Evaluation of circuit lifetime in continuous renal replacement therapy using two types of polysulfone membranes

The Relationship Between Acute-Phase Circuit Occlusion and Blood Calcium Concentration in an Ex Vivo Continuous Renal Replacement Therapy Model

Background and objective Continuous renal replacement therapy (CRRT) is a blood purification therapy modality for the treatment of renal failure in critically ill hospitalized patients with multiorgan dysfunction, effectively preventing uremia and multiple organ failure while improving renal function. However, the perfusion of patient blood through extracorporeal circulation often results in unexpected early occlusion of the CRRT circuit or hemofilter, leading to frequent interruptions in CRRT and wastage of medical resources. Moreover, clinical research on such circuit occlusions is limited. In Japan, CRRT circuits require long-term perfusion, often lasting 24 hours or more, indicating the need for a model capable of inducing occlusion at any arbitrary time; this model can evaluate various aspects, including causes and underlying mechanisms, and contribute to the development of an occlusion prediction method. Hence, we hypothesized the need for a model for inducing occlusion at arbitrary time points. Consequently, we strove to develop an ex vivo circuit occlusion model involving the injection of calcium into circulating citrated animal blood to evaluate the relationship between the amount of calcium chloride injected, circuit occlusion time, and changes in circuit pressure over time. Methods We developed a circuit occlusion model using a commercially available CRRT circuit, polysulfone membrane hemofilter, heating extension tube, and thermostatic water bath, along with commercially available citrated bovine whole blood. The circuit was filled with blood over a 10-min duration using a roller pump and was occluded after a specific period by varying the flow rate of calcium injected into bovine whole blood. Additionally, continuous injection of 1 mEq/mL calcium chloride into the circuit was maintained while bovine whole blood circulated. Measurements were performed at each calcium injection flow rate (2, 3, and 4 mL/h), with each measurement performed five times. The group that did not receive calcium injection was used as the control (0 mL/h: Con), and the experiment was performed three times. Groups were defined as "0, 2, 3, and 4" for each calcium injection flow rate. The relationship among the amount of calcium chloride injected, circuit occlusion time, and changes in circuit pressure over time was evaluated. Furthermore, blood tests and blood viscoelastic tests were performed at arbitrary times. Results The circuit occlusion time varied with each calcium injection flow rate, and a significant difference was observed between each group (p<0.05). Circuit pressure gradually changed at four min before occlusion when calcium was injected at 2, 3, and 4 mL/h, with a more rapid change at one min before occlusion. We measured circuit pressure at four and one min before occlusion (-4 min, and -1 min, respectively), and at the time of circuit occlusion (0 min) in the Con and 4 mL/h groups. Significant differences were observed in AP between -4 min and 0 min and -1 min and 0 min at a calcium flow rate of 4 mL/h. Additionally, significant differences were seen in prefilter and return pressures between -4 min and 0 min, -4 min and -1 min, and -1 min and 0 min at a calcium flow rate of 4 mL/h (p<0.05). Conclusions Our proposed model accurately estimated the occlusion time based on changes in circuit pressure. This model can be used to create various experimental systems depending on the desired occlusion time.

Diabetes and hypertension MobileHealth systems: a review of general challenges and advancements

Mobile health (mHealth) systems are sipping into more and more healthcare functions with self-management being the foremost modus operandi. However, there has been challenges. This study explores challenges with mHealth self-management of diabetes and hypertension, two of the most comorbid chronic diseases. Existing literature present the challenges in fragments, certain subsets of the challenges at a time. Nevertheless, feedback from patient/users in extant literature depict very variegated concerns that are also interdependent. This work pursues provision of an encyclopedic, but not redundant, view of the challenges with mHealth systems for self-management of diabetes and hypertension.

Furthermore, the work identifies machine learning (ML) and self-management approaches as potential drivers of potency of diabetes and hypertension mobile health systems. The nexus between ML and diabetes and hypertension mHealth systems was found to be under-explored. For ML contributions to management of diabetes, we found that machine learning has been applied most to diabetes prediction followed by diagnosis, with therapy in distant third. For diabetes therapy research, only physical and dietary therapy were emphasized in reviewed literature. The four most considered performance metrics were accuracy, ROC-AUC, sensitivity, and specificity. Random forest was the best performing algorithm across all metrics, for all purposes covered in the literature. For hypertension, in descending order, hypertension prediction, prediction of risk factors, and prediction of prehypertension were most considered areas of hypertension management witnessing application of machine learning. SVM averaged best ML algorithm in accuracy and sensitivity, while random forest averaged best performing in specificity and ROC-AUC.

Does a small-diameter rod-type tunneler reduce postoperative swelling? An evaluation using a canine arteriovenous graft model

PURPOSE

Sheath-type tunnelers are frequently used to create vascular access using vascular grafts. However, during vascular access creation, tunnelers damage the surrounding tissues, consequently causing problems, such as swelling, failure to heal, and infection. This study evaluated a novel rod-type tunneler that was designed to prevent tunneler-related tissue damage and its sequelae.

METHODS

We developed a small-diameter rod-type tunneler that reduces injuries during subcutaneous tunnel creation. The rod diameter of this tunneler is smaller than the vascular graft diameter being implanted. It has a structure in which a vascular graft is implanted at a target site by grasping and pulling the vascular graft. Three dogs were used in the experiment, and arteriovenous grafts were created using a rod-type and a sheath-type tunneler on the left and right thighs, respectively, with a different type of commercially available graft used in each dog. The edema of the tissues surrounding the vascular graft was measured at 11 sites by ultrasonography at prespecified intervals.

RESULTS

Compared with implantation using a sheath-type tunneler, when the self-sealing Rapidax II was implanted using the small-diameter rod-type tunneler, the postimplantation edema (degree of change) decreased by 28-53% and 80-247% in the peri-vascular-graft area and within the loop, respectively. The MAXIFLO and SEALPTFE did not significantly reduce postoperative edema but exhibited a tendency for improved postimplantation tissue healing.

CONCLUSIONS

The reduced-diameter rod-type tunneler may be a useful device for vascular graft implantation.

Epidemiology of peritoneal dialysis outcomes

Peritoneal dialysis (PD) is an important home-based treatment for kidney failure and accounts for 11% of all dialysis and 9% of all kidney replacement therapy globally. Although PD is available in 81% of countries, this provision ranges from 96% in high-income countries to 32% in low-income countries. Compared with haemodialysis, PD has numerous potential advantages, including a simpler technique, greater feasibility of use in remote communities, generally lower cost, lesser need for trained staff, fewer management challenges during natural disasters, possibly better survival in the first few years, greater ability to travel, fewer dietary restrictions, better preservation of residual kidney function, greater treatment satisfaction, better quality of life, better outcomes following subsequent kidney transplantation, delayed need for vascular access (especially in small children), reduced need for erythropoiesis-stimulating agents, and lower risk of blood-borne virus infections and of SARS-CoV-2 infection. PD outcomes have been improving over time but with great variability, driven by individual and system-level inequities and by centre effects; this variation is exacerbated by a lack of standardized outcome definitions. Potential strategies for outcome improvement include enhanced standardization, monitoring and reporting of PD outcomes, and the implementation of continuous quality improvement programmes and of PD-specific interventions, such as incremental PD, the use of biocompatible PD solutions and remote PD monitoring.

The use of peritoneal dialysis (PD) can be advantageous compared with haemodialysis treatment, although several barriers limit its broad implementation. This review examines the epidemiology of peritoneal dialysis (PD) outcomes, including clinical, patient-reported and surrogate PD outcomes.

Peritoneal dialysis (PD) has distinct advantages compared with haemodialysis, including the convenience of home treatment, improved quality of life, technical simplicity, lesser need for trained staff, greater cost-effectiveness in most countries, improved equity of access to dialysis in resource-limited settings, and improved survival, particularly in the first few years of initiating therapy.

Important barriers can hamper PD utilization in low-income settings, including the high costs of PD fluids (owing to the inability to manufacture them locally and the exorbitant costs of their import), limited workforce availability and a practice culture that limits optimal PD use, often leading to suboptimal outcomes.

PD outcomes are highly variable around the world owing in part to the use of variable outcome definitions, a heterogeneous practice culture, the lack of standardized monitoring and reporting of quality indicators, and kidney failure care gaps (including health care workforce shortages, inadequate health care financing, suboptimal governance and a lack of good health care information systems).

Key outcomes include not only clinical outcomes (typically defined as medical outcomes based on clinician assessment or diagnosis) — for example, PD-related infections, technique survival, mechanical complications, hospitalizations and PD-related mortality — but also patient-reported outcomes. These outcomes are directly reported by patients and focus on how they function or feel, typically in relation to quality of life or symptoms; patient-reported outcomes are used less frequently than clinical outcomes in day-to-day routine care.

Brachial artery transposition versus catheters as tertiary vascular access for maintenance hemodialysis: a single-center retrospective study

Some hemodialysis patients are not suitable for creation of an arteriovenous fistula (AVF) or arteriovenous graft (AVG). However, they can receive a tunneled cuffed central venous catheter (tcCVC), but this carries risks of infection and mortality. We aimed to evaluate the safety and effectiveness of brachial artery transposition (BAT) versus those of tcCVC. This retrospective study evaluated hemodialysis patients who underwent BAT or tcCVC placement because of severe heart failure, hand ischemia, central venous stenosis or occlusion, inadequate vessels for creating standard arteriovenous access, or limited life expectancy. The primary outcome was whole access circuit patency. Thirty-eight patients who underwent BAT and 25 who underwent tcCVC placement were included. One-year patency rates for the whole access circuit were 84.6% and 44.9% in the BAT and tcCVC groups, respectively. The BAT group was more likely to maintain patency (unadjusted hazard ratio: 0.17, 95% confidence interval: 0.05–0.60, p = 0.006). The two groups did not have significantly different overall survival (log-rank p = 0.146), although severe complications were less common in the BAT group (3% vs. 28%, p = 0.005). Relative to tcCVC placement, BAT is safe and effective with acceptable patency in hemodialysis patients not suitable for AVF or AVG creation.