Impact of different hemodiafiltration solutions on ionemia in long-term CRRT.

Critical patients with Acute Kidney Injury (AKI) requiring renal replacement therapy are in most cases eligible only for continuous modalities where the electrolyte balance control is a critical issue. The standard solutions used for hemodiafiltration, containing potassium at 2 mmol/L and no phosphorus, determines during the extended renal replacement therapy hypokalemia and hypophosphatemia. Therefore, solutions containing potassium and phosphate in physiological concentrations were formulated to avoid electrolyte imbalances and reduce ion alterations in prolonged treatments, these solutions are not routinely used in the standard clinical practice. To avoid electrolyte imbalances, we have first introduced in our practice two different solutions and then we have retrospectively analyzed the electrolyte balance upon these two solutions in order to identity the impact of these solutions on potassium and phosphate according to our clinical practice. We retrospectively analyzed 96 patients treated with Continuous Renal Replacement Therapy (CRRT) in the intensive care units (ICU) at Padua's University Hospital to evaluate the role on electrolyte balance of Phoxilium® and Prismasol 2® that differ in their composition and the need for electrolytes infusions. In the Phoxilium group the frequency of hypokalemia, hypophosphatemia, and the need of potassium and phosphate replacement were significantly reduced resulting in a reduction in complications, workload, and clinical risk associated with infusions of electrolytes. Our data demonstrated that the use of these two different hemodiafiltration solutions can reduce the occurrence of hypokalemia and hypophosphatemia during CRRT performing personalized treatments without the use of potassium and phosphate infusions.

The Pivotal Role of Oxidative Stress in the Pathophysiology of Cardiovascular-Renal Remodeling in Kidney Disease.

The excessive activation of the renin-angiotensin system in kidney disease leads to alteration of intracellular pathways which concur altogether to the induction of cardiovascular and renal remodeling, exposing these patients since the very beginning of the renal injury to chronic kidney disease and progression to end stage renal disease, a very harmful and life threatening clinical condition. Oxidative stress plays a pivotal role in the pathophysiology of renal injury and cardiovascular-renal remodeling, the long-term consequence of its effect. This review will examine the role of oxidative stress in the most significant pathways involved in cardiovascular and renal remodeling with a focus on the detrimental effects of oxidative stress-mediated renal abnormalities on the progression of the disease and of its complications. Food for thoughts on possible therapeutic target are proposed on the basis of experimental evidences.

Oxidative stress, inflammation, and peritoneal dialysis: A molecular biology approach.

The key role of oxidative stress (OxSt) and inflammation for the induction of cardiovascular disease, the leading cause of excess morbidity/mortality in chronic kidney disease and dialysis patients, is known and both the activations of NADPH oxidase and RhoA/Rho kinase (ROCK) pathway are pivotal for their effects. While specific hemodialysis procedures, such as hemodiafiltration with on-line reinfusion of ultrafiltrate and/or the use of vitamin E-coated dialyzers, are beneficial for OxSt and inflammation, studies in peritoneal dialysis (PD) are instead scarce and results seem not favorable. In nine patients under PD OxSt in terms of mononuclear cell protein level of p22phox (Western blot), subunit of NADPH oxidase, essential for the generation of OxSt, and MYPT-1 phosphorylation state (Western blot), a marker of ROCK activity, have been measured at the beginning and after 3 and 6 months of PD. Blood levels of interleukin 6 (IL-6), ferritin, and albumin have been considered for evaluating the inflammatory state. p22phox protein expression, MYPT-1-phosphorylation, and ferritin level were increased both at baseline vs healthy subjects (P = .02, P < .0001, P = .004, respectively) and vs baseline after 3 and 6 months of peritoneal dialysis (P = .007, P < .001, P = .004, respectively). Albumin was lower after 6 months of PD (P = .0014). IL-6 was increased at baseline vs reference values and remained unchanged at 3 and 6 months. OxSt and inflammation increase during PD confirming via molecular biology approach a report at biochemical level. To improve OxSt state in PD, a multitarget approach is necessary. It might include the use of more physiologic pH, low glucose degradation products, low lactate and iso-osmolar PD solutions, patients' strict glycemic control, optimal volume management, and antioxidant administration, such as N-acetylcysteine.

Efficacy of weekly administration of cholecalciferol on parathyroid hormone in stable kidney-transplanted patients with CKD stage 1-3.

Objectives: Kidney transplant (KTx) recipients frequently have deficient or insufficient levels of serum vitamin D. Few studies have investigated the effect of cholecalciferol in these patients. We evaluated the efficacy of weekly cholecalciferol administration on parathyroid hormone (PTH) levels in stable KTx patients with chronic kidney disease stage 1-3. Methods: In this retrospective cohort study, 48 stable KTx recipients (37 males, 11 females, aged 52 ± 11 years and 26 months post-transplantation) were treated weekly with oral cholecalciferol (7500-8750 IU) for 12 months and compared to 44 untreated age- and gender-matched recipients. Changes in levels of PTH, 25(OH) vitamin D (25[OH]D), serum calcium, phosphate, creatinine and estimated glomerular filtration rate (eGFR) were measured at baseline, 6 and 12 months. Results: At baseline, clinical characteristics were similar between treated and untreated patients. Considering the entire cohort, 87 (94.6%) were deficient in vitamin D and 64 (69.6%) had PTH ≥130 pg/mL. Serum calcium, phosphate, creatinine and eGFR did not differ between groups over the follow-up period. However, 25(OH)D levels were significantly higher at both 6 (63.5 vs. 30.3 nmol/L, p < 0.001) and 12 months (69.4 vs. 30 nmol/L, p < 0.001) in treated vs. untreated patients, corresponding with a significant reduction in PTH at both 6 (112 vs. 161 pg/mL) and 12 months (109 vs. 154 pg/mL) in treated vs. untreated patients, respectively (p < 0.001 for both). Conclusions: Weekly administration of cholecalciferol can significantly and stably reduce PTH levels, without any adverse effects on serum calcium and renal function.

Ultrasound for the Clinical Management of Vascular Access Cannulation and Needle Position in Hemodialysis Patients.

A native arteriovenous fistula (AVF) is the vascular access of choice for hemodialysis (HD) treatment. Compared with other types of vascular access such as grafts and central venous catheters, it functions longer and is associated with a lower risk of complications. The aim of the study described here was to assess, in an HD population, the position of the fistula needles during an HD session and evaluate the role of ultrasound in the management of AVF puncture. Forty-five consecutive chronic HD patients with an AVF or an arteriovenous vascular graft were included in the study for ultrasound evaluation. Each patient underwent an ultrasound evaluation during HD treatment to assess the position of the needles inside the vascular access. The ultrasound evaluation revealed that 81.8% of the traditional needles were incorrectly adjacent to the vessel walls, in the absence of clinical symptoms or hemodynamic alterations detectable on the dialysis monitor. A greater frequency of malpositioning has been observed for needles in the arterial portion of the vascular access, closer to the anastomosis. The absence of clinically detectable signs of venipuncture-related complications does not ensure correct positioning of the needles within the AVF. Ultrasound evaluation may not only resolve suboptimal cannulation problems of new or complicated vascular accesses but may also be useful in the prevention of acute and chronic damage to the AVF.

Vascular Endothelial Growth Factor Inhibitor Therapy and Cardiovascular and Renal Damage in Renal Cell Carcinoma.

BACKGROUND: Sunitinib, a tyrosine kinase inhibitor of vascular endothelial growth factor (VEGF), is approved for first and second line treatment of advanced renal cell carcinoma (RCC). Knowledge on the effects of sunitinib on cardiovascular (CV) risk and renal damage is limited. AIM: To evaluate possible renal and CV damage in patients with RCC treated with sunitinib. MATERIALS AND METHODS: Patients with metastatic RCC treated with sunitinib were enrolled. This population was evaluated before starting treatment (T0) and after 3 months (T1). Laboratory and instrumental parameters, including interventricular septum (IVS) and left ventricular mass index (LVMI) were recorded before and after treatment. RESULTS: Thirty-two patients (13 female, 19 male, mean age 62.7±9.9 years) were enrolled. We observed overtime, a significant reduction in estimated glomerular filtration rate (eGFR) (p=0.01), hemoglobin (Hb) (p=0.04) and 25-hydroxyvitamin D (25-OH-VitD) (p=0.002), in association with a significant increase in serum phosphorus (p<0.001), systolic blood pressure (SBP) (p<0.001), diastolic blood pressure (DBP) (p<0.001), IVS (p=0.03) and proteinuria (p<0.001), while we showed no significant differences in glycosuria, phosphaturia, serum uric acid, intact parathormone, and LVMI. CONCLUSION: We observed the development of renal damage and worsening of CV indices in patients treated with sunitinib. We suggest to consider a careful assessment of renal function and CV risk factors, before initiation and during administration of this drug.

Cardiac, Inflammatory and Metabolic Parameters: Hemodialysis versus Peritoneal Dialysis.

INTRODUCTION: Mortality in dialysis patients is higher than in the general population, and cardiovascular disease represents the leading cause of death. Hypertension and volume overload are important risk factors for the development of left ventricular hypertrophy (LVH) in hemodialysis (HD) and peritoneal dialysis (PD) patients. Other factors are mainly represented by hyperparathyroidism, vascular calcification, arterial stiffness and inflammation. The aim of this study was to compare blood pressure (BP) and metabolic parameters with cardiovascular changes [cardiothoracic ratio (CTR), aortic arch calcification (AAC) and LV mass index (LVMI)] between PD and HD patients. MATERIALS AND METHODS: 45 patients (23 HD and 22 PD patients) were enrolled. BP measurements, echocardiography and chest X-ray were performed in each patient to determine the LVMI and to evaluate the CTR and AAC. Inflammatory indexes, intact parathyroid hormone (iPTH) and arterial blood gas analysis were also evaluated. RESULTS: LVMI was higher in PD than HD patients (139 y 19 vs. 104 y 22; p = 0.04). In PD patients, a significant correlation between iPTH, C-reactive protein and the presence of LVH was observed (r = 0.70, p = 0.04; r = 0.70, p = 0.03, respectively). The CTR was increased in PD patients as compared to HD patients, while no significant differences in cardiac calcifications were determined. CONCLUSIONS: Our data indicate that HD patients present more effective BP control than PD patients. Adequate fluid and metabolic control are necessary to assess the adequacy of BP, which is strongly correlated with the increase in LVMI and with the increased CTR in dialysis patients. PD is a home therapy and allows a better quality of life, but PD patients may present a further increased cardiovascular risk if not adequately monitored.

Tenofovir-Related Nephropathies in HIV-Infected Patients.

BACKGROUND: The number of human immunodeficiency virus (HIV)-infected patients has increased significantly, although the number of deaths due to HIV and acquired immunodeficiency syndrome (AIDS) has dramatically reduced. Highly active antiretroviral therapy (HAART) has increased not only survival but also the risk of deaths caused by other diseases or by long-term side effects of these drugs. AIM: The aim of this study is to evaluate the nephrotoxicity of one of the most common anti-retroviral drugs, tenofovir disoproxil fumarate (TDF). MATERIALS AND METHODS: We examined 27 patients with HIV infection (10 women). Patients assumed TDF for a mean period of 8.03 months. Indexes of renal function and serum electrolytes were measured, and glomerular filtration rate was estimated (eGFR). Proteinuria, glycosuria, bicarbonaturia, and phosphaturia were assessed, and renal ultrasound examination was carried out. RESULTS: Acute kidney injury with glycosuria, bicarbonaturia, and phosphaturia was seen in 22 patients. Substantial recovery of renal function occurred in 19 patients. CONCLUSION: This study highlights that TDF nephrotoxicity is a widely frequent but reversible form of renal damage with preferentially proximal tubular dysfunction. We suggest that all patients at the time of HIV diagnosis should carry out a screening for kidney disease with eGFR assessment, proteinuria, and urine analysis.

Early markers of cardiovascular risk in chronic kidney disease.

BACKGROUND: Patients with chronic kidney disease (CKD) present a markedly increased cardiovascular (CV) morbidity and mortality since the early stages and have a high prevalence of accelerated atherosclerosis, inflammation and endothelial dysfunction. Nontraditional cardiovascular risk factors and serum cardiac biomarkers would contribute to explain this increased morbidity. AIM: The aim is to investigate the relation among serum cardiac biomarkers (N-terminal pro-brain natriuretic peptide (NT-proBNP), cardiac troponin T (cTnT), nontraditional cardiovascular risk factors (serum uric acid, homocysteine), inflammatory indexes (C-reactive protein (CRP) serum ferritin, fibrinogen) and noninvasive predictors of atherosclerosis (carotid intima-media thickness (cIMT), brachial artery flow mediated dilation (baFMD), and left ventricular mass index (LVMI)) in CKD patients. MATERIALS AND METHODS: In 50 patients with CKD in stage 2/3 kidney disease outcomes quality initiative (KDOQI) and 18 age- and sex-matched healthy controls, the following parameters were measured: cardiac markers (cTnT and NT-proBNP), renal function, inflammatory markers (CRP, serum ferritin and fibrinogen), serum uric acid and homocysteine. We have also evaluated LVMIs, cIMT and baFMD. RESULTS: In our study, we showed an increase of NT-proBNP and the serum cTnT, of serum uric acid and homocysteine with a positive correlation with the increase of cIMT and LVMI and reduced baFMD compared with the controls. CONCLUSIONS: Serum cardiac biomarkers and nontraditional cardiovascular risk factors increase already in the stage 2/3 KDOQI contributing to explain the high cardiovascular morbidity and mortality of these patients. The NT-proBNP seems to have a rise earlier compared with serum cTnT; however, both seemed to be a useful clinical biomarker for evaluating noninvasive predictors of atherosclerosis in CKD patients.

Vitamin D deficiency, insulin resistance, and ventricular hypertrophy in the early stages of chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is associated with markedly increased cardiovascular (CV) risk. This increase is not fully explained by traditional CV risk factors but may in part be mediated by nontraditional risk factors, such as inadequate vitamin D (vit D) levels and insulin resistance (IR). Although IR is shown in nondiabetic CKD, its association with vit D deficiency and vascular disease in this population is unknown and what this study aims to investigate. MATERIALS AND METHODS: The study comprised 67 patients with CKD (eGFR ≥ 30 mL/min) and 15 healthy controls matched for age and sex. The phlogosis indexes, vit D levels, IR, carotid intima-media thickness (cIMT), and left ventricular mass index (LVMI) were measured. RESULTS: In our study, the mean value of LVMI and cIMT was significantly higher in patients with eGFR ≥ 30 mL/min compared with controls (p = 0.037 and p < 0.001). The IR and intact parathyroid hormone (iPTH) levels were increased in CKD patients, whereas the serum levels of vit D were significantly reduced (p = 0.044, p = 0.012, p = 0.038). A positive correlation was found between LVMI and IR (r = 0.704, p = 0.041) and a negative correlation was found between IR and vit D levels (r = -0.238, p = 0.031). CONCLUSIONS: In our study, IR and vit D deficiency were found to be independent predictors of left ventricular hypertrophy and atherosclerotic disease. Vitamin D deficiency and IR are thus associated with increased CV risk. More novel approaches to improving IR and vit D supplementation in the CKD population might lead to potential strategies for preventing excess CV mortality.