International Journal of Artificial Organs最新文献

Introduction: In this study, we aimed to evaluate cognitive functions in Stage 4 and 5 CKD patients using the Montreal Cognitive Assessment (MoCA) Scale, which objectively assesses cognitive dysfunction and various cognitive functions, and to compare them with a control group with normal kidney functions.

Methods: All participants in our case-control study were administered the Montreal Cognitive Assessment (MoCA) Test, and total scores, subscale scores, and the presence of cognitive dysfunction were recorded.

Results: When the groups were compared in terms of cognitive dysfunction (CD), 12.9% of the control group and 37.1% of the case group were found to have CD, which was statistically significant. When the groups were compared in terms of data and scale scores, the visual construction subscale score, naming, delayed recall subscale score, and total MoCA score were found to be significantly lower in the case group compared to the control group.

Conclusion: Our study is the first to use the MoCA test with the correct reference range. The significant impairment observed in the cognitive functions of patients with advanced-stage CKD in our study suggests that the decision for renal replacement therapy should not be made by the patient alone, as it may be incorrect.

Utilizing magnetic coupling to drive the artificial heart blood pump in a non-contact and wireless manner offers a viable solution that can effectively avoid problems such as percutaneous lead infection. However, the existing magnetic drive blood pumps have problems such as low utilization efficiency and limited transmission torque due to significant leakage of permanent magnets. To address these limitations, this paper introduces a magnetic modulation-based magnetic drive blood pump, which uses salient pole iron sheets to modulate the magnetic field generated by permanent magnets, thereby minimizing leakage and enhancing the efficiency of permanent magnet utilization. Through finite element analysis of electromagnetic fields, the magnetic circuit structure of the magnetic modulation type magnetic drive blood pump is optimized. Additionally, the influence of the air gap distance of the magnetic drive blood pump on transmission performance is analyzed. Finally, a comprehensive experimental setup for blood pump is developed. By measuring the load torque and spatial magnetic flux density parameters of the magnetic drive blood pump and comparing them to the simulation outcomes, the effectiveness of the proposed magnetic modulation type blood pump is verified.

Given the growing obesity pandemic, the impact of obesity on outcomes of Extracorporeal Membrane Oxygenation (ECMO) would be increasingly relevant to our daily practise. This meta-analysis aims to evaluate the impact of obesity on ECMO outcomes, integrating the latest evidence. Systematic literature search was conducted from inception until December 2024 on MEDLINE, Embase and the Cochrane Library using the terms 'ECMO', 'obesity', and their related terms. Twenty-eight studies were included from 2013 to 2024, including a total of 74,330 ECMO patients (Mean age 52.84 ± 13.55 years). Obese patients had a similar risk of in-hospital or 30-day mortality when compared to non-obese patients (Risk difference -2%, 95%CI -5% to -1%, I² = 85%, p = 0.25). Subgroup analysis of patients on V-V-ECMO showed a trend towards lower mortality in obese patients which did not reach statistical significance (risk difference -6%, 95%CI -13% to 0%, I² = 53%, p = 0.06). Subgroup analysis of patients on V-A-ECMO showed significantly higher mortality in obese patients (risk difference 5%, 95%CI 1% to 9%, I² = 54%, p = 0.007). Regarding secondary outcomes, obesity had no significant association with major bleeding or thrombotic complications (Risk difference 0%, 95%CI -1% to 2%, I² = 15%, p = 0.63). Obesity was associated with significantly shorter hospital length-of-stay (Mean difference -2.92 days, 95% CI -5.03 to -0.80, I² = 74%, p = 0.007), but had no impact on ECMO duration (Mean difference 0.35 days, 95%CI -0.03 to 0.74, I² = 41%, p = 0.07). In summary, our meta-analysis showed that obesity was a favourable prognostic factor in V-V-ECMO. However, obesity increased mortality in V-A-ECMO patients. The modality of ECMO support should be taken into consideration when evaluating ECMO candidacy in individual obese patients.

Significant changes in pre-dialytic partial pressure of CO₂ (pCO₂) during a week-long cycle of hemodialysis (HD) can be an effect of the intermittent supplementation of bicarbonate to correct chronic acidosis in patients. Mathematical modeling efforts carried out using the same parameters before each HD session might fail to produce accurate predictions of pCO₂ and plasma bicarbonate concentration (C_Bic) because of this variability. A numerical model describing acid-base equilibrium changes during HD was applied to predict pCO₂, pH, and C_Bic in 24 chronic HD patients, using both fixed parameters for the whole week and estimating a new value of minute ventilation (V_E) and net acid generation rate (G_H) for each interdialytic interval. Dialysances of bicarbonate and dissolved CO₂ were also estimated independently for each HD session. The error of the model compared to the pre-dialytic data of C_Bic and pCO₂ significantly decreased when V_E and G_H were estimated piecewise throughout the week. To fit the data, V_E changed from 3.9 ± 1.0 mL/min before HD1, to 3.8e1 mL/min after HD1, 3.6 ± 1.0 mL/min after HD2, and 3.9 ± 1.1 mL/min after HD3 (p < 0.05). G_H changes after each session were not statistically significant. V_E values strongly correlated with pre-dialytic pCO₂ (Spearman's ρ = -0.97), but G_H only weakly correlated with pre-dialytic C_Bic (ρ = -0.30). Acid-base equilibrium is extremely sensitive to respiratory regulation. When attempting to predict the evolution of pCO₂ a C_Bic during the HD cycle, changes in the respiration parameters must be accounted for by the model, at the risk of a significant loss of prediction accuracy.

Objectives: A systematic characterization of the long-term sequelae after the severest form of COVID-19 requiring ECMO-therapy is lacking. Here, we present 2-year follow-up data of COVID-19 ECMO survivors, and analyze the cardiopulmonary, neurocognitive, psychological, and functional status, plus health-related quality of life (HRQL).

Methods: From 04/2020 to 09/2021, 60 COVID patients were supported with ECMO. Survival to discharge was 40.0% (n = 24), and 6-month survival was 33.3% (n = 20). Follow-ups were performed via phone and mail using validated tools. Six-month outcomes have been published before.

Results: At 2 years, 20 patients were alive. N = 19 agreed to participate in this study (median age 57.0 (45.0-63.0) years, 21.1% female). The cardiopulmonary status was satisfactory (78.9% in NYHA level I-II). Altogether, 84.2% were vastly independent in daily life. However, 47.4% still showed cognitive impairment, 21.1% moderate, 15.8% severe depression, and 15.8% posttraumatic stress disorder symptoms. HRQL subscale results were similar to 6 months, but patients self-rated their overall health significantly better (70.0% (50.0%-80.0%) vs 50.0% (30.0%-80.0%), p = 0.04). The number of patients working was increasing. Social life remained markedly affected.

Conclusions: Two-year outcomes in COVID-19 ECMO patients were stable to improving as compared to 6-month results. However, long-term impairments affected all aspects of life. Long COVID specifically, and post ECMO sequelae in general need to be characterized further to enable maximum recovery.

Introduction: Management of severe circulatory collapse in the setting of amlodipine toxicity can be challenging. High doses of vasopressors and conventional therapies fail to improve hemodynamics, resulting in the use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) to treat severe cardiogenic shock and peripheral vasodilatation. Therapeutic plasma exchange (TPE), which helps remove plasma protein-bound toxins and significantly reduces mortality, may be a useful adjunct to invasive hemodynamic support in severe cases of amlodipine poisoning.

Case summary: A 32-year-old female with a history of intentional consumption of ninety 5-mg amlodipine tablets (totaling 450 mg) was admitted to our intensive care unit (ICU) after 3 h. Her amlodipine serum concentration was 147 ng/mL. She presented with cardiogenic shock and fatal vasoplegia and received VA-ECMO and TPE. The patient was weaned off ECMO after 4 days and discharged home on Day 10 of hospitalization.

Conclusion: Amlodipine toxicity can result in severe cardiac failure with circulatory collapse. We describe the case of a patient with cardiovascular collapse who successfully bridged to recovery from refractory shock secondary to severe amlodipine toxicity as a result of ECMO and TPE treatment.

Collagen is an abundant component in the human body and plays a fundamental role in the integrity and function of various tissues, including skin, bones, joints, and connective tissues. This natural polymer also contributes to physiological balance and individual health. Within this context, this article reviews the structure of collagen, describing intrinsic characteristics that range from its molecular composition to its organization into bundles. Additionally, the review highlights some of the applications of collagen in tissue engineering, particularly its mimicry of the skin's extracellular matrix. For this review, searches were performed in PubMed, Scopus, and Web of Sciences. The inclusion criteria were established based on the relevance of the studies for the objectives of the review and methodological quality. After selection of the articles, a critical analysis of their content was conducted and the information was synthesized and presented concisely. Analysis of the properties of collagen revealed its key importance for the design of bioactive materials in regenerative applications. However, challenges such as the need for improvement of the integration of implanted materials and a better understanding of the underlying biological processes remain.

Introduction: To the best of our knowledge, a possible predictive relationship between the systemic coagulation-inflammation index (SCI) and arteriovenous fistula (AVF) failure following AVF creation has not yet been examined. We therefore designed this study to examine the predictive ability of SCI on postoperative early AVF failure in patients undergoing primary radiocephalic AVF operation.

Methods: A total of 189 patients who underwent primary radiocephalic AVF operation for hemodialysis access were included in this retrospective observational cohort study, and then divided into two groups according to whether AVF failure occurred within the first 3 months after the operation; as failed AVF group (n = 44) and non-failed AVF group (n = 145). The patients' baseline clinical characteristics and laboratory parameters were recorded and then compared between the groups.

Results: Patients in failed AVF group were significantly older and had higher smoking rate than those in non-failed AF group. The median values of fibrinogen, platelet-to-lymphocyte ratio and SCI were significantly higher in failed AVF group than in non-failed AVF group. With regards to other clinical characteristics and laboratory parameters, no significant differences were detected between the groups in the univariate analyses. Only age and SCI maintained their significances in the multivariate logistic regression analysis, and were therefore considered as the independent predictors of AVF failure. ROC curve analysis revealed that SCI of 37.9 constituted the optimum cut-off value with 97.7% sensitivity and 94.5% specificity rates for predicting AVF failure.

Conclusion: The present study demonstrated for the first time in the literature that SCI significantly and independently predicted early AVF failure following radiocephalic AVF creation.

Polytetrafluoroethylene (PTFE) grafts are of great importance for vascular surgery and many methods have been developed to improve their biocompatibility. The most important of these methods is the coating of the inner surfaces of the grafts. In this study, the effects of surface coatings used in vascular grafts on endothelialization and bacterial biofilm formation were investigated. Three different PTFE graft types, heparin coated, carbon coated and uncoated, were compared. HUVEC cell culture was used for endothelialization experiments and Staphylococcus aureus strain was used for biofilm formation. Endothelialization was evaluated by inverted microscopy and scanning electron microscopy (SEM). Heparin-coated grafts showed more biofilm formation than other graft types (p < 0.01). Moderate biofilm formation was observed in carbon-coated grafts (p < 0.05). When evaluating endothelialization, heparin-coated grafts showed more cell adhesion in the first days, but lagged behind the other graft types in the following days. Carbon-coated grafts showed more endothelial cell proliferation in the long term. While biofilm formation was high in heparin-coated grafts, carbon-coated grafts provided better endothelialization. Our study showed that the coating of PTFE grafts significantly affects biocompatibility and infection risk.

Introduction: Amikacin is sequestered in polyacrylonitrile filters. Methods mitigating sequestration are unknown. Amikacin elimination in a polyacrylonitrile-derived filter preloaded with amikacin was studied in a preliminary study.

Methods: Amikacin concentrations were determined using an immunochemical method. Prismaflex™, Baxter-Gambro, and the ST™150 filter were used. Sessions were performed in a continuous diafiltration mode. Diafiltration flow rate was set to 2500 mL/h and filtration to 500 mL/h pre- and 1000 mL/h post-dilution. Net loss was set to zero. In sessions with preload, a 150 mg dose of amikacin was injected in the first 1 L bag of physiological saline when starting the priming. NeckEpur^® method was used for pharmacokinetic calculations.

Results: In the central compartment (CC), the mean initial concentration in the sessions without and with preload was 81.8 ± 6.0 mg/L. There were no significant differences in the AUC_cc and AUC_inlet without or with preload. The preloading dose induced a significant increase in the AUC_outlet. Compared with sessions without preload, the clearance from the CC in sessions with preload decreased from 4.94 ± 0.43 to 3.75 ± 0.32 L/h, respectively. The elimination rates by diafiltration and sequestration in the sessions without and with preload were 82.3 ± 6.2/17.8 ± 6.2% and 125 ± 9.2%/0 ± 0%, respectively. The 150 mg loading dose was eliminated by diafiltration (42.5%) and by sequestration (57.5%).

Conclusion: Preloading filter with amikacin modifies the disposition of amikacin by preventing further sequestration. Studies are needed to define an efficient preloading dosage regimen in actual condition of use.