Assessment of haemostatic risk factors in patients with acute renal failure associated with severe systemic inflammatory response syndrome. Development of a prognostic index.

The prognosis of acute renal failure (ARF) in the Intensive Care Unit (ICU) is variable and depends mainly on the underlying disease. Consequently, the outcome prediction is difficult.

The majority of the prognostic measures used include clinical parameters and routine laboratory tests but not no study has considered the prognostic value of haemostatic disturbances. These disturbances play a key role in the evolution of multiple organ dysfunction syndrome (MODS) in patients with ARF, which occurs as part of systemic inflammatory response syndrome (SIRS).

The aim of the present study was to search for early significant predictive factors among a group of haemostatic parameters in these patients.

METHODS
Forty patients (age: 60.1 +/- 14.1 years) with ARF (requiring renal replacement therapy) associated with SIRS and haemodynamic instability (systolic blood pressure <90 mm Hg and/or vasopressor drugs) were included. The plasmatic levels of the following haemostatic factors were measured within the first 6 h of the SIRS evolution: von Willebrand Factor (vWF), thrombomodulin, plasminogen activity inhibitor type 1 (PAI-1 antigen), tissue type plasminogen activator (t-PA antigen), prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complexes (TAT) and D-dimer. Age, sex, medical or surgical disease, septic status or not, type of ARF (prerenal or acute tubular necrosis, oliguric or nonoliguric), and requirement for inotropics and mechanical ventilation were also considered. Univariate and multivariate logistic regressions were used to identify the risk factors for death and to develop a possible mortality prediction model on this basis.

RESULTS
By univariate analysis, high levels of PAI-1 antigen (>or=60 ng/ml) and F1 + 2 (>2.5 nmol/l) at early phases of ARF-severe SIRS were found to be independent risk factors for death (odds ratio (OR) = 6.37, p = 0.0181 and OR = 5.49, p = 0.0238, respectively). Age over 61 years and requirement of mechanical ventilation were independent death risk factors (OR = 4.33, p = 0.0251 and OR = 2.4, p = 0.0078, respectively). A possible mortality prediction model was obtained including the age and the PAI-1 antigen and F1 + 2 variables.

CONCLUSION
In patients with ARF associated with severe SIRS, the independent risk factors from the early phases of the process are not only the known variables such as advanced age, but also high levels of PAI-1 antigen and F1 + 2. In the future, the individual probability of death could be calculated by a prediction model which includes these variables.

CITA DEL ARTÍCULO  Nephron. 2002 Sep;92(1):97-104