International Journal of Artificial Organs最新文献

Introduction: New dialysis membranes with new properties are being developed to improve efficacy and tolerance. The hemocompatibility of a polymeric biomaterial is influenced by the layer of water at the blood membrane interface. The new dialyzer TORAY NV-U^® has a membrane Hydrolink™, designed to suppress platelet adhesion and to improve the hemocompatibility. Until now, there is no experience in online hemodiafiltration (OL-HDF).The objective of the present study is to evaluate the efficacy of this new membrane in OL-HDF therapy compared to another membrane commonly used. Other objectives are to evaluate the inflammatory response, hemodynamic tolerance, and the anticoagulation regimes.

Methods: This is a prospective pilot study performed in five anuric patients receiving OL-HDF. For 1 month patients were kept with their usual dialyzer FX1000^® (FMC). Subsequently, the dialyzer was changed to TORAY NV-U^® (Hydrolink^®) for 1 month. In the last dialysis session of each dialyzer, blood tests were performed to evaluate inflammation and depurative capacity.

Results: We did not find differences in medium size removal molecules and convective volume: FX1000^®: 31 ± 9 l per session and Hydrolink™ 30 ± 8 l; p = 0.7); β2microglobulin reduction ratio (RR) FX1000^® FMC 83 ± 3%; Hydrolink™ 79 ± 4; p = 0.14; Myoglobin RR FX1000^® FMC 72 ± 7%; Hydrolink™ 76 ± 4; p = 0.28. We did not find differences in inflammation parameters: serum IL6 with FX1000^® 6.0 ± 4.2 pg/mL; Hydrolink™ 7.6 ± 5.0 pg/mL; p = 0.3.During all sessions with the two dialyzers there was adequate plasmatic filling, reaching 85 % filling. All patients had "good" dialyzer status in all dialysis sessions with TORAY NV-U^®, while the dialyzer status with FX1000^® was "good" in 20% of the sessions, "medium" in 30%, and "dirty" in the remaining 50% dialysis sessions.

Conclusions: The new dialyzer Hydrolink™, TORAY NV-U^® is not inferior to perform OL-HDF compared to dialyzers usually used for this therapy, and could allow decrease heparin doses. Further studies with a bigger sample size and longer follow-up will answer if Hydrolink improves inflammation and assess a better hemodynamic tolerance.

Hepatopulmonary syndrome (HPS) poses a significant challenge in liver transplant patients, affecting between 10% and 30% of candidates. Historically, HPS was considered a contraindication for liver transplantation due to its association with high mortality rates. However, recent studies have shown improvements in pulmonary function post-transplant, leading to the inclusion of these patients as candidates. Despite this progress, approximately one-fifth of liver transplant recipients develop severe postoperative hypoxia, further complicating their clinical course and contributing to increased mortality. The management of post-transplant HPS involves various strategies, including extracorporeal membrane oxygenation (ECMO), although its use remains infrequently reported. Theoretical models suggest that oxygenation typically improves within 10 days post-transplant, while resolution of HPS may take 6-12 months, making ECMO an attractive possibility as a bridge to recovery in this population. We present a case were ECMO was used in this context.

Previously, we found analytic solutions for single ventricular system based on the lumped parameter model (LPM). In this study, we generalized the method to biventricular system and derived its analytic solutions. LPM is just a set of differential equations, but it is difficult to solve due to time-varying ventricular elastance and high order. Mathematically, there exist no elementary solutions for time-varying equations. It turns out that instead of differential equations, according to volume conservation, a set of algebraic equations can be carried out. The solutions of the set of equations are just physiological states at end of systolic and diastolic phases such as end systolic/diastolic pressure/volume of left ventricle. As a preliminary application, the method is utilized to deduce the hemodynamic effects of VA ECMO. Left ventricular (LV) distension, a serious complication of VA ECMO, is usually attributed to factors such as increased afterload, inadequate LV unloading, reduced myocardial contractility or aortic valve regurgitation (AR), bronchial and Thebesian return in the absence of aortic valve (AoV) opening. Among these, reduced contractility and AR are strongly associated with LV distension. However, in the absence of reduced contractility or AR, it is less clear whether increased afterload or inadequate LV unloading alone can cause LV distension. This leads to the critical question: under what conditions does LV distension occur in the absence of reduced contractility or AR? The analytic formulas derived in this study give conditions for LV distension. Furthermore, the results show that the analytic hemodynamics are coincident with simulated results.

Background: Postoperative urination dysfunction is a common complication after surgery in patients with cervical cancer. Portable bladder ultrasound are commonly utilized in clinical practice for measuring residual urine volume. This study aimed to the effect of bladder function training combined with portable ultrasound monitoring on bladder function recovery in patients with cervical cancer after training.

Methods: A total of 40 postoperative patients with cervical cancer were randomly divided into a control group (A) and an experimental group (B) of 20 cases each. Group A was given routine postoperative care, while group B was given bladder function training. Urgent urine bladder volume were taken twice daily after removal of the urinary catheter and monitored for five consecutive days. The difference of urgent urine bladder volume and bladder filling rate were compared by t-test and chi-square test respectively. The 36-item Short Form Health Survey (SF-36) was used to evaluate the quality of life of patients before and after intervention, and compared by Mann-Whitney U test.

Results: There was no significant difference in preoperative urgent urine volume between the two groups. After catheter removal, the bladder volume of patients in the B increased, while the bladder volume of patients in the A increased less and fluctuated greatly. The bladder filling rate in the A was significantly lower than that in the B (5/15 vs 17/18, p < 0.05). After intervention, the quality of life of the experimental group was better than that of the control group, including scores of general health, mental health, vitality, and physical role (p < 0.05).

Conclusion: Postoperative cervical cancer patients trained to hold urine by portable ultrasound monitoring are able to recover bladder function.

Purpose: The clinical efficacy and safety of ertapenem use in patients undergoing renal replacement therapies (RRT) are not well-documented. Therefore, we aimed to investigate the safety and efficacy of ertapenem in patients with sepsis secondary to Enterobacterales who are undergoing RRT.

Methods: A retrospective cohort study was conducted on patients who met the inclusion criteria at our hospital between May 2015 and December 2021. The primary endpoint was 30-day mortality. Secondary endpoints included clinical cure, microbiologic cure, recurrence rate, and incidence of seizures.

Results: During the study period, 158 patients met the inclusion criteria. Of these, 86 were male (54.4%), the mean age was 66.4 ± 13.8 years, and the mean weight was 77 ± 22.4 kg. The most common diagnosis was bacteremia in 48 (30.4%) subjects, followed by urinary tract infection in 39 (24.7%) subjects, and pneumonia in 35 (22.2%) patients. The most isolated pathogens were Escherichia coli, followed by Klebsiella species. The median ertapenem dose was 0.5 g intravenously (IV) daily in those who received intermittent hemodialysis (IHD) and 1 g IV daily for those who received continuous veno-venous hemofiltration (CVVH). The 30-day mortality rate was 24%, the clinical cure rate was 89.2%, the microbiologic cure rate was 82%, the 30-day recurrence rate was 41.1%, and the incidence of seizures was 2.5%. Multivariate logistic regression analysis indicated that age (OR 1.04 [95% CI: 1.003-1.075]), being critically ill at therapy initiation (OR 2.9 [95% CI: 1.1-7.5]), and Enterobacterales other than Klebsiella species and Escherichia coli (OR 3.8 [95% CI: 1.1-12.5]) were significant independent risk factors associated with mortality in this population. Ertapenem dose was not associated with mortality.

Conclusion: Our findings suggest that the commonly used doses of ertapenem in patients undergoing IHD and CVVH are clinically effective but may pose a higher risk of seizures. A comprehensive pharmacokinetic study is needed to determine the most effective and safe dose for this population.

Introduction: This study investigates the potential of an in-situ forming scaffold using a fibrin-based scaffold derived from autologous plasma combined with Synthetic Teriparatide (TP) for bone regeneration application. TP is known for its bone formation stimulation but has limited clinical use due to side effects. This autologous delivery system aims to provide precise, controlled, localized, and long-term release of TP for accelerating bone regeneration.

Methods: Fibrinogen from autologous plasma was extracted using ethanol, and thrombin was precipitated with ammonium sulfate to create the fibrin scaffold. Characterization of fibrinogen was done through FTIR, SDS-Page, porosity, SEM, degradation, and rheology tests. Viability was assessed by MTT in five groups with different concentrations of TP in fibrin scaffold (50, 100, and 150 µl/ml), fibrin alone, and a control group against HEK and Wharton's jelly cells. The release profile of different concentrations of TP in the fibrin scaffold was also examined.

Results: The formation time of the fibrin scaffold was 4 ± 0.2 s. The highest Infrared absorption for fibrinogen was confirmed. Rheology assessment revealed a higher elastic modulus than the viscous modulus. The created fibrin scaffold displayed a consistent three-dimensional microstructure with an interconnected porous network. Cytotoxicity assays demonstrated good biocompatibility and enhanced cell growth with different concentrations of TP in the fibrin scaffold. The TP release increased with higher concentrations, peaking at an average of 61% over 54 h.

Conclusion: Autologous plasma-derived fibrin scaffolds incorporating TP exhibit satisfactory release within the scaffold and hold promise as a versatile bone filler for clinical use, facilitating osteoregeneration.

The main challenges of Biventricular Assist Devices (BiVAD) as a treatment modality for patients with Bicardiac heart failure heart failure are the balance of systemic blood flow during changes in physiological activity and the prevention of ventricular suction. In this study, a model of the Biventricular Circulatory System (BCS) was constructed and a physiological combination controller based on Starling-Like controller and Sliding Mode Controller (SMC) was proposed. The effects of the physiological controller on the hemodynamics of the BCS were investigated by simulating two sets of physiological state change experiments: elevated pulmonary artery resistance and resting-exercise, with constant speed (CS) control and combined Starling-like and PI control (SL-PI) as controllers. Simulation and experimental results showed that the Starling-like and Sliding Mode Control (SL-SMC) physiological combination controller was effective in preventing the occurrence of ventricular suction, providing higher cardiac output, maintain balance of systemic blood flow, and have higher response speed and robustness in the face of physiological state changes.

Reconstruction of mandible implants to address segmental abnormalities is still a challenging task, both in vitro and in vivo. The mechanical strength of the materials used is a critical factor that determines how well bone is regenerated. The reconstruction technique of mandibular abnormalities widely uses polymeric implants. It is critical to evaluate the mechanical resilience under different load cases, including axial, combined, and flexural loading conditions. This study developed implants for mandibular defects using a combination of four materials: polylactic acid (PLA), polyethylene terephthalate glycol (PETG), thermoplastic polyurethane (TPU), and polycaprolactone (PCL), with the aim of mimicking the inherent characteristics of cortical and cancellous bone structures and evaluating their mechanical properties to support bone Osseo integration. The eleven of these combinations of structures result below the micro strain threshold level of <3000 µε, and the five combinations of the structures result in micro strain above the threshold value. The intact bone study results show that the stress under axial, combined, and flexural loading conditions is 27.6, 38.9, and 64.9 MPa, respectively. This study's stress results are lower than those from the intact bone study. The study found that the combinations of PLA and TPU material were most preferred for the cortical and cancellous bone regions of polymeric implants. These materials are also compatible with 3D printing. The results of this study can be used to find multi-material combinations that are strong and flexible.

Introduction: Intra-dialytic hypotension (IDH) remains the commonest problem associated with routine haemodialysis treatments. Fluid shifts from intracellular(ICW) and extracellular(ECW) compartments to refill plasma volume during haemodialysis with ultrafiltration.

Methods: We studied the effect of relative changes in ICW and ECW indifferent body segments using multifrequency segmental bioimpedance during haemodialysis and IDH episodes.

Results: Of 42 haemodialysis patients,16 patients (38.1%) developed IDH within the first hour of dialysis. Patients with and without early IDH were well-matched for demographics and starting bioimpedance measurements. However, after 60 min, the relative change in in ECW/ICW ratio between the non-fistula arm and leg was significantly different for the early IDH group median -1.07 (-3.33 to 0.8) versus 0.61 (-0.78 to 1.8), p < 0.05, whereas there no differences in ultrafiltration rate, relative blood volume monitoring or on-line clearance.

Conclusion: Monitoring serial changes in fluid status in different body compartments with bioimpedance may potentially prevent IDH in the future.