Jaume Almirall

Infection of hemodialysis catheters: incidence and mechanisms.

Fifty-three consecutive subclavian or jugular hemodialysis catheters inserted into 41 patients were prospectively studied over a period of 8 months in order to determine the incidence of infection and its mechanisms. The intravascular, intradermal and the Y catheter segments as well as both connections were cultured using a quantitative technique for the intraluminal surface. In addition, the intravascular and intradermal portions of the catheter were cultured using a semiquantitative technique for the external surface. Skin smears of the catheter entry site were also cultured, and blood cultures were similarly obtained if fewer developed. Twenty-nine of the 53 catheters (55%) were significantly colonized by one (19 cases) or more (10 cases) microorganisms. The source of the colonizing microorganisms was the skin in 17 cases (58%), intraluminal in 5 (17%), both routes in 5 (17%) and others in 2 (6.8%). Staphylococcus epidermidis (22 cases) and Staphylococcus aureus (4 cases) were the bacteria most frequently isolated. Nine of the 53 catheterizations (17%) were complicated by catheter-related septicemia due to S. aureus in 4 cases, S. epidermidis in 3 cases, Streptococcus faecalis in 1 and Proteus vulgaris in 1. Catheter-related bacteremia contributed to a patients death in 1 case. Suppurative local infections of the catheter entry site developed in 3 cases, 2 of them with septicemia. We conclude that the rate of infection due to subclavian or jugular hemodialysis catheters is very high and that the skin is the most frequent origin of the microorganisms.

Evaluation of culture techniques for identification of catheter-related infection in hemodialysis patients

A prospective study was conducted over eight months to evaluate the usefulness of two culture techniques using different catheter parts for detection of bacterial colonization or catheter-related bacteremia in patients with jugular or subclavian hemodialysis catheters. A combination of semiquantitative culture of the external surface and quantitative culture of the intraluminal surface of the intradermal catheter segment provided the best means of detecting catheter colonization. For detection of catheter-related bacteremia, this combination had 100% sensitivity and a positive predictive value similar to the actual rate of catheter-related bacteremia.

Calcium acetate versus calcium carbonate for the control of serum phosphorus in hemodialysis patients.

Recent in vitro and in vivo studies have shown that calcium acetate (CaAC) is a more effective phosphorus binder than, among other calcium salts, calcium carbonate (CaCO3). More efficient binding allows serum phosphorus to be controlled with a lower dose; moreover, less calcium seems to be absorbed when CaAC is used. These properties could reduce the incidence of hypercalcemia; however, in clinical practice few reports have compared these two calcium salts, and results disagree. We evaluated in a 24-week prospective cross-over study the clinical efficiency of CaCO3 and CaAC in 10 selected chronic hemodialysis patients. Only 7 patients completed the study period. The patients were randomly assigned to start treatment with one of the two calcium salts; after 12 weeks they shifted to the other treatment. Serum analytical tests included weekly control of calcium, phosphorus, and alkaline phosphatase. PTH values (intact molecule) were obtained initially and at the end of every study period. The same good control of the phosphorus level (4.79 +/- 0.6 vs. 4.94 +/- 0.8 mg/dl) was obtained with CaAC (mean doses 4.1 +/- 0.3 g/day) as with CaCO3 (mean doses 4.01 +/- 0.8 g/day). The mean serum calcium levels were similar (10.36 +/- 0.5 vs. 10.20 +/- 0.5 mg/dl). The dose of elemental calcium administered was significantly less with CaAC (957 +/- 83 mg/day) than with CaCO3 (1,590 +/- 317 mg/day). However, the incidence of hypercalcemia (Ca > 11 mg/dl) was similar during the two treatment periods (13% with CaAC vs. 14% with CaCO3). Also the incidence of Ca x P products 765 was comparable (9.5 vs. 11.9%).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood and Graft Eosinophilia as a Rejection Index in Kidney Transplant

The relevance of eosinophilia in the physiopathology of transplant rejection has yet to be established. The appearance of eosinophilia has been occasionally associated with an adverse prognosis on graft rejection episodes. The aim of the present study was to evaluate the role and prognostic implications of blood and graft eosinophilia in kidney transplant rejection. We have examined the intrarenal infiltrate in 173 fine-needle aspiration biopsies from 36 consecutively transplant patients, and blood samples obtained simultaneously with fine-needle aspirations. Two different immunosuppressive regimens were administered: triple therapy (azathioprine + prednisone + antilymphocytic globulin) in patients with posttransplant acute tubular necrosis and cyclosporine A monotherapy in the rest of the patients. Comparing the two immunosuppressive groups, more elevated eosinophil values were observed in the monotherapy group during stable graft and also at the rejection episode. In the monotherapy group, a significant increase in the eosinophil values, in peripheral blood samples and in the intragraft infiltrates were noted at the rejection episode with respect to the stable situation. Following pulsed-steroid treatment an immediate disappearance of the eosinophils was evident. In contrast, no differences could be demonstrated between these two clinical situations in the TT group. Higher rates of eosinophils in the intrarenal infiltrate with respect to peripheral blood samples were observed during rejection episodes, suggesting some role of the eosinophils in the physiopathology of graft rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Propoxyphene-Induced Hypoglycemia in a Patient with Chronic Renal Failure

A 36-year-old man with ankylosing spondylitis, amyloidosis and chronic renal failure on maintenance hemodialysis developed severe hypoglycemia while being treated with propoxyphene. Upon discontinuation of the drug blood glucose levels returned to normal and hypoglycemia did not recur. Simultaneously with hypoglycemia, plasma glucagon and growth hormone levels were appropriately raised and serum insulin levels were adequately suppressed, thus ruling out hyperinsulinemia as the cause of hypoglycemia. A review of the literature disclosed four similar cases of propoxyphene-induced hypoglycemia, two of them with renal dysfunction. Propoxyphene should be remembered as a potential cause of hypoglycemia, particularly in patients with renal failure.

Usefulness of Non‐invasive Tests for Diagnosing Helicobacter pylori Infection in Patients Undergoing Dialysis for Chronic Renal Failure

Background.  Helicobacter pylori infection in chronic renal failure patients has been linked to peptic ulcer and gastric neoplasia after kidney transplantation. It may also contribute to the accelerated arteriosclerosis that is usual in this population. Few data are available on the usefulness of noninvasive diagnostic tests for H. pylori infection in dialyzed patients, especially regarding the new fecal antigen detection tests. The objective of this study was to determine the efficacy of a noninvasive test for H. pylori infection in patients with chronic renal failure.

Calciphylaxis in a Hemodialysis Patient: Appearance After Parathyroidectomy During a Psoriatic Flare

Chronic renal failure patients are prone to soft tissue calcifications. A phenomenon of acute ischemic skin necrosis and dermohypodermic arteriolar medial calcification has been described recently in patients with chronic renal failure and secondary hyperparathyroidism (HPT). This phenomenon, termed calciphylaxis, occurs in response to certain factors, the most important of which appears to be an elevated blood calcium-phosphate product. Accordingly, parathyroidectomy in addition to normalization of calcium-phosphate product has been proposed as the only effective therapeutic approach for this condition. We describe a case of chronic renal failure with severe secondary HPT in which the patient developed calciphylaxis 4 days after the appearance of a psoriatic flare. Four months before, a subtotal parathyroidectomy was performed for severe HPT and at the time the ulcerations appeared, blood calcium-phosphate product was correct. Etiological and physiopathological aspects of calciphylaxis are discussed.

Effects of chronotherapy on blood pressure control in non-dipper patients with refractory hypertension

BACKGROUND Refractory arterial hypertension (RAH) is frequently associated to a non-dipping blood pressure (BP) pattern; this profile has been shown to have a worse clinical prognosis. It is a common clinical practice that patients receive anti-hypertensive medication preferentially in the morning. Non-dipping could be related to the timing of anti-hypertensive drug administration. We analysed whether switching anti-hypertensive medication to bedtime could improve BP control in non-dipper patients with RAH. METHODS Twenty-seven consecutive patients with RAH and non-dipper or riser BP pattern on ambulatory blood pressure (ABP) monitoring were studied before and after 6 weeks of a change in the timing of anti-hypertensive medications. The intervention consisted of shifting all non-diuretic anti-hypertensive drugs from morning to evening, maintaining the same drugs at the same doses. A parallel group of 12 consecutive patients with similar characteristics and no changes in the therapeutic regimen formed the control group. RESULTS There were 59% women, mean age 65.7 ± 8.4 years. They were treated with 4 ± 0.7 anti-hypertensive drugs, 90% administered in the morning. At baseline, diurnal and nocturnal ABP averaged 141.6 ± 10.6/81.5 ± 9.3 and 141.7 ± 11/78 ± 8.8, respectively. After the drug shift, mean diurnal and nocturnal ABP was 140.5 ± 10.4/80.5 ± 9.6 and 135.7 ± 12.5/73.8 ± 9.3 (P = 0.005 and 0.04 for systolic and diastolic ABP), 15% of the patients restored a normal ABP circadian rhythm. No changes were observed in the control group. CONCLUSION In non-dipper or riser patients with RAH, changing the timing of anti-hypertensive medication to the evening could improve BP control.

Safety and Efficacy of Sevelamer in the Treatment of Uncontrolled Hyperphosphataemia of Haemodialysis Patients

Background/Aim: The treatment of hyperphosphataemia is of major importance in the management of patients on dialysis. Traditional phosphate binders can be associated with undesirable effects. Recently, a new non-absorbable phosphate-binding polymer, sevelamer hydrochloride, has been available. Clinical information is scarce, and its cost could be a limiting factor for its wider use. No studies have evaluated its usefulness in uncontrolled hyperphosphataemic patients. Methods: We identified 34 patients with a maintained serum phosphorus concentration >6.5 mg/dl and/or toxicity related to standard phosphorus-binding treatment (aluminium or calcium based). Sevelamer was added and titrated up fortnightly to achieve phosphorus control. Previous phosphate binders were decreased, whenever possible. The period of the study was 6 months. Results: Thirteen patients (38%) dropped out because of side effects, mainly related to the gastro-intestinal tract. The efficacy analysis disclosed that the phosphorus concentration decreased from 2.39 ± 0.48 to 1.84 ± 0.48 mmol/l (p < 0.001). The mean dose of sevelamer was stabilised at 3.4 ± 1.8 g/day. The amount of calcium- and aluminium-based phosphate binders could be decreased from 5.1 ± 3.5 to 3.1 ± 2.7 g/day (38% decrease) and from 2.4 ± 1.5 to 1.5 ± 1.7 g/day (36% decrease), respectively. The Ca × P product was significantly decreased from 5.83 ± 1.19 to 4.36 ± 1.12 mmol/l2 (p < 0.001). The total cholesterol concentration decreased from 4.34 ± 0.9 to 3.98 ± 0.9 mmol/l (p < 0.01) and the low-density lipoprotein cholesterol level from 2.61 ± 0.98 to 2.20 ± 0.77 mmol/l (p < 0.03). Conclusions: Sevelamer is an effective phosphate binder that allows a better serum phosphorus control, while allowing a decrease in the dose of calcium- and aluminium-based phosphate binders in these difficult patients. The drawbacks are the high intolerance rate and the price of the product.

Penicillamine-induced rapidly progressive glomerulonephritis in a patient with rheumatoid arthritis.

A 67-year-old woman with rheumatoid arthritis presented rapidly progressive glomerulonephritis (RPGN) after 5 months of D-penicillamine (250 mg/day) treatment. Light microscopy study showed severe glomerulonephritis with crescent formation in 60% of the glomeruli and infiltration of inflammatory cells in the wall of an arteriole. Immunofluorescence revealed scanty granular IgG, IgA and C3 deposits along the capillary walls and mesangium. The patient was treated with steroid pulse, plasmapheresis, cyclophosphamide and antiplatelet agents. A complete recovery of renal function was achieved in a few weeks. This new case of RPGN in the course of D-penicillamine treatment emphasizes the need for frequent monitoring of renal function and evaluation of urinary sediment and proteinuria in these patients. The prompt discontinuation of D-penicillamine and vigorous treatment measures could allow for a good prognosis as in this case.