Fenoldopam Infusion for Renal Protection in High-Risk Cardiac Surgery Patients: A Randomized Clinical Study
ABSTRACT The purpose of this study was to evaluate the renoprotective effects of fenoldopam in patients at high risk of postoperative acute kidney injury undergoing elective cardiac surgery requiring cardiopulmonary bypass.
A double-blind randomized clinical trial. Setting: Hospital. Participants: One hundred ninety-three patients. Interventions: Patients undergoing cardiac surgery were randomly assigned to receive a continuous infusion of fenoldopam, 0.1 microg/kg/min (95 patients), or placebo (98 patients) for 24 hours. Patients were included if at least 1 of the following risk factors was present: preoperative serum creatinine > or =1.5 mg/dL, age >70 years, diabetes mellitus, or prior cardiac surgery. Serum creatinine and urinary output were measured at baseline (T1), 24 hours (T2), and 48 hours after surgery (T3). Acute kidney injury was defined as a postoperative serum creatinine level of > or =2 mg/dL with an increase in serum creatinine level of 0.7 mg/dL or greater from preoperative to maximum postoperative values.
Acute kidney injury developed in 12 of 95 (12.6%) patients receiving fenoldopam and in 27 of 98 (27.6%) patients receiving placebo (p = 0.02), whereas renal replacement therapy was started in 0 of 95 and 8 of 98 (8.2%) patients, respectively (p = 0.004). Serum creatinine was similar at baseline (1.8 +/- 0.4 mg/dL v 1.9 +/- 0.3 mg/dL) in the fenoldopam and placebo groups but differed significantly (p < 0.001 and p < 0.001) 24 hours (1.6 +/- 0.2 mg/dL v 2.5 +/- 0.6 mg/dL) and 48 hours (1.5 +/- 0.3 mg/dL v 2.8 +/- 0.4 mg/dL) after the operation.
A 24-hour infusion of 0.1 mug/kg/min of fenoldopam prevented acute kidney injury in a high-risk population undergoing cardiac surgery.
Conference Paper: Learning methods in space technology[Show abstract] [Hide abstract]
ABSTRACT: To begin, we must agree on what we mean by a learning system and a learning control system. A system is called learning if the information pertaining to the unknown features of a process or its environment is acquired by the system, and the obtained experience is used for future estimation, recognition, classification, decision or control such that the performance of the system will be improved. A learning system is called a learning control system if the acquired information is used to control a process with unknown features (these standardized definitions are taken from Reference 1). The attribute of "learning" that is associated with learning systems, derives from psychological learning theories, especially reinforcement learning theories.Decision and Control including the 13th Symposium on Adaptive Processes, 1974 IEEE Conference on; 01/1974
Conference Paper: On learning method in modelling and analysis of biocybernetic systems[Show abstract] [Hide abstract]
ABSTRACT: This paper reviews a learning process for the development of a model of a specific physiological control system. It provides an example of a nonlinear system structure, and elucidates processes of aggregating biological variables and of decomposing a system model at different time scales. A quasilinear approximate analysis of the model suggests an adaptive control mechanism which is yet to be explored.Decision and Control including the 13th Symposium on Adaptive Processes, 1974 IEEE Conference on; 01/1974