analysis, including rotational thromboelastometry (ROTEM®, Tem International GmbH, Munich, Germany), yield prognostic benefits. Results of ROTEM® in citrated whole blood could be generated within 10-12 min and allow for a qualitative and semiquantitative characterisation of clot kinetics. Based on ROTEM® results, the switch between empiric approaches of treating coagulopathy to a goal-directed approach could be accelerated. Introduction of ROTEM® reduces transfusion requirements and the need for single factor concentrates. Thus, ROTEM® reduces transfusion-related adverse events, and additionally implement therapeutic cost effectiveness.

OBJECTIVES

This review provides a short introduction in the methodology of ROTEM®, showing how the combination of assays with different commercially available ROTEM® reagents allows for rapid differential diagnosis of common coagulopathies in clinical practice. Furthermore, prognostic benefits and limitations of ROTEM® diagnostics are described. Finally, we discuss the potential fields of ROTEM® application in different surgical settings.

CONCLUSION

ROTEM® appears to be a contemporary, applicable and effective method in diagnosing coagulopathy and for subsequent algorithm-based goal-directed therapy.

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 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.