Disseminated intravascular coagulation with multiple arterial thromboses responding to antithrombin-III concentrate infusion

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.

Anti-thrombin III in the management of hematopoietic stem-cell transplantation-associated toxicity

OBJECTIVE

To describe the evidence assessing the use of anti-thrombin III (AT-III) in the management of toxicity associated with hematopoietic stem-cell transplantation (HSCT)-conditioning regimens.

DATA SOURCES

Clinical literature was accessed through conference proceedings, EMBASE, the Cochrane database, and MEDLINE (1966-December 2003).

STUDY SELECTION AND DATA EXTRACTION

Case reports, small case series, case-control and cohort studies, and randomized controlled trials of AT-III in HSCT were evaluated. Publications examining AT-III use in the non-HSCT setting were also explored. Key search terms included AT-III, transplantation, and veno-occlusive disease (VOD).

DATA SYNTHESIS

Severe VOD and ensuing multiple organ dysfunction is associated with high mortality in HSCT. A low AT-III level has been shown to correlate with the development of organ dysfunction. Phase II trials, case series, and one small, randomized, placebo-controlled study suggest a benefit when AT-III therapy is instituted early in the course of VOD/multiple organ dysfunction syndrome. In all of these reports, AT-III use was devoid of adverse events.

CONCLUSIONS

Although further studies are needed to ascertain the optimal target level, method, and duration of administration, AT-III is still a viable alternative for the treatment of severe VOD and ensuing multiple organ dysfunction.

The impact of antithrombin (H) concentrate infusions on pulmonary function in the acute phase of thermal injury

BACKGROUND

Pulmonary complications occur frequently after thermal injury.

OBJECTIVE

This open pilot study was performed as an initial assessment of the safety and efficacy of antithrombin H [AT(H)] concentrate in ameliorating the respiratory morbidity during the acute phase of injury.

MATERIALS & METHODS

Thirty-two patients were eligible for the study; of these, nine opted for treatment with q8 h [AT(H)]. The mean daily peak values of pulmonary parameters such as PaO(2)/FiO(2) ratio, and RAW scores were computed for days 1-8.

RESULTS

Control and AT(H)-treated patients were similar in age, % total burn surface area, inhalation injury, and mortality. Forty-three percent of the burn controls, and 23% of the AT(H)-treated patients had pneumonia, p<0.01. The median hospital stay for both groups was 42 days; however, the median number of ventilatory days for burn controls was 23 days vs 10 days for AT(H)-treated patients. The AT(H)-treated patients had admission AT plasma levels of 46+/-14% vs 49+/-18% in burn controls, (normal=100+/-20%). The AT plasma level was maintained at 120+/-24% in the AT(H)-treated patients vs 50+/-15% in the burn control group for the first four days following the acute injury, p<0.002. Thrombate(R) concentrate infusions were, in general, well tolerated by patients. The median dose was 97 u/kg/dose q8 h. Compared to burn controls, AT(H)-treated patients had higher PaO(2)/FiO(2) ratios between days 4-6, p<0.01. In comparing these two groups with and without inhalation, airway resistance (assessed by the RAW score) was significantly lower in the AT(H)-treated group with inhalation compared to the burn controls with inhalation on days 2 and 6, p<0.02.

CONCLUSIONS

With a trend toward decreased airway resistance during AT(H) concentrate infusions, and increased oxygenation, AT(H)-treated patients had significantly fewer episodes of pneumonia compared to controls. AT(H) concentrates may modify the impact of thrombin on acute inflammation, and improve respiratory function in the acute phase of thermal injury.

Pre-operative coagulopathy management of a neonate with complex congenital heart disease: a case study

Severe coagulation defects often develop in neonates undergoing cardiac surgery, both as a result of the surgical intervention, and as pre-existing defects in the hemostatic mechanisms. The following case report describes a newborn patient with complex congenital heart disease and respiratory failure whose pre-operative coagulopathy was aggressively managed prior to surgical correction. A 5-day-old, 2.5 kg child presented with interrupted aortic arch, ventricular septal defect, atrial septal defect, and patent ductus arteriosus. On admission, he was in respiratory arrest suffering from profound acidemia. In addition, the child was hypothermic (30.1 degrees C), septic (Streptococcus viridans), and coagulopathic (disseminated intravascular coagulation-DIC). The patient was immediately intubated and initial coagulation assessment revealed the following: prothrombin time (PT) 48.9 s (international normalized ratio (INR) 15.7), activated partial thromboplastin time (aPTT) >106 s, platelet count 30,000 mm(3), fibrinogen 15 mg dL(-1) and antithrombin III (AT-III) 10%. Before cardiac surgery could be performed, the patient's DIC was corrected with the administration of cryoprecipitate (15 ml), fresh frozen plasma (300 ml), and platelets (195 ml). In spite of the large transfusion of fresh frozen plasma, the AT-III activity, measured as a percentage, remained depressed at 33. Initial thromboelastographic (TEG) determination revealed an index of +2.02, and following 100 IU administration of an AT-III concentrate, declined to -2.32. Sequential TEG profiles were performed over several days, with the results used to guide both transfusion and medical therapy. The congenital heart defect correction was subsequently performed with satisfactory initial results, but the patient developed a fungal infection and expired on the 16th post-operative day. The present case describes techniques of coagulation management for a newborn with both a severe hemostatic defect and congenital heart disease.

Functional assay of plasma antithrombin using polyethylene glycol (PEG) defibrinated plasma

Polyethylene glycol(PEG) was used to precipitate fibrinogen to prepare defibrinated plasma in the two stage clotting assay of antithrombin activity. Five percent PEG-8000 precipitated fibrinogen from plasma without loss of antithrombin activity in the defibrinated plasma. Fibrin degradation products(FDP) as high as 640 ug/ml did not interfere the two stage clotting assay using PEG defibrinated plasma possibly because part of FDP was precipitated by PEG in the process of plasma defibrination. The two stage clotting assay was very sensitive to the changes of antithrombin activity in the range of 60%-100% of normal level. The assay was reproducible and correlated with chromogenic assay. The decrease of plasma antithrombin activity in a baboon septic shock model was demonstrated with this assay.

Disseminated Intravascular Coagulation: Pathogenesis and Management

Disseminated intravascular coagulation (DIC) is a clini-copathological syndrome secondary to an underlying disease. Characteristic laboratory abnormalities of DIC should suggest, much like the recognition of fever, anemia, or congestive heart failure, that an inciting disease process must be searched for. The clinical and laboratory consequences of DIC can be ascribed to the unregulated and unbalanced formation of thrombin, the main clot-forming enzyme, and plasmin, the main clot-lysing enzyme. If too much plasmin is formed in relation to thrombin, a hemorrhagic state, which appears in 60 to 75% of patients with deep vein thrombosis, will occur. Alternatively, if too much thrombin is formed in relation to the degree of secondary fibrinolysis, a thrombotic condition, which appears in 25 to 40% of patients with DIC, will become manifest. The diagnosis of DIC is dependent on the presence of an appropriate clinical situation with concurrent laboratory evidence of thrombin and plasmin formation. Thrombin formation, plasmin formation, or both, can be assessed by detection of fibrin monomer, fibrin/fibrinogen degradation products, and D-dimer or E fragment, respectively. Treatment of DIC should initially be addressed to treatment of the primary, underlying condition inciting the disorder. If treatment for DIC is specifically needed, blood product replacement is the first order of therapy. This replacement should be tailored to each patient's specific needs (i.e., platelets, fibrinogen, or plasma proteins). Heparin has a definite but limited use in conditions associated with acral cyanosis and dermal ischemia. Other specific therapies for DIC may be of use in individualized situations.