V. Dalmastri

Standard heparin versus low-molecular-weight heparin. A medium-term comparison in hemodialysis.

Background: To compare standard heparin (SH) and low molecular weight heparin (LMWH) in terms of anticoagulation, platelet activation and lipid metabolism, we selected 54 patients who had been on 4-hour hemodialysis three times weekly for at least 12 months, without bleeding disorders or dyslipidemic diseases. 28 were on hemodialysis with Polysulfone low-flux, 26 were on hemodiafiltration with Polysulfone high-flux. All patients underwent EPO. Methods: During the first 18 months, we administered SH 1,500 IU on starting dialysis and 1,500 ± 500 IU in continuous intradialytic infusion per session. In the following 18 months, we administered LMWH 64.6 IU/kg on starting dialysis in a single arterious bolus. We assessed aPTT, anti-factor Xa activity, TAT and FPA, β-TG and PF4. Blood samples were taken monthly at times 0, 30, 60, 180 and 240 min, as well as 1, 4 and 20 h after dialysis end. Predialysis cholesterol, HDL, LDL, triglycerides and lipoprotein(a) were checked monthly. Results: During both LMWH and SH sessions no clotting or major bleeding complications were observed. APTT with LMWH was lower than that found with SH (p < 0.001); aFXa using LMWH was higher than when using SH (p < 0.001); TAT and FPA were lower in LMWH sessions (p < 0.01) than in SH sessions. We also detected lower β-TG (p < 0.05) and PF4 levels (p < 0.05) using LMWH than using SH. As regards lipids, we only observed a significant decrease in triglycerides after 18 months of LMWH treatment. Conclusions: Routine use of LMWH during hemodialysis affords a safe and effective alternative to SH, and causes reduced platelet activation.

EVIDENCE OF PROFILED HEMODIALYSIS EFFICACY IN THE TREATMENT OF INTRADIALYTIC HYPOTENSION

In the last 10 years the percentage of dialysis patients suffering from clinical intradialytic intolerance has greatly increased. Profiled hemodialysis (PHD) is a new technical approach, alternative to standard hemodialysis (SHD) for the treatment of intradialytic symptomatic hypotension. It is based on intradialytic modulation of the dialysate sodium concentration, using a dialysate sodium concentration profile elaborated by a new mathematical kinetic model. The aim of PHD is to reduce the intradialytic blood volume decrease, thanks to a dialysate sodium profile, which allows a reduction in the plasma osmolarity decrease, thereby boosting intravascular fluid refilling. This work aims at clinically validating the PHD technique, by testing its ability, against SHD, to maintain a more stable intradialytic blood volume; this evaluation was supported by monitoring some hemodynamic parameters. Twelve dialysis patients on SHD treatment were selected because of their intradialytic symptomatic hypotension. Twelve SHD (one per patient) and 12 PHD sessions (one per patient) were performed to achieve the same sodium mass removal and body weight decrease on both PHD and SHD. During these sessions we monitored the blood volume variation % by the critline (a non invasive blood volume monitoring device), the mean blood pressure and heart rate directly and, finally, the stroke volume and cardiac output indirectly by bidimensional doppler-echocardiography. Comparison of the results obtained with the two techniques shows PHD to achieve a significantly more stable blood volume, blood pressure and cardiovascular function than SHD, in particular during the second and the third hour of the dialysis session.

Posttraumatic Chyluria Due to Lymphorenal Fistula Regressed after Somatostatin Therapy

A sudden-onset chyluria after trauma was evaluated giving evidence of a lymphatic-urinary fistula in the right kidney. Treatment with somatostatin normalized the urinary pattern and the result was maintained even after the discontinuation of the therapy.

Evaluation of intradialytic solute and fluid kinetics. Setting Up a predictive mathematical model.

A mathematical model of solute kinetics for the improvement of hemodialysis treatment is presented. It includes a two-compartment description of the main solutes and a three-compartment model of body fluids (plasma, interstitial and intracellular). The main model parameters can be individually assigned a priori, on the basis of body weight and plasma concentration values measured before beginning the session. Model predictions are compared with clinical data obtained in vivo during 11 different hemodialysis sessions performed on 6 patients with a profiled sodium concentration in the dialysate and a profiled ultrafiltration rate. In all cases, the agreement between the time pattern of model solute concentrations in plasma and the in vivo data proves fairly good as to urea, sodium, chloride, potassium and bicarbonate kinetics. Only in two sessions was blood volume directly measured in the patient, and in both cases the agreement with model predictions was good. In conclusion, the model allows a priori computation of the amount of sodium removed during hemodialysis, and makes it possible to predict the plasma volume changes and plasma osmolarity changes induced by a given sodium concentration profile in the dialysate and by a given ultrafiltration profile. Hence, it can be used to improve clinical tolerance to the dialysis session taking the characteristics of individual patients into account, in order to minimize intradialytic hypotension.

Incidence and predictors of postoperative atrial fibrillation in kidney transplant recipients.

Background Postoperative atrial fibrillation (POAF) is a complication of cardiothoracic and noncardiothoracic surgery. Kidney transplant recipients bear several known risk factors and may have a higher incidence of POAF. We retrospectively studied kidney and kidney/liver transplant recipients to estimate their POAF incidence and identify relevant risk factors. We also adapted a clinical score originally designed to predict thromboembolic risk in atrial fibrillation (AF; CHA2DS2-VASc) for assessing transplant patients. Methods We reviewed the clinical charts of kidney or kidney/liver transplant recipients from January 2005 to December 2008 at St. Orsola University Hospital Kidney Transplant Centre. Patients with and without POAF were compared on a number of clinical, laboratory, and instrumental data. Results The POAF incidence in kidney transplant recipients was 8.2%. Risk factors for POAF identified in univariate analyses included older recipient age, history of myocardial infarction, history of AF, liver/kidney transplantation, arterial stiffness, atherosclerotic plaques in the aorta or lower limbs, and diabetes mellitus. In a multivariate analysis, age, myocardial infarction history and combined liver/kidney transplantation were significant independent predictors of POAF. The modified CHA2DS2-VASc score proved to have a better predictive validity that the original CHA2DS2-VASc (area under the curve=0.71, 95% confidence interval=0.63–0.79 vs. area under the curve=0.62, 95% confidence interval=0.52–0.73, respectively). Conclusion AF is a notable complication of kidney, and particularly simultaneous liver/kidney, transplant surgery. Age, previous myocardial infarction, and simultaneous liver/kidney transplant independently predicted POAF. The modified CHA2DS2-VASc score could be useful to predict POAF risk in kidney transplant candidates.

Relationship between coronary artery disease and C-reactive protein levels in NSTEMI patients with renal dysfunction: a retrospective study

BackgroundWhile chronic renal damage is a condition with low-grade inflammation, the potential role of inflammation in kidney disease as a marker of cardiovascular damage is of current interest. This study analyzed the relationship between renal dysfunction, chronic inflammation, and extension of coronary atherosclerosis in patients with non-ST-segment elevation myocardial infarction (NSTEMI).MethodsThis retrospective study was carried out on consecutive patients presenting with NSTEMI to Maggiore Hospital’s emergency department between January 1, 2010 and December 31, 2011. Patients’ electronic charts were reviewed to gather information on patients’ history, clinical and biochemical variables, with a special focus on inflammatory markers, coronary vessel damage, and drug treatments.ResultsOf the 320 individuals in the study population, 138 (43.1%) had an admission GFR <60 mL/min/1.73 m2. Kidney dysfunction was significantly associated with age (OR = 1.09, 95% CI 1.06 to 1.12), history of heart failure (OR = 2.13, 95% CI 1.08 to 4.17), and hypertension (OR = 2.31, 95% 1.12 to 4.74). C-reactive protein (CRP) and uric acid levels were significantly increased in patients with severe renal dysfunction (SRD) by bivariate and multivariate analyses, adjusted for gender, age and comorbidities at admission. The extent of coronary artery disease (CAD) was significantly higher in the SRD group (p < 0.001). Individuals with SRD were less likely to receive immediate evidence-based therapies (62.9% vs. 76.7% and 82.0% in those with intermediate and no/mild renal dysfunction, p < 0.001). Hospital stay was significantly longer in individuals with a greater extent of CAD, diabetes, and a history of heart failure, and was borderline significantly associated with renal dysfunction (p = 0.08). Older age, CAD severity, and renal function were associated with worsening GFR during hospitalization, whereas immediate evidence-based treatment was unrelated to a GFR change.ConclusionsAmong individuals hospitalized for NSTEMI, those with SRD had a more extensive CAD and a higher prevalence of pre-existing cardiovascular disease. CRP was positively correlated with renal dysfunction and the number of involved coronary vessels, confirming its potential as a biomarker. Uric acid was associated with renal dysfunction but not with the number of diseased coronary vessels.

Incidence of Late Deep Venous Thrombosis Among Renal Transplant Patients

BACKGROUND Kidney transplant recipients (KTRs) manifest hypercoagulable state that contributes to an increased incidence of deep vein thrombosis (DVT), not only early but also late in their course. KTRs display an imbalance of hemostatic mechanisms with a multifactorial rise in procoagulant factors, partly related to traditional risk factors and partly to transplantation. The aim of this study was to evaluate the incidence of first episodes of DVT among KTRs, focusing on risk factors. METHODS From 2008 to 2011, we evaluated 30 kidney transplant patients who ≥4 months there after transplantation developed DVT in the lower limbs only, lower limbs complicated by pulmonary embolism or retinal thrombosis. We analyzed causes of primary nephropathy, immunosuppressive regimen, post-transplantation infections, and erythrocytosis. DVT was diagnosed by color Doppler ultrasound or eye examination. RESULTS A significantly increased incidence of DVT was observed among patients receiving cyclosporine or cyclosporine + mammalian target of rapamycin inhibitors, affected by polycystic kidney diseases, systemic lupus erythematosus or nephrotic syndrome, or displaying rapid and/or excessive correction of hematocrit values. DVT was not significantly related to an acute infection (cytomegalovirus) or to the prior dialysis modality. CONCLUSIONS Hypercoagulability is a multifactorial condition in KTRs, representing a severe complication in stable patients. Prevention may consist of either accurate pretransplantation screening for thrombophilia or identification of patients at higher DVT risk.

Artificial Kidney: Status of the Art and New Perspectives

Extracorporeal dialysis was first performed in 1943 and has become a routine for End Stage Renal Patients from the early sixties. In the last 30 years researchers have focused on biocompatibility of artificial materials and optimisation of removal of uremic toxins by the membrane as in the long term treatment many complications like amylodosis heart and bone lesions, accelerated amyloidosis and immune system failure can occur. From this point of view high flux dialytic membranes are currently considered more biocompatible therefore being able to prevent such diseases.

Effect of Hemoadsorption for Cytokine Removal in Pneumococcal and Meningococcal Sepsis

Bacterial meningitis and septicemia are invasive bacterial diseases, representing a significant cause of morbidity and mortality worldwide. Both conditions are characterized by an impressive inflammatory response, resulting rapidly in cerebral edema, infarction, hydrocephalus, and septic shock with multiple organ failure. Despite advances in critical care, outcome and prognosis remain critical. Available adjunctive treatments to control the inflammatory response have shown encouraging results in the evolution of patients with sepsis and systemic inflammation, but meningococcal or pneumococcal infection has not been investigated. We herein report five patients with similar critical pathological conditions, characterized by pneumococcal or meningococcal sepsis and treated with hemoadsorption for cytokine removal. All patients showed a progressive stabilization in hemodynamics along with a rapid and marked reduction of catecholamine dosages, a stabilization in metabolic disorders, and less-than-expected loss of extremities. Therapy proved to be safe and well tolerated. From this first experience, extracorporeal cytokine removal seems to be a valid and safe therapy in the management of meningococcal and pneumococcal diseases and may contribute to the patient stabilization and prevention of severe sequelae. Further studies are required to confirm efficacy in a larger context.

Sudeck’s Atrophy of the Left Tibiotarsal Joint in a Renal Transplant Patient: Effects of Medical and Physical Therapy

Dr. Claudio Campieri, Department of Nephrology, S. Orsola University Hospital, via Massarenti 9, I-40138 Bologna (Italy) Dear Sir, In view of the diversity of osteoarticular entities affecting the transplanted patient, special attention must be paid to Sudeck’s atrophy [1-3]. To our knowledge, no such cases have been reported up to now. Sudeck’s atrophy manifests as pain restricted to a bone segment, palpable edema, vasomotor skin instability, and focal bone deminerali-zation. A 49-year-old woman with a cadaver donor renal transplant since June 1982 complained of acute pain in the left ankle with hypothermia of the same leg in March 1992. The graft function had always been normal, and treatment included azathioprine 100 mg and prednisone 10 mg daily. Both X-ray and Doppler sonography of the left tibiotarsal joint were negative. After 15 days during which pain continued, the ankle swelled, and walking became difficult (fig. la). A repeat X-ray revealed traces of mottling and an irregularity in frontal cortex of the left astragalus, with swelling of the soft periarticular tissues. Bone technetium scintigraphy showed accumulation of the marker substance at left tibiotarsal joint and homolateral knee, while the iliofemoral-popliteal axis appeared normal. Nuclear magnetic resonance imaging and computerized tomography of the tibiotarsal joint exluded any focal bone lesions of the segment examined, only visualizing the Fig. 1. Ankle swelling (a) regressed after 5 months of therapy (b).