fibrinopeptide-a and Acute-Kidney-Injury

Hematocrit plays a major role in primary hemostasis by influencing blood viscosity and platelet adhesion. During continuous venovenous hemofiltration (CVVH), it is suspected that an increased hematocrit is accompanied by an activation of hemostasis and frequently leads to thromboses in the extracorporeal system. In order to examine this hypothesis, we studied the influence of hematocrit on hemostasis during CVVH.. Fourteen patients (8 men and 6 women, mean age 65+/-10 years) with acute renal failure undergoing CVVH were prospectively enrolled. Polysulfone hemofilters (AV 600; Fresenius, Oberursel, Germany) were used in all of the patients; blood flow rates were adjusted to 120 ml/min. No blood products and coagulation-related medication, except unfractionated heparin, were applied. Study exclusion criteria included a history of thromboembolism and artificial heart valves. Hemostasis activation markers (fibrinopeptide A, thrombin-antithrombin III complex, beta-thromboglobulin, platelet retention) and hematocrit values were determined before and at three-day intervals during the course of CVVH treatment.. The mean hematocrit value (mean +/- SEM) was 29+/-1% (range, 22 to 35%). Patients with hematocrit values of less than 30% (N = 7) were compared with patients with higher hematocrit values (>30%, N = 7). The patients with a lower hematocrit (<30%) showed a stronger activation of hemostasis during CVVH when compared with those with a higher hematocrit (>30%), as indicated by a tendency toward higher values for fibrinopeptide A (25+/-8 vs. 14+/-5 ng/ml, P = 0.35), thrombin-antithrombin III complex (15+/-4 vs. 10+/-2 ng/ml, P = 0.66), and a higher beta-thromboglobulin/creatinine ratio (0.62+/-0.17 vs. 0.48+/-0.12, P = 0.8).. Contrary to our hypothesis, hematocrit values of more than 30% are not accompanied by an increased hemostasis activation during CVVH. Concerning hemostasis activation, hematocrit values between 30 and 35% may be suitable for patients on CVVH.

Topics: Acute Kidney Injury; Aged; Antithrombin III; Female; Fibrinopeptide A; Hematocrit; Hemofiltration; Hemoglobins; Hemostasis; Humans; Male; Middle Aged; Peptide Hydrolases; Prospective Studies

Fibrinopeptide A and thrombin-antithrombin III complex were used respectively as markers for in vivo thrombin formation and beta-thromboglobulin as a marker for platelet activation. In cases of acute renal failure (ARF) a heightened plasma concentration in the hemostasis activation markers may occur, because of a renal elimination disturbance, without a previous activation of the hemostasis. In order to check the validity of fibrinopeptide A, thrombin-antithrombin III complex and beta-thromboglobulin as markers for the hemostasis activation in cases of ARF we examined 32 patients prior to renal replacement therapy. A significant rise in fibrinopeptide A (x +/- SD: 34 +/- 22 ng/mL, ref < 3.0), thrombin-antithrombin III complex (19 +/- 15 ng/mL, ref 1.0-4.0) and beta-thromboglobulin (149 +/- 58 U/mL, ref 10-40) was found. None of the parameters examined showed a correlation to the serum creatinine. A correlation was observed respectively between fibrinopeptide A (r = 0.34, p < .05), beta-thromboglobulin (r = 0.39, p < .05) and the beta-thromboglobulin/creatinine coefficient (0.50 +/- 0.30, r = 0.72, p < .001) on the one side and the thrombin-antithrombin III complex on the other. A greater rise in the concentration of all parameters in patients with disseminated intravascular coagulation (DIC) was established, in contrast to patients without DIC (fibrinopeptide A: 44 +/- 31 vs. 32 +/- 20 ng/mL, beta-thromboglobulin: 169 +/- 57 vs. 144 +/- 60 U/mL, thrombin-antithrombin III complex 40 +/- 21 vs. 14 +/- 7 ng/mL, p < .05). Fibrinopeptide A and beta-thromboglobulin/creatinine coefficient in combination with the thrombin-antithrombin III complex can be employed as markers for the activation of hemostasis in cases of ARF there is no direct relationship between restricted kidney function in ARF and the plasma concentration of these markers, which behave similarly in spite of their varying elimination patterns.

Topics: Acute Kidney Injury; Antithrombin III; beta-Thromboglobulin; Case-Control Studies; Creatinine; Disseminated Intravascular Coagulation; Female; Fibrinopeptide A; Hemofiltration; Hemostasis; Humans; Kidney; Male; Middle Aged; Peptide Hydrolases; Renal Dialysis

A preparation of low molecular weight heparin (Fragmin) was administered to patients with multiorgan failure receiving continuous venovenous hemodialysis. Three patients received a high-dose regimen (35 IU/kg bolus followed by 13 IU/kg infusion), and 7 received a low-dose regimen (8 and 5 IU/kg, respectively) for 36 h. High-dose Fragmin was associated with minimal clotting in the extracorporeal circuit. Plasma fibrinopeptide A levels declined, and mean anti-Xa activity was in the range 0.47-0.79 IU/ml. The urea equilibration coefficient (UEC) (100% at initiation) remained above 90% throughout. All 3 patients had mild bleeding episodes, which led to discontinuation of Fragmin in 1. During all low-dose treatments, marked thrombus formation occurred in the extracorporeal circuit, and in 2, the circuit clotted within the study period. Fibrinopeptide A levels further increased in 4 patients, and mean anti-Xa activity was in the range 0.27-0.53 IU/ml. UEC declined appreciably in 3 treatments (including the 2 in which early circuit clotting occurred). One patient experienced a mild bleeding episode. The low-dose Fragmin regimen produced safer anticoagulation in patients at risk from bleeding and is suitable for prolonged renal support although the tendency to thrombosis may necessitate more frequent circuit changes.

Topics: Acute Kidney Injury; Adult; Aged; Blood Coagulation; Critical Care; Dalteparin; Female; Fibrinopeptide A; Hemorrhage; Humans; Male; Middle Aged; Renal Dialysis; Thrombosis