Wearable devices for blood purification: principles, miniaturization, and technical challenges.

The prevalences of end-stage renal disease (ESRD) and renal replacement therapy (RRT) continue to increase across the world imposing staggering costs on providers. Therefore, strategies to optimize the treatment and improve survival are of fundamental importance. Despite the benefits of daily dialysis, its implementation is difficult and wearable hemodialysis might represent an alternative by which frequent treatments can be delivered to ESRD patients with much less interference in their routines promoting better quality of life. The development of the wearable artificial kidney (WAK) requires incorporation of basic components of a dialysis system into a wearable device that allows mobility, miniaturization, and above all, patient-oriented management. The technical requirements necessary for WAK can be divided into the following broad categories: dialysis membranes, dialysis regeneration, vascular access, patient monitoring systems, and power sources. Pumping systems for blood and other fluids are the most critical components of the entire device.

Wak engineering evolution.

The wearable artificial kidney (WAK) is a device that allows prolonged and frequent dialysis treatments for patients with end stage renal disease. It potentially provides a practical and feasible solution to satisfy the need for an optimal delivered dialysis. Until now, the WAK has already been presented in several models, proposing different therapeutic modalities and engineering approaches. The ideal solution of a WAK may come from a combination of all the prototypes developed and/or those currently in development. Consequently, it is important to have a complete overview and a deep knowledge of the possible engineering solutions in order to achieve the incremental steps necessary to solve the remaining issues of wearable extracorporeal blood purification devices. Since technical advances are continuously evolving and it is important to focus on clinical requirements and needs, a multidisciplinary collaboration has to be coordinated to achieve the final objective of the practical realization of a wearable artificial kidney. In such a context, the main aim of this article was to analyze more in detail the WAK Engineeristic Development.

Pumps in wearable ultrafiltration devices: pumps in wuf devices.

The wearable artificial kidney (WAK) is a device that is supposed to operate like a real kidney, which permits prolonged, frequent, and continuous dialysis treatments for patients with end-stage renal disease (ESRD). Its functioning is mainly related to its pumping system, as well as to its dialysate-generating and alarm/shutoff ones. A pump is defined as a device that moves fluids by mechanical action. In such a context, blood pumps pull blood from the access side of the dialysis catheter and return the blood at the same rate of flow. The main aim of this paper is to review the current literature on blood pumps, describing the way they have been functioning thus far and how they are being engineered, giving details about the most important parameters that define their quality, thus allowing the production of a radar comparative graph, and listing ideal pumps' features.

Survey of acute kidney injury and related risk factors of mortality in hospitalized patients in a third-level urban hospital of Shanghai.

OBJECTIVE: The main aim of this study is to investigate the incidence and prognosis of acute kidney injury (AKI) and to clarify the risk factors associated with the prognosis of AKI in hospitalized patients. METHOD: All patients hospitalized from January 1st to December 31st 2012 in Ren Ji Hospital, School of Medicine Shanghai Jiao Tong University were screened by the Lab Administration Network. All the patients with an intact medical history of AKI according to the Acute Kidney Injury Network (AKIN) were enrolled in the study cohort. AKI's incidence and etiology, as well as the patient's characteristics and prognosis, were retrospectively analyzed. Logistic regression analysis was used to investigate the risk factors on the patient prognosis and renal outcome. RESULTS: 934 AKI patients were enrolled. The incidence of AKI in hospitalized patients was 2.41%. The ratio of males to females of patients was 1.88:1 and the mean age was 60.82 ± 16.94. The incidence of AKI increased with increase in age. Among hospitalized patients, 63.4% were from the surgical department, 35.4% from the internal medicine department, and 1.2% from the obstetric and gynecologic department. Regarding the cause of AKI, pre-renal AKI, acute tubular necrosis (ATN), acute glomerulonephritis and vasculitis (AGV), acute interstitial nephritis (AIN), and post-renal AKI contributed with 51.7, 37.7, 3.8, 3.5, and 3.3%, respectively. The survival rate on the day 28 after AKI was 71.8%. In addition, 65.7% patients got complete renal recovery, while 16.9% got partial renal recovery and 17.4% got renal loss. The mortality of AKI in hospitalized patients at Stage I, Stage II and Stage III was 24.8, 31.2 and 43.7%, respectively. Multivariate Logistic regression analysis showed that use of nephrotoxic drugs, [Odds Ratio (OR) = 2.313], hypotension in the previous week (OR = 4.482), oliguria (OR = 5.267), the number of extra-renal organ failures (OR = 1.376), and need for renal replacement therapy (RRT) (OR = 4.221) were independent risk factors for mortality. The number of extra-renal organ failures (OR = 1.529) and RRT (OR = 2.117) were independent risk factors for renal loss. CONCLUSION: AKI is one of the most common complications in hospitalized patients. The mortality is high and renal prognosis is poor after AKI. The prognosis is closely associated with the severity of AKI. Nephrotoxic drugs, hypotension within the last week, oliguria, the number of extra-renal organ failures, and RRT are independent risk factors for mortality, while the number of extra-renal organ failures and RRT are independent risk factors for renal loss.

Survival and renal recovery after acute kidney injury requiring dialysis outside of intensive care units.

BACKGROUND: The incidence of acute kidney injury requiring dialysis (AKI-D) is increasing globally and it is usually associated to chronic kidney disease (CKD) and high mortality. Literature is lacking in short- and intermediate-term data on recovery of renal function after acute kidney injury (AKI). OBJECTIVES: The objective was to evaluate the overall survival and renal recovery after an episode of AKI requiring dialysis out of intensive care units (ICUs). MATERIALS AND METHODS: Retrospective study including patients admitted in two nephrology units along a period of 2 years. Patients admitted to ICUs and renal transplant patients were excluded. Baseline renal function, mortality and glomerular filtration rate (GFR) improvement were evaluated. RESULTS: 151 consecutive adult patients with AKI requiring renal replacement therapy (RRT) were included. Mean age was 70.5 ± 15.2 years, 60.3% were males. Median baseline creatinine (bCr) and baseline GFR (bGFR) were 1.4 mg/dL and 46 mL/min/1.73 m2, respectively. After 1 year of follow-up, we completed the monitoring of 94 patients: 64.9% had died, 10.6% were alive on dialysis and 24.5% were alive without need for RRT. Patients with bGFR > 60 mL/min/1.73 m2 prior to AKI episode had a slower but sustained GFR improvement through the follow-up in comparison with patients with bGFR < 60 mL/min/1.73 m2 whose recovery was incomplete. CONCLUSIONS: Patients with AKI requiring RRT have high short- and intermediate-term mortality and some require maintenance dialysis. Patients with GFR > 60 mL/min/1.73 m2 prior to AKI had a renal recovery closer to the basal renal function than in patients with a previously diminished GFR.