Renal Benefits of CO2 as a Contrast Media for EVAR Procedures: New Perspectives on 1 Year Outcomes.

BACKGROUND AND OBJECTIVES: Endovascular aneurism repair (EVAR) is a minimally invasive alternative to open surgery for the treatment of abdominal aortic aneurysm. Iodine contrast medium (ICM) is considered the gold standard, at the high price of related nephrotoxicity and allergic reactions. Carbon dioxide (CO2) has been suggested as an alternative non-nephrotoxic contrast media agent. We aimed to evaluate the safety and the renal impact of the administration of CO2, compared with ICM in EVAR procedures. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: We retrospectively reviewed data of patients who underwent EVAR at the Vascular Surgery Department of the Sant'Orsola Hospital in Bologna. Estimated glomerular filtration rate (eGFR) was evaluated before intervention, immediately after and at 12 months. RESULTS: In total, 22 patients received CO2 and low-dose ICM (CO2 Group) and 22 received standard ICM (Control Group), matched for clinical characteristics and renal function at the time of procedure. Pre and post-operative renal function values (eGFR) were compared between the two groups: in the immediate post-operative the group treated with CO2 and low-dose ICM globally showed a slight improvement in renal function (mean eGFR +5.10%±3.2), meanwhile the group treated with standard dose of ICM presented a significant worsening of renal function compared with pre-procedure values (mean eGFR -9.65%±4). Incidence of post-contrast acute kidney injury (PC-AKI) was 9% in the CO2 group vs 27% in the Control group. At 12 months, the renal impairment was significantly greater in the ICM group than in the CO2 group (mean eGFR decrease -19.2%±11.1 and -7.40%±3.5, respectively). CONCLUSIONS: Administration of either CO2 alone or along with low-dose ICM showed to be safer than full-dose ICM alone, lowering the incidence of PC-AKI in patients undergoing EVAR. Unexpectedly, our study revealed also a significant worsening of renal function in patients treated with standard dose of ICM in 1-year follow-up, introducing the concept that acute renal damage caused by ICM could elicit a chronic injury process that affect long-term renal outcomes. CLINICAL IMPACT: Evaluating the safety and the renal impact of the administration of CO2, compared to Iodinate Contrast Medium, in EVAR procedures represents a first step in order to further tayloring medical procedures on patients characteristics. Our findings can guide the clinicians and surgeons in the procedures choice, not considering only the immediate effect of ICM on renal function but also the potential long-term effects.

Sodium Prescription in the Prevention of Intradialytic Hypotension: New Insights into an Old Concept.

BACKGROUND: Sodium prescription in patients with intradialytic hypotension remains a challenge for the attending nephrologist, as it increases dialysate conductivity in hypotension-prone patients, thereby adding to dietary sodium levels. METHODS: New sodium prescription strategies are now available, including the use of a mathematical model to compute the sodium mass to be removed during dialysis as a physiological controller. RESULTS: This review describes the sodium load of patients with end-stage renal disease on chronic hemodialysis (HD) and discusses 2 strategies to remove excess sodium in patients prone to intradialytic hypotension, namely, Profiled HD and the hemodiafiltration Aequilibrium System. CONCLUSION: The Profiled HD and Aequilibrium System trial both proved effective in counteracting intradialytic hypotension.

Dialyzability of Oxycodone and Its Metabolites in Chronic Noncancer Pain Patients with End-Stage Renal Disease.

OBJECTIVES: Opioids are the preferred analgesic drugs to treat severe chronic pain conditions among dialysis patients; however, knowledge about their dialyzability features is limited. Oxycodone is increasingly used for the treatment of chronic pain conditions as oral controlled release (CR) tablets; however, evidence about this drug and its metabolites' dialyzability is lacking. METHODS: We assessed, during 4-hour dialysis sessions, the effect of standard hemodialysis (HD) and online hemodiafiltration (HDF) methods on the plasma concentration of oxycodone and its metabolites in n = 20 chronic pain patients with end-stage renal disease who were stably treated with oral CR oxycodone. Chromatographic techniques were used to evaluate the studied compounds' plasma concentrations at three different time points during dialysis. RESULTS: Mean plasma concentrations of oxycodone and noroxycodone in the sample showed an overall reduction trend over time, but it was less enhanced for noroxycodone. Mean reduction in oxycodone and noroxycodone arterial concentrations was significant and higher with HDF (54% and 27%, respectively) than with HD (22% and 17%, respectively). Analysis of the regression of these compounds' clearance on their increasing arterial concentration showed a more stable and linear clearance prediction with HDF (roughly 85 mL/min); with HD, for increasing arterial concentration, clearance of oxycodone decreased while noroxycodone clearance increased. DISCUSSION: While no oxymorphone or noroxymorphone metabolites were detected, limited dialyzability of oxycodone and noroxycodone was documented along with insignificant postdialysis pain increment. This evidence will contribute toward considerations as to the safety of the use of oxycodone in dialysis patients in the future.

Tissue Ki67 proliferative index expression and pathological changes in hemodialysis arteriovenous fistulae: Preliminary single-center results.

BACKGROUND: Arteriovenous fistula (AVF) for hemodialysis integrates outward remodeling with vessel wall thickening in response to drastic hemodynamic changes. Aim of this study is to determine the role of Ki67, a well-established proliferative marker, related to AVF, and its relationship with time-dependent histological morphologic changes. MATERIALS AND METHODS: All patients were enrolled in 1 year and stratified in two groups: (A) pre-dialysis patients submitted to first AVF and (B) patients submitted to revision of AVF. Morphological changes: neo-angiogenesis (NAG), myointimal thickening (MIT), inflammatory infiltrate (IT), and aneurysmatic fistula degeneration (AD). The time of AVF creation was recorded. A biopsy of native vein in Group A and of arterialized vein in Group B was submitted to histological and immunohistochemical (IHC) analysis. IHC for Ki67 was automatically performed in all specimens. Ki67 immunoreactivity was assessed as the mean number of positive cells on several high-power fields, counted in the hot spots. RESULTS: A total of 138 patients were enrolled, 69 (50.0%) Group A and 69 (50.0%) Group B. No NAG or MIT were found in Group A. Seven (10.1%) Group A veins showed a mild MIT. Analyzing the Group B, a moderate-to-severe MIT was present in 35 (50.7%), IT in 19 (27.5%), NAG in 37 (53.6%); AD was present in 10 (14.5%). All AVF of Group B with the exception of one (1.4%) showed a positivity for Ki67, with a mean of 12.31 ± 13.79 positive cells/hot spot (range 0-65). Ki67-immunoreactive cells had a subendothelial localization in 23 (33.3%) cases, a myointimal localization in SMC in 35 (50.7%) cases. The number of positive cells was significantly correlated with subendothelial localization of Ki67 (p = 0.001) and with NA (p = 0.001). CONCLUSIONS: Native veins do not contain cycling cells. In contrast, vascular cell proliferation starts immediately after AVF creation and persists independently of the time the fistula is set up. The amount of proliferating cells is significantly associated with MIT and subendothelial localization of Ki67-immunoreactive cells, thus suggesting a role of Ki-67 index in predicting AVF failure.

Patterns of renal toxicity from the combination of pemetrexed and pembrolizumab for advanced nonsquamous non-small-cell lung cancer (NSCLC): A single-center experience.

OBJECTIVES: The combination of immune-checkpoint inhibitors (ICI) and platinum-pemetrexed chemotherapy (CT) in first-line setting improved survival outcomes of advanced non-small cell lung cancer (NSCLC) patients. Among the various adverse events, renal toxicity can be a relevant safety issue. MATERIALS AND METHODS: We conducted a single-center, observational retrospective study including consecutive patients treated with upfront CT-ICI for advanced nonsquamous NSCLC to investigate incidence and clinical characteristics of acute kidney injury (AKI) using 'Acute Kidney Injury Working Group of Kidney Disease: Improving Global Outcomes' (KDIGO) definition. RESULTS: A total of 89 patients received a first-line CT/ICI. The median age was 69 years. 60.7 % were male, and 87.6 % had an ECOG PS of 0-1. 92.1 % had a baseline glomerular filtration rate of at least 60 ml/min. According to KDIGO criteria, 25 (28 %) patients developed AKI. Considering risk factors for AKI onset, patients receiving >10 cycles of CT/ICI were more likely to experience AKI (p < 0.001). No other associations were found with other variables, including concomitant medications. Any component of the treatment was discontinued (pemetrexed pembrolizumab or both) in 10 (40 %) patients, and 9 patients (36 %) were addressed to nephrological consultation. These patients had higher mean creatinine variation from baseline (1 vs 0.6 mg/dl, p = 0.025) and creatine level (1.8 vs 1.4 mg/dl, p = 0.015), but lower eGFR (35.7 vs 54.2 ml/min, p = 0.011) in comparison to patients not addressed. No patients had microscopic hematuria or pyuria, but mild proteinuria (<0.8 g/24 h) was found in 4 patients. A renal biopsy was performed on 3 patients, revealing acute tubule interstitial nephritis (ATIN), karyomegalic interstitial nephritis, and acute tubular necrosis (ATN). CONCLUSION: Renal toxicity represents a challenging adverse event that could negatively impact outcomes of metastatic nonsquamous NSCLC patients receiving CT/ICI demanding a multidisciplinary approach.

The link between homocysteine, folic acid and vitamin B12 in chronic kidney disease.

Patients with chronic kidney disease or end-stage renal disease experience tremendous cardiovascular risk. Cardiovascular events are the leading causes of death in these patient populations, thus the interest in non-traditional risk factors such as hyperhomocysteinemia, folic acid and vitamin B12 metabolism is growing. Hyperhomocysteinemia is commonly found in CKD patients because of impaired renal metabolism and reduced renal excretion. Folic acid, the synthetic form of vitamin B9, is critical in the conversion of homocysteine to methionine like vitamin B12. Folic acid has also been shown to improve endothelial function without lowering homocysteine, suggesting an alternative explanation for the effect of folic acid on endothelial function. Whether hyperhomocysteinemia represents a reliable marker of cardiovascular risk and cardiovascular mortality or a therapeutic target in this population remains unclear. However, it is reasonable to consider folic acid with or without methylcobalamin supplementation as appropriate adjunctive therapy in patients with CKD. The purpose of this review is to summarize the characteristics of homocysteine, folic acid, and vitamin B12 metabolism, the mechanism of vascular damage, and the outcome of vitamin supplementation on hyperhomocysteinemia in patients with CKD, ESRD, dialysis treatment, and in kidney transplant recipients.

Detoxification of bilirubin and bile acids with intermittent coupled plasmafiltration and adsorption in liver failure (HERCOLE study).

BACKGROUND: CPFA is an extracorporeal treatment used in severe sepsis to remove circulating proinflammatory cytokines. Limited evidence exists on the effectiveness of bilirubin adsorption by the hydrophobic styrenic resin, the distinctive part of CPFA. The aim of this study is to validate CPFA effectiveness in liver detoxification. METHODS: In this prospective observational study, we enrolled patients with acute or acute-on-chronic liver failure (serum total bilirubin > 20 mg/dL or MELD Score > 20) hospitalized from June 2013 to November 2017. CPFA was performed using the Lynda (Bellco/MedTronic, Mirandola, Italy) or the Amplya (Bellco/MedTronic, Mirandola, Italy) machines. Anticoagulation was provided with unfractionated heparin or citrate. Bilirubin and bile acids reduction ratios per session (RRs) were the main parameters for hepatic detoxification. RESULTS: Twelve patients with acute (n = 3) or acute-on-chronic (n = 9) liver failure were enrolled. Alcohol was the main cause of liver disease. Thirty-one CPFA treatments of 6 h each were performed, 19 with heparin and 12 with citrate. RRs was 28.8% (range 2.2-40.5) for total bilirubin, 32.7% (range 8.3-48.9) for direct bilirubin, 29.5% (range 6.5-65.4) for indirect bilirubin and 28.9% (16.7- 59.7) for bile acids. One patient received liver transplantation and 8/9 were alive at 1 year of follow-up. Three patients (25%) died: 2 during hospitalization and 1 for a cardiac event at 4 months of follow up with restored liver function. CONCLUSIONS: CPFA resulted to be effective in liver detoxification. Thus, it may be considered as a "bridge technique" both to the liver transplant and to the recovery of the basal liver function.

Bloodstream infections and patient survival with tunneled-cuffed catheters for hemodialysis: A single-center observational study.

BACKGROUND: In hemodialysis patients, a tunneled-cuffed permanent catheter is mandatory when the arteriovenous fistula is not feasible. The major risks of the use of tunneled-cuffed permanent catheter are bloodstream infections. The aim of this study is to analyze bloodstream infections from tunneled-cuffed permanent catheter in hemodialysis patients. METHODS: An observational prospective study was carried out and 79 hemodialysis patients with tunneled-cuffed permanent catheter were enrolled. Patients were divided into those with bloodstream infections from tunneled-cuffed permanent catheter and those without. Their clinical and laboratory characteristics were compared. An original tunneled-cuffed permanent catheter lock therapy sequence was carried out combined with systemic antibiotic therapy. In case of antibiotic resistance, the tunneled-cuffed permanent catheter was removed. RESULTS: The patients affected by bloodstream infections from tunneled-cuffed permanent catheter were 16/79 (20.3%). The bloodstream infection from tunneled-cuffed permanent catheter's incidence rate was 0.52 per 1000 catheter days. Twenty-three bloodstream infections from tunneled-cuffed permanent catheter were found in 16/79 patients who used tunneled-cuffed permanent catheter. Staphylococcus aureus was the cause of bloodstream infection from tunneled-cuffed permanent catheter in 35% of the cases and Staphylococcus epidermidis in 30% of the cases. Risk factors were infection located in other organs and the presence of peripheral obstructive arterial disease. CONCLUSION: The enrolled cohort showed a reduced bloodstream infection from tunneled-cuffed permanent catheter incidence rate in comparison with the reference value (1 per 1000 catheter days). To reduce the number of bloodstream infections from tunneled-cuffed permanent catheter, hand hygiene and asepsis management of the tunneled-cuffed permanent catheter during the connection to the extracorporeal circuit and an original tunneled-cuffed permanent catheter lock therapy sequence seem to be the most efficient measures. Infections of other organs and the presence of peripheral obstructive arterial disease are the most important risk factors for bloodstream infections from tunneled-cuffed permanent catheter.

Early use of PEPA dialyzer for light chains removal and for the recovery from myeloma cast nephropathy: A case report.

Chemotherapy and extracorporeal treatment reduce serum free light chains (FLCs) allowing the recovery of acute kidney injury (AKI) caused by myeloma cast nephropathy (MCN). We report the first case of recovery from AKI in a patient with MCN who underwent the removal of FLCs using the PEPA filter, with an undisclosed cut-off, combined with chemotherapy for multiple myeloma (MM).

Coupled Plasma Filtration Adsorption Application for Liver and Thyroid Toxins.

Coupled plasma filtration and adsorption (CPFA) is a detoxification system that combines a plasma adsorption circuit and a continuous renal replacement therapy circuit. Its main application is for sepsis and septic shock with or without acute renal failure. Several recent studies have suggested that CPFA can reduce the mortality when the volume of plasma absorbed on the styrenic resin is at least >0.18 L/kg/day. At present, new applications for CPFA are under investigation, also in patients without significant kidney failure. We report here a successful case of CPFA use during acute liver failure, with a complete recovery of liver function in a patient after severe cholangitis and relapsing hemolytic anemia. The resin enabled the removal of bilirubin and protein-bound toxins, while the hemofilter removed the hydrophilic toxins such as ammonia and non-protein-bound toxins as free bilirubin. We also describe a second case of CPFA application during thyrotoxicosis to achieve free triiodothyronine (FT3) and free thyroxin (FT4) adsorptions. The CPFA efficacy seems to exceed that obtained by plasma exchange (PEX) as to FT3 and FT4 adsorptions. The resin allowed the adsorption of FT3 and FT4. The role of the hemofilter is to enhance the hemodynamic tolerance of the extracorporeal treatment and remove water-soluble toxins. The reduced duration of CPFA treatments, in case of normal renal function, is confirmed by the assessment of the resin cartridge saturation. Thus, multipurpose CPFA can play a role in the case of resistance to current medical therapy or as a bridge to liver transplantation or thyroidectomy.

An in vitro model of renal inflammation after ischemic oxidative stress injury: nephroprotective effects of a hyaluronan ester with butyric acid on mesangial cells.

BACKGROUND: Acute kidney injury, known as a major trigger for organ fibrosis and independent predictor of chronic kidney disease, is characterized by mesangial cell proliferation, inflammation and unbalance between biosynthesis and degradation of extracellular matrix. Therapeutic approaches targeting the inhibition of mesangial cell proliferation and matrix expansion may represent a promising opportunity for the treatment of kidney injury. An ester of hyaluronic acid and butyric acid (HB) has shown vasculogenic and regenerative properties in renal ischemic-damaged tissues, resulting in enhanced function recovery and minor degree of inflammation in vivo. This study evaluated the effect of HB treatment in mesangial cell cultures exposed to H2O2-induced oxidative stress. MATERIALS AND METHODS: Lactate dehydrogenase release and caspase-3 activation were measured using mesangial cells prepared from rat kidneys to assess necrosis and apoptosis. Akt and p38 phosphorylation was analyzed to identify the possible mechanism underlying cell response to HB treatment. The relative expressions of matrix metallopeptidase 9 (MPP-9) and collagen type 1 alpha genes were also analyzed by quantitative real-time polymerase chain reaction. Cell proliferation rate and viability were measured using thiazolyl blue assay and flow cytometry analysis of cell cycle with propidium iodide. RESULTS: HB treatment promoted apoptosis of mesangial cells after H2O2-induced damage, decreased cellular proliferation and activated p38 pathway, increasing expression of its target gene MPP-9. CONCLUSION: This in vitro model shows that HB treatment seems to redirect mesangial cells toward apoptosis after oxidative damage and to reduce cell proliferation through p38 MAPK pathway activation and upregulation of MPP-9 gene expression involved in mesangial matrix remodeling.