Value of magnetic resonance/computed tomography peritoneography technique in the evaluation of dialysate leakage and hernia following peritoneal dialysis.

Magnetic resonance and computed tomography peritoneography are diagnostic imaging procedures that involve the intraperitoneal administration of a mixture of contrast material and dialysate for direct visualization of the peritoneal cavity and assessment of the integrity of peritoneal membrane. In a clinical series of patients with end-stage renal disease treated with continuous ambulatory peritoneal dialysis, who presented with genital or low abdominal edema, advanced peritoneographic imaging studies allowed direct visualization of the dialysate leakage and peritoneal hernias. Both magnetic resonance and computed tomography peritoneographic procedures allowed accurate diagnosis of continuous ambulatory peritoneal dialysis-related complications that may need to be addressed promptly so that the effectiveness of continuous ambulatory peritoneal dialysis is not compromised.

Takotsubo Syndrome during Haemodialysis.

Takotsubo syndrome (TS) is typically characterized by transient (reversible) systolic dysfunction of the apical and mid segments of the left ventricle (LV), usually without obstruction of coronary arteries, in postmenopausal women after a stressful event. Usually, patients may experience symptoms such as chest pain, shortness of breath, palpitations, and rarely syncope or cardiogenic shock. There are many theories about pathophysiology of TS. Among these, most acceptable is the catecholamine theory. The prognosis is usually good with recovery of symptoms and imaging findings at most within a few weeks. However, complications may occur. We present the 11th published case of a patient on hemodialysis, who presented with TS and discuss why this situation may occur in patients on hemodialysis. Contrary to our patient, half of previously published cases presented with atypical symptoms. Therefore, it is important to be alert in order to timely diagnose, support the patient, and treat if any complications appear.

Studying survival studies in PD versus HD: is there something more to know?

Peritoneal dialysis (PD) has been introduced more than 25 years ago as an alternative to hemodialysis for the treatment of end-stage renal disease. However, after the peak of the number of PD patients, which was noted in the mid-1980s, and despite the fact that in some countries there is a tendency for PD first, the number of incident PD patients in Europe and the United States is constantly decreasing. A large number of studies comparing the effect of these two treatment modalities on patients' outcomes have yielded conflicting results, which raise confusing messages to nephrologists. Epidemiologic methods, survival analysis models, and interpretation of results are not always clear and understandable for the average nephrologist. This review will focus on the exploration of possible causes of discrepancy among survival studies and it will try to clarify the basic key points of survival analysis in order to make the results as clear as possible.

Epidemiology of acute renal failure in ICUs: a multi-center prospective study.

BACKGROUND AND AIM: Acute kidney injury (AKI) is a common complication in intensive care units (ICUs). However, its incidence and outcome vary in several studies depending on definitions used or even the geographic origin of the study. We aimed to evaluate the epidemiology of AKI in ICUs in Greece. METHOD: Prospective multicenter study of ICU patients presented with AKI during a 3-month period. RESULTS: One-hundred and seventy patients presented with AKI (16% of total admissions in 23 ICUs). The most common contributing factor to AKI was sepsis (45%). Half of the patients required renal replacement therapy, which was mainly managed by ICU clinicians. Nearly 65% of the AKI patients died, whereas 15% were discharged with renal impairment. Age (RR 1.01, p = 0.046), sepsis (RR 1.62, p = 0.015) and urine output (RR 0.99, p = 0.009) were independently associated with outcome. CONCLUSION: AKI involves a large number of patients in Greek ICUs and is associated with adverse outcomes.

Sevelamer hydrochloride versus aluminum hydroxide: effect on serum phosphorus and lipids in CAPD patients.

BACKGROUND: Dietary phosphorus restriction, oral administration of phosphorus binders, and dialysis are the main strategies to control hyperphosphatemia in patients with stage 5 chronic kidney disease. Aluminum hydroxide (AH) and calcium carbonate, the most commonly used phosphorus binders, have serious disadvantages, such as aluminum toxicity and hypercalcemia. Sevelamer hydrochloride (SH) is a relatively new nonabsorbed calcium- and aluminum-free phosphorus binder. The present study was designed to evaluate the efficacy of SH in the control of hyperphosphatemia and its effect, compared to AH, on serum lipid parameters in patients on continuous ambulatory peritoneal dialysis (CAPD). METHODS: 30 stable patients on CAPD were included in an open-label, randomized crossover study. After a 2-week phosphorus binder washout period, 15 patients (group I) were administered SH for 8 weeks and in the remaining patients (group II), AH was introduced (phase A). After a new 2-week washout period, patients crossed over to the alternate agent for another 8 weeks (phase B). RESULTS: There were similar reductions in serum phosphorus levels over the course of the study with both agents: by 1.18 +/- 0.07 mg/dL (0.38 +/- 0.03 mmol/L) with SH and by 1.25 +/- 0.15 mg/dL (0.40 +/- 0.05 mmol/L) with AH in phase A (p = NS), and by 1.35 +/- 0.25 mg/dL (0.43 +/- 0.08 mmol/L) with AH and by 1.23 +/- 0.80 mg/dL (0.39 +/- 0.25 mmol/L) with SH in phase B (p = NS). Moreover, SH administration was associated with a 10.5% +/- 9.4% and a 20.1% +/- 6.8% fall in total cholesterol (p < 0.05) and low-density Lipoprotein cholesterol (p < 0.001) in phase A, and 11.9% +/- 7.2% (p < 0.05) and 21.5% +/- 2.4% (p < 0.001), respectively, in phase B. In both phases of the study, AH administration was not followed by a significant change in serum lipid parameters. CONCLUSION: Sevelamer hydrochloride is a well-tolerated alternative to calcium- or aluminum-containing phosphorus binder in the control of serum phosphorus in CAPD patients. Furthermore, SH improves the lipid profile in these patients.

A new machine for continuous renal replacement therapy: from development to clinical testing.

A new continuous renal replacement therapy machine has been designed to fulfill the expectations of nephrologists and intensivists operating in the common ground of critical care nephrology. The new equipment is called Prismaflex and it is the natural evolution of the PRISMA machine that has been utilized worldwide for continuous renal replacement therapy in the last 10 years. The authors performed a preliminary alpha-trial to establish the usability, flexibility and reliability of the new device. Accuracy was also tested by recording various operational parameters during different intermittent and continuous renal replacement modalities during 62 treatments. This article will describe our first experience with this new device and touch upon the historic and technologic background leading to its development.

Protective effect of urate oxidase on uric acid induced-monocyte apoptosis.

Uremic patients have a higher risk of infection and malignancy than normal subjects. Previous studies have deomonstrated that monocytes isolated from uremic patients display an increased apoptosis rate compared to normal subjects; furthermore uremic plasma can increase apoptosis rates on U937, a human monocytic cell line. In several pathological conditions, precipitation of uric acid crystals can lead to renal insufficiency or acute renal failure by different mechanisms. In recent studies uric acid has been shown to induce inflammatory response from monocytes and it has been suggested to be involved in cell dysfunction. Rasburicase is a new recombinant urate oxidase developed to prevent and treat hyperuricaemia in patients with cancer or renal failure; it degrades uric acid to allantoin, a less toxic and more soluble product. In the present study, we aimed at determining whether uric acid may be a factor affecting U937 apoptosis, and whether urate oxidase may reduces or even prevent uric acid induced cell apoptosis. Hoechst staining and internucleosome ledder fragmentation of DNA showed that uric acid increased the percentage of apoptotic cells comparing to the control and that when the U937 cells were incubated with uric acid and urate oxidase the percentage of apoptosis significantly decreased (from 43+/-7% to 19+/- 3%, p<0.05). Also, the activity of caspase-8 and caspase-3 showed the same trend (caspase 3: from 2.7+/-0.53 to 1.6+/-0.42; caspase-8: from 2.2+/-0.43 to 1.3+/-0.57). A reduction of intracellular reduced glutathione (GSH) concentration was found in uric acid treated cells while the addition of urate oxidase in the uric acid incubated cells decreased the GSH extrusion. The concentration of TNF-alpha was increased in the sample incubated with uric acid comparing to the control. Uric acid is an inducer of apoptosis on U937 cell line, and therefore it may be a component of the mosaic of uremic toxins both in acute and chronic renal disease. We can hypothesize that uric acid might be directly involved in the apoptotic process trough the activation of both death receptor and mitochondrial-mediated pathways. We have, also, demonstrated that urate oxidase is able to prevent at least in part, the effect of uric acid on U937 apoptosis. This effect might be a result of different mechanisms of action.

Rasburicase therapy in acute hyperuricemia and renal dysfunction.

Neoplastic disorders may be complicated by acute renal failure (ARF). Different tumors may cause ARF: solid tumors involving the kidney, solid tumors not of hematological origin and not primarily involving the kidney or, more frequently, rapidly developing hematological tumors. The pathogenesis of ARF is different depending on the type of cancer, but the most frequent clinical feature is the acute tumor lysis syndrome, characterized by hyperuricemia, hyperphosphatemia, hyperkalemia, hypocalcemia and acute, frequently oliguric, ARF. The presence of a neoplastic disorder and associated acute illness may sometimes lead to the presence of immunodysfunction, septic complications and multiple organ dysfunction. In these settings patients develop systemic inflammation and diffuse endothelial damage, related to different mediators. Among these substances, in cancer patients, high circulating levels of uric acid are a common finding. Hyperuricemia is caused by the increase of purine metabolism, which is result of the increased cellular turnover or the aggressive cancer chemotherapy regimens that worsen cell lysis and release of purine metabolites. Even if hyperuricemia is not the first insult to the kidney, its development might represent a concomitant factor aggravating other previous or simultaneous insults. The most efficient therapy for lowering uric acid is rasburicase, a recombinant form of urate oxidase, a nonhuman proteolytic enzyme that oxidizes uric acid to allantoin. It is efficacious in reducing serum uric acid levels with associated diuresis more effectively and much faster than allopurinol, and to correct renal dysfunction more rapidly than allopurinol.

Magnesium homeostasis in patients undergoing continuous ambulatory peritoneal dialysis: role of the dialysate magnesium concentration.

We carried out this retrospective study to examine the magnesium status of our chronic ambulatory peritoneal dialysis (CAPD) patients dialyzed with 0.75 mmol/L (group I) or 0.50 mmol/L (group II) magnesium peritoneal dialysis solution. A total of 34 anuric patients on CAPD (age:31-72 years; duration of CAPD:7-74 months) were studied. None of them received magnesium-containing phosphate binders or vitamin D. Biochemical parameters including magnesium, calcium, phosphate, parathormone, and albumin were measured in all patients. The corrected for hypoalbuminemia serum magnesium concentration in group I was significantly higher compared to that found in group II. However, there were no significant differences in the other measured parameters between the two groups of CAPD patients, though iPTH levels were somewhat increased in group II patients. Serum magnesium levels were weakly correlated with serum prealbumin levels in both groups of CAPD patients (r=0.16, P=0.08 and r=0.17, P=0.07). The incidence of hypermagnesemia was significantly higher in group I patients versus those in group II (13/19 68.4%] vs. 2/15 13.3%], P<0.01). On the other hand, no patient developed hypomagnesemia (corrected total magnesium <0.65 mmol/L), despite the trend toward decreased magnesium levels in group II patients. Our results point out that serum iPTH levels and nutritional parameters, such as prealbumin levels, should be taken into account in the choice of the magnesium concentration of the peritoneal dialysis fluid.