Antithrombin attenuates myocardial dysfunction and reverses systemic fluid accumulation following burn and smoke inhalation injury: a randomized, controlled, experimental study. Crit Care. 2013;17:R86. [PMID: 23663695 PMCID: PMC3706920 DOI: 10.1186/cc12712]

Prognostic Value of Antithrombin Activity Levels in the Early Phase of Intensive Care: A 2-Center Retrospective Cohort Study

To investigate the relationship between antithrombin (AT) activity level and prognosis in patients requiring intensive care. Patients whose AT activity was measured within 24 h of intensive care unit (ICU) admission were enrolled for analysis. The primary endpoint was mortality at discharge. Prognostic accuracy was examined using receiver operating characteristic (ROC) curves and cox hazard regression analysis. Patients were divided into 6 groups based on predicted mortality, and a χ2 independence test was performed on the prognostic value of AT activity for each predicted mortality; P < .05 was considered significant. A total of 281 cases were analyzed. AT activity was associated with mortality at discharge (AT% [interquartile range, IQR]): survivor group, 69 (56-86) versus nonsurvivor group, 56 (44-73), P = .0003). We found an increasing risk for mortality in both the lowest level of AT activity (<50%; hazard ratio [HR] 2.43, 95% confidence interval [CI] 1.20-4.89, P = .01) and the middle-low level of AT activity (≥ 50% and < 70%; HR 2.06, 95% CI 1.06-4.02, P = .03), compared with the normal AT activity level (≥ 70%). ROC curve analysis showed that the prediction accuracy of AT was an area under the curve (AUC) of 0.66 (cutoff 58%, sensitivity 61.4%, specificity 68.2%, P = .0003). AT activity was significantly prognostic in the group with 20% to 50% predicted mortality (AUC 0.74, sensitivity: 24.0%-55.5%, specificity: 83.3%-93.0%). An early decrease in AT activity level in ICU patients may be a predictor of mortality at discharge.

Diagnostic Value of Neutrophil CD64 in Burn Patients With Infection in Chinese Population: A Systematic Review and Meta-analysis

Infection is one of the leading causes of death in burn patients. Many researchers regard neutrophil CD64 (nCD64) as a biomarker in the early diagnosis of burn patients with infection. Nevertheless, the conclusions are controversial. A comprehensive analysis of the diagnostic value of nCD64 for burn infection was performed in China using a meta-analysis method. Pubmed, Cochrane Library, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), and China Wanfang databases were searched for studies on nCD64 as a diagnostic biomarker of burn patients with infection from the establishment of the databases to September 29, 2020. The data were analyzed by Stata 15.0 software. Six studies were identified. The results showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.92 (95% confidence interval [CI]: 0.88~0.95), 0.82 (95% CI: 0.76~0.87), 5.10 (95% CI: 3.90~6.80), 0.10 (95% CI: 0.06~0.15), and 52 (95% CI: 29~94), respectively. The area under the curve was 0.94 (95% CI: 0.92~0.94). According to the analysis of the sepsis subgroup, it showed that nCD64 had good diagnostic value in the patients with burn sepsis in Chinese population. Neutrophil CD64 is highly efficient to diagnose burn infection in Chinese population. Therefore, nCD64 could be regarded as a valuable biomarker for the early diagnosis of burn infection in China, especially in patients with burn sepsis. Combined with other diagnostic indexes, nCD64 can be clinically used in the early diagnosis of burn infection to improve the sensitivity and specificity.

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.

Single Low Dose of Human Recombinant Antithrombin (ATryn) has no Impact on Endotoxin-Induced Disseminated Intravascular Coagulation: An Experimental Randomized Open Label Controlled Study

BACKGROUND

Antithrombin (AT) III physiological levels are decreased during septic shock and supplementation therapy could therefore be beneficial.

OBJECTIVE

We hypothesized that the use of recombinant human AT could reduce disseminated intravascular coagulation (DIC) occurrence.

METHODS

We conducted a randomized open label controlled experimental study. Ten female "Large White" pigs were challenged with i.v. infusion of Escherichia coli endotoxin. Two groups of 5 pigs were randomly assigned to receive either recombinant human AT 100 U/kg over 30 min (ATryn group) or 0.9% saline (control group). AT III levels, coagulation, hemostasis, inflammation parameters, hemodynamics, and microcirculatory parameters were measured over a 5-h period. Immediately after euthanasia, kidneys were withdrawn for histology evaluation. Statistical analysis was performed with nonparametric tests and Dunn's test for multiple comparisons.

RESULTS

AT III activity was significantly higher in the ATryn group than in the control group from 60% (213% [203-223] vs. 104% [98-115], P = 0.008, respectively) to 300 min (115% [95-124] vs. 79% [67-93], P = 0.03). Recombinant human AT supplementation had no impact on hemodynamics, microcirculatory parameters, and sequential changes of coagulation parameters (platelet count, fibrinogen level, thrombin-AT complexes, and von Willebrand factor). Interleukin 6 and tumor necrosis factor α values were statistically the same for both groups throughout the study. Percentage of thrombosed glomeruli and percentage of thrombosed capillary in glomerulus were not significantly different between both groups.

CONCLUSIONS

In our model of endotoxic shock, a single low dose of recombinant human AT did not prevent DIC occurrence, severity, inflammatory profile, or hemodynamic alterations.

Antithrombin use and 28-day in-hospital mortality among severe-burn patients: an observational nationwide study

BACKGROUND

Previous studies have suggested that antithrombin may be beneficial for treating coagulopathy in patients with severe burns. However, robust evidence for this idea is lacking. We examined the hypothesis that antithrombin may be effective in treating patients with severe burns.

METHODS

We performed propensity score-matched analyses of the nationwide administrative Japanese Diagnosis Procedure Combination inpatient database. We identified patients with severe burns (burn index ≥ 10) who were recorded in the database from 1 July 2010 to 31 March 2013. We compared patients who were administered antithrombin within 2 days of admission (antithrombin group) and those who were not administered antithrombin (control group). The main outcomes were 28-day mortality and ventilator-free days (VFDs).

RESULTS

Eligible patients (n = 3223) from 618 hospitals were categorized into either an antithrombin group (n = 152) or control group (n = 3071). Propensity score matching created a matched cohort of 103 pairs with and without antithrombin. Twenty-eight-day mortality was lower in the antithrombin group compared with the control group in propensity-matched analysis (control vs. antithrombin, 47.6 vs. 33.0%; difference, 14.6%; 95% confidence interval [CI] 1.2-28.0). Cox regression analysis showed a significant difference in 28-day in-hospital mortality between the control and antithrombin propensity-matched groups (hazard ratio 0.58; 95% CI 0.37-0.90). There were significantly more VFDs in the antithrombin compared with the control group in propensity score-matched analysis (control vs. antithrombin, 12.6 vs. 16.4 days; difference -3.7; 95% CI -7.2 to -0.12).

CONCLUSIONS

This nationwide database study demonstrated that antithrombin use may improve 28-day survival and increase VFDs in patients with severe burns. Further prospective studies are required to confirm these results.

Antithrombin in the treatment of burn trauma

Antithrombin (AT) is a natural anticoagulant with anti-inflammatory properties that has demonstrated value in sepsis, disseminated intravascular coagulation and in burn and inhalation injury. With high doses, AT may decrease blood loss during eschar excision, reducing blood transfusion requirements. There are no human randomized, placebo-controlled studies, which have tested the true benefit of this agent in these conditions. Two main forms of AT are either plasma-derived AT (phAT) and recombinant AT (rhAT). Major ovine studies in burn and smoke inhalation injury have utilized rhAT. There have been no studies which have either translated the basic rhAT research in burn trauma, or determined the tolerance and pharmacokinetics of rhAT concentrate infusions in burn patients. Advantages of rhAT infusions are no risk of blood borne diseases and lower cost. However, the majority of human burn patient studies have been conducted utilizing phAT. Recent Japanese clinical trials have started using phAT in abdominal sepsis successfully. This review examines the properties of both phAT and rhAT, and analyzes studies in which they have been utilized. We believe that it is time to embark on a randomized placebo-controlled multi-center trial to establish the role of AT in both civilian and military patients with burn trauma.

Diagnosis and management of inhalation injury: an updated review

In this article we review recent advances made in the pathophysiology, diagnosis, and treatment of inhalation injury. Historically, the diagnosis of inhalation injury has relied on nonspecific clinical exam findings and bronchoscopic evidence. The development of a grading system and the use of modalities such as chest computed tomography may allow for a more nuanced evaluation of inhalation injury and enhanced ability to prognosticate. Supportive respiratory care remains essential in managing inhalation injury. Adjuncts still lacking definitive evidence of efficacy include bronchodilators, mucolytic agents, inhaled anticoagulants, nonconventional ventilator modes, prone positioning, and extracorporeal membrane oxygenation. Recent research focusing on molecular mechanisms involved in inhalation injury has increased the number of potential therapies.

Clinical syndromes associated with acquired antithrombin deficiency via microvascular leakage and the related risk of thrombosis

Antithrombin (AT) is a 65kDa glycoprotein belonging to a group of inhibitory factors known as serpins (serine protease inhibitors). It plays a critical role in the inhibition of coagulation and inflammation processes within the environment of the vascular endothelium. Inadequate levels of functional AT in plasma results in an increased risk of thrombotic events, both venous and arterial. AT deficiency can be inherited or acquired. Congenital AT deficiency is the most severe inherited thrombophilic condition with an odds ratio of 20 for the increased risk of venous thrombosis. Acquired AT deficiency occurs in a variety of physiologic and pathologic medical conditions with similar risks of increased thrombosis. In this article, we review clinical settings characterized by an acquired AT deficiency largely or partly subsequent to protein microvascular leakage. Other different mechanisms of AT depletion are implied in some clinical conditions together with endothelial loss, and, therefore, outlined. In addition, we provide a description of the current knowledge on the specific mechanisms underlying endothelial AT leakage and on the consequences of this protein decrease, specifically looking at thrombosis. We identify potential directions of research that might prove useful in patients with acquired AT deficiency.