The survival of patients with end-stage renal disease (ESRD) on hemodialysis is largely dependent upon the maintenance of vascular access. Yet catheter related blood stream infection remains one of the most important causes of sepsis and repeat hospital admissions among hemodialysis patients. While observance of strict sterile technique and the use of chemical antiseptics to disinfect catheter connectors is accepted practice in hemodialysis units, these methods have not significantly reduced clinical infection rate. The use of antibiotic lock techniques has resulted in a modest reduction of catheter related infections, yet this practice is also known to accelerate the growth of antibiotic resistant specie. To address this clinical need, Med-Conduit, Inc has developed a microwave sterilization device that enables the application of moist heat to saline filled connectors. The current Phase I research will be focused on the development of an in-vitro bench model to characterize the lethality of such microwave energy on bacteria populations present in finite volumes of liquid. Our long term goal will be to generate a system that exhibits rapid and energy efficient reduction of bacterial colony formation and biofilm deposition in the connectors used to attach a central venous catheter to a hemodialysis instrument. Our project will be designed to optimize the power and frequency of the underlying radio frequency signals, the shape of the signal-receiving antenna, the location and orientation of the target volume, and the shape and topology of the wave-guide structure in a manner that improves heat transfer and disinfection in the target volume and thus optimizes the rate and efficacy of disinfection. To address this goal, we propose the following Specific Aims:
Aim 1 : To complete the design of a microwave-based disinfection system for use in hemodialysis.
Aim 2 : Based on the system simulation, to fabricate and evaluate the heating capacity of a prototype disinfection system.
Aim 3 : To assess performance of prototype systems in terms of bacterial colony reduction. If this Phase I research is successful, we will propose in Phase II to design, fabricate and test a finalized device that meeting the practical demands of size, weight, and performance of the clinical setting.
Catheter related bacteremia (CRB) comprises the most common reason for hospitalization for patients with end-stage renal disease (ESRD) undergoing chronic hemodialysis, accounts for nearly one third of the cost of disease management, and is associated with a mortality of 12-25.9%. The success of hemodialysis in provide life support to patients with ESRD remains inextricably linked to the ability to limit bacterial colonization of th access catheters and thereby to reduce the incidence of CRB. Current clinical practice, including the use strict sterile technique and various antibiotic delivery systems, has not been successful in ameliorating this problem. Med-Conduit has developed a microwave technology which promotes rapid heating of fluids at the catheter interface with the extracorporeal circuit, and thus promotes disinfection. The goal of this Phase I research will be to design, fabricate and test a novel microwave system to provide disinfection at the catheter interface with the hemodialysis system. If this Phase I research is successful, will be propose in Phase II to create a finalized device that meets the practical demands of size, weight and performance of the clinical setting.
