Conceptual model of adding antibiotics to dialysate fluid during renal replacement therapy

Studies have shown significant variability in antibiotic trough concentrations in critically ill patients receiving renal replacement therapy (RRT). The purpose of this study was to assess whether adding beta-lactam antibiotics to dialysate solution can maintain stable antibiotic concentrations during RRT in experimental conditions. A single compartment model reflecting the patient was constructed and connected to the RRT machine. Dialysate fluid was prepared in three different concentrations of meropenem (0 mg/L; 16 mg/L; 64 mg/L). For each dialysate concentration various combinations of dialysate and blood flow rates were tested by taking different samples. Meropenem concentration in all samples was calculated using spectrophotometry method. Constructed experimental model results suggest that decrease in blood meropenem concentration can be up to 35.6%. Moreover, experimental data showed that antibiotic loss during RRT can be minimized and stable plasma antibiotic concentration can be achieved with the use of a 16 mg/L Meropenem dialysate solution. Furthermore, increasing meropenem concentration up to 64 mg/L is associated with an increase antibiotic concentration up to 18.7–78.8%. Administration of antibiotics to dialysate solutions may be an effective method of ensuring a constant concentration of antibiotics in the blood of critically ill patients receiving RRT.

Control system for glucose level regulation in peritoneal dialysis

Kidney failure leads to the serious health issues associated with abnormal water-salt balance. In this case, peritoneal dialysis therapy is often prescribed: 1-2 liters of dialysis solution is administered in peritoneal cavity for 3-4 hours. During this time, due to diffusion and osmosis, toxins and excess water are transferred from blood to solution. One of the method’s downsides is the transition of glucose (osmotic agent) into the bloodstream, which leads to a gradual decrease in the fluid removal rate. To mitigate this problem, one must use the system, which will measure current glucose concentration and inject glucose into solution to compensate absorption. The paper proposes such a control system for automatic regulation of the glucose concentration in peritoneal dialysate solution. Its structure, elements, their functions and characteristics are discussed. Proposed system is capable to work autonomously or can be incorporated into wearable “artificial kidney” device.

IR-Photometry Method for Measuring Glucose Concentration in Peritoneal Dialysis Fluid

Introduction. The transition of glucose into the blood during automated peritoneal dialysis with regeneration of the dialysis fluid leads to a decreased removal of excess fluid from the body and corresponding violations of the water-salt balance.Aim. To consider a system for automatically maintaining the concentration of glucose in the dialysate solution, which provides effective ultrafiltration, as well as to propose a non-contact photometric feedback sensor.Materials and methods. The sensor is an optical system of an IR laser diode with a power of 30 mW and a wavelength of 1600 nm, a photodiode and a quartz tube, through which the test solution circulates. The sensor measures the attenuation of the radiation passing through the solution in a pulsed mode and calculates the glucose concentration. The selected combination of digital filters provides compensation for the noise of the optical system. Experimental studies of the efficiency of the sensor were carried out on peritoneal dialysis solutions with various concentrations of urea, creatinine, uric acid and glucose. At the beginning of the experiments, the sensor was calibrated in a pure solution.Results. It was shown that the developed sensor makes it possible to measure the concentration of glucose in a solution for peritoneal dialysis in the range of 42…220 mmol / l with a relative error of about 15%. The time of one measurement is about 1 minute, which makes it possible to obtain up-to-date information on the current concentration of the solution.Conclusion. This combination of characteristics will allow the sensor to be used in artificial kidney wearable devices for assessing the glucose content in the solution, calculating the time to change the solution and as a feedback sensor in a system for maintaining the concentration of the osmotic agent.

An easy disinfection strategy for pipes connecting hemodialysis equipment

Introduction: A hemodialysis room has pipes connecting the console and central fluid equipment. While these pipes require disinfection, reports detailing disinfection strategies are unavailable. Therefore, we aimed to compare two easy disinfection strategies differing in sanitization frequency and sanitizer concentration. Methods: Reverse osmosis water (ROW) purifying equipment and six dialysis consoles were connected by 20 m of pipes. Only ROW flowed through these pipes, because the dialysate solution was constituted at each console. The pipes were sanitized by two strategies: (1) strong and monthly (hypochlorite concentration: 100 ppm) or (2) weak and weekly (5 ppm). Both strategies were easy because the sodium hypochlorite was simply added to the ROW tank. To estimate sanitization efficacy, endotoxin counts at the ROW tank outlet, the end of the pipe, and the pipe after the endotoxin-cutting filter in each console were measured monthly for six continuous months. These counts were compared between the two sanitization strategies. Results: The endotoxin counts at the ROW tank outlet and the end of the pipe were 0.004–0.017 and 0.012–0.081 EU/mL, respectively, in the strong and monthly strategy, and 0.001–0.003 and 0.001–0.005 EU/mL, respectively, in the weak and weekly strategy. The endotoxin counts at the pipe after the endotoxin-cutting filter were less than 0.001 EU/mL during the study period in both strategies. Conclusion: A weekly disinfection strategy was more effective than a monthly one, despite the lower hypochlorite concentration. The present study suggests that frequency is the most important factor in the disinfection of pipes in a dialysis room.

Fuzzy Controller to Prepare the Dialysate Solution in Hemodialysis Machine: المتحكم الضبابي لتحضير محلول الديلزة في جهاز غسيل الكلية

We concentrate on designing a fuzzy controller, its task is management the operation of preparing the dialysate solution with the required Specifications and continuous monitoring to set the value of conductivity that takes major role to success the bloody Purification operation, where any error in this operation lead to reduce the efficiency of hemodialysis machine so the patient will face the damage. In this research, we reduced the time to treatment (TTT) by speeding the preparing operation of the dialysate solution, and achieve more reliable value of required conductivity so it reduces the alarms that result of override the allowable values which lead to stop the preparing operation and wait for the required values. The fuzzy controller gave us more efficiency when we compared with other controllers which was achieved in previous researches, so we can use the learning algorithms to make this controller more adaptive.

The Performance Enhancement of Hemodialyzers: Computational Fluid Dynamics Study

Computational fluid dynamics simulations are conducted to study the hemodialysis process in separation modules containing hollow fiber membranes. Hemodialysis is the filtration process which removes waste out of the blood. In this work, three-dimensional steady-state laminar flow simulations are conducted to investigate the effect of disk baffles on the performance of the hemodialysis process. The uniformly spaced baffles are placed along the axis of the shell within the dialyzer. The disk baffles of diameter 2.85 dhd were considered, where dhd is the shell hydraulic diameter. The inlet solute mass fraction of the blood solution is fixed at 0.00074, while the inlet solute mass fraction of the dialysate solution varied as 0.004 and 0.007. The blood and the dialysate flow rates are fixed. Our results revealed that the presence of disk baffles in the shell mitigates the concentration polarization and yields higher urea permeation. The higher dialysate concentration solute yields a 41.2% increase in the urea permeate rate compared to the lower dialysate solute concentration.

Management of a Rare Case With Severe Hydrofluoric Acid Burns: Important Roles of Neutralizers and Continuous Renal Replacement Therapy

Hydrofluoric acid (HF), a dangerous inorganic acid, is widely used in various industries and in daily life. Chemical burns caused by HF exposure occur more frequently in some regions worldwide. It has been reported that some cases with HF burns can be lethal due to the hypertoxicity of HF. In this article, we present a case of a 24-year-old worker who suffered HF burns by 53% HF solution to his face, neck, and nasal cavity. This patient quickly developed electrolyte disturbance, that is, hypocalcemia, and hypopotassemia, and myocardial injury after exposure. Multiple measures had been taken to treat this patient, including fluid resuscitation, electrolyte replacement, timely wound treatment with neutralizers, and respiratory tract care. Moreover, continuous renal replacement therapy was also employed to remove fluoride in the circulatory system and rectify the electrolyte disturbance and acid-base imbalance. The patient smoothly pulled though and survived. High fluoride levels in the dialysate solution were confirmed, indicating that continuous renal replacement therapy is an effective and potentially lifesaving treatment for acute HF poisoning.

Derivation for Electric Current Regulation Equation of a Gradient Magnetic Field to Control Suspending Magnetic Particles Inside Dialysate Solution

To design a better adsorption performance in a novel magnetic adsorption device used for hemodialysis (HD), the mechanical properties of magnetic absorbents trapped inside a two-phase system are studied in this paper. A gradient magnetic coil field is assumed to produce the magnetic driving force that balances other hydraulic forces for the adsorbents. For this field, a related winding equation for the solenoid coil is obtained in our previous work; and a complement practical form of the winding equation is derived in this paper. Case studies are also described in this paper to explore the design aspects of the field.