Identification of Cost-Saving Opportunities for the Use of Antithrombin III in Adult and Pediatric Patients

Antithrombin restriction in extracorporeal membrane oxygenation support (ARES): A multidisciplinary approach

Background: Antithrombin (AT) replacement is occasionally utilized in the setting of extracorporeal membrane oxygenation (ECMO)-associated heparin resistance. Although past studies emphasized the high costs and limited clinical benefit of AT supplementation,  guidance on strategies to prevent unnecessary use remain lacking.Methods: In this retrospective study, we evaluated the cost, efficacy, and safety outcomes three years pre- and post-implementation of an AT restriction protocol in adult ECMO patients. The primary endpoint was the cost spent on anticoagulation and AT normalized to ECMO duration. Secondary endpoints included thromboembolic and bleeding outcomes.Results: 175 patients were included for analysis (pre-restriction protocol n = 87; post-restriction protocol n = 88). Implementation of the restriction resulted in complete elimination of AT use and significantly reduced the primary cost endpoint from $1009.20 to $42.99 per ECMO day (p < .001). There was no significant change in occurrence of new Venous Thromboembolism (VTE) (p = .099). Those in the pre-implementation group had significantly higher rates of transfusions (p < .001) and ISTH major bleeding (p < .001). Outcomes remained significant after exclusion of patients with coronavirus infections.Conclusion: Results of this study exemplify how AT restriction can be successfully implemented to decrease anticoagulation-associated costs without jeopardizing the risk of bleeding and thrombosis in ECMO patients.

Safe and effective anticoagulation use: case studies in anticoagulation stewardship

Anticoagulant use is prevalent and associated with significant potential for harm. Anticoagulation stewardship practice has emerged to address care gaps and promote safe, effective, and cost-conscious anticoagulation use across health care systems. We present 4 patient cases describing common challenges in anticoagulation management: inappropriate dosing of direct oral anticoagulants, the diagnosis and management of heparin-induced thrombocytopenia, periprocedural anticoagulation management, and heavy menstrual bleeding on anticoagulation. We discuss available examples of successful stewardship programs that can address the challenges of each case, demonstrating how an investment in anticoagulation stewardship can improve patient outcomes.

Normalizing Anti-Thrombin III for heparin management during routine cardiopulmonary bypass for congenital cardiothoracic surgery: A single institution practice review

INTRODUCTION

Over the past decade, there has been an increase in the use of recombinant Anti-Thrombin III (AT-III) administration during neonatal and pediatric short- and long-term mechanical support for the replacement of acquired deficiencies. Recombinant AT-III (Thrombate) administration is an FDA licensed drug indicated primarily for patients with hereditary deficiency to treat and prevent thromboembolism and secondarily to prevent peri-operative and peri-partum thromboembolism. Herein we propose further use of Thrombate for primary AT-III deficiency of the newborn as well as for acquired dilution and consumption secondary to cardiopulmonary bypass (CPB).

METHODOLOGY

All patients undergoing CPB obtain a preoperative AT-III level. Patients with identified deficiencies are normalized in the OR using recombinant AT-III as a patient load, in the CPB prime, or both. Patient baseline Heparin Dose Response (HDR) is assessed using the Heparin Management System (HMS) before being exposed to AT-III. If a patient load of AT-III is given, a second HDR is obtained and this AT-III Corrected HDR is used as the primary goal during CPB. Once CPB is initiated, an AT-III level is obtained with the first patient blood analysis. A subtherapeutic level results in an additional dose of AT-III. During the rewarm period, a final AT-III level is obtained and AT-III treated once again if subtherapeutic. A retrospective, matched analysis review of practice analyzing two groups, a Study Group (Repeat HDR, May 2022 onward) and Matched Group (Without Repeat HDR, July 2019 to April 2022), for age (D), weight (Kg) and operation was conducted. The focus of the study was to determine any change in heparin sensitivity identified post AT-III patient bolus load in the HDR (U/mL), Slope (U/mL/s), ACT (s), and total amount of heparin on CPB (U) and protamine (mg) used in each group.

RESULTS

No significance was seen in Baseline AT-III (%), post heparin load HDR (U/mL), first CPB ACT (s), first CPB HDR (U/mL), or total CPB heparin (u/Kg) between the two groups. Statistical significance was seen in Baseline ACT (s), Baseline HDR (U/mL), Baseline Slope (U/mL/s), Post Heparin Load ACT (s), first CPB AT-III (%), and Protamine (mg/Kg) (p < .05). No statistical significance was seen in the Study Intragroup between pre versus post AT-III patient load baseline sample in ACT (s), however significance was seen in HDR (U/mL) and Slope (U/mL/s) (p < .05).

CONCLUSION

Implementation of AT-III monitoring and therapy before and during CPB in conjunction with the HMS allows patients to maintain a steady state of anticoagulation with overall less need for excessive heparin replacement and potentially thrombin activation. The result is obtaining a steady state of anticoagulation, a reduced fluctuation in the heparin and ACT levels and a potential for lower co-morbidities associated with prolonged CPB times.

Finding a common definition of heparin resistance in adult cardiac surgery: communication from the ISTH SSC subcommittee on perioperative and critical care thrombosis and hemostasis

Ensuring adequate anticoagulation for patients requiring cardiac surgery and cardiopulmonary bypass (CPB) is important due to the adverse consequences of inadequate anticoagulation with respect to bleeding and thrombosis. When target anticoagulation is not achieved with typical doses, the term heparin resistance is routinely used despite the lack of uniform diagnostic criteria. Prior reports and guidance documents that define heparin resistance in patients requiring CPB and guidance documents remain variable based on the lack of standardized criteria. As a result, we conducted a review of clinical trials and reports to evaluate the various heparin resistance definitions employed in this clinical setting and to identify potential standards for future clinical trials and clinical management. In addition, we also aimed to characterize the differences in the reported incidence of heparin resistance in the adult cardiac surgical literature based on the variability of both target-activated clotting (ACT) values and unfractionated heparin doses. Our findings suggest that the most extensively reported ACT target for CPB is 480 seconds or higher. Although most publications define heparin resistance as a failure to achieve this target after a weight-based dose of either 400 U/kg or 500 U/kg of heparin, a standardized definition would be useful to guide future clinical trials and help improve clinical management. We propose the inability to obtain an ACT target for CPB of 480 seconds or more after 500 U/kg as a standardized definition for heparin resistance in this setting.

Outcomes of a Vial-Sparing Antithrombin III Protocol in Pediatric Extracorporeal Membrane Oxygenation

Exogenous antithrombin III (AT3) may be administered to pediatric patients supported by extracorporeal membrane oxygenation (ECMO) to achieve a greater systemic response to heparin. Antithrombin III administration and dosing practices vary between ECMO centers. This study compared the outcomes of two different AT3 replacement protocols used by a single pediatric ECMO center for 47 patients between December 2013 and August 2021. In May 2016, a weight-based continuous infusion protocol (WBP) was transitioned to a vial-sparing protocol (VSP) as a cost-saving measure. No difference was observed in the percentage of heparin monitoring levels within goal range, with a median of 56.5% therapeutic levels on the WBP compared with a median of 60.7% on the VSP ( p = 0.170). No significant differences were observed in amount of exogenous blood products administered, number of hemorrhagic or thrombotic events, number of mechanical failures, or number of circuit changes required. The VSP resulted in fewer AT3 dispenses ( p < 0.001) and units dispensed ( p = 0.005), resulting in a significant median cost reduction from $15,610.62 on the WBP to $7,765.56 on the VSP ( p = 0.005). A vial-sparing AT3 replacement protocol resulted in significant cost savings with similar efficacy and safety outcomes.

Antithrombin III supplementation during neonatal and pediatric extracorporeal membrane oxygenation

BACKGROUND

Bleeding and thrombosis are common extracorporeal membrane oxygenation (ECMO) complications associated with increased mortality. Heparin is the most commonly used ECMO anticoagulant, employed in 94% of cases. Reduced antithrombin III (AT3) levels could decrease heparin effectiveness. Neonates have inherently lower levels of AT3 than adults, and pediatric patients on ECMO can develop AT3 deficiency. One potential approach for patients on ECMO with AT3 deficiency is exogenous AT3 supplementation. However, there is conflicting data concerning the use of AT3 for pediatric and neonatal patients on ECMO.

METHODS

We analyzed the Bleeding and Thrombosis during ECMO database of 514 neonatal and pediatric patients on ECMO. We constructed daily regression models to determine the association between AT3 supplementation and rates of bleeding and thrombosis. Given the physiological differences between pediatric patients and neonates, we constructed separate models for each.

RESULTS

AT3 administration was associated with increased rates of daily bleeding among pediatric (adjusted odds ratio [aOR] 1.59, p < 0.01) and neonatal (aOR 1.37, p = 0.04) patients. AT3 supplementation did not reduce the rate of thrombosis for either pediatric or neonatal patients.

CONCLUSION

AT3 administration was associated with increased rates of daily bleeding, a hypothesized potential complication of AT3 supplementation. In addition, AT3 supplementation did not result in lower rates of thrombosis. We recommend clinicians utilize caution when considering supplementing patients on ECMO with exogenous AT3.

Antithrombin concentrates may benefit cardiopulmonary bypass patients with suspected heparin resistance: A retrospective analysis of real-world data

Background

Heparin resistance is a common complication of surgical patients requiring anticoagulation, such as those undergoing cardiopulmonary bypass (CPB). Treatments to address heparin resistance include supplementation of antithrombin (AT) or fresh frozen plasma (FFP). This retrospective database analysis compared key outcomes in suspected heparin-resistant patients undergoing CPB treated with AT or FFP.

Methods

De-identified United States electronic health records (Cerner Health Facts®) were queried. International Classification of Diseases (ICD-9/10) codes were used to determine CPB procedures and FFP administration. AT administration was identified using medication data, while a combination of lab and medication data examining activated clotting times detected heparin resistance in FFP patients. Adult inpatients (≥18 years old) seen between 2001 and 2018 were included. Differences in mortality, intensive care unit (ICU) length of stay (LOS), and hospital-free days (using a 30-day post-discharge period) were assessed with univariate models as well as adjusted logistic regression models controlling for patient characteristics and Charlson Comorbidity Index (CCI) scores.

Results

Of the 502 patients identified, 247 received AT and 255 received FFP. The FFP cohort was associated with a higher CCI compared to the AT cohort (3.3 ± 2.4 vs. 2.3 ± 2.0, P < .001). The AT cohort was associated with a 71% (Odds Ratio [OR]: 0.29, 95% Confidence Interval [CI]: P = .003) and 66% (OR: 0.34, 95% CI: P = .01) reduction in mortality when compared to FFP using univariate and adjusted logistic regression models, respectively. Similarly, use of AT also showed a 22% shorter ICU LOS (P = .02) and 10% more hospital-free days in the 30 days following discharge (P = .004) according to the univariate models, though statistical significance was absent within adjusted models in both ICU LOS (P = .08) and hospital-free days (P = .53).

Conclusions

Compared to FFP, AT use suggests a reduction in the odds of mortality in suspected heparin-resistant patients undergoing CPB, though larger prospective studies are necessary to elucidate potential differences in hospital-free days or ICU LOS across treatment modalities.

Analysis of Wholesale Drug Acquisition and Laboratory Assessment Costs Between Heparin Compared With Bivalirudin-Based Systemic Anticoagulation Strategies in Adult Extracorporeal Membrane Oxygenation

OBJECTIVES

To assess the wholistic costs of systemic anticoagulation delivery in heparin versus bivalirudin-based maintenance of adult patients supported on extracorporeal membrane oxygenation (ECMO).

DESIGN

Single-center retrospective cohort study.

SETTING

Large academic ECMO center.

PATIENTS

Adults on ECMO receiving heparin or bivalirudin for primary maintenance systemic anticoagulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Electronic data were abstracted from a database maintained by our ECMO center, which transitioned to a preferred bivalirudin-based anticoagulation management in 2017. The pretransition group consisted of 126 patients (123 heparin and three bivalirudin), whereas the posttransition group included 275 patients (82 heparin and 193 bivalirudin). Drug costs were estimated using the wholesale acquisition cost, and laboratory assays costs were estimated using reimbursement fee schedules. Cost data were normalized to the duration of the ECMO run and reported in U.S. Dollar per ECMO day. Following the practice change, bivalirudin patients were less likely to receive AT supplementation (31.0 vs 12.4%; p < 0.0001) and had fewer coagulation assays ordered (6.1 vs 5.4 per ECMO day; p = 0.0004). After the transition, there was a dramatic decrease in costs related to AT assay assessments ($11.78 [interquartile range {IQR}, $9.48-$13.09] vs $1.03 [IQR, $0-$5.75]; p < 0.0001) and AT supplementation ($0 [IQR, $0-$312.82] vs $0 [IQR, $0-$0]; p < 0.0001) per ECMO day. Unadjusted survival at 28 days was higher posttransition (64.3 vs 74.9%; p = 0.0286).

CONCLUSIONS

Antithrombin assays and supplementation compromise a significant proportion of heparin-based anticoagulation costs in ECMO patients and is substantially reduced when a bivalirudin-based anticoagulation strategy is deployed. A favorable association exists between the aggregate cost of administration of bivalirudin compared with heparin-based systemic anticoagulation in adults supported on ECMO driven by reductions in antithrombin activity assessments and the cost of antithrombin replacement.

Evaluation of acquired antithrombin deficiency in paediatric patients supported on extracorporeal membrane oxygenation

AIMS

There remains a paucity of literature regarding best practice for antithrombin (AT) monitoring, dosing and dose-response in paediatric extracorporeal membrane oxygenation (ECMO) patients.

METHODS

We conducted a retrospective cohort study at a quaternary care paediatric intensive care unit in all patients <18 years of age supported on ECMO from 1 June 2011 to 30 April 2020. Adverse events and outcomes were characterized for all ECMO runs. AT activity and replacement were characterized and compared between two clinical protocols. AT activities measured post- vs. pre-AT replacement were compared in order to characterize a dose-response relationship.

RESULTS

The final cohort included 191 patients with 201 ECMO runs and 2028 AT activity measurements. The median AT activity was 65% (interquartile range [IQR], 51-82) and 879 (43.3%) measurements met the criteria of deficient. The overall median AT dose and increase in AT activity were 50.6 units/kg/dose (IQR, 39.5-67.2) and 23.5% (IQR, 9.8-36.0), respectively. In the protocol that restricted AT activity measurements to clinical scenarios concerning for heparin resistance, there was significantly higher dosing in conjunction with significantly fewer overall administrations. Approximately one third of AT activity remained deficient after repletion. There was no difference in mechanical complications, reasons for discontinuation of ECMO support, time on ECMO or survival between protocols.

CONCLUSIONS

There was a high prevalence of AT deficiency in paediatric ECMO patients. An AT replacement protocol based on evaluating heparin resistance is associated with fewer AT administrations, with similar circuit and patient outcomes. Further data are needed to identify optimal dosing strategies.

Antithrombin Therapy: Current State and Future Outlook

Antithrombin (AT) is a natural anticoagulant pivotal in inactivating serine protease enzymes in the coagulation cascade, making it a potent inhibitor of blood clot formation. AT also possesses anti-inflammatory properties by influencing anticoagulation and directly interacting with endothelial cells. Hereditary AT deficiency is one of the most severe inherited thrombophilias, with up to 85% lifetime risk of venous thromboembolism. Acquired AT deficiency arises during heparin therapy or states of hypercoagulability like sepsis and premature infancy. Optimization of AT levels in individuals with AT deficiency is an important treatment consideration, particularly during high-risk situations such as surgery, trauma, pregnancy, and postpartum. Here, we integrate the existing evidence surrounding the approved uses of AT therapy, as well as potential additional patient populations where AT therapy has been considered by the medical community, including any available consensus statements and guidelines. We also describe current knowledge regarding cost-effectiveness of AT concentrate in different contexts. Future work should seek to identify specific patient populations for whom targeted AT therapy is likely to provide the strongest clinical benefit.

How we manage blood product support and coagulation in the adult patient requiring extracorporeal membrane oxygenation

Use of extracorporeal membrane oxygenation (ECMO) is increasing among critically ill adults with cardiac and/or respiratory failure. Use of ECMO is associated with hemostatic alterations requiring use of anticoagulation and blood product support. There are limited guidelines to direct transfusion management in the adult patient supported with ECMO. The objective of this article is to describe (1) the role of the transfusion service in providing transfusion support and current understanding of transfusion thresholds, (2) the complexities of monitoring anticoagulation, and (3) the consideration regarding additional factor concentrates and antifibrinolytics within the context of ECMO support. The information provided should assist ECMO care teams in informing transfusion and anticoagulation practice while highlighting key areas for future research and collaboration.

Antithrombin III Contributes to the Protective Effects of Fresh Frozen Plasma Following Hemorrhagic Shock by Preventing Syndecan-1 Shedding and Endothelial Barrier Disruption

BACKGROUND

Endothelial dysfunction during hemorrhagic shock (HS) is associated with loss of cell-associated syndecan-1 (Sdc1) and hyperpermeability. Fresh frozen plasma (FFP) preserves Sdc1 and reduces permeability following HS, although the key mediators remain unknown. Antithrombin III (ATIII) is a plasma protein with potent anti-inflammatory and endothelial protective activity. We hypothesized that the protective effects of FFP on endothelial Sdc1 and permeability are mediated, in part, through ATIII.

METHODS

ATIII and Sdc1 were measured in severely injured patients upon admission (N = 125) and hospital day 3 (N = 90) for correlation analysis. In vitro effects of ATIII on human lung microvascular endothelial cells (HLMVECs) were determined by pretreating cells with vehicle, FFP, ATIII-deficient FFP, or purified ATIII followed by TNFα stimulation. Sdc1 expression was measured by immunostaining and permeability by electrical impedance. To determine the role of ATIII in vivo, male mice were subjected to a fixed pressure exsanguination model of HS, followed by resuscitation with FFP, ATIII-deficient FFP, or ATIII-deficient FFP with ATIII repletion. Lung Sdc1 expression was assessed by immunostaining.

RESULTS

Pearson correlation analysis showed a significant negative correlation between plasma levels of Sdc1 and ATIII (R = -0.62; P < 0.0001) in injured patients on hospital day 3. Also, in vitro, FFP and ATIII prevented TNFα-induced permeability (P < 0.05 vs TNFα) in HLMVECs. ATIII-deficient FFP had no effect; however, ATIII restoration reestablished its protective effects in a dose-dependent manner. Similarly, FFP and ATIII prevented TNFα-induced Sdc1 shedding in HLMVECs; however, ATIII-deficient FFP did not. In mice, Sdc1 expression was increased following FFP resuscitation (1.7 ± 0.5, P < 0.01) vs. HS alone (1.0 ± 0.3); however, no improvement was seen following ATIII-deficient FFP treatment (1.3 ± 0.4, P = 0.3). ATIII restoration improved Sdc1 expression (1.5 ± 0.9, P < 0.05) similar to that of FFP resuscitation.

CONCLUSIONS

ATIII plays a role in FFP-mediated protection of endothelial Sdc1 expression and barrier function, making it a potential therapeutic target to mitigate HS-induced endothelial dysfunction. Further studies are needed to elucidate the mechanisms by which ATIII protects the endothelium.

Antithrombin Dosing Guidelines in Children Underestimate Dose Needed for Plasma Level Increase

OBJECTIVES

Antithrombin is a cofactor in the coagulation cascade with mild anticoagulant activity and facilitates the action of heparin as an anticoagulant. Antithrombin concentrate dosing guidelines vary but most commonly suggest that each unit of antithrombin concentrate per body weight increases the plasma antithrombin level by 1.5% to 2.2% (depending on manufacturer). We aimed to establish a dosing recommendation dependent on age and disease state.

DESIGN

A retrospective analysis of all antithrombin concentrate doses over a period of 5 years. We calculated the increase any respective antithrombin concentrate dose achieved, indexed by body weight, and performed a multivariable analysis to establish independent factors associated with the effectiveness of antithrombin concentrate.

SETTING

A PICU at a university-affiliated children's hospital.

PATIENTS

One hundred fifty-five patients treated in a PICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The effect of 562 doses of antithrombin concentrate on plasma antithrombin levels administered to 155 patients, of which 414 (73.7%) antithrombin concentrate doses administered during extracorporeal life support treatment, were analyzed. For all patients, each unit of antithrombin concentrate/kg increased plasma antithrombin level by 0.86% (SD 0.47%). Plasma antithrombin level increase was influenced by body weight (increase of 0.76% [interquartile range, 0.6-0.92%] for patients < 5 kg; 1.38% [interquartile range, 1.11-2.10%] for > 20 kg), disease state (liver failure having the poorest antithrombin increase) and whether patients were treated with extracorporeal circulatory support (less antithrombin increase on extracorporeal life support). Heparin dose at the time of administration did not influence with amount of change in antithrombin level.

CONCLUSIONS

Current antithrombin concentrate dosing guidelines overestimate the effect on plasma antithrombin level in critically ill children. Current recommendations result in under-dosing of antithrombin concentrate administration. Age, disease state, and extracorporeal life support should be taken into consideration when administering antithrombin concentrate.

Antithrombin use during pediatric cardiac extracorporeal membrane oxygenation admission: insights from a national database

INTRODUCTION

The frequency of extracorporeal membrane oxygenation in pediatric patients continues to increase, especially in patients with complex congenital heart disease. Providing adequate anticoagulation is necessary for patients on extracorporeal membrane oxygenation and is achieved with adequate heparin administration. Antithrombin is administered to potentiate heparin's effects. However, the efficacy of antithrombin supplementation is unclear and a clear clinical benefit has not been established. We present a large retrospective study examining the effects of antithrombin on pediatric patients receiving extracorporeal membrane oxygenation.

METHODS

Data for this study were obtained from the Pediatric Health Information System and Pediatric Health Information System+ databases from 2004 to 2015. Pediatric patients receiving extracorporeal membrane oxygenation with a congenital heart disease diagnosis were included and divided into groups that did or did not utilize antithrombin. For all admissions, the following were captured: age of admission, gender, year of admission, length of stay, billed charges, inpatient mortality, the presence of specific congenital malformations of the heart, specific cardiac surgeries, and comorbidities.

RESULTS

A total of 9,193 admissions were included and 865 (9.4%) utilized antithrombin. Between groups, there were significantly different frequencies of co-morbidities, cardiac lesion types and antithrombin usage over the study period. There were significantly lower odds in the antithrombin group of venous thrombosis. Antithrombin was not significantly associated with hemorrhage; however, antithrombin was associated with increased inpatient mortality and a decrease in length of stay and billed charges.

CONCLUSION

Antithrombin administration is associated with increased mortality, a shorter length of stay, and decreased billing cost. Recently, antithrombin usage has been decreasing-potentially due to the reported lack of clinical benefit. Together, these results reinforce that antithrombin may not be indicated for all pediatric extracorporeal membrane oxygenation patients.

Bivalirudin Dosing Requirements in Adult Patients on Extracorporeal Life Support With or Without Continuous Renal Replacement Therapy

Systemic anticoagulation with unfractionated heparin is standard of care for patients receiving extracorporeal life support (ECLS); however, an alternative anticoagulant may be necessary when challenges with heparin therapy arise. Evidence for alternative anticoagulation in ECLS patients is limited. This retrospective analysis evaluated the dosing and outcomes associated with bivalirudin use in 14 adult ECLS patients. Indications for bivalirudin included heparin-induced thrombocytopenia, heparin resistance, or persistent clotting or bleeding while on heparin. The median initial bivalirudin dose to achieve target activated partial thromboplastin time was 0.15 mg/kg/h (range 0.04-0.26 mg/kg/h). Dosing requirements increased by 75-125% when renal replacement was included. Median time on bivalirudin was 5.2 days (range 0.9-28 days). Five patients (36%) required a circuit change while on bivalirudin because of clotting or failing oxygenation, and four (28.6%) had bleeding significant enough to require either reduction in activated partial thromboplastin time goals or temporary holding of anticoagulation. Bivalirudin appears to be a potential option for adult patients on ECLS who are unable to receive or fail heparin therapy; however, the wide variation in dosing suggests the need for careful management.

Antithrombin During Extracorporeal Membrane Oxygenation in Adults: National Survey and Retrospective Analysis

The impact of antithrombin replacement during extracorporeal membrane oxygenation (ECMO) in adults remains unclear. This work comprises a survey, showing that antithrombin is routinely supplemented in many Italian ECMO-Centers, and a retrospective analysis on 66 adults treated with veno-venous ECMO and unfractionated heparin at our Institution. Twenty-four to 72 h after the beginning of ECMO, antithrombin activity was ≤70% in 47/66 subjects and activated partial thromboplastin time (aPTT) ratio was <1.5 in 20/66 subjects. Activated partial thromboplastin time ratio <1.5 was associated not with lower antithrombin activity (61 ± 17 vs. 63 ± 22%; p = 0.983) but with higher circulating level of C-reactive protein (23 ± 8 vs. 11 ± 9 mg/dl; p < 0.001). In 34 subjects who received antithrombin concentrate, antithrombin activity increased (from 54 ± 9 to 84 ± 13%; p < 0.001); the proportion of subjects with aPTT ratio ≥1.5 increased (from 21/34 [62%] to 31/34 [91%]; p = 0.004); heparin dosage remained constant (from 19 ± 7 to 19 ± 6 IU/kg/h; p = 0.543); and C-reactive protein decreased (from 17 ± 10 to 13 ± 9 mg/dl; p = 0.013). Among those with aPTT ratio <1.5, aPTT ratio remained <1.5 in 3 out of 13 subjects. Antithrombin is frequently supplemented during veno-venous ECMO although low antithrombin activity does not constantly impede, and antithrombin replacement does not constantly ensure, reaching the target aPTT ratio. Inflammation possibly affects the individual response to heparin.

The effect of antithrombin added to recombinant human-soluble thrombomodulin for severe community-acquired pneumonia-associated disseminated intravascular coagulation: a retrospective cohort study using a nationwide inpatient database

Background

Studies showed potential benefits of recombinant human-soluble thrombomodulin (rhTM) and antithrombin for treating sepsis associated disseminated intravascular coagulation. However, benefits of their combination have been inconclusive.

Methods

Using a nationwide inpatient database in Japan, we performed propensity-score matched analyses to compare outcomes between rhTM combined with antithrombin and rhTM alone for severe community-acquired pneumonia associated disseminated intravascular coagulation from July 2010 to March 2015. The outcomes included in-hospital mortality and requirement of red cell transfusion.

Results

Propensity score matching created 189 pairs of patients who received rhTM combined with antithrombin or rhTM alone within 2 days of admission. There was no significant difference between the two groups for in-hospital mortality (40.2% vs. 45.5%). Patients treated with rhTM and antithrombin were more likely to require red cell transfusion than those treated with rhTM alone (37.0% vs. 25.9%).

Conclusions

Compared with rhTM alone, combination of rhTM with antithrombin for severe community-acquired pneumonia-associated disseminated intravascular coagulation may be ineffective for reducing mortality and may increase bleeding.

The Development and Impact of Hemostatic Stewardship Programs

The approval of several new clotting factor concentrates and anticoagulation antidotes has resulted in increased complexity and cost of care. A multidisciplinary hemostatic stewardship program is essential to optimize utilization of these resources. This article summarizes the authors' approach to the stewardship of clotting factor concentrates and anticoagulation antidotes.

Antithrombin supplementation in adult patients receiving extracorporeal membrane oxygenation

INTRODUCTION

Extracorporeal membrane oxygenation is associated with an increased risk of thrombosis and hemorrhage. Acquired antithrombin deficiency often occurs in patients receiving extracorporeal membrane oxygenation, necessitating supplementation to restore adequate anticoagulation. Criteria for antithrombin supplementation in adult extracorporeal membrane oxygenation patients are not well defined.

METHODS

In this retrospective observational study, adult patients receiving antithrombin supplementation while supported on extracorporeal membrane oxygenation were evaluated. Antithrombin was supplemented when anti-Xa levels were subtherapeutic with unfractionated heparin infusion rates of 15-20 units/kg/h and measured antithrombin activity <50%. Patients were evaluated for changes in degree of anticoagulation and signs of bleeding 24 hours pre- and post-antithrombin supplementation.

RESULTS

A total of 14 patients received antithrombin supplementation while on extracorporeal membrane oxygenation. The median percentage of time therapeutic anti-Xa levels were maintained was 0% (0-43%) and 40% (9-84%) in the pre-antithrombin and post-antithrombin groups, respectively (p = 0.13). No difference was observed in the number of patients attaining a single therapeutic anti-Xa level (pre-antithrombin = 6, post-antithrombin = 13; p = 0.37) or unfractionated heparin infusion rate (pre-antithrombin = 7.35 (1.95-10.71) units/kg/h, post-antithrombin = 6.81 (3.45-12.58) units/kg/h; p = 0.33). Thirteen patients (92%) achieved an antithrombin activity at goal following supplementation. Antithrombin activity was maintained within goal range 52% of the time during the replacement period. Four bleeding events occurred pre-antithrombin and 10 events post-antithrombin administration (p = 0.26) with significantly more platelets administered post-antithrombin (pre-antithrombin = 0.5 units, post-antithrombin = 4.5 units; p = 0.01).

CONCLUSION

Therapeutic anticoagulation occurred more frequently following antithrombin supplementation; however, this difference was not statistically significant. More bleeding events occurred following antithrombin supplementation while observing an increase in platelet transfusions.