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.

[Acute kidney failure and losartan: a recently observed event of antagonists of angiotensin II AT1 receptors]

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.

[Evaluation of urea recirculation and dialysis efficiency of central venous jugular catheters when the venous lumen is used as an arterial lumen]

BACKGROUND

The dual lumen internal jugular venous catheter has proven to be the most useful temporary vascular access for hemodialysis. According to this evidence it was decided to evaluate urea recirculation rate during hemodialysis performed by dual lumen internal jugular catheter (IJC) under normal condition (R1) and when the arterial lumen of the catheter is used as venous lumen, and the venous lumen as arterial lumen (R2).

METHODS

In 71 patients who underwent hemodialysis using a dual lumen IJC, urea recirculation rate was measured during a conventional bicarbonate hemodialysis, under normal condition R1 and during the experimental condition R2.

RESULTS

Urea recirculation rate < 5% was achieved for almost all patients under normal condition R1. In the different condition R2, urea recirculation rate increased in all patients, from an average value of 3.7 +/- 1.7 to 5.1 +/- 1.8 p < 0.0001. This increment was expected ut surprisingly low.

CONCLUSIONS

In conclusion during hemodialysis with dual lumen IJC efficient treatment can be provided in normal condition and also when the venous lumen is used as arterial lumen.

[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?]

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]

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.

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.

Percutaneous renal biopsy utilizing ultrasonic guidance and a semiautomated device

Percutaneous renal biopsy is a fundamental diagnostic technique in urology and nephrology, recently refined by real-time ultrasonic guidance. The technique described in this article is a biopsy method employing real-time ultrasonic guidance and a semiautomated device. The new device has been constructed to improve percutaneous biopsy technique and to obtain more perfect specimens. This technique was successfully performed in 20 patients undergoing renal biopsy. Diagnostically satisfactory material containing an average of ten glomeruli per specimen was obtained. The results obtained with the new device Biopty Bard have been compared with the results obtained from the same number of biopsies performed with the traditional technique.

[Arterial hypertension secondary to Conn's disease: an infrequent pathology in nephrology. Report of a clinical case]

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]

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.

[Performance of echo-guided renal biopsy using a new semi-automatic instrument]

Percutaneous renal biopsy is a fundamental diagnostic technique in clinical nephrology, recently refined by real-time ultrasonic guidance. The technique described in this paper is a biopsy method employing real-time ultrasonic guidance and a semi-automated device. This technique has been successfully performed in 10 patients undergoing renal biopsy. Diagnostically satisfactory material containing an average of 9 glomeruli for specimen was obtained.

[Nutritional evaluation of a group of patients with terminal uremia treated with an 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.

[Humoral markers of iron status in patients on maintenance hemodialysis]

In forty-nine patients on regular dialysis treatment (RDT) we evaluated following parameters for a period of twenty-four months: serum ferritin (SF), transferrin, T.I.B.C. percental saturation (Fe/TIBC%), haemoglobin (Hb). Twenty-five patients had received more than 5 g intra-venous iron or several blood transfusions, before the beginning of the study, while the other twenty four patients had never received iron treatment nor transfusions. Serum ferritin and Fe/TIBC% proved to be a good estimate of iron stores in RDT patients. In fact both parameters showed significantly higher levels in iron loaded patients than in never treated patients. Furthermore, in patients who no longer received iron loads during the study period, both SF and Fe/TIBC% showed a significant decrease, without changes in haematologic values. This study demonstrated that oral ferritinic iron (40 mg/day for 6 months) doesn't increase either SF and Fe/TIBC% levels, or modifies haematologic values.

[Acute renal insufficiency caused by diflunisal. Description of a case]

A case of kidney failure in a patient with cirrhosis of the liver in the ascitic stage after treatment of a non-steroid anti-inflammatory drug, diflunisal, is reported. The pathogenesis of the kidney impairment, quickly reversed by withdrawal of the drug, is attributed to pharmacological inhibition of cyclo-oxygenase and prostaglandin synthesis with consequent alterations of intrarenal haemodynamics and renal blood flow.

[Effects of long-term treatment with L-carnitine on dyslipemia in hemodialysis patients]

The effect of long-term intravenous administration of L-carnitine on the lipid pattern of 18 patients on intermittent haemodialysis has been evaluated. Serum levels of carnitine were assayed at the beginning and after 4 months of treatment: no significant change was observed. At the end of our investigation, we found a significant reduction of HDL-cholesterol and a significant increase of triglyceride levels, compared with basal values. On the contrary cholesterol levels did not change. Five of the patients though behaved as responders to the treatment: their triglyceride levels decrease while their carnitine values rose significantly. The Authors discuss the therapeutic importance of L-carnitine and its possible influence on dyslipaemia of uremic haemodialysed patients.

[Nephrotoxicity of contrast media for urography in patients with chronic renal insufficiency]

The incidence of nephrotoxicity caused by intravenous pielography (IVP) contrast media was retrospectively evaluated in 42 patients with chronic renal failure. In 14 patients renal function was acutely impaired after IVP. In most cases the dysfunction was only temporary; in 3 cases permanent damage was induced, one of which required dialytic treatment. In the cases described there appears to be no correlation between the degree of renal failure and the incidence of nephrotoxicity but the former is clearly linked to the severity of the nephrotoxic response.