International Journal of Artificial Organs最新文献

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.

Cefiderocol, a novel broad-spectrum cephalosporin, exhibits promising efficacy against carbapenem-resistant Gram-negative bacteria via a "Trojan horse" mechanism. Its pharmacokinetics (PK) and pharmacodynamics (PD) in critically ill patients, particularly under extracorporeal therapies such as Continuous Renal Replacement Therapy (CRRT) and hemoadsorption (HA), remain underexplored. This case report evaluates the PK/PD profile of cefiderocol in a 16-year-old male with relapsed B-cell leukemia, multi-organ failure, and septic shock treated with Continuous Venous-Venous Hemodiafiltration (CVVHDF) and Cytosorb® HA. Cefiderocol clearance and drug removal were monitored using Therapeutic Drug Monitoring (TDM). Data demonstrated that cefiderocol was susceptible to removal during CVVHDF and HA, with variable clearance rates and removal percentages across time points. HA displayed significant cefiderocol removal during the initial 120-180 min, tapering thereafter, while CVVHDF exhibited a fluctuating clearance pattern influenced by effluent rates. Despite achieving PK/PD efficacy targets (C_min/MIC ⩾ 4) in 71.4% of cases, variability was observed. Findings highlight the need for personalized antibiotic dosing in critically ill patients undergoing extracorporeal therapies. Adjustments such as additional dosing during early HA or extended cefiderocol infusion (2-3 h) at shorter intervals (every 6 h) may optimize therapeutic outcomes. These insights underscore the critical role of TDM in ensuring effective PK/PD target attainment, though further research is required to substantiate these preliminary observations.

Sleeve gastrectomy is safe and effective in patients with left ventricular assist devices (LVADs) and morbid obesity to improve candidacy for transplantation and increase survival rates. Literature describing warfarin anticoagulation in this population is limited. A single-center, propensity score-matched, retrospective cohort study was conducted to determine if sleeve gastrectomy in LVAD-implanted patients has an effect on warfarin dose requirements in the outpatient setting. Patients were eligible for inclusion if they were 18 years of age or older, underwent LVAD implant at the study center, and were discharged from the hospital on warfarin therapy. They must have at least 8 weeks of available follow-up data post-discharge. Propensity matching was utilized to identify a non-sleeve gastrectomy LVAD-only patients for comparison. A total of 96 LVAD-only patients and 48 LVAD plus sleeve gastrectomy patients were included in the final analysis. Outpatient warfarin requirements increased from baseline over time in both groups, with no significant differences between groups except at month 12, with a mean total weekly dose of 38.1 ± 21.4 mg in the LVAD only group and 46.8 ± 18.6 mg in the LVAD with sleeve gastrectomy group (p = 0.05). The sleeve gastrectomy group had a significantly lower warfarin doses per kilogram of body weight until month 6 post-discharge. The percent time in therapeutic range was significantly lower in the SG group at the 8 week, 3 month, and 6 month interval time point. There were no significant differences in the incidence of bleeding or thromboembolic events.

Objective: To evaluate the effectiveness and safety of artificial intermittent infusion hemodiafiltration (I-HDF) in maintenance hemodialysis (MHD) patients with intradialytic hypotension (IDH), and to determine the optimal infusion dosage.

Methods: This single-center, prospective, self-controlled study included 30 MHD patients with IDH, treated from December 2022 to July 2023. Patients underwent three sessions of I-HDF as treatment group and conventional hemodialysis as control group. Comparisons were made between the two groups regarding changes in blood pressure, hypotension symptoms, changes in body water content, and achievement of infusion doses.

Results: 1. The fluctuation amplitude of SBP in the treatment group was 18.96 ± 10.400, while in the control group it was 27.4 ± 11.796. There was a significant difference between the two groups (p < 0.05). 2. During 90 sessions of dialysis, 39 interventions were needed in the treatment group, compared to 59 interventions in the control group. The treatment group required fewer interventions, with a significant difference (p < 0.05). 3. No hypotension symptoms occurred in the treatment group, whereas six cases were observed in the control group, which was significantly higher (p < 0.05). 4. One patient in the 250 ml infusion group experienced chest tightness. Among the three infusion groups, the 250 ml group had the greatest fluctuation in DBP, with a significant difference (p < 0.05). 5. Among the three infusion volumes groups, there was a significant difference between the theoretical and actual infusion volumes in the 150 and 200 ml groups (p < 0.05).

Conclusion: The artificial I-HDF mode effectively improves the occurrence of IDH. An infusion dose of 150-200 ml is deemed appropriate.