Patients' representations of their end-stage renal disease: relation with mortality.

BACKGROUND: Self-regulation theory explains how patients' illness perceptions influence self-management behaviour (e.g. via adherence to treatment). Following these assumptions, we explored whether illness perceptions of ESRD-patients are related to mortality rates. METHODS: Illness perceptions of 182 patients participating in the NECOSAD-2 study in the period between December 2004 and June 2005 were assessed. Cox proportional hazard models were used to estimate whether subsequent all-cause mortality could be attributed to illness perception dimensions. RESULTS: One-third of the participants had died at the end of the follow-up. Mortality rates were higher among patients who believed that their treatment was less effective in controlling their disease (perceived treatment control; RR = 0.71, P = 0.028). This effect remained stable after adjusting for sociodemographic and clinical variables (RR = 0.65, P = 0.015). CONCLUSIONS: If we consider risk factors for mortality, we tend to rely on clinical parameters rather than on patients' representations of their illness. Nevertheless, results from the current exploration may suggest that addressing patients' personal beliefs regarding the effectiveness of treatment can provide a powerful tool for predicting and perhaps even enhancing survival.

[Hypocalcemia as a cause of reversible heart failure]. / Hypocalciëmie als oorzaak van reversibel hartfalen.

A 72-year-old woman with therapy resistant congestive heart failure presented with severe hypocalcaemia due to hypoparathyroidism after strumectomy more than 25 years before. After suppletion of calcium her complaints resolved and there was considerable improvement in left ventricular function. Our case report suggests that hypocalcaemia induced cardiomyopathy should be considered in the differential diagnosis of therapy resistant heart failure and that myocardial impairment is reversible after administration of calcium.

CAPD patients exhibit a nocturnal fall in blood pressure: a single-centre study.

BACKGROUND: In 29 CAPD (continuous ambulatory peritoneal dialysis) patients the height and diurnal variation of the blood pressure (BP) and heart-rate (HR) were analyzed by means of 24-hour ambulatory blood pressure monitoring (ABPM). METHODS: Normal diurnal variation was defined as a fall of 10% or more during nighttime (NT) compared with daytime (DT) BP or HR (DT = 10.00 a.m.-9.00 p.m., NT = midnight-06.00 a.m.). To evaluate high BP in the course of time we used the concept of "whole-day BP load", defined as the percentage of BP readings above 140/90 mmHg during a 24-h period. A "hypertensive BP load" was defined as a systolic BP (SBP) load of more than 50% and/or a diastolic BP (DBP) load in excess of 40%. In addition to analysis of the circadian rhythm of BP and HR and the prevalence of a hypertensive BP load in CAPD patients, the influence of various factors such as gender, creatinine clearance, recombinant human erythropoietin, antihypertensive medication, haematocrit, whole-day BP load, and the nightly dialysis glucose concentration on the diurnal variation of BP and HR were studied. RESULTS: Based on the 95% confidence intervals for the proportional nocturnal decrease, normal diurnal variation of BP and HR was present in most CAPD patients. No correlation could be demonstrated between a blunted circadian rhythm and the variables mentioned above. However, when other time-period definitions (DT = 6.00 a.m.-11.00 p.m., NT = 11.00-6.00 and DT = 8.00 a.m.-8.00 p.m., NT = 8.00 p.m.-8.00 a.m.) were applied to the data, considerably fewer patients displayed normal diurnal variation. Whereas all patients showed normal home BP readings, ABPM of 21 out of 29 patients displayed a hypertensive BP load. CONCLUSION: The majority of our CAPD patients exhibited normal diurnal variation of SBP and DBP depending, however, on the definitions of DT and NT used. The absence of a normal circadian rhythm could not be explained by any of the variables analyzed. Surprisingly, uncontrolled hypertension, as defined by a hypertensive BP load, was found in 72% of the patients.

Biocompatibility and performance of a modified cellulosic and a synthetic high flux dialyzer. A randomized crossover comparison between cellulose triacetate and polysulphon.

The biocompatibility and performance of two high flux membranes (modified cellulosic: cellulose-triacetate (CTA), and a synthetic material: polysulphon [PS]) were assessed in 31 stable patients on hemodialysis (HD) in a randomized crossover study. Parameters evaluated included leukocytes, complement activation products C3a and C5a, cytokines, lymphocyte subpopulations, urea, creatinine, phosphate, and beta 2 microglobulin. Considering biocompatibility, the drop in the number of leukocytes was more pronounced during CTA HD compared with PS (p = 0.045), although both were low in comparison with cuprammonium dialysis in the same patients, as observed during a separate study. Both membranes induced a low and transient state of complement activation. Interleukin 1 beta and interleukin 6 could not be detected at all, whereas tumor necrosis factor alpha levels were marginally elevated before and after HD with both membranes. During the first 30 min of HD with either membrane, the numbers of CD8+ cells decreased significantly, resulting in an increase in the CD4/CD8 ratios; in addition, the number of NK cells decreased. Performance, as measured by extraction ratios for small molecular weight solutes and Kt/V urea, was significantly better during CTA dialysis (p < 0.001), but almost similar after correction for membrane surface area. On the basis of these data, it seems justified to conclude that, whereas biocompatibility of the PS dialyzer appeared slightly superior to CTA, performance of both dialyzers was comparable.

Clinical value of labeled red blood cell scintigraphy in patients with difficult to diagnose gastrointestinal bleeding.

A retrospective study was conducted using 36 patients with gastrointestinal bleeding in whom the diagnosis was not directly apparent from first line diagnostic procedures. Final diagnosis was established by surgery, endoscopy, or postmortem examination in 20 patients. Scintigraphic examination with Tc-99m or In-111 labeled red blood cells yielded 24 positive and 18 negative results. Nine out of 13 positive scans (verified by other diagnostic procedures) accurately identified the site of bleeding. This was considered to be a satisfactory result in this group of difficult to diagnose patients. The lowest success rate was observed in patients taking drugs that interfered with coagulation, or in patients prone to diffuse blood loss because of coagulopathy. Late scans did not offer additional information and the use of In-111 for this purpose was not thought to be of benefit. Although the technique is rather noninvasive and simple, its application should be restricted to selected patients and its interpretation related to the results of other investigations.

Bacterial and clinical sequelae of the Twin bag system in continuous ambulatory peritoneal dialysis. A single centre study.

Since the introduction of disconnect systems, a marked reduction in continuous ambulatory peritoneal dialysis (CAPD)-related peritonitis has been reported in the literature. At our centre too, a highly significant decline in the peritonitis rate was observed after the introduction of the Twin bag in 1990. In a multivariate analysis which we published recently, the Twin bag system, in conjunction with the more frequent use of the swan neck catheter, correlated significantly (p < 0.001) with an increase in the peritonitis-free interval. In the present study we retrospectively analyzed the bacteriological cultures of the peritonitis episodes, the antibiotic treatment prescribed, and the number of hospitalization days (HDs) before (non-Twin bag group; NTG) and after the introduction of the Twin bag system in our centre (Twin bag group; TG). In terms of absolute numbers, the decreased incidence of peritonitis in the TG was due by and large to a decline in all pathogenic micro-organisms, but mostly to a reduction of coagulase-negative staphylococci (CNS) compared with the NTG. The incidence of culture-negative episodes, however, showed no difference between the two groups. Proportionally, there was a significant increase in culture-negative peritonitis in the TG, whereas infections caused by CNS significantly decreased in comparison with the NTG (p < 0.01). The pattern of the antibiotics prescribed, i.e. mono- versus multi-drug regimens, did not differ between the two groups. Since, of all micro-organisms involved, CNS infections showed the largest decline in absolute numbers. Staphylococcus aureus increased relatively (43%) after the introduction of the Twin bag system.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term results of continuous ambulatory peritoneal dialysis: the first hundred patients. A single centre study.

In the present survey our experience on the first 100 patients on CAPD, treated from the start in 1982 till September 1991, is described. Sixteen were diabetics. Both the absolute numbers and the proportion of the total dialysis population have increased almost every year. Mean age did not change over the years due to an equilibrium between younger patients who received a transplant and elderly who stopped CAPD for other reasons. Patient survival at 3 years was 68%. Seventy patients stopped CAPD, of whom 25 died and 16 switched to haemodialysis. Twenty-four patients received a transplant, patient and transplant survival at 3 years being 89% and 77% respectively. Fifteen patients have had a follow-up period of 3 years or more, the longest being 123 months currently. Seventy-three CAPD-related complications occurred, the majority catheter-related. After the introduction of a 'break-in' period a significant reduction in leakage alongside the catheter was observed. In recent years there was a dramatic decrease in the incidence of CAPD-related peritonitis, from once every 8 to once every 30 months, which could be attributed mainly to the introduction of a new disconnect system in our centre, the so-called 'Twinbag'.

Major reduction of CAPD peritonitis after the introduction of the twin-bag system.

In recent years an impressive decrease in the incidence of CAPD-related peritonitis was observed in our centre, from 1.4 in the mid-eighties to 0.4 per patient year in 1991. In order to analyse which factors were most responsible for this decline, the present study was performed. From the start of our CAPD programme in 1982 until September 1991, 100 patients were enrolled. For each patient, time elapsed from catheter insertion until first peritonitis episode was recorded. Outcome was measured as the peritonitis-free interval in days. The following variables have been evaluated: age, gender, type of catheter, type of system, presence of diabetes mellitus, leakage, break-in period, presence of an exit-site infection, and performing surgeon. Data were analysed first by Kaplan-Meier product-limit estimate of survival (peritonitis-free interval). Thereafter Cox proportional hazard analysis was applied to the data, providing a conditional probability of peritonitis at each moment during follow-up, given a certain combination of risk factors. Our results show that the system, in conjunction with the type of catheter, was a decisive factor in the decline of the peritonitis rate in our centre. Patients on the twin-bag system (twin-bag group) showed a significant increase in the peritonitis-free interval in comparison with patients using other systems (non-twin bag group). Among the other variables analysed, only diabetes mellitus appeared to be relatively important. Episodes of culture negative peritonitis were more frequently observed in the twin-bag group, compared to the non-twin bag group. In absolute numbers Staph. non-aureus was the micro-organism most effectively reduced.

Influence of erythropoietin treatment on urea kinetic parameters in hemodialysis patients.

Urea kinetic parameters were studied by means of dialysate collection in 8 stable hemodialysis patients before and after treatment with recombinant human erythropoietin (r-HuEPO), in order to investigate the impact of a rising hematocrit (Ht) on dialyzer performance and nutritional status. After 6 months, the average in vivo dialyzer urea clearance had fallen from 152 to 132 ml/min and consequently Kt/V values had become undesirably low in most of the patients in whom the relatively short dialysis regimens had been kept unchanged. There was also a significant decrease of protein intake. As a result of both changes there was only a moderate increase of predialysis mean blood urea concentration. These findings indicate that after correction of anemia by r-HuEPO dialyzer performance decreased. The concomitant decrease of protein intake seems to contrast to the improved general physical condition and appetite as indicated in the questionnaires. Although body weight remained the same, there might have been a tendency to avoid protein consumption with maintained total calory intake as a result of slight underdialysis. Therefore, in individual cases dialysis prescriptions may need reconsideration when Ht levels rise after r-HuEPO administration, especially in short dialysis regimens.

Increase in plasma prorenin during the menstrual cycle of a bilaterally nephrectomized woman.

To investigate the origin of the prorenin peak that occurs during the normal menstrual cycle, plasma levels of prorenin, renin, oestradiol, progesterone, LH and FSH were measured serially in a nephrectomized woman having regular haemodialysis. The prorenin peak coincided with the LH surge and preceded the rise of progesterone, whereas renin was below the detection limit during the whole cycle. These findings indicate that the rise in prorenin during the menstrual cycle is not of renal origin but is probably due to increased production by the ovary and supports the increasing evidence for the existence of a local renin-angiotensin system in the ovary.

Continuous arteriovenous haemofiltration and haemodiafiltration in acute renal failure.

Continuous arteriovenous haemofiltration (CAVH) was employed in ten patients with acute renal failure using an AN-69 plate filter. Special measures were taken to improve the efficiency of the technique, including the use of short, large-bore catheters for vascular access, predilution infusion of the substitution fluid, and moderate vacuum suction to the ultrafiltrate compartment. In five patients continuous arteriovenous haemodiafiltration was performed by the addition of slow dialysis at a dialysate flow of 1 litre per hour. This technically simple manoeuvre enhanced solute clearances up to 20 ml/min and obviated the need for standard intermittent dialysis sessions in all cases. Repeated measurements of transmembrane pressure and ultrafiltration rate permitted calculation of the in vivo membrane permeability index, which showed a reproducible decline with time. With relatively low heparin requirements an adequate filter performance could be maintained for over 48 h. The encouraging clinical results indicate that CAVHD, in spite of the invasive nature of this technique, may be considered a first-choice treatment for patients with acute renal failure in the intensive care unit.

Bicarbonate versus acetate hemodialysis in ventilated patients.

Hemodynamic tolerance to bicarbonate versus acetate hemodialysis was studied in seven ventilated, critically ill patients, suffering from acute renal failure. Both kinds of hemodialysis were carried out with a recirculating dialysate delivery system and a relatively low blood flow (180 ml/min). Each patient underwent two hemodialysis procedures, one with bicarbonate and one with acetate, lasting for four hours. Ultrafiltration rates were kept below 250 ml/h and only biocompatible membranes with a relatively small surface area (Biospal 2400, Hospal, France) were used. Despite the mild hemodialysis conditions, hypotensive episodes with a mean blood pressure below 70 mmHg were observed in 3 out of 7 bicarbonate sessions and 4 out of 7 acetate sessions. Thus, we could not demonstrate a hemodynamic advantage of bicarbonate hemodialysis in this group of ventilated patients. This contrasts with other studies conducted in non-ventilated patients. Prevention of hypoxemia by mechanical ventilation and control of vascular tone by the use of vasoactive drugs may be of more clinical relevance than the kind of hemodialysis procedure that is used.

Immune response to hepatitis B vaccine in hemodialysis patients.

The impaired immune reactivity of hemodialysis patients has been reported to interfere with adequate antibody responses to standard doses of hepatitis B vaccine. In 22 hemodialysis patients, however, a 92% conversion rate could be obtained by administering multiple doses of plasma-derived MSD-vaccine. As the cost of such an amplified vaccination schedule is still lower than the cost of one dialysis treatment, this active vaccination policy for highly susceptible patients appears financially justified.