Antithrombin deficiency is associated with mortality and impaired organ function in septic pediatric patients: a retrospective study

Comparison of Three Different Disseminated Intravascular Coagulation (DIC) Criteria and Diagnostic and Prognostic Value of Antithrombin Investigation in Patients with Confirmed Sepsis-Induced Coagulopathy (SIC)

A new scoring system termed sepsis-induced coagulopathy (SIC) has been proposed to diagnose early sepsis-induced disseminated intravascular coagulation (DIC). This study performed DIC-related analyses in patients with confirmed SIC. Data from the intensive care unit (ICU) departments of the three hospitals between 2020 and 2022 were retrospectively analyzed. Finally, 125 patients with confirmed SIC were enrolled in the study. The diagnostic value of three widely used DIC criteria was assessed in patients with newly diagnosed SIC. In addition, the diagnostic and prognostic value of antithrombin (AT) was analyzed in patients with SIC. The Japanese Association for Acute Medicine DIC criteria (JAAM) exhibited the highest DIC diagnostic rate, while the mortality risk of SIC patients demonstrated a proportional increase with higher International Society on Thrombosis and Haemostasis (ISTH) and Chinese DIC scoring system (CDSS) scores. Low AT activity (<70%) in septic patients upon SIC diagnosis predicted a very high 28-day mortality rate, almost twice as high as in the normal AT activity (≥70%) group. A decreasing tendency in AT activity after clinical interventions was correlated with increased mortality. The area under the ROC curve (AU-ROC) of AT in DIC diagnosis was statistically significant when CDSS and ISTH were used as diagnostic criteria, but not JAAM. Each of the three DIC diagnostic criteria showed diagnostic and prognostic advantages for SIC. AT could be an independent prognostic indicator for SIC but demonstrated a relatively limited DIC diagnostic value. Adding AT to the SIC scoring system may increase its prognostic power.

Antithrombin activity and central venous catheter-associated thrombosis in critically ill children at high risk of bleeding

BACKGROUND

Normalization of antithrombin activity may prevent catheter-associated thrombosis in critically ill children at high risk of bleeding.

OBJECTIVES

To characterize the temporal pattern of antithrombin activity, assess its association with catheter-associated thrombosis and clinically relevant bleeding, and evaluate its relationship with thrombin generation in these children.

METHODS

In this prospective cohort study, critically ill children <18 years old at high risk of bleeding with central venous catheter were eligible. Antithrombin activity and thrombin generation were measured from platelet-poor plasma and after in vitro antithrombin supplementation. Systematic surveillance ultrasound was performed to diagnose thrombosis. Children were followed for bleeding.

RESULTS

We enrolled 8 infants (median age: 0.2 years, IQR: 0.2, 0.3 years) and 72 older children (median age: 14.3 years, IQR: 9.1, 16.1 years). Mean antithrombin on the day of catheter insertion was 64 IU/dL (SD: 32 IU/dL) in infants and 83 IU/dL (SD: 35 IU/dL) in older children. Antithrombin normalized by the day of catheter removal. Thrombosis developed in 27 children, while 31 children bled. Thrombosis (regression coefficient: 0.008, 95% CI: -0.01, 0.03) and bleeding (regression coefficient: -0.0007, 95% CI: -0.02, 0.02) were not associated with antithrombin. Antithrombin was not correlated with in vivo change in endogenous thrombin potential (correlation coefficient: -0.07, 95% CI: -0.21, 0.08). In vitro supplementation reduced endogenous thrombin potential (correlation coefficient: -0.78; 95% CI: -0.95, -0.23).

CONCLUSION

These findings may not support normalization of antithrombin activity to prevent catheter-associated thrombosis in critically ill children at high risk of bleeding.

A Global Assessment of Coagulation Profile and a Novel Insight into Adamts-13 Implication in Neonatal Sepsis

Neonatal sepsis is a life-threatening condition associated with significant morbidity and mortality. Sepsis-induced coagulopathy is a well-recognized entity, signifying the strong cross-talk between inflammation and coagulation. The aim of the present study was to compare the coagulation profile between the acute phase of sepsis and recovery in term and preterm neonates. Additional comparisons to healthy neonates were undertaken. Levels of clotting, anti-clotting factors and ADAMTS-13 (A disintegrin and metalloprotease with thrombospondin type-1 motives), the cleaving protein of von Willebrand factor (VWF), were measured in 16 term and preterm neonates in the acute phase of infection and following recovery, as well as in 18 healthy neonates. Clotting times were prolonged, while levels of particular clotting factors were lower in the acute phase of infection compared to controls and recovery. On the other hand, levels of fibrinogen, factor VIII (FVIII) and VWF were significantly higher in the acute phase in comparison to controls and recovery, while they remained persistently higher in the infection group compared to controls. In regard to the anticlotting mechanism, a clear suppression was observed in septic neonates. ADAMTS-13 levels were significantly lower in the acute phase of infection in comparison to controls and recovery (p = 0.015 and 0.004, respectively), while a trend toward superimposed normalization was demonstrated post infection, as higher ADAMTS-13 levels were measured in recovered neonates compared to controls (p = 0.002). The coagulation profile is considerably deranged in neonatal sepsis. ADAMTS-13 deficiency in septic neonates is a novel finding with promising future implications, as ADAMTS-13 substitution may serve as a useful therapeutic option in neonatal sepsis, prompting further investigation in future studies.

Sepsis-Induced Coagulopathy: An Update on Pathophysiology, Biomarkers, and Current Guidelines

Significant cross talk occurs between inflammation and coagulation. Thus, coagulopathy is common in sepsis, potentially aggravating the prognosis. Initially, septic patients tend to exhibit a prothrombotic state through extrinsic pathway activation, cytokine-induced coagulation amplification, anticoagulant pathways suppression, and fibrinolysis impairment. In late sepsis stages, with the establishment of disseminated intravascular coagulation (DIC), hypocoagulability ensues. Traditional laboratory findings of sepsis, including thrombocytopenia, increased prothrombin time (PT) and fibrin degradation products (FDPs), and decreased fibrinogen, only present late in the course of sepsis. A recently introduced definition of sepsis-induced coagulopathy (SIC) aims to identify patients at an earlier stage when changes to coagulation status are still reversible. Nonconventional assays, such as the measurement of anticoagulant proteins and nuclear material levels, and viscoelastic studies, have shown promising sensitivity and specificity in detecting patients at risk for DIC, allowing for timely therapeutic interventions. This review outlines current insights into the pathophysiological mechanisms and diagnostic options of SIC.

Antithrombin Activity is Associated with Persistent Thromboinflammation and Mortality in Patients with Severe COVID-19 Illness

BACKGROUND

Severe COVID-19 illness can lead to thrombotic complications, organ failure, and death. Antithrombin (AT) regulates thromboinflammation and is a key component of chemical thromboprophylaxis. Our goal was to examine the link between AT activity and responsiveness to thromboprophylaxis, markers of hypercoagulability, and inflammation among severe COVID-19 patients.

METHODS

A single-center, prospective observational study enrolling SARS-CoV-2 positive patients admitted to the intensive care unit on prophylactic enoxaparin. Blood was collected daily for 7 days to assess AT activity and anti-FXa levels. Patient demographics, outcomes, and hospital laboratory results were collected. Continuous variables were compared using Mann-Whitney tests, and categorical variables were compared using Chi-square tests. Multivariable logistic regression was used to determine the association between AT activity and mortality.

RESULTS

In 36 patients, 3 thromboembolic events occurred, and 18 (50%) patients died. Patients who died had higher fibrinogen, D-dimer, and C-reactive protein (CRP) levels and lower AT activity. Reduced AT activity was independently associated with mortality and correlated with both markers of hypercoagulability (D-dimer) and inflammation (CRP).

CONCLUSIONS

Low AT activity is associated with mortality and persistent hypercoagulable and proinflammatory states in severe COVID-19 patients. The anti-thromboinflammatory properties of AT make it an appealing therapeutic target for future studies.

Thromboprophylaxis with argatroban in critically ill patients with sepsis: a review

During sepsis, an initial prothrombotic shift takes place, in which coagulatory acute-phase proteins are increased, while anticoagulatory factors and platelet count decrease. Further on, the fibrinolytic system becomes impaired, which contributes to disease severity. At a later stage in sepsis, coagulation factors may become depleted, and sepsis patients may shift into a hypo-coagulable state with an increased bleeding risk. During the pro-coagulatory shift, critically ill patients have an increased thrombosis risk that ranges from developing micro-thromboses that impair organ function to life-threatening thromboembolic events. Here, thrombin plays a key role in coagulation as well as in inflammation. For thromboprophylaxis, low molecular weight heparins (LMWH) and unfractionated heparins (UFHs) are recommended. Nevertheless, there are conditions such as heparin resistance or heparin-induced thrombocytopenia (HIT), wherein heparin becomes ineffective or even puts the patient at an increased prothrombotic risk. In these cases, argatroban, a direct thrombin inhibitor (DTI), might be a potential alternative anticoagulatory strategy. Yet, caution is advised with regard to dosing of argatroban especially in sepsis. Therefore, the starting dose of argatroban is recommended to be low and should be titrated to the targeted anticoagulation level and be closely monitored in the further course of treatment. The authors of this review recommend using DTIs such as argatroban as an alternative anticoagulant in critically ill patients suffering from sepsis or COVID-19 with suspected or confirmed HIT, HIT-like conditions, impaired fibrinolysis, in patients on extracorporeal circuits and patients with heparin resistance, when closely monitored.

Criteria for Pediatric Sepsis-A Systematic Review and Meta-Analysis by the Pediatric Sepsis Definition Taskforce

OBJECTIVE

To determine the associations of demographic, clinical, laboratory, organ dysfunction, and illness severity variable values with: 1) sepsis, severe sepsis, or septic shock in children with infection and 2) multiple organ dysfunction or death in children with sepsis, severe sepsis, or septic shock.

DATA SOURCES

MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from January 1, 2004, and November 16, 2020.

STUDY SELECTION

Case-control studies, cohort studies, and randomized controlled trials in children greater than or equal to 37-week-old postconception to 18 years with suspected or confirmed infection, which included the terms "sepsis," "septicemia," or "septic shock" in the title or abstract.

DATA EXTRACTION

Study characteristics, patient demographics, clinical signs or interventions, laboratory values, organ dysfunction measures, and illness severity scores were extracted from eligible articles. Random-effects meta-analysis was performed.

DATA SYNTHESIS

One hundred and six studies met eligibility criteria of which 81 were included in the meta-analysis. Sixteen studies (9,629 patients) provided data for the sepsis, severe sepsis, or septic shock outcome and 71 studies (154,674 patients) for the mortality outcome. In children with infection, decreased level of consciousness and higher Pediatric Risk of Mortality scores were associated with sepsis/severe sepsis. In children with sepsis/severe sepsis/septic shock, chronic conditions, oncologic diagnosis, use of vasoactive/inotropic agents, mechanical ventilation, serum lactate, platelet count, fibrinogen, procalcitonin, multi-organ dysfunction syndrome, Pediatric Logistic Organ Dysfunction score, Pediatric Index of Mortality-3, and Pediatric Risk of Mortality score each demonstrated significant and consistent associations with mortality. Pooled mortality rates varied among high-, upper middle-, and lower middle-income countries for patients with sepsis, severe sepsis, and septic shock (p < 0.0001).

CONCLUSIONS

Strong associations of several markers of organ dysfunction with the outcomes of interest among infected and septic children support their inclusion in the data validation phase of the Pediatric Sepsis Definition Taskforce.

Peritoneal lavage with hydrogen-rich saline can be an effective and practical procedure for acute peritonitis

PURPOSE

Acute peritonitis has remained a fatal disease despite of recent advances in care and treatment, including antibiotic and anticoagulant treatments. The cause of death is mostly sepsis-induced multiple organ failure. Oxidative stress can play an important role in this situation, but antioxidant therapy to capture any excessive reactive oxygen species has not yet been fully established.

METHODS

Two experiments were performed. In the first experiment, we confirmed the effects of peritoneal lavage with hydrogen-rich saline (HRS) after a cecal ligation and puncture (CLP) operation in rats. In the second experiment, the changes in the hemodynamic state following this procedure were observed in a porcine model of abdominal sepsis to evaluate its safety and utility.

RESULTS

Peritoneal lavage with HRS significantly improved the survival after CLP in rats, and it ameliorated the levels of sepsis-induced organ failure. Moreover, it showed anti-inflammatory and anti-apoptosis as well as antioxidant effects. The second experiment demonstrated the potential safety and feasibility of this procedure in a large animal model.

CONCLUSION

This procedure can improve survival after sepsis through mitigating the sepsis-induced organ failure by inhibiting oxidative stress, apoptosis, and inflammatory pathways. Peritoneal lavage with HRS may therefore be an effective, safe, and practical therapy for patients with acute peritonitis.

Antithrombin and Its Role in Host Defense and Inflammation

Antithrombin (AT) is a natural anticoagulant that interacts with activated proteases of the coagulation system and with heparan sulfate proteoglycans (HSPG) on the surface of cells. The protein, which is synthesized in the liver, is also essential to confer the effects of therapeutic heparin. However, AT levels drop in systemic inflammatory diseases. The reason for this decline is consumption by the coagulation system but also by immunological processes. Aside from the primarily known anticoagulant effects, AT elicits distinct anti-inflammatory signaling responses. It binds to structures of the glycocalyx (syndecan-4) and further modulates the inflammatory response of endothelial cells and leukocytes by interacting with surface receptors. Additionally, AT exerts direct antimicrobial effects: depending on AT glycosylation it can bind to and perforate bacterial cell walls. Peptide fragments derived from proteolytic degradation of AT exert antibacterial properties. Despite these promising characteristics, therapeutic supplementation in inflammatory conditions has not proven to be effective in randomized control trials. Nevertheless, new insights provided by subgroup analyses and retrospective trials suggest that a recommendation be made to identify the patient population that would benefit most from AT substitution. Recent experiment findings place the role of various AT isoforms in the spotlight. This review provides an overview of new insights into a supposedly well-known molecule.

Antithrombin Deficiency in Trauma and Surgical Critical Care

Antithrombin deficiency (ATD) was described in 1965 by Olav Egeberg as the first known inherited form of thrombophilia. Today, it is understood that ATDs can be congenital or acquired, leading to qualitative, quantitative, or mixed abnormalities in antithrombin (AT). All ATDs ultimately hinder AT's ability to serve as an endogenous anticoagulant and antiinflammatory agent. As a result, ATD patients possess higher risk for thromboembolism and can develop recurrent venous and arterial thromboses. Because heparin relies on AT to augment its physiologic function, patients with ATD often exhibit profound heparin resistance. Although rare as a genetic disorder, acquired forms of ATD are seen with surprising frequency in critically ill patients. This review discusses ATD in the context of surgical critical care with specific relevance to trauma, thermal burns, cardiothoracic surgery, and sepsis.

Reversal of Factor Xa Inhibitors by Andexanet Alfa May Increase Thrombogenesis Compared to Pretreatment Values

Recombinant coagulation factor Xa (FXa), inactivated Zh-zo, also known as andexanet alfa (AA), is a modified version of human FXa that has been developed to neutralize FXa inhibitors. We studied the reversal effect of AA for these inhibitors in various anticoagulant and thrombin generation (TG) assays. Individual aliquots of normal human plasma containing 1 µg/mL of apixaban, betrixaban, edoxaban, and rivaroxaban, were supplemented with saline or AA at a concentration of 100 µg/mL. Clotting profiles include prothrombinase-induced clotting time, activated partial thromboplastin time, and prothrombin time. Factor Xa activity was measured using an amidolytic method. Thrombin generation was measured using a calibrated automated thrombogram. Differential neutralization of all 4 anticoagulants was noted in the activated clotting time and other clotting tests. The FXa activity reversal profile varied with an observed decrease in apixaban (22%), betrixaban (56%), edoxaban (28%), and rivaroxaban (49%). Andexanet alfa also led to an increased TG in comparison to saline. The peak thrombin was higher (40%), area under the curve (AUC) increased (15%), whereas the lag time (LT) decreased (17%). Andexanet alfa added at 100 µg/mL to various FXa supplemented systems resulted in reversal of the inhibitory effects, restoring the TG profile; AUC, LT, and peak thrombin levels were comparable to those of unsupplemented samples. Andexanet alfa is capable of reversing anti-Xa activity of different oral FXa inhibitors but overshoots thrombogenesis in both the saline and FXa inhibitor supplemented systems. The degree of neutralization of Xa inhibitor is specific to each agent.

Thrombin Generation Profile in Various Lymphoma Sub-Groups and Its Augmentation by Andexanet Alfa

The prevalence of thrombosis in lymphoma patients is reportedly high and ranges from 3-10%. Vascular malfunction and inflammatory processes further contribute to the thrombotic activation process in these patients. Andexanet alfa (AA) is an antidote for factor Xa inhibitors and its usage has been reported with thrombotic complications. This study was designed to compare the effect of AA on the thrombin generation (TG) potential. Blood samples from 78 patients with confirmed diagnosis of non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL) and Chronic lymphocytic leukemia (CLL) were collected from the University of Belgrade Clinic, Serbia. Normal human plasma (NHP) was used for referencing purposes. Individual samples were supplemented with AA at 100 ug/ml. TG studies were carried out using a commercially available fluorogenic substrate method. TG parameters such as peak thrombin (PT), lag time (LT) and area under the curve (AUC) were compiled. Cumulatively, lymphoma patients showed an increase in LT compared to NHP which decreases with AA. The PT and AUC levels were decreased compared to NHP and increases with AA. Upon sub-grouping of lymphoma patients, PT levels for all sub-groups were increased with AA. The AUC values increased for HL and NHL and decreased for CLL with AA. Variations in lag time were noted in all 3 sub-groups. Lymphoma represents a heterogenous group of patients where both the hypercoagulable state and inflammatory responses simultaneously occur. Increased thrombin generation in post AA supplemented samples suggest that the use of this agent may potentially be associated with thrombotic complications.

Low antithrombin levels accompanied by high urine protein/creatinine ratios are predictive of acute kidney injury among CS patients with preeclampsia

OBJECTIVES

Previous acute kidney injury (AKI) is reportedly a risk factor for future preeclampsia (PE), and PE in current pregnancies may trigger the onset of AKI. In this study, we identified risk factors for AKI among Cesarean section (CS) patients with PE.

METHODS

We performed a retrospective study at a single center. Among 4602 deliveries between January 2017 and July 2018, 944 women underwent CS. Of these, 90 women had hypertensive disorders during their pregnancies, with 53 diagnoses of PE and 37 diagnoses of gestational hypertension. Medical records of the 90 women were reviewed retrospectively.

RESULTS

The rate of AKI was significantly higher in the PE group than in the GH group (17 versus 3%, p < .05). Univariate analyses of the PE group identified low preoperative serum albumin levels, low antithrombin III (ATIII) activities, and urine protein/creatinine ratios (U-P/Cr) as significant predictors of AKI. Cutoff values for these factors were calculated using ROC analyses, and the combination of ATIII and U-P/Cr, which were poorly correlated, was predictive of AKI. Specifically, the proportion of AKI in patients with low ATIII-high U-P/Cr was 50% (7/14), higher than that among patients with high ATIII-low U-P/Cr (0%, 0/19, p < .05), low ATIII-low U-P/Cr (10%, 1/10, p < .05), and high ATIII-high U-P/Cr (10%, 1/10, p < .05).

CONCLUSIONS

These data demonstrate that lower preoperative serum albumin levels, ATIII activities, and heavy proteinuria among CS patients with PE are risk factors for AKI.

Effects of Serum Albumin Levels on Antithrombin Supplementation Outcomes Among Patients With Sepsis-Associated Coagulopathy: A Retrospective Study

Background

Severe sepsis is commonly associated with mortality among critically ill patients and is known to cause coagulopathy. While antithrombin is an anticoagulant used in this setting, serum albumin levels are known to influence serum antithrombin levels. Therefore, this study aimed to evaluate the outcomes of antithrombin supplementation in patients with sepsis-associated coagulopathy, as well as the relationship between serum albumin levels and the effects of antithrombin supplementation.

Methods

This retrospective study evaluated patients who were >18 years of age and had been admitted to either of two intensive care units for sepsis-associated coagulopathy. The groups that did and did not receive antithrombin supplementation were compared for outcomes up to 1 year after admission. Subgroup analyses were performed for patients with serum albumin levels of <2.5 g/dL or ⩾2.5 g/dL.

Results

Fifty-one patients received antithrombin supplementation and 163 patients did not. The Cox proportional hazards model revealed that antithrombin supplementation was independently associated with 28-day survival (hazard ratio [HR]: 0.374, P = 0.025) but not with 1 year survival (HR: 0.915, P = 0.752). In addition, among patients with serum albumin levels of <2.5 g/dL, antithrombin supplementation was associated with a significantly lower 28-day mortality rate (9.4% vs 36.8%, P = .009).

Conclusion

Antithrombin supplementation may improve short-term survival, but not long-term survival, among patients with sepsis-associated coagulopathy.

Impact of Antithrombin Supplementation and Concomitant Anticoagulation Therapy in Pediatric Patients With Disseminated Intravascular Coagulation

We aimed to evaluate the efficacy and safety of antithrombin (AT) supplementation and concomitant anticoagulation therapy in 65 children who met the Japanese Ministry of Health and Welfare (JMHW) disseminated intravascular coagulation (DIC) criteria and had received AT concentrate and/or other concomitant anticoagulants. The primary efficacy end point was to determine standardized mortality ratio (SMR). The secondary efficacy end points were DIC resolution rate and pediatric sequential organ failure assessment (pSOFA) score on day 3. The 28-day mortality rate was 6.8%; SMR was 0.55. Disseminated intravascular coagulation resolution rate on day 3 was 54.5%. The JMHW DIC scores at day 0 ( P = .005) and pSOFA scores at day 3 ( P = .018) were significantly lower in patients with resolution of DIC than in those without resolution of DIC. The target cutoff value for JMHW DIC score on day 0 was 6. No bleeding-related adverse events were associated with AT administration. In children with DIC, AT supplementation and concomitant anticoagulation therapy can be safely used as initial treatment when JMHW DIC score is 6; it may improve DIC resolution, organ failure, and mortality rates.