An Intraoperative Fluid Therapy Fuzzy Logic Control System for Renal Transplantation

The number of kidney transplants has increased sharply in recent years mainly due to addition of pathologic cases, (e.g. patient with type diabetes II, advanced cardiomyopathy, various forms of vasculitis, sickle cell disease and morbid obesity) which were considered as high risk group, to regular renal transplantation (RT) operations. However, it is still a fact that many patients undergoing RT operations have a higher chance of getting intraoperative complication than regular patient group. As a result, anesthesiologists load was increased significantly in RT operations. Maximal hydration during RT is of utmost importance. The most important intraoperative measure that improves the likelihood of immediate graft function is to maintain an adequate intravascular volume and ensure satisfactory perfusion of the transplanted kidney. Intravascular volume is a crucial factor in the maintenance of hemodynamic stability, tissue oxygenation and organ function. Crystalloid solutions are the first choice to correct fluid and electrolyte deficits in these patients. However, in case of major hypovolemia, particularly in situations of increased capillary permeability, colloid solutions are indicated to achieve sufficient tissue perfusion. Because of the fluid abnormalities usually found in patients with renal failure, the high incidence of cardiac disease and the importance of graft perfusion and early function, central venous pressure (CVP) monitoring is recommended. A CVP of 10–15 mm Hg has been recommended to maintain optimal intravascular volume. To lower the risk for acute tubular necrosis and transplant failure caused by hypovolemia. In this study, a fuzzy logic system is used to control fluid balance during RT by changes in blood pressure, heart rate and CVP value. Currently, the administration of intravascular volume is carried out primarily based on the experience and expertise of the anesthesiologist as there is no analytical method available to estimate the transplant patient's fluid level. To increase kidney viability in transplant surgery, patient safety and comfort during RT is one of the most important potential benefits of the system. For this project, A total of 30 kidney transplantation operations performed in Akdeniz University Organ Transplantation Center were followed and all physiological data recorded during the last year. This data base is used for contribution of the fuzzy system membership functions and to determine base variable intervals. Also the developed system was tested with these operations records.