Knowledge of the anomalies of the big central veins reduces the morbidity during the cannulation for hemodialysis: Description of a case of persistent left superior vena cava and revision of literature.

The persistence of a left superior vena cava is the result of a lack of an embryological involution of the left anterior cardinal vein. This anomaly is very rare: about 0.3% of the general population. Its incidence increases remarkably from 3-10% in those patients affected with congenital heart disease. Described herein is a case of persistent left superior vena cava, discovered by chance, following the placement of a central venous catheter for hemodialysis. A chest X-ray in projection back-forward showed the central venous catheter along the left sternal margin simulating a placement in the aorta artery. This clinical picture, as described in the literature, is often accompanied by other anatomical anomalies, in our case, by the congenital agenesis of a solitary pelvic kidney. In agreement with the literature and in contrast with what has been reported recently, we sustain that a central venous catheter placed, for any reason, in the persistent left superior vena cava must be removed immediately because it can induce hyperkinetic arrhythmia and cardiac arrest as in our case. Our case report should be a warning that lack of awareness of the anomalies of the big central veins can cause a rise in morbidity.

Verapamil versus amlodipine in proteinuric non-diabetic nephropathies treated with trandolapril (VVANNTT study): design of a prospective randomized multicenter trial.

Angiotensin converting enzyme inhibitors (ACEI) are the most effective antiproteinuric agents and should be used as first-line drugs in both diabetic and non-diabetic proteinuric nephropathies. The role of calcium channel blockers (CCB) is much more controversial. In diabetic patients verapamil and diltiazem seem more effective than dihydropyridines in reducing urinary protein excretion, and have additive effects with ACEI, but little is available on chronic treatment of non-diabetic nephropathies for non-dihydropyridine CCBs. To test whether the combination of verapamil 180 mg or amlodipine 5 mg with trandolapril 2 mg reduces urinary protein excretion more than trandolapril 2 mg alone, we planned a prospective, randomized, double-blind, multicenter trial. The secondary aims are to evaluate the effects of both treatments on the selectivity of proteinuria and check their safety. Consecutive patients aged between 18 and 70 years with non-diabetic proteinuria > or =2 g/24 h and plasma creatinine < 3 mg/dl or creatinine clearance > or = 20 ml/min are asked to participate. After a four-week run-in during which previous antihypertensive therapy is withdrawn, a single dose of trandolapril 2 mg is given once a day in open conditions for four weeks. At the end of this period patients are randomly assigned to receive once a day, in a double blind fashion, either trandolapril 2 mg and verapamil 180 mg [plus a placebo], or trandolapril 2 mg plus amlodipine 5 mg. They are monitored after one, two, five and eight months.

[Acute kidney failure and losartan: a recently observed event of antagonists of angiotensin II AT1 receptors]. / Insufficienza renale acuta e losartan: una nuova recente segnalazione degli inibitori dei recettori AT1 dell'angiotensina II.

Losartan is the first of a new category of drug that inhibits angiotensin II (ANG II) AT1 receptors antagonists. This drug lowers blood pressure by inhibiting the activity of ANG II and reduces proteinuria and progression of chronic renal failure (CRF). It seems therefore an extremely interesting drug. Aim of this study is to describe 3 cases of acute renal failure (ARF), occurred during therapy with losartan. None of the patients showed renal arteries stenosis or other predisposing factors for the development of ARF. In conclusion, we want pointed out that losartan could affect renal function in a similar way as angiotensin converting enzyme inhibitors (ACEI). We suggested that use of losartan in risk situations, like old age, preexiting CRF, stenosis of renal arteries, solitary kidney and diuretic therapy, should be carefully monitored as well as that of ACE I.

[Drugs used in the treatment of arterial hypertension in dialysis patients in the Piedmont. What correlations between personal and clinical data can be made from the registry data?]. / I farmaci utilizzati per il trattamento della ipertensione arteriosa nei pazienti in dialisi in Piemonte. Quali correlazioni con i dati anagrafici e clinici sono possibili dai dati del registro?

The therapeutical approach to arterial hypertension in the general population is now relatively well classified, whereas it remains a controversial problem in dialytic patients. The aim of this study was to evaluate the antihypertensive drugs used in dialytic patients in Piedmont and to identify correlations with other personal and clinical data. The authors analysed the data in the Piedmont Dialysis and Transplant Register concerning new patients admitted to dialysis during the period 1990-1995 (2,664 patients at 31/12/1995) and 1,373 patients who began dialysis during the period 1990-1993. A study of the antihypertensive drugs using in single and combined therapy over the five-year period shows major variations in the 45-65 year-old age bracket (increased ACE-inhibitors in single therapy, 15.5-25.6%, increased vasodilators in combined therapy, 15.3-21%). In patients aged > or = 65 years old a slight increase was found in the use of beta-blockers in monotherapy. Antihypertensive drugs at the 1st control (1990-1995 entries) appeared to be stable over the five-year period. From the 1,373 patients who started dialysis in the period 1990-1993, with at least three subsequent controls, the authors selected those hypertensive or normotensive patients receiving ACE-inhibitor therapy (best survival in general population) and compared their survival with that of patients receiving alternative antihypertensive treatment. No significant differences were found. The stability of the antihypertensive drugs taken by these patients over the past 5 years backs the hypothesis of a greater attention paid by nephrologists to the introduction of new drugs, both because of the frequent onset of collateral effects and owing to the special pharmacokinetics present in dialytic patients.

Influence of the hydration state on blood pressure values in a group of patients on regular maintenance hemodialysis.

The pathophysiology of hypertension in patients on renal replacement therapy is not yet clear, and the role of extracellular fluid overload is still a matter of debate. The main problem is the lack of techniques to determine the fluid state. Recently new noninvasive techniques have become available which make it possible to accurately determine the hydration state in these patients. We have studied the influence of the hydration state on interdialytic blood pressure in 45 patients: 21 (46.6%) using antihypertensive medication and 24 (53.4%) without antihypertensive medication. Total body water (TBW) was determined by bioelectrical impedance analysis performed just before a hemodialysis session. The TBW was then related to the fat-free mass calculated by the anthropometric method (aFFM) of Durnin. The hydration state was defined using the following formula: TBW/aFFM 100. Furthermore, for each patient the ideal TBW was calculated according to the Watson formula. The difference between TBW and ideal TBW was considered a further index of the hydration state. Ambulatory blood pressure monitoring was performed by using a Takeda 24200 recorder according to the Korotkoff method during the 24 h before the midweek hemodialysis session. Blood pressure monitoring showed a significant correlation with the hydration state of these patients. In conclusion, the hydration state seems to play a major role in interdialytic blood pressure control.

[Epidemiology and clinical course in hepatitis C-positive patients treated with dialysis in Piemonte. Work group of the RPDT]. / Epidemiologia e comportamento clinico nei pazienti epatite C positivi in dialisi in Piemonte. Gruppo di lavoro dell' RPDT.

The high prevalence of HCV positivity in dialysis patients has recently prompted several studies on this controversial subject. The aim of the study was an evaluation of HCV positivity and of influence on clinical outcome in 2,404 patients on dialysis in Piedmont (Northern Italy Region, about 4,400,000 inhab., 20 Dialysis Centers) at December 1993 (32.7% HCV-positive according to the Regional Registry of Dialysis and Transplantation). As expected, a strong correlation was found with time on dialysis (94.4% in patients with treatment follow-up > or = 20 years) and blood transfusions (41.3% HCV positivity in transfused patients versus 22.6% in not transfused ones; p < 0.0001). Dialysis in a hospital setting is confirmed as at high risk of infection, since HCV positivity was 19.6% in patients always treated by bicarbonate dialysis in hospital versus 8.9% in those treated only by CAPD (start of dialysis in 1992-1993). Despite the high prevalence of HCV positivity, however, death rates for liver disease and for all gastrointestinal causes are very low, regardless of HCV antibody status (1.2% in HCV positive versus 2.3% in HCV negative, NS). Whether this depends upon different clinical features of HCV infection in dialysis patients or merely deflects a relatively short follow-up will be matter of discussion in the future.

Recurrent secondary hyperparathyroidism due to parathyroid carcinoma: usefulness of Ki-67 immunostaining in the diagnosis of a malignant parathyroid tumor.

Parathyroid carcinoma is a very rare disease occurring in less than 2-3% of all the cases showing clinical features of primary hyperparathyroidism. Several histological markers have been used for distinguishing between benign and malignant tumors of the parathyroid glands. However, most of these markers are not easily applicable and clinical prognosis cannot be predicted by histopathological criteria alone. A recent study has drawn attention to the role of the cell cycle associated antigen Ki-67 detected by MIB-1 monoclonal immunocytochemistry in parathyroid tumors: in fact, Ki-67 seems to be a valuable marker of malignancy in such tumors since it permits an easy detection of proliferating and dividing cells. Here we report in detail a case of severe recurrent hyperparathyroidism in a 51-year-old female patient undergoing regular hemodialysis treatment. In the surgical specimens of the parathyroid glands, the tumor proliferative fraction of 56, expressed as the number of Ki-67-positive nuclei per thousand cells, and the mean mitosis count of 0.5, expressed as the percentage of the total amount of Ki-67 positive nuclei, support the diagnosis of parathyroid carcinoma despite the scanty amount of microscopical signs considered characteristic of malignancy, i.e. extensive thick fibrous bands or prominent nucleoli. To our knowledge this paper is the first clinical report that supports the diagnostic role of the cell cycle associated antigen Ki-67 in parathyroid carcinoma in a case of secondary hyperparathyroidism in a patient undergoing hemodialysis.

Monitoring of central venous dual-lumen catheter placement in haemodialysis: improvement of a technique for the practising nephrologist.

Mismanagement in the placement of central venous catheter (CVC) may occur in up to 20% of cases. The catheter can be inadvertently placed in the contralateral brachiocephalic vein, the ipsi or contralateral internal jugular vein, and usually a thoracic radiograph is necessary to evaluate its location. We propose a technique first described by Serafini et al. to establish the position of a CVC by endocavitary electrocardiography (EC-ECG) and its employment in a large number of uraemic patients requiring haemodialysis. This technique uses the tip of the CVC as reference lead in a standard electrocardiograph. The best employment of this technique has been obtained by echotomographic visualization of the internal jugular vein executed just before transcutaneous puncture of the vessel. For 13 months we have successfully applied this technique in CVC placement in 81 patients requiring haemodialysis. In our opinion this method is a safe and simple technique that avoids the need for thoracic radiographs and time lost waiting for radiographs that prolong the start of the haemodialysis session. According to our experience, we confirm that the EC-ECG technique provides a method for ensuring compliance with Food and Drug Administration guidelines regarding catheter tip location in uraemic patients.

Monitoring of central venous dual-lumen catheter placement in haemodialysis: improvement of a technique for the practising nephrologist.

Mismanagement in the placement of central venous catheter (CVC) may occur in up to 20% of cases. The catheter can be inadvertently placed in the contralateral brachiocephalic vein, the ipsi or contralateral internal jugular vein, and usually a thoracic radiograph is necessary to evaluate its location. We propose a technique first described by Serafini et al. to establish the position of a CVC by endocavitary electrocardiography (EC-ECG) and its employment in a large number of uraemic patients requiring haemodialysis. This technique uses the tip of the CVC as reference lead in a standard electrocardiograph. The best employment of this technique has been obtained by echotomographic visualization of the internal jugular vein executed just before transcutaneous puncture of the vessel. For 13 months we have successfully applied this technique in CVC placement in 81 patients requiring haemodialysis. In our opinion this method is a safe and simple technique that avoids the need for thoracic radiographs and time lost waiting for radiographs that prolong the start of the haemodialysis session. According to our experience, we confirm that the EC-ECG technique provides a method for ensuring compliance with Food and Drug Administration guidelines regarding catheter tip location in uraemic patients.

Longitudinal assessment of body composition in continuous ambulatory peritoneal dialysis patients using bioelectric impedance and anthropometric measurements.

We assessed the utility of bioelectric impedance analysis (BIA) and anthropometry for longitudinal evaluation of body composition in continuous ambulatory peritoneal dialysis (CAPD) patients. Eleven subjects were studied at the beginning of CAPD and again at regular intervals during the first 6 months of treatment. The significant weight gain that occurs in our patients is mainly due to a rise in total body water (TBW), as measured by BIA, during the first weeks of CAPD, and later on due to a body fat increase. Anthropometry seems more reliable than BIA in the evaluation of body mass, because the latter is derived from TBW in BIA. Therefore, any change in TBW that occurs in a CAPD patient necessarily causes a similar change in the fat-free mass. In our experience, only the combined use of both anthropometry and BIA allows a proper assessment of body composition in patients on CAPD.

[Arterial hypertension secondary to Conn's disease: an infrequent pathology in nephrology. Report of a clinical case]. / Ipertensione arteriosa secondaria a morbo di Conn: una patologia di non frequente osservazione nefrologica. Presentazione di un caso clinico.

In this work we describe a case of Conn's syndrome caused by a suprarenal adenoma in a sixty-one year female. The patient had come to our observation because of severe hypertension and hypokalemia. Primary aldosteronism resulting from the secretion of excessive amounts of aldosterone caused by autonomous hyperfunction of the adrenal cortex usually by a solitary adenoma. In most series of unselected patients, it is found in fewer than 0.5% of hypertensives. In our study we demonstrated the circadian changes of arterial blood pressure but we failed to demonstrate the presence of hypertrophic cardiomyopathy as recently emphasized in the literature. Regardless of its rarity, primary aldosteronism is a fascinating disease, protean in its manifestations, logical in its pathophysiology.

[Protein metabolism and nutritional status in hemodialysis]. / Metabolismo proteico e stato nutrizionale in emodialisi.

We have studied protein metabolism and nutritional status in a group of patients in regular dialysis treatment. In forty-five patients (mean age 58 +/- 11 yr), undergoing maintenance hemodialysis we have measured protein (DPI) ad caloric (CI) intake by a three-day dietary recall. Protein catabolic rate (PCR) using the urea kinetic model (Gotch' variable volume), anthopometric parameters such as weight, height, midarm circumference, skinfold thickness, midarm muscle circumference (AMC), midarm muscle area (AMA), total muscle mass (TMM) and the percentage of body fat were measured as well. PCR was weakly correlated with DPI. TMM showed a direct relationship with DPI and correlated inversely with UNA/NI (Urea Nitrogen Appearance/Nitrogen Intake). 18% of patients were underweight; 17% showed a decrease of AMA. TMM was inversely correlated with total hospitalization days. There were no significant variations of the examined parameters in a year later evaluation. In our experience TMM is the parameter which better correlates with clinical findings.

[Nutritional evaluation of a group of patients with terminal uremia treated with an artificial diet]. / Valutazione nutrizionale di un gruppo di pazienti in uremia terminale trattati con "artificial diet".

The effects of a low protein died supplemented with essential aminoacids (EAA) and keto analogues (KA) on nutritional status have been evaluated in eight chronic uremic patients. After six months of diet, no significant reduction of protidemia (changing from 6.66 +/- 0.5 g/dl to 6.61 +/- 0.8 g/dl) and albuminemia (changing from 4.13 +/- 0.4 g/dl to 3.90 +/- 0.5 g/dl) was observed. Moreover, neither body weight (changing from 70.437 +/- 8.03 kg to 69.500 +/- 8.26 kg) nor total muscular mass (changing from 25.26 +/- 3.83 kg to 25.36 +/- 5.74 kg) showed significant variations. Therefore, in our experience, low protein diet supplement with EAA and KA has not induced any deterioration of nutritional status.

Pathogenesis of arterial hypertension in chronic uraemia: the role of reduced Na,K-ATPase activity.

In 38 uraemic dialysed patients (17 normotensive, 21 hypertensive) we measured (1) erythrocyte sodium concentration [Nai] and ouabain-sensitive sodium efflux, and (2) arterial pressure, cardiac index and total peripheral resistance. Erythrocyte Na-K pump activity was lower in hypertensive than in normotensive patients (P less than 0.02). Hypertensive patients had significantly higher peripheral resistance than normotensive patients (P less than 0.05), while the cardiac index was similar in both groups. Inverse correlations were found between the rate constant for ouabain-sensitive sodium efflux in erythrocytes and both systolic and diastolic pressure (r = -0.43 and r = -0.45, respectively; P less than 0.01) and total peripheral resistance (r = -0.76; P less than 0.0001). Our data suggest that reduced sodium transport by the Na-K pump plays a role in the pathogenesis of arterial hypertension in patients with chronic uraemia.

Erythrocyte Na,K pump activity and arterial hypertension in uremic dialyzed patients.

We have evaluated in 26 uremic patients [21 on hemodialysis, 5 on continuous ambulatory peritoneal dialysis (CAPD)], 11 normotensive, and 15 hypertensive (MAP greater than 110 mm Hg) patients the following properties: a) erythrocyte (RBC) Na concentration [Nai] and ouabain-sensitive and -resistant Na effluxes; b) the effect of uremic sera on ouabain-sensitive Na efflux in normal RBC; c) serum digoxin-like immunoreactivity; d) cardiac index and total peripheral resistance. In 19 healthy subjects a) and c) were also evaluated. RBC Na,K pump activity was lower in uremic patients than in normal subjects (P less than 0.0005), and lower in hypertensive (P less than 0.02) than in normotensive patients. Serum from uremic patients inhibited ouabain-sensitive Na efflux in normal RBC, the inhibition being correlated with both the rate constant for ouabain-sensitive Na efflux (r = -0.67; P less than 0.005) and [Nai] (r = 0.43; P less than 0.05) of RBC of patients from whom the serum was obtained. Inhibition of ouabain-sensitive Na efflux was significantly higher with serum from hypertensive than from normotensive patients (P less than 0.05). Serum digoxin-like immunoreactivity was present in all uremic patients (0.402 +/- 0.054 ng/ml in normotensive and 0.428 +/- 0.040 ng/ml in hypertensive, P = ns), while it was not detectable in normal subjects. Hypertensive patients had peripheral resistance significantly higher than normotensive (P less than 0.05), while cardiac index was similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)