RESUMO
Assessment of vascular size and of its phasic changes by ultrasound is important for the management of many clinical conditions. For example, a dilated and stiff inferior vena cava reflects increased intravascular volume and identifies patients with heart failure at greater risk of an early death. However, lack of standardization and sub-optimal intra- and inter- operator reproducibility limit the use of these techniques. To overcome these limitations, we developed two image-processing algorithms that quantify phasic vascular deformation by tracking wall movements, either in long or in short axis. Prospective studies will verify the clinical applicability and utility of these methods in different settings, vessels and medical conditions.
RESUMO
BACKGROUND: Acute renal failure requiring replacement therapy occurs in 1% to 2% of patients who have undergone cardiac surgery with cardiopulmonary bypass and is associated with a very high mortality rate. The aim of this study was to determine if prophylactic treatment with fenoldopam mesylate of patients at high risk of postoperative acute renal failure reduced the incidence of this event. METHODS: This was a multicenter, prospective, cohort study in which 108 patients at high risk of postoperative acute renal failure and undergoing cardiac surgery with cardiopulmonary bypass were treated with fenoldopam mesylate (0.08 microg x kg(-1) x min(-1)) starting at the induction of anesthesia and throughout at least the next 24 hours. A homogeneous control group of 108 patients was created using a propensity-score analysis. RESULTS: Fenoldopam prophylaxis was significantly associated with a reduction in acute renal failure incidence (from 22% to 11%, p = 0.028), a less pronounced creatinine clearance decrease (p = 0.05), and a lower mortality rate (6.5% versus 15.7%, p = 0.03) by the univariate analysis, but these results were not confirmed by a multivariable analysis. Within the subgroup of patients who suffered a postoperative low output syndrome, fenoldopam prophylaxis was an independent protective factor for postoperative renal failure (odds ratio, 0.14; 95% confidence interval, 0.03 to 0.7; p = 0.017). CONCLUSIONS: Given the limitations of a nonrandomized prospective trial, our results support the hypothesis that fenoldopam may reduce the risk of acute renal failure in patients in whom endogenous and exogenous cathecolamines action may induce a renal vascular constrictive condition.