Michel D'haene

Complications related to subclavian catheters for hemodialysis. Report and review.

Personal experience with subclavian vein cannulations for hemodialysis are given, and the pertinent literature on the subject is reviewed. Two hundred subclavian dialysis catheters were placed in 148 patients who kept them in place for a total of 2,798 days. Immediate complications were two pneumothoraxes and two hemothoraxes due to subclavian artery puncture. Seventeen cases of bacteremia were related to subclavian catheter infections. In 1 case, a complication of sepsis was a vertebral osteomyelitis. Clinical evidences of subclavian vein thrombosis occurred in 5 cases. Life-threatening complications were met in 2 cases: 1 with pericardial tamponade due to right atrium perforation and 1 with mediastinal hematoma and right hemothorax due to superior vena cava perforation. Review of the literature indicates that pneumothoraxes and/or hemothoraxes occurred in 1.7% of the catheter insertions and that sepsis related to subclavian dialysis catheters occurred in 8.9% of the patients. As systematically investigated subclavian vein thrombosis involved at least 50% of the patients. Our 2 personal cases of life-threatening complications and 14 similar cases of the literature were analyzed: left subclavian catheters were associated with superior vena cava perforation with right hemothorax or mediastinal hematoma, while right subclavian catheters gave atrial perforation with pericardial tamponade. Death occurred in 3 of 16 cases, and emergency surgery was required in 5 of 16 cases. Taking into account all these complications, recommendations are made for the use of subclavian dialysis catheters.

Adsorption of ß2-microglobulin on dialysis membranes: comparison of different dialyzers and effects of reuse procedures

In order to measure ß2-microglobulin adsorption on dialysis membranes, uremic plasma was passed through different dialyzers in a simulated hemodialysis circuit in which both plasma and dialysate compartments were organized as closed loops, the ultrafiltration pressure being adjusted to minimize water shifts. Under these conditions, comparison of the amounts of ß2-m in the plasma and dialysate compartments allowed us to calculate the binding of ß2-m to the membrane at different times of the procedure. Whereas cuprophane membrane (Gambro gf 180m, 1.8m2) did not bind ß2-m, AN69 (Filtral, 1.1 m2), high flux polysulfone (F60, 1.2m2) and modified polyamide (Polyflux 130, Gambro, 1.3m2) were found to adsorb 49 ± 8 mg (mean ± SEM), 17 ± 5 mg and 38 ± 4 mg of 82-m, respectively. These data were confirmed in trace labeling experiments with 125I-ß2-m. Adsorption was a saturable phenomenon occurring during the first 90 min of in vitro dialysis. After reuse with peracetic acid, the adsorption capacity of AN69 membrane was lowered to 20 ± 4 mg of ß2-m, contrasting with the unchanged adsorption after reuse with sodium hypochlorite. These data indicate that adsorption significantly contributes to ß2-m removal during hemodialysis with certain dialyzers and that reuse procedures may affect the propensity of dialysis membranes to bind 82-m.

Infections Associated with Subclavian Dialysis Catheters: The Key Role of Nurse Training

Two hundred subclavian dialysis catheters were placed in 148 patients who kept them in place for a total of 2,798 days. Catheterization time ranged from 1 to 79 days with an average of 14.0 +/- 1.0 days per catheter and 18.9 +/- 1.0 days per patient. Twenty nine catheters were infected, 17 of which were the source of bacteremias due to Staphylococcus epidermidis in 13 cases and to Staphylococcus aureus in 4 cases. The incidence of sepsis was not significantly greater in diabetic patients, in patients with corticotherapy or in patients presenting an underlying systemic disease. On the contrary, the incidence was greater in hospitalized patients (15 bacteremias during 1,948 catheter days) than in ambulatory patients (2 bacteremias during 850 catheters-days) as well as during a period corresponding to a greater number of untrained nurses enrolled in the dialysis team. During this period, 6 sepsies occurred in 19 catheters (other periods: 7 sepsies/116 catheters, p less than 0.01). 6 of 28 nurses had less than 3 months of professional experience (other periods: 1 of 25, p less than 0.01). These data underline the key role of nurse training in the prevention of catheter-related infections.

Rapid, enhanced, and persistent protection of patients with renal insufficiency by AS02V-adjuvanted hepatitis B vaccine

The adjuvanted hepatitis B vaccine, HB-AS04, elicits more rapid and persistent protective antibody concentrations than double doses of conventional recombinant vaccines in patients with renal insufficiency. We compared the immunogenicity, reactogenicity, and safety of the AS02(V)-adjuvanted hepatitis B vaccine HB-AS02 with that of HB-AS04. In this phase III, open, randomized study, 151 hepatitis B vaccine-naïve pre-dialysis, peritoneal dialysis, and hemodialysis patients aged 15 years and older received three doses of HB-AS02 at 0, 1, and 6 months. Another 149 similar patients received four doses of HB-AS04 at 0, 1, 2, and 6 months, and all were followed up for 12 months. HB-AS02 elicited more rapid and persistent seroprotection than HB-AS04, with rates of 77 and 39%, respectively, 1 month after the second vaccine dose, and 94 and 79%, respectively, at 12 months. Superiority of HB-AS02 over HB-AS04 in anti-hepatitis B geometric mean concentrations was found at all time points. HB-AS02 was more reactogenic than HB-AS04, but adverse events were mainly transient, of mild to moderate intensity with no reportable vaccine-related serious events. We conclude that a three-dose primary course of HB-AS02 induced more rapid, enhanced, and persistent protection in patients with renal insufficiency than the licensed four-dose primary schedule of HB-AS04. This adjuvanted vaccine affords greater protection with reduced need for booster doses in patients at high risk of hepatitis B infection.

Immunogenicity and safety of an investigational AS02v-adjuvanted hepatitis B vaccine in patients with renal insufficiency who failed to respond or to maintain antibody levels after prior vaccination: results of two open, randomized, comparative trials

An investigational AS02(v)-adjuvanted hepatitis B (HB-AS02) was compared with a licensed conventional recombinant hepatitis B vaccine (HBVAXPRO™; Sanofi Pasteur MSD, Lyon, France) in pre-dialysis, peritoneal dialysis and hemodialysis patients aged ≥18 years who had failed either to respond to prior vaccination with a conventional hepatitis B vaccine (Study A; n=251) or to maintain protective antibody concentrations after prior hepatitis B vaccination (Study B; n=181). These were open, randomized, comparative trials. Mean (range) age was 65.9 (31-92) and 64.6 (29-92) years in the two studies, respectively. In Study A, two doses of HB-AS02 given one month apart were found to be superior to two doses of the licensed vaccine in terms of seroprotection rate (76.9% versus 37.6%) and anti-HBs geometric mean antibody concentration (GMC; 139.3 versus 6.9mIU/ml), with antibody concentrations ≥100mIU/ml in 61.1% and 15.4% of subjects in the two groups, respectively. In Study B, one month after administration of a single booster dose, seroprotection rates were 89.0% in the HB-AS02 group and 90.8% in the licensed vaccine group, 81.3% and 60.9% of subjects had antibody concentrations ≥100mIU/ml, and anti-HBs GMCs were 1726.8 and 189.5mIU/ml. HB-AS02 was found to be more reactogenic than the licensed vaccine. In summary, the investigational HB-AS02 vaccine induced higher seroprotection rates and anti-HBs GMCs than a licensed conventional hepatitis B vaccine in uremic patients who had failed to respond or to maintain protective antibody titers after prior hepatitis B vaccination.

Evaluation of surgical treatment of renal hyperparathyroidism by measuring intact parathormone blood levels on first postoperative day

Abstract. Intact parathormone (inPTH) has a short half-life. Its blood level on the first day after total parathyroidectomy and subcutaneous parathyroid implantation (PTX + G) should therefore allow an early diagnosis of missed residual parathyroid tissue. We tested this hypothesis in 72 uremic patients who were followed for 6 to 110 months after operation. Nine were reoperated for recurrence of the disease. Graft removal was successful in four patients who had post-PTX inPTH levels of 16 pg/ml or lower. In five patients, an overlooked parathyroid gland had to be resected. All of them had elevated post-PTX inPTH blood levels ranging from 72 to 791 pg/ml (upper normal limit 55 pg/ml). Three of these patients had presented with hypocalcemia after PTX. We conclude that the inPTH blood concentration on the first day after PTX allows more precise evaluation of the efficacy of the surgical procedure than the postoperative evolution of blood calcium levels. It is also useful for localizing the source of excessive PTH secretion (graft or overlooked gland) when the disease recurs.

Renal functional reserve of transplanted kidneys.

Michel Dhaene, CUB Hôpital Erasme, Service de Néphrologie, Route de Lennik 808, B-1070 Brussels (Belgium) Dear Sir, Protein intake has been shown to raise the glomerular filtration rate (GFR). A renal functional reserve has been defined [1, 2] as the difference between preand postprandial GFR following an oral protein load. We wonder whether the investigation of renal reserve could be of interest to transplanted patients. The renal reserve of 7 transplanted patients was evaluated after ingestion of 2 g of protein/kg body weight in the form of cooked red meat. All patients, aged from 16 to 44 years, were selected on the basis of a standard creatinine clearance superior to 50 ml/min. They had received a kidney graft 3–22 months prior to the study. Their residual renal function before transplantation was negligible. Immunosuppressive therapy consisted of prednis-olone (10 mg) and either azathioprine (50–150 mg) or cyclosporin (150–300 mg/daily). Metoprolol (100 mg) was given to 3 patients for hypertension. After drinking 20 ml/kg of water in half an hour, the patients underwent preand postprandial creatinine clearances and urinary urea nitrogen excretion measurements. Simultaneous in-ulin clearances were measured in 4 subjects. Baseline and postprandial GFR were calculated as the mean value of three and four successive clearance measurements. Detailed results are given in table I: only 3 patients exhibited a significant renal functional reserve after a protein load. The results obtained from inulin clearances were comparable and it should be noted that these 3 patients are set apart by their lower urinary urea excretion. These observations lead to several conclusions. First, they confirm that a denervated kidney is able to exhibit a protein-induced hyperfiltration. Secondly, despite the fact that baseline GFR could already have been raised by the glucocorticoids [3, 4], the response to proTable I. Creatinine clearances and urinary urea nitrogen excretion Patients Baseline Baseline Postprandial Renal

Primary high-dose intradermal hepatitis B vaccination in hemodialysis: Cost-effectiveness evaluation at 2 years

Reinforced hepatitis B (HB) vaccination schedules have been tested in nonresponsive hemodialysis (HD) patients. Primary high‐dose intradermal (ID) vaccination in HD has been proposed in one study with higher seroconversion rate, but no cost analysis was made. The aim of this prospective study was to confirm this previous report and focus on a cost‐effectiveness evaluation of the thorough vaccination with a maintenance program. Thirty‐five chronic incident HD patients received primary ID HB vaccination with a reinforced schedule (20 μg Engerix‐B® every 2 weeks). Revaccination with a monthly single ID dose of 20 μg was performed whenever anti‐HBs titer fell under 20 IU/L and continued until a titer of 20 U/L was reached. Outcome measures were cumulative seroconversion rates, mean levels of anti‐HBs, maintenance booster doses, rate of seroprotection at the end of the 2‐year follow‐up and subsequent costs. The present study was associated with an earlier peak of anti‐HBs titer (3.9±1.7 months) and a higher cumulative seroconversion rate (96.9%) after 1 year. Moreover, a low‐booster shot (17.4 μg) of ID Engerix‐B®/year/patient confers a 100% seroprotection for all responders for a second‐year period. The mean cost of our schedule is 127.7€/patient for a 2‐year period, revaccination included. This current study demonstrates that primary reinforced ID HB vaccination with a maintenance program for a 2‐year period warrants the best cost‐effectiveness ratio with rapid and sustained seroprotection in almost all HD patients.