[Vaccination Against COVID-19 in a Network of Hemodialysis Units in Portugal: A Promising Experience].

INTRODUCTION: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for coronavirus disease 2019 (COVID-19) seriously affected Portugal, particularly in the elderly population with a high number of comorbidities, including patients with chronic kidney disease in stage 5 (CKD-5D) undergoing a regular dialysis program. The aims of this study were to identify the impact of vaccination on the incidence of new daily cases and mortality in the CKD-5D population. MATERIAL AND METHODS: Prospective, observational study, involving patients with CKD-5D from 38 NephroCare clinics, Portugal. Daily SARS-CoV-2 infections and mortality among these patients was compared with the incidence in the general population. Three periods were analysed: before vaccination, during the vaccination process, and a third period after complete vaccination with the Pfizer-BioNTech' Comirnaty® vaccine. The primary outcome was infection by the SARS-CoV-2 virus and the secondary outcome was death associated with the infection. RESULTS: A total of 4617 patients (average of 69.37 years of age) were analysed. During the first period, there was a significantly higher COVID-19 incidence of 14.9% in patients with CKD-5D compared with the general population (7.9%; p < 0.001). During the fifteen days after the complete vaccination, results reverted to a significant decrease in COVID-19 cases was observed (p < 0.001). The mortality rate among CKD-5D was significantly higher than in the general population (p < 0.001). DISCUSSION: A high incidence rate of infection was observed in CKD-5D patients, probably due to several factors such as advanced age, number of comorbidities, inability to remain in confinement, among others. After vaccination there was a significant reduction of new cases. CONCLUSION: Vaccination significantly reduced SARS-CoV-2 infection in patients with CKD-5D.

Introdução: Portugal foi atingido severamente pela síndrome respiratória aguda grave (SARS-CoV-2), responsável pela doença por coronavírus 2019 (COVID-19). A população idosa e com comorbilidades, na qual estão incluídas as pessoas com doença renal crónica em estádio 5 em programa regular de hemodiálise (CKD-5D), foi particularmente afetada. Definimos como objetivos deste estudo a identificação do impacto da vacinação no surgimento de novos casos diários e a sua influência na mortalidade na população CKD-5D.Material e Métodos: Estudo observacional, prospetivo, envolvendo doentes com CKD-5D de 38 clínicas da NephroCare, Portugal. A infeção e a mortalidade diárias por SARS-CoV-2 destes doentes foi comparada com a taxa de incidência na população em geral. Foram analisados três períodos: antes da vacinação, durante, e um terceiro período após a vacinação completa pela vacina Comirnaty ®, da Pfizer-BioNTech. Foi considerado desfecho primário a infeção pelo vírus SARS-CoV-2 e como desfecho secundário, a morte associada à infeção.Resultados: Foram analisados 4617 doentes com uma média de 69,37 anos. Durante o primeiro período, verificou-se uma taxa de incidência de COVID 19 de 14,9%, significativamente maior nos doentes CKD-5D quando comparado com a taxa de incidência de 7,9% da população em geral (p < 0,001). Durante os quinze dias após a vacinação completa observámos uma reversão, com diminuição significativa de casos de COVID-19 (p < 0,001). A mortalidade atribuível a COVID-19 no grupo CKD-5D foi significativamente superior ao da população em geral (p < 0,001).Discussão: Observámos uma elevada taxa de incidência de infeção nos doentes CKD-5D, presumivelmente correlacionada com vários fatores como a idade avançada, as comorbilidades, a impossibilidade de confinar, entre outros. Após a vacinação verificou-se uma redução significativa de novos casos.Conclusão: A vacinação reduziu significativamente a infeção por SARS-CoV-2 nos doentes CKD-5D.

Multiple single cannulation technique of arteriovenous fistula: A randomized controlled trial.

INTRODUCTION: Despite the impact needling has had on vascular access survival and patient outcome, there is no universal or standardized method proposed for proper cannulation. Rigorous studies are needed, examining cannulation practices, and challenges to achieving complication-free cannulation. METHODS: This randomized, open-label trial was conducted at 18 dialysis units owned by a large private dialysis provider operating in Portugal. Eligible patients were adults on chronic hemodialysis, with a new arteriovenous fistula (AVF); cannulated for at least 4 weeks complication-free. Patients were randomly assigned in a 1:1 ratio to one of three cannulation techniques (CT): Multiple Single cannulation Technique (MuST), rope-ladder (RLC), and buttonhole (BHC). The primary endpoint was AVF primary patency at 1 year. FINDINGS: One hundred seventy-two patients were enrolled between March 2014 and March 2017. Fifty-nine patients were allocated to MuST, 56 to RLC, and 57 to BHC. MuST and RLC were associated with a better AVF primary patency than BHC. Primary patency at 12 months was 76.3% in MuST, 59.6% in BHC, and 76.8% in RLC group. Mean AVF survival times were 10.5 months (95% CI = 9.6, 11.3) in the MuST group, 10.4 months (95% CI = 9.5, 11.2) in RLC, and 9.5 months (95% CI = 8.6, 10.4) in BHC. BHC was a significant risk predictor for AVF survival with 2.13 times more events than the other two CT (HR 2.13; 95% CI = 1.07, 4.21; p = 0.03). DISCUSSION: MuST was easy to implement without a diagram and there is no need to use blunt needles. This study showed MuST was efficacious and safe in maintaining the longevity of AVF in dialysis patients.

Development and Validation of a Machine Learning Model Predicting Arteriovenous Fistula Failure in a Large Network of Dialysis Clinics.

Background: Vascular access surveillance of dialysis patients is a challenging task for clinicians. We derived and validated an arteriovenous fistula failure model (AVF-FM) based on machine learning. Methods: The AVF-FM is an XG-Boost algorithm aimed at predicting AVF failure within three months among in-centre dialysis patients. The model was trained in the derivation set (70% of initial cohort) by exploiting the information routinely collected in the Nephrocare European Clinical Database (EuCliD®). Model performance was tested by concordance statistic and calibration charts in the remaining 30% of records. Features importance was computed using the SHAP method. Results: We included 13,369 patients, overall. The Area Under the ROC Curve (AUC-ROC) of AVF-FM was 0.80 (95% CI 0.79-0.81). Model calibration showed excellent representation of observed failure risk. Variables associated with the greatest impact on risk estimates were previous history of AVF complications, followed by access recirculation and other functional parameters including metrics describing temporal pattern of dialysis dose, blood flow, dynamic venous and arterial pressures. Conclusions: The AVF-FM achieved good discrimination and calibration properties by combining routinely collected clinical and sensor data that require no additional effort by healthcare staff. Therefore, it can potentially enable risk-based personalization of AVF surveillance strategies.

Safe Needling of Arteriovenous Fistulae in Patients on Hemodialysis: Literature Review and a New Approach.

Although buttonhole cannulation has some benefits compared to rope-ladder cannulation, the increase of infection rates represents a major obstacle to patient safety, and its use is questionable in routine clinic practice. On the other hand, rope-ladder cannulation is difficult to implement even with a prescribed protocol, leading the cannulator in daily practice to a possible use of the area technique. This article provides a reflection on the impact of cannulation technique on the safety of patients on regular hemodialysis treatment and describes a new approach for arteriovenous fistula cannulation, the Multiple Single Cannulation Technique (MuST). The MuST has not been described before, but it has been used with promising results. Further studies are needed to confirm the benefits of this cannulation technique.

Does subjective assessment of dialyzer appearance reflect dialyzer performance in online hemodiafiltration?

INTRODUCTION: In post-dilution online hemodiafiltration, a very thin balance subsists in preventing coagulation of the extracorporeal circuit (ECC) during treatment and bleeding in the patient, concerning dialyzer status and anticoagulation dose. The aim of this study was to assess whether there are clinical outcome differences between the visual aspect of the dialyzer's status in terms of clotted fibers at end of dialysis treatments, single-pool urea kinetic modeling (spKt/V) and substitution volume (SubsVol). METHODS: It is a multicenter, descriptive-correlational study, involving 2829 patients during April 2016. Previous training was given to the Nursing staff to evaluate and classify both the dialyzer's and the venous chamber's appearance of the ECC venous line. Registration was performed at bedside immediately after the patient disconnection. FINDINGS AND DISCUSSION: Mean age was 68.96 years (SD = 13.75), 60.8% were men. The average hematocrit was 33.91% (SD = 3.45%). The average dry weight was 68.53 kg (SD = 13.27 kg). Mean unfractioned heparin (UFH) dose was 58.13 IU/kg. Only 32.4% of the patients had a clean dialyzer at the end of treatment. 19.4% of patients finished the treatment with more than 10% of clotted fibers. Patients with no residual blood (clean, 32.4%) presented a higher UFH dose (66.32 IU/kg) compared to overall average dose. UFH dose had a significant effect on dialyzer status. There were significant differences in average of spKt/V and SubsVol between the category clean and the other categories of dialyzer's status. Evaluating the dialyzer status represents an excellent opportunity to help the physicians to establish an ideal heparin dose. Only the category clean is significant to achieve the target. The nursing staff, by classifying the ECC appearance at patient's bedside and recording it in a centralized database, can be a major contributor to achieve an individualized and optimal UFH dose and subsequently better patient outcomes.

SELF-REPORTED MEDICATION ADHERENCE IN PATIENTS WITH END-STAGE KIDNEY DISEASE UNDERGOING ONLINE-HAEMODIAFILTRATION.

INTRODUCTION: Non-adherence to therapeutic regimens is a recognised problem in the dialysis population that compromises the opportunity to achieve maximum treatment effect and, therefore, might lead to increased morbidity and mortality. In this study, we aimed to evaluate the prevalence of self-reported medication non-adherence in patients with end-stage kidney disease (ESKD) undergoing online-haemodiafiltration (OL-HDF), as well as to evaluate the factors that could affect medication adherence. PATIENTS AND METHODS: We evaluated 122 patients with ESKD undergoing OL-HDF. Patients' reported medication adherence was measured by the Measure Treatment Adherence (MTS) scale. Social support was evaluated by the abbreviated Lubben Social Network Scale (LSNS); depression status by the Geriatric Depression Scale (GDS). Socio-demographic, co-morbidity and clinical data were also evaluated. RESULTS: Our results showed that 10.7% of patients with ESKD perceived themselves as non-adherent to medication. When two groups of patients (adherent and non-adherents) were compared, significantly higher levels of triglycerides, and higher diastolic and systolic blood pressure were found in the non-adherent group. Significant correlations were found between the MTS score, and diastolic blood pressure, age and GDS score. Multiple regression analysis identified age and the GDS score as independent variables significantly associated with the MTS score. CONCLUSIONS: Non-adherence to therapeutic regimens in patients with ESKD is associated with higher levels of triglycerides and higher blood pressure and are, therefore, at a higher cardiovascular risk. Moreover, we found that age and depression status are important variables in non-adherence to therapeutic regimens.