Anticoagulation therapy for renal insufficiency after burns

Early anticoagulation therapy for severe burns complicated by inhalation injury in a rabbit model

The aim of the present study was to determine the effects of early anticoagulation treatment on severe burns complicated by inhalation injury in a rabbit model. Under anesthetization, an electrical burns instrument (100°C) was used to scald the backs of rabbits for 15 sec, which established a 30% III severe burns model. Treatment of the rabbits with early anticoagulation effectively improved the severe burns complicated by inhalation injury-induced lung injury, reduced PaO₂, PaCO₂ and SPO₂ levels, suppressed the expression of tumor necrosis factor-α, interleukin (IL)-1β and IL-6, and increased the activity of IL-10. In addition, it was found that early anticoagulation treatment effectively suppressed the activities of caspase-3 and caspase-9, upregulated the protein expression of vascular endothelial growth factor (VEGF) and decreased the protein expression of protease-activated receptor 1 (PAR1) in the severe burns model. It was concluded that early anticoagulation treatment affected the severe burns complicated by inhalation injury in a rabbit model through the upregulation of VEGF and downregulation of PAR1 signaling pathways. Thus, early anticoagulation is a potential therapeutic option for severe burns complicated by inhalation injury.

A pilot study of antithrombin replacement in intensive care management: the effects on mortality, coagulation and renal function

A prospective, randomized, controlled trial to examine the effects of antithrombin supplementation on mortality, coagulation and renal function has been carried out on 132 intensive care patients. Antithrombin activity was measured in all patients on admission to the intensive care unit (ICU). Patients with an antithrombin activity of less than 70% were randomized to either receive antithrombin replacement or to act as controls. Antithrombin activity was maintained above 70% in the treated patients throughout their stay on ICU. Ninety-three patients had an antithrombin activity of less than 70% and 35 received replacement therapy. Patients with antithrombin activity below 70% remained on the ICU significantly longer and had a significantly higher mortality rate than patients with antithrombin activity above 70%. Antithrombin supplementation neither reduced mortality nor shortened the intensive care stay. Fifty patients with reduced antithrombin activity remained on the ICU for at least 4 days, 25 received antithrombin and 25 acted as controls; coagulation parameters and renal function have been monitored in these patients. Fibrinogen concentration and platelet count were unaffected by antithrombin replacement. Antithrombin supplementation did not appear to reduce the incidence of impaired renal function in sepsis, trauma and postoperative patients. The creatinine clearance fell below 20 ml/min in eight patients in the no-treatment arm while by comparison only three patients in the treatment arm developed impaired renal function. Our study does not demonstrate a clear role for the use of antithrombin supplementation in intensive care, however the finding that antithrombin reduced renal impairment is encouraging and a larger study to confirm this finding is at present underway.

Efficacy of antithrombin III supplementation in animal models of fulminant Escherichia coli endotoxemia or bacteremia

Plasma antithrombin III (ATIII) levels decrease early during gram-negative septicemia, and even a moderate decrease in this major inhibitor of the coagulation system is associated with serious disseminated intravascular coagulation (DIC). Herein the efficacy of high-dose (at least 250 units/kg) ATIII supplementation in animal models of Escherichia coli endotoxemia or bacteremia is reported. An endotoxemic rat model demonstrated that: (1) DIC occurs very early, before the appearance of deleterious cardiovascular abnormalities; (2) ATIII prophylaxis attenuates DIC, metabolic dysfunction, and organ damage; (3) ATIII prophylaxis increases permanent survival; (4) ATIII treatment one hour after endotoxin challenge attenuates DIC, metabolic dysfunction, and organ damage, although not as well as when given prophylactically, and survival is not increased. An endotoxemic sheep pulmonary dysfunction model demonstrated that: (1) ATIII prophylaxis prevents the typical decrease in arterial oxygen partial pressure; (2) ATIII prophylaxis combined with alpha-1-proteinase inhibitor significantly attenuates indices of pulmonary dysfunction. An E. coli bacteremic baboon model demonstrated that ATIII prophylaxis and treatment significantly attenuate indices of DIC and organ damage and prevent death in an otherwise completely lethal dose bacterial challenge. In conclusion, prophylactic treatment with high doses of ATIII may be efficacious in disease states of impending disseminated intravascular coagulation, such as primary or secondary gram-negative septicemia.

The effect of drugs which affect the arachidonate cascade in burned rabbits

A full skin thickness burn covering 35 per cent of the total body surface area was inflected on the back of rabbits. The animals were divided into seven groups and the effectiveness of OP-41483, aspirin (ASA), OKY-046 and CV-3988 was studied. All rabbits died between 8 and 24 h after injury in the no therapy group. Renal function tests in this group showed a decrease in Cler and an increase in FENa and CH2O. Such changes were improved slightly with infusion therapy. On the contrary, with OP-41483, OKY-046 and ASA, distinct improvements were observed (in order of extent of improvement), but with CV-3988 the improvements were rather small. As a result these drugs may also be effective in preventing organ failure after burn injury, but as such changes presumably occur immediately after the burn it is considered that a fast-acting agent such as OP-41483 is the most effective form of treatment.

The effect of a prostaglandin I2 analogue (OP-41483) on renal function in burned rabbits

It is known that the number of platelets decreases after burn injury. However, the mechanism of such a decrease and its influence on systemic organs have not been fully elucidated. In this study, we evaluated the efficacy of OP-41483 (a derivative of the prostaglandin I2 (PGI2) in burned rabbits with special reference to its association with renal function. Full thickness skin loss burns, covering 35 per cent of the total body surface area, were experimentally produced on the back of rabbits. Among the following groups of rabbits (six rabbits each), the time courses of renal function and platelet function were compared; Group I (no treatment), Group II (fluid therapy only), Group III (treated with OP-41483 + fluid therapy; IIIa: 50 ng/kg/min, IIIb: 75 ng/kg/min, IIIc: 100 ng/kg/min). The results show that in Group I, all rabbits died after 8 h. Renal function tests in this group showed a decrease in creatinine clearance and increases in FENa and CH2O. Such changes were improved in Groups IIIb, IIIa and II (in order of the degree of improvement). Group IIIc showed no improvement. As for the platelets the decrease in platelets was the smallest in Group IIIb, where platelets showed no decrease until 8 h after injury and the fibrinogen concentration increased. No improvement was found in Group IIIc by our tests, presumably owing to an overdose of OP-41483. The optimal dose of OP-41483 for improving the renal function of burned rabbits was 75 ng/kg/min in our study.