The use of intravascular contrast media in patients with impaired kidney function - joint clinical practice position statement of the Polish Society of Nephrology and the Polish Medical Society of Radiology.

Radiological procedures utilising intravascular contrast media (ICM) are fundamental to modern medicine, enhancing diagnostics and treatment in diverse medical fields. However, the application of ICM has been constrained in patients with compromised kidney function due to perceived nephrotoxic risks, called contrast-induced nephropathy or contrastinduced acute kidney injury. Historical evidence marked ICM as a possible contributor to kidney damage. This led to restrictive guidelines advocating limited ICM use in patients with impaired renal function, preventing crucial radiographic interventions in patients with acute kidney injury (AKI) and chronic kidney disease. Recent advances challenge these traditional views. In particular, no direct causal relationship has been confirmed between contrast admi-nistration and elevated serum creatinine concentrations in humans. Furthermore, contemporary research models and meta-analyses do not associate AKI with contrast usage. This paper, prepared by a cross-disciplinary team of nephrologists and radiologists, presents updated guidelines for ICM application amid renal function impairments, emphasising the reduced nephrotoxic risks currently understood and loosening the previous restrictive approach in patients with renal dysfunction.

Point-of-Care Testing to Differentiate Various Acid-Base Disorders in Chronic Kidney Disease.

BACKGROUND: Normal-anion-gap metabolic acidosis (AGMA) and high-anion-gap metabolic acidosis (HAGMA) are two forms of metabolic acidosis, which is a common complication in patients with chronic kidney disease (CKD). The aim of this study is to identify the prevalence of various acid-base disorders in patients with advanced CKD using point-of-care testing (POCT) and to determine the relationship between POCT parameters. METHODS: In a group of 116 patients with CKD in stages G4 and G5, with a mean age of 62.5 ± 17 years, a sample of arterial blood was taken during the arteriovenous fistula procedure for POCT, which enables an assessment of the most important parameters of acid-base balance, including: pH, base excess (BE), bicarbonate (HCO3-), chloride(Cl-), anion gap (AG), creatinine and urea concentration. Based on this test, patients were categorized according to the type of acidosis-base disorder. RESULTS: Decompensate acidosis with a pH < 7.35 was found in 68 (59%) patients. Metabolic acidosis (MA), defined as the concentration of HCO3- ≤ 22 mmol/L, was found in 92 (79%) patients. In this group, significantly lower pH, BE, HCO3- and Cl- concentrations were found. In group of MA patients, AGMA and HAGMA was observed in 48 (52%) and 44 (48%) of patients, respectively. The mean creatinine was significantly lower in the AGMA group compared to the HAGMA group (4.91 vs. 5.87 mg/dL, p < 0.05). The AG correlated positively with creatinine (r = 0.44, p < 0.01) and urea (r = 0.53, p < 0.01), but there was no correlation between HCO3- and both creatinine (r = -0.015, p > 0.05) and urea (r = -0.07, p > 0.05). The Cl- concentrations correlated negatively with HCO3- (r = -0.8, p < 0.01). CONCLUSIONS: The most common type of acid-base disturbance in CKD patients in stages 4 and 5 is AGMA, which is observed in patients with better kidney function and is associated with compensatory hyperchloremia. The initiation of renal replacement therapy was significantly earlier for patients diagnosed with HAGMA compared to those diagnosed with AGMA. The more advanced the CKD, the higher the AG.

The Influence of Healthy Habits on Cognitive Functions in a Group of Hemodialysis Patients.

(1) Background: Cognitive impairment (CI) is more prevalent in hemodialysis (HD) patients than in the general population. The purpose of this study was to examine if behavioral, clinical, and vascular variables are linked with CI in individuals with HD. (2) Methods: Initially, 47 individuals with chronic HD volunteered to participate in the trial, but only 27 patients ultimately completed the Montreal Cognitive Assessment (MoCA) and the Computerized Cognitive Assessment Tool (CompBased-CAT). We collected information on smoking, mental activities, physical activity (Rapid Assessment of Physical Activity, RAPA), and comorbidity. The oxygen saturation (rSO2) and pulse wave velocity (PWV; IEM Mobil-O-Graph) of the frontal lobes were measured. (3) Results: Significant associations were discovered between MoCA and rSO2 (r = 0.44, p = 0.02 and r = 0.62, p = 0.001, right/left, respectively), PWV (r = -0.69, p = 0.0001), CCI (r = 0.59, p = 0.001), and RAPA (r = 0.72, p = 0.0001). Those who actively occupied their time during dialysis and non-smokers achieved higher cognitive exam results. A multivariate regression study demonstrated that physical activity (RAPA) and PWV had separate effects on cognitive performance. (4) Conclusions: Cognitive skills are related to inter-dialysis healthy habits (physical activity, smoking) and intra-dialysis activities (tasks and mind games). Arterial stiffness, oxygenation of the frontal lobes, and CCI were linked with CI.

High Serum IL-31 Concentration Is Associated with Itch among Renal Transplant Recipients.

Chronic itch (CI) is a common symptom caused by both dermatological and systemic disorders. CI is also a frequent, burdensome symptom among renal transplant recipients (RTR); however, its pathophysiology is not fully understood. The aim of this study was to assess the differences in concentration of IL-31 among itchy RTR. The study was performed on a group of selected 129 RTRs (54 itchy and 75 non-itchy patients). Itch severity was assessed with the use of the numeral rating scale (NRS) and the 4-item itch questionnaire (4IIQ). Every subject had his blood drawn to measure the concentration of IL-31. The results were subsequently compared and correlated. The mean concentration differed significantly between RTR suffering from itch (602.44 ± 534.5 pg/mL), non-itchy RTR (161.49 ± 106.61 pg/mL), and HC (110.33 ± 51.81 pg/mL) (p < 0.001). Post-hoc analysis revealed a statistically significantly increased IL-31 serum concentration in itchy RTR in comparison to the non-itchy RTR group (p < 0.001) and HC (p < 0.001). No significant difference was observed in IL-31 serum levels between non-itchy RTRs and HC. No correlation between IL-31 and itch intensity was found. The results of our study clearly demonstrate the association between IL-31 levels and CI in patients after renal transplantation.

Psychosocial Burden of Itch among Renal Transplant Recipients.

Itch is the most common symptom of chronic dermatoses. Moreover, itch may be associated with systemic disorders. Chronic kidney disease­associated itch (CKD-aI) may affect up to 20% of renal transplant recipients (RTR). The aim of the study was to assess psychosocial burden of itch in RTR. The study was performed on a group of 129 RTR, out of which 54 (41.9%) experienced itch in the previous 3 days. A specially designed questionnaire assessing anxiety, depression, stigmatization, and quality of life was used. Results: Patients suffering from itch in the previous 3 days achieved significantly higher scores in GAD-7 (p < 0.001), BDI (p < 0.001), HADS total score (p < 0.001), HADS Depression (p = 0.004), and HADS Anxiety (p < 0.001). Severity of itch correlated positively with HADS, stigmatization scale, and GAD-7. Itch in RTR was associated with higher incidence of depression assessed with BDI (OR 3.7). Moreover, higher prevalence of anxiety was found among patients suffering from CKD-aI, assessed with HADS A and GAD-7 (OR 2.7 and OR 4.8, respectively) The results of our study clearly demonstrate that itch among RTR is a significant burden. Higher prevalence of depression and anxiety in this groups indicate the necessity of addressing itch relief as a part of holistic approach to patients after renal transplantation.

Cognitive Impairment in End Stage Renal Disease Patients Undergoing Hemodialysis: Markers and Risk Factors.

(1) Background: Cognitive impairment (CI) is common in chronic kidney disease (CKD) and patients treated with hemodialysis. (2) Methods: The systematic review was prepared following the PRISMA statement (2013). The biomedical electronic databases MEDLINE and SCOPUS were searched. (3) Results: out of 1093 studies, only 30, which met problem and population criteria, were included in this review. The risk factors for CI can be divided into three groups: traditional risk factors (present in the general population), factors related to dialysis sessions, and nontraditional risk factors occurring more frequently in the HD group. (4) Conclusions: the methods of counteracting CI effective in the general population should also be effective in HD patients. However, there is a need to develop unique anti-CI approaches targeting specific HD risk factors, i.e., modified hemodialysis parameters stabilizing cerebral saturation and blood flow.

Arterial Stiffness Assessed by Oscillometric Method in Kidney Transplant, Predialysis, and Dialysis Patients.

INTRODUCTION: Chronic kidney disease (CKD) is strongly associated with a higher risk of cardiovascular disease (CV). An important nontraditional risk factor of cardiovascular disease in renal patients is vascular stiffness, which currently can be evaluated by oscillometric measuring of pulse wave velocity (PWV) and heart rate-corrected augmentation index (AIx@75). AIM: The aim of our study was to compare vascular stiffness between kidney transplant (KTx) recipients, patients on dialysis maintenance, and those in the predialysis period. MATERIALS AND METHODS: A cross-sectional study of 140 patients (52 in CKD stage 3-4; 37 in CKD stage 5 on hemodialysis maintenance [HD]; and 51 KTx recipients) had their PWV and AIx@75 measured with Mobil-O-Graph (IEM Gmbh, Stolberg, Germany) blood and pulse pressure monitor. RESULTS: KTx, HD, and CKD G3-4 were comparable in term of age, sex, body mass index, and diagnoses of diabetes mellitus and hypertension. The PWV was higher in the HD group than in the KTx and CKD G3-4 (9.4 m/s vs 8.4 m/s vs 7.9 m/s respectively; P < .05 for HD vs other groups), while the difference between the KTx and CKD G3-4 was not significant. AIx@75 values were similar in the HD and KTx groups (27.1 and 25.6; P > .05) and significantly lower in CDK G3-4 (17.8; P < .05). CONCLUSIONS: According to our results, the highest CV risk expressed by PWV (vascular stiffness) was found in hemodialysis patients. Although patients with CKD 3-4 and after KTx showed comparable large artery stiffness, transplant recipients additionally showed higher stiffness in smaller arteries as measured by heart rate-corrected AIx.

Clinical Characteristics of Itch in Renal Transplant Recipients.

Background: Chronic itch is the most common symptom in dermatology. End-stage renal disease-associated chronic itch (ESRDCI) is a common burden affecting up to 35% of patients treated with hemodialysis. Kidney transplant (KTx) is believed to be the best renal replacement therapy leading to the elimination of ESRDCI. The study was undertaken to characterize and assess the prevalence of itch among patients after renal transplantation. Methods: Between October 2019 and January 2020, we analyzed the data of 197 patients comprising 121 males (61.4%) and 76 females (38.6%) and aged 54.5 ± 13.6 years. The data collection was performed with a specially designed questionnaire. Level of itch after renal transplantation was assessed with the use of a Numeral Rating Scale, a Visual Rating Scale, and 4-Item Itch Questionnaire. Moreover, the previous 3 days of itching were evaluated. Results: The patients suffered from chronic renal disease for 20.2 ± 12.3 years, with a mean time of pre-transplant dialysis of 2.6 ± 2.4 years and a mean time after the KTx of 8.0 ± 6.5 years. The itch was present in 38.6% of the patients during the hemodialysis, and in 73.7% of cases, the itch ceased completely after the successful transplantation. Moreover, only 2.63% of the cases had no improvement. Nevertheless, the itch was reported in 42 (21.3%) renal transplant recipients (RTR), and in 22 (52.4%) cases, the itch appeared after transplantation. The majority of patients suffering from itch were women (54.8%). Itch in the last 3 days was reported in 21 patients. The itch's severity was assessed with a numerical rating scale (NRS), with the worst severity measured at 6 ± 2.2 points indicating moderate itch. In most cases (57.1%), itch affected multiple body areas. Extremities (50%) and the back (50%) were among the most frequently affected areas. The sensation had a mostly short duration and was most frequently reported in the evening. Only eight patients suffered for the whole day. Hot water was the most frequently reported (16.7%) alleviating factor, whilst sweat was responsible for itch aggravation in 35.9% of cases. Conclusion: Our analysis on representative patients' population indicates that itch after KTx is an important problem. Moreover, it is worth noting that more than half of the RTR did not suffer from itch during dialysis.

Dialysis membranes: A 2018 update.

Dialysis membranes are the basic element of a hemodialyzer. Synthetic and natural materials characterized by various fiber arrangements are used in their production. The most up-to-date ones are made of synthetic polymers such as polyamide, phosphatidylserine (PS), polyacrylonitrile-based fiber (PAN), polyarylethersulfone, polyethersulfone, or polymethylmethacrylate. Dialysis membranes are characterized by the ability to remove uremic molecules, which can be divided into small water-soluble compounds, protein-bound compounds and larger "middle molecules". Newer membranes such as medium cut off membranes (MCO) allow the removal of a wider spectrum of uremic molecules, which reduces the risk of late complications of dialysis. Dialysis membranes are used in therapy methods such as low flux, high flux or HDx therapy. An important aim in dialysis membrane development is to increase their biocompatibility. Insufficient biocompatibility can result in complement activation or platelet activation, which can lead to an increased risk of cardiovascular complications. The aim of the study is to discuss the latest reports on dialysis membranes.