International Journal of Artificial Organs最新文献

Objective: We investigated the effect of Remote Ischemic Preconditioning (RIPC) on the inflammatory response during CPB by means of serum presepsin levels at preoperative and postoperative 1st and 24th h.

Methods: In this prospective, randomized, cross-sectional study we included 81 patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass (CPB). Patients were randomized and RIPC was applied to 40 patients in the study group before anesthesia. The remaining 41 patients were determined as the control group. The relationships between RIPC and factors such as presepsin, C-reactive protein (CRP), and leukocyte levels were investigated.

Results: There was no significant difference between the groups in postoperative leukocyte and CRP values (p = 0.52, p = 0.13, respectively). When the preoperative and postoperative first hour presepsin values of the patients were compared, no significant difference was found in the control group (p = 0.17), but a significant difference was found in the study group (p < 0.05). When the presepsin values were compared between the groups, a significant difference was found only in the postoperative first hour value (p < 0.05).

Conclusions: It was observed that RIPC application caused to increase the presepsin levels in the postoperative first hour significantly in the study group (p < 0.05).

Introduction: A feared complication of an acute myocardial infarction (AMI) is cardiac arrest (CA). Even if return of spontaneous circulation is achieved, cardiogenic shock (CS) is common. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) supports patients with CS and is often used in conjunction with an Impella device (2.5 and CP) to off-load the left ventricle, although limited evidence supports this approach.

Methods: The goal of this study was to determine whether a mortality difference was observed in VA-ECMO alone versus VA-ECMO with Impella (ECPELLA) in patients with CS from AMI and CA. A retrospective chart review of 50 patients with AMI-CS and CA and were supported with VA-ECMO (n = 34) or ECPELLA (n = 16) was performed. The primary outcome was all-cause mortality at 6-months from VA-ECMO or Impella implantation. Secondary outcomes included in-hospital mortality and complication rates between both cohorts and intensive care unit data.

Results: Baseline characteristics were similar, except patients with ST-elevation myocardial infarction were more likely to be in the VA-ECMO group (p = 0.044). The ECPELLA cohort had significantly worse survival after VA-ECMO (SAVE) score (p = 0.032). Six-month all-cause mortality was not significantly different between the cohorts, even when adjusting for SAVE score. Secondary outcomes were notable for an increased rate of minor complications without an increased rate of major complications in the ECPELLA group.

Conclusions: Randomized trials are needed to determine if a mortality difference exists between VA-ECMO and ECPELLA platforms in patients with AMI complicated by CA and CS.

Artificial disc replacement (ADR) is a clinical procedure used to diagnose cervical degenerative disc disease, preserving range of motion (ROM) at the fixation level and preventing adjacent segment degeneration (ASD). This study analyzed the biomechanics of ADR by examining range of motion (ROM), stress levels in bone and implants, and strain in the bone-implant interface using multi-scale loadings. The study focused on single- and double-level patients across various loading scales during physiological motions within the cervical spine. Results showed increased ROM in single-level and double-level fixations during physiological loadings, while ROM decreased at the adjacent level of fixation with the intact cervical spine model. The Prodisc-Implant metal endplate experienced a maximum von Mises stress of 432 MPa during axial rotation, confirming the long durability and biomechanical performance of the bone-implant interface.

Background/objective: A high prevalence of fatigue and a positive association between fatigue and post-hemodialysis recovery have been reported in predominantly white populations of maintenance hemodialysis (MHD) patients. The present study evaluates associations between self-reported fatigue by the 11-item Chalder Fatigue Questionnaire (CFQ-11) and the need for post-hemodialysis recovery in a predominantly African-descent MHD population.

Methods: A total of 233 patients (94% Black or Mixed-Race) participating in the "Prospective Study of the Prognosis of Patients on Maintenance Hemodialysis" (PROHEMO), Salvador, Brazil were recruited for this cross-sectional study. The CFQ-11 was used to measure fatigue: <4 for absent or mild, ⩾4 for moderate to severe. Patients were also asked if they needed some time to recover after the hemodialysis. Logistic regression was used to estimate odds ratio (OR) of the association with adjustments for age, sex, race, educational level, economic class level, diabetes, hearth failure, and hemoglobin.

Results: Mean age was 51.5 ± 12.5 years. Moderate to severe fatigue (⩾4 points) was observed in 70.8% (165/233), and absent or mild fatigue (<4 points) in 29.2% (68/233). Compared to patients with fatigue scores <4 (20.6%), the need for post-hemodialysis recovery was 2.5 times greater in patients with fatigue scores ⩾4 (52.7%). The covariate-adjusted logistic regression OR was 4.60, 95% CI: 2.27, 9.21.

Conclusion: This study in MHD patients of predominantly African descent supports self-reported fatigue assessed by the CFQ-11 as a relevant predictor of the need for post-hemodialysis recovery. The results offer a rationale for investigating whether interventions to prevent fatigue reduce the need of post-hemodialysis recovery.

Performance evaluation of new dialysis membranes is primarily performed in vitro, which can lead to differences in clinical results. Currently, data on dialysis membrane performance and safety are available only for haemodialysis patients. Herein, we aimed to establish an in vivo animal model of dialysis that could be extrapolated to humans. We created a bilateral nephrectomy pig model of renal failure, which placed a double-lumen catheter with the hub exposed dorsally. Haemodialysis was performed in the same manner as in humans, during which clinically relevant physiologic data were evaluated. Next, to evaluate the utility of this model, the biocompatibility of two kinds of membranes coated with or without vitamin E used in haemodiafiltration therapy were compared. Haemodialysis treatment was successfully performed in nephrectomized pigs under the same dialysis conditions (4 h per session, every other day, for 2 weeks). In accordance with human clinical data, regular dialysis alleviated renal failure in pigs. The vitamin E-coated membrane showed a significant reduction rate of advanced oxidation protein products during dialysis than non-coated membrane. In conclusion, this model mimics the pathophysiology and dialysis condition of patients undergoing haemodialysis. This dialysis treatment model of renal failure will be useful for evaluating the performance and safety of dialysis membranes.

Background: This study investigates the hypothesis that presence of atrial fibrillation (AF) in LVAD patients increases thrombogenicity in the left ventricle (LV) and exacerbates stroke risk.

Methods: Using an anatomical LV model implanted with an LVAD inflow cannula, we analyze thrombogenic risk and blood flow patterns in either AF or sinus rhythm (SR) using unsteady computational fluid dynamics (CFD). To analyze platelet activation and thrombogenesis in the LV, hundreds of thousands of platelets are individually tracked to quantify platelet residence time (RT) and shear stress accumulation history (SH).

Results: The irregular and chaotic mitral inflow associated with AF results in markedly different intraventricular flow patterns, with profoundly negative impact on blood flow-induced stimuli experienced by platelets as they traverse the LV. Twice as many platelets accumulated very high SH in the LVAD + AF case, resulting in a 36% increase in thrombogenic potential score, relative to the LVAD + SR case.

Conclusions: This supports the hypothesis that AF results in unfavorable blood flow patterns in the LV adding to an increased stroke risk for LVAD + AF patients. Quantification of thrombogenic risk associated with AF for LVAD patients may help guide clinical decision-making on interventions to mitigate the increased risk of thromboembolic events.

Background: Thrombosis within extracorporeal membrane oxygenation (ECMO) circuits is a common complication that dominates clinical management of patients receiving mechanical circulatory support. Prior studies have identified that over 80% of circuit thrombosis can be attributed to tubing-connector junctions.

Methods: A novel connector was designed that reduces local regions of flow stagnation at the tubing-connector junction to eliminate a primary source of ECMO circuit thrombi. To compare clotting between the novel connectors and the traditional connectors, both in vitro loops and an in vivo caprine model of long-term (48 h) ECMO were used to generate tubing-connector junction clots.

Results: In vitro, the traditional connectors uniformly (9/9) formed large thrombi, while novel connectors formed a small thrombus in only one of nine (p < 0.0001). In the long-term goat ECMO circuits, the traditional connectors exhibited more thrombi (p < 0.04), and these thrombi were more likely to protrude into the lumen of the tubing (p < 0.001).

Conclusion: Both in vitro and in vivo validation experiments successfully recreated circuit thrombosis and demonstrate that the adoption of novel connectors can reduce the burden of circuit thrombosis.

Introduction: Several studies have reported that patients with low levels of Vitamin D₃ have impaired responses to vaccination, including COVID-19 vaccines, so we reviewed the response to COVID-19 vaccination in haemodialysis patients, who typically have reduced Vitamin D₃ levels.

Methods: The inhibitory antibody (IC50) responses to several COVID-19 variants following vaccination in a cohort of United Kingdom haemodialysis patients receiving two vaccinations between March 2021 and May 2021 were reviewed.

Results: A total of 183 haemodialysis patients, 65.5% male, mean age 65.6 ± 14.1 years, 46.4% diabetic, 42.1% white ethnicity, body mass index 26.9 ± 6.5 kg/m² dialysis vintage 36.2 (18.3-69.3) months were studied. Following the first vaccination, the median IgG microneutralisation IC50 response was undetectable for all variants (wild-type, alpha, beta and delta). Follow-up after the second vaccination showed that the microneutralisation response to all variants increased and was greater for the wild-type variant compared to alpha, beta and delta, all p < 0.001, There were no differences comparing the IC50 responses according to 25-Vitamin D₃ levels, and the prescription of activated Vitamin D. Although patients who had previously tested positive for COVID-19 prescribed higher doses of alfacalcidol had higher seroprotection responses to the alpha (χ² = 15, p = 0.002) and beta variants. (χ² = 13, p = 0.005).

Conclusions: The response to COVID-19 vaccination was reduced in our elderly haemodialysis patients compared to younger less frail patients, however there was no overall demonstrable effect of either 25-Vitamin D₃ levels or the prescription of activated forms of Vitamin D on the immune response following vaccination against COVID-19, unless patients had previously tested positive for COVID-19.

Objective: Our study aimed to compare the outcomes of COVID-19 patients who met a low-risk inclusion criteria for veno-venous extra corporeal membrane oxygenation (VV ECMO) with those who did not meet criteria due to higher risk but were subsequently cannulated.

Methods: This was a retrospective observational cohort study that included adult patients who were placed on VV ECMO for COVID-19 related acute respiratory distress syndrome (ARDS) at a tertiary care academic medical center. The primary outcome was the association between the low-risk criteria and mortality. The patients met the criteria if they met EOLIA severe ARDS criteria, no absolute contraindications (age > 60 years, BMI > 55 kg/m², mechanical ventilation (MV) duration >7 days, irreversible neurologic damage, chronic lung disease, active malignancy, or advanced multiorgan dysfunction), and had three or less relative contraindications (age > 50 years, BMI > 45 kg/m², comorbidities, MV duration > 4 days, acute kidney injury, receiving vasopressors, hospital LOS > 14 days, or COVID-19 diagnosis > 4 weeks).

Results: Sixty-five patients were included from March 2020 through March 2022. Patients were stratified into low-risk or high-risk categories. The median Sequential Organ Failure Assessment score was 7 and the median PaO2/FiO2 ratio was 44 at the time of ECMO cannulation. The in-hospital mortality was 47.8% in the low-risk group and 69.0% in the high-risk group (p = 0.096).

Conclusion: There was not a statistically significant difference in survival between low-risk patients and high-risk patients; however, there was a trend toward higher survival in the lower-risk group.

Reliable stratification of the risk of early mortality after postcardiotomy veno-arterial extracorporeal membrane oxygenation (V-A-ECMO) remains elusive. In this study, we externally validated the PC-ECMO score, a specific risk scoring method for prediction of in-hospital mortality after postcardiotomy V-A-ECMO. Overall, 614 patients who required V-A-ECMO after adult cardiac surgery were gathered from an individual patient data meta-analysis of nine studies on this topic. The AUC of the logistic PC-ECMO score in predicting in-hospital mortality was 0.678 (95%CI 0.630-0.726; p < 0.0001). The AUC of the logistic PC-ECMO score in predicting on V-A-ECMO mortality was 0.652 (95%CI 0.609-0.695; p < 0.0001). The Brier score of the logistic PC-ECMO score for in-hospital mortality was 0.193, the slope 0.909, the calibration-in-the-large 0.074 and the expected/observed mortality ratio 0.979. 95%CIs of the calibration belt of fit relationship between observed and predicted in-hospital mortality were never above or below the bisector (p = 0.072). The present findings suggest that the PC-ECMO score may be a valuable tool in clinical research for stratification of the risk of patients requiring postcardiotomy V-A-ECMO.