Volume control in treatment-resistant congestive heart failure: role for peritoneal dialysis.

Chronic congestive heart failure (HF) has a rising prevalence and increasing impact on health care systems. Current treatment consists of diuretics, renin-angiotensin-aldosterone system blockers, and restriction of salt and fluids. This strategy is often hampered by a drop in effective circulating volume and hence renal perfusion and function, triggering harmful counter regulatory mechanisms. Slow ultrafiltration by peritoneal dialysis (PD) might be an effective treatment strategy to relieve fluid overload without compromising cardiac output and thereby renal function. In this review, we discuss the (patho)physiological mechanisms of the cardiorenal interaction and the current literature on PD strategies in congestive HF.

B-type natriuretic peptide and interdialytic fluid retention are independent and incremental predictors of mortality in hemodialysis patients.

AIM: Management of fluid homeostasis remains a major challenge in hemodialysis patients. We aimed to establish whether the cardiac strain marker B-type natriuretic peptide (BNP) could help to identify hypervolemic patients at increased risk of death. METHODS: BNP levels were determined before dialysis in the entire HD population at our institution (n = 57). IDWG and BNP were stratified above or below 1.5 kg or the median value, respectively. All patients were prospectively followed for 35 months. The influence of IDWG and BNP on mortality was assessed with a Cox proportional hazards model, adjusted for each other, as well as for demographics, comorbidities, cardiac function, residual diuresis, dialysis duration and efficiency and complications of renal failure. RESULTS: Median BNP was 303 (135 - 692) and 21 (36%) patients displayed an average IDWG below 1.5 kg. During follow up a total of 25 (44%) patients died, 5 (26%) in the low IDWG group and 20 (53%) in the high IDWG group (adjusted hazard ratio (adjusted HR) 5.31 95% CI (1.47 - 19.1), p = 0.011). In the low BNP group 7 (25%) patients died and in the high BNP Group 18 (62%) patients died (adjusted HR 3.53 95 CI (1.37 - 9.09), p = 0.009). When both factors were considered simultaneously, patients with low BNP and low IDWG had an 11 times lower risk of death compared to patients with high BNP and high IDWG (HR. 0.08 95% CI (0.01 - 0.6129, p = 0.015). CONCLUSIONS: BNP and IDWG are independent and incremental predictors of mortality in HD patients. These findings suggest that BNP guided fluid management could improve survival in these patients.

[Flank pain caused by a renal artery dissection]. / Flankpijn door een nierarteriedissectie.

BACKGROUND: A spontaneous renal artery dissection is a very rare diagnosis. The clinical presentation can vary and its course can be atypical. There are no guidelines available regarding treatment; however, the options are a conservative (medication) or interventional (radiological or surgical) approach. CASE DESCRIPTION: A 45-year-old man presented to the emergency department with hypertensive urgency after earlier episodes of flank pain. The cause appeared to be a spontaneous bilateral renal artery dissection with infarction. After a multidisciplinary consultation, the decision was made to manage the patient conservatively since symptoms had subsided, blood pressure was acceptable and renal function remained stable. Eventually, kidney function restored to normal and CT images showed almost complete recovery of the previously damaged renal parenchyma. CONCLUSION: This case demonstrates that in the event of renal artery dissection, a conservative medication policy may be a good option in clinically stable patients with non-deteriorating renal function. Timely recognition and adequate follow-up are important to prevent serious complications, such as renal ischaemia or renal infarction that could necessitate a nephrectomy.

Effect and mechanism of hydrocortisone on organ function in patients with severe burns.

INTRODUCTION: In patients with severe burns, resuscitation with large volumes of fluid is needed, partly because of an increase in capillary leakage. Corticosteroids might be beneficial by diminishing capillary leakage. This study aimed to assess in severely burned nonseptic patients whether hydrocortisone (HC) improved outcome and diminished capillary leakage. METHODS: Retrospective analyses of a prospectively collected database were performed, including 39 patients (age 52 [35-62] years, 72% male). Patients were divided based on HC therapy. First, in patients in whom HC was started late, that is when deteriorating (late; 5-12 days postburn) data before and after start of HC were compared. Second, patients in whom HC was started day 0 or 1 postburn (upfront; within 48 hours) were compared with patients who did not receive HC (control). Outcome was assessed as organ dysfunction by Denver Multiple Organ Failure (MOF) score and Sequential Organ Failure Assessment (SOFA) score. As markers for capillary leakage and hydration state, proteinuria, B-type natriuretic peptide (BNP), and fluid administration were assessed. Follow-up was 20 days postburn. Possible adverse effects including mortality were recorded. Repeated measurement regression analyses were performed using MLwiN. RESULTS: In the late group, Denver MOF and SOFA scores significantly decreased after HC (P<.001). Proteinuria tended to decrease (P=.13), BNP increased on the days HC was used (P<.001), and amounts of fluids diminished (P<.001). In the upfront vs control group, Denver MOF and SOFA scores (P<.001) decreased more quickly. Proteinuria (P=.006) and administered fluids decreased more rapidly (P<.001). Mortality rate, numbers of positive blood cultures, incidence of pneumonia, and graft loss were similar in all groups. CONCLUSIONS: Hydrocortisone treatment in severe burned patients without sepsis might improve organ dysfunction possibly because of a reduction in capillary leakage, as reflected by a decrease of proteinuria, an increase of BNP, and diminished fluid resuscitation volumes.

Excessive urinary albumin levels are associated with future cardiovascular mortality in postmenopausal women.

BACKGROUND: Microalbuminuria is an early predictor of cardiovascular morbidity and mortality, in both diabetic patients and hypertensive patients. Little is known about the relation of microalbuminuria to cardiovascular disease in women of the general population. METHODS AND RESULTS: We have studied the relation of urinary albumin levels to cardiovascular mortality in a cohort study of 12 239 postmenopausal women living in Utrecht, the Netherlands. The initial age was between 52 and 67 years. Women were followed on vital status between 1976 and 1995 (168 513 women-years). Albumin was determined in the urine of 561 cases and 557 controls. Data were analyzed by using a nested case-control design. The cardiovascular mortality rate (95% CI) for women who were in the highest quintile of urinary albumin levels was 13.2/1000 years (8.1 to 20.9) compared with 2.6/1000 years (2.3 to 3.1) in women without detectable urinary albumin. The age-adjusted rate ratio (95% CI) between these groups was 4.4 (2.6 to 7.6). CONCLUSIONS: This is the first large cohort study that confirms a predictive role of urinary albumin for the risk of future cardiovascular mortality independent of hypertension and diabetes. Our findings support the hypothesis that microalbuminuria is a reflection of vascular damage and a marker of early arterial disease in women from the general population.

Oral contraceptive use and hormone replacement therapy are associated with microalbuminuria.

BACKGROUND: Controversy exists regarding the adverse and beneficial effects of oral contraceptive use and hormone replacement therapy. Microalbuminuria is associated with increased risk of renal and cardiovascular disease. OBJECTIVE: To examine the association between oral contraceptive use or hormone replacement therapy and microalbuminuria. METHODS: We performed a case-control study of the baseline data and historical pharmacy data of 4301 female subjects of the Prevention of Renal and Vascular End Stage Disease study cohort, aged 28 to 75 years, excluding women who were pregnant or had type 1 diabetes mellitus. The main outcome measure was microalbuminuria, defined as a urinary albumin excretion of 30 to 300 mg per 24 hours (recorded as the mean of two 24-hour urine collections). RESULTS: After adjusting for age, hypertension, diabetes, obesity, hyperlipidemia, and smoking, the odds ratio (OR) for having microalbuminuria was 1.90 (95% confidence interval [CI], 1.23-2.93) for premenopausal oral contraceptive users and 2.05 (95% CI, 1.12-3.77) for postmenopausal hormone replacement therapy users. The point estimate increased in a dose-dependent fashion, albeit insignificantly, according to the estrogen content of the oral contraceptives (<30 microg ethinyl estradiol: OR, 1.11; 95% CI, 0.14-8.56; 30 to <50 microg: OR, 1.83; 95% CI, 1.17-2.87; and 50 microg: OR, 2.72; 95% CI, 0.81-9.08). The OR was greater in oral contraceptives with a second-generation (OR, 2.04; 95% CI, 1.28-3.25) vs a third-generation progestin (OR, 1.39; 95% CI, 0.63-3.06). The OR increased with the duration of hormone replacement therapy (< or =5 years, OR, 1.28; 95% CI, 0.37-4.50; >5 years, OR, 2.56; 95% CI, 1.32-4.97). CONCLUSION: Regular and long-term oral contraceptive use and hormone replacement therapy are associated with an increased risk for microalbuminuria and cardiovascular disease.

Antihypertensive effect of a 5-day infusion of atrial natriuretic factor in humans.

Atrial natriuretic factor was infused in a low dose (0.2 microgram/min) during 5 days in six patients with essential hypertension. Atrial natriuretic factor infusion caused plasma levels of atrial natriuretic factor to increase from 49 +/- 10 to 106 +/- 19 pg/ml. Within 4 hours after the start of the atrial natriuretic factor infusion, urinary sodium excretion increased in all subjects. Sodium balance was regained after 24 hours with a net loss of 72.3 +/- 14.6 mmol. However, systolic as well as diastolic blood pressure started to decrease gradually in all subjects only after 12 hours of atrial natriuretic factor infusion, reaching a stable level after 36 hours with a decrease of 11.5 +/- 1.5% and 10.3 +/- 0.8%, respectively. Heart rate increased in parallel by 12.6 +/- 3.1%. Hematocrit rose 7.1 +/- 2.3%. After cessation of atrial natriuretic factor infusion, plasma atrial natriuretic factor levels, sodium balance, and hematocrit returned to baseline within 24 hours, whereas blood pressure slowly returned toward baseline values over 3 days. These data show that chronic atrial natriuretic factor infusion in patients with essential hypertension causes a negative sodium balance and a rise in hematocrit, followed by a smooth decrease in blood pressure with a rise in heart rate until a new equilibrium is reached after approximately 2 days. Thus, atrial natriuretic factor in low doses appears intimately involved in the regulation of sodium balance and blood pressure in humans. Moreover, these data suggest that atrial natriuretic factor-like substances will eventually become useful antihypertensive drugs.

Atrial natriuretic factor influences renal diurnal rhythm in essential hypertension.

We investigated in six patients with essential hypertension the effect of a low dose atrial natriuretic factor infusion for 5 days on the diurnal rhythm of renal electrolyte excretion. Atrial natriuretic factor infusion increased the net excretion of sodium and caused a delay in its time of maximal diurnal urinary excretion. Similarly, atrial natriuretic factor caused an increase in the net excretion of chloride, calcium, and magnesium and also changed the diurnal rhythms of these electrolytes. In contrast, atrial natriuretic factor did not change the net excretion of potassium, phosphate, and uric acid, nor did atrial natriuretic factor change the diurnal rhythms of these solutes. During baseline, the time points of maximal urinary excretion of sodium and potassium overlapped, whereas atrial natriuretic factor infusion caused sodium excretion to peak 2.2 +/- 0.3 hours (p less than 0.02) after the potassium excretion peak. During baseline, the time of maximal urinary excretion of sodium did not correlate with the time of highest blood pressure, whereas it correlated negatively with mean plasma aldosterone concentration. In contrast, during atrial natriuretic factor infusion the time of maximal urinary excretion of sodium correlated positively with the time of highest blood pressure, whereas it did not correlate with mean plasma aldosterone concentration. These data suggest that atrial natriuretic factor is involved with the diurnal rhythm of the urinary excretion of sodium and that atrial natriuretic factor-induced natriuresis is mediated in part by blood pressure and plasma aldosterone.

Renal tubular sensitivity to atrial natriuretic factor in essential hypertension.

OBJECTIVE: To study the tubular site or sites of the natriuretic action of atrial natriuretic factor and the possible differences between healthy subjects and patients with essential hypertension. DESIGN: Nine healthy volunteers and six patients with essential hypertension were studied on four test days under standard conditions, water loading and hydropenia with mannitol or saline loading. On each test day baseline, atrial natriuretic factor infusion (1 microgram/min) and recovery measurements were performed after equilibrium had been reached. The measurements included the atrial natriuretic factor (ANF) plasma levels, blood pressure, glomerular filtration rate (GFR), effective renal plasma flow, urinary osmolality and the (fractional) excretions of (free) water, sodium and potassium. METHODS: Fractional free-water excretion and free-water reabsorption (as a function of osmolar clearance) were calculated during water loading and hydropenia with mannitol or saline loading, respectively, using standard formulae. [125I]-iothalamate and [131I]-hippuran were infused continuously for the measurement of GFR and effective renal plasma flow, respectively. RESULTS: The plasma ANF concentration rose five- to eightfold during the infusion of ANF, which induced an increase in urinary sodium excretion, a small increase in GFR and a decrease in the effective renal plasma flow. Moreover, ANF induced an increase in fractional free-water excretion and a decrease in fractional free-water reabsorption. These changes did not correlate with changes in GFR. The blood pressure and potassium excretion were not affected. The effects of ANF on the plasma ANF levels, natriuresis and renal haemodynamics did not differ between the normotensive and the essential hypertensives. However, the increase in fractional free-water excretion was significantly greater in the patients with essential hypertension and correlated significantly with blood pressure (r = 0.56, P < 0.05). CONCLUSIONS: These results indicate that the infusion of ANF at a low dose induces a similar natriuretic response in normotensive subjects and in patients with essential hypertension. This natriuresis is probably the result of both a glomerular and a tubular effect of ANF. Proximal as well as distal tubular sites seem to be involved. In essential hypertension an enhanced proximal as well as an impaired distal tubular action of ANF can be hypothesized.

Rationale, design, and baseline characteristics of a trial of prevention of cardiovascular and renal disease with fosinopril and pravastatin in nonhypertensive, nonhypercholesterolemic subjects with microalbuminuria (the Prevention of REnal and Vascular ENdstage Disease Intervention Trial [PREVEND IT]).

This study describes the rationale, design, and baseline characteristics of a trial to determine whether treatment with fosinopril 20 mg/day and/or pravastatin 40 mg/ day will prevent cardiovascular and renal disease in nonhypertensive (RR <160/100 mm Hg and not using antihypertensive medication) and nonhypercholesterolemic (total cholesterol <8.0 or <5.0 mmol/L in case of previous myocardial infarction and not using lipid lowering medication) men and women with persistent microalbuminuria (urinary albumin excretion >10 mg/L once in an early morning spot urine and 15 to 300 mg/24-hour at least once in two 24-hour urine collections). The Prevention of REnal and Vascular ENdstage Disease Intervention Trial is a single-center, double-blind, randomized, placebo-controlled trial with a 2 x 2 factorial design. The 864 randomized subjects will be monitored for a minimum of 4 years and a maximum of 5 years. The primary efficacy parameter is defined as the combined incidence of all-cause mortality or hospital admission for documented (1) nonfatal myocardial infarction, (2) myocardial ischemia, (3) heart failure, (4) peripheral vascular disease, (5) cerebrovascular accident and/or (6) end-stage renal disease.

The influence of respiration induced motion of the kidneys on the accuracy of radiotherapy treatment planning, a magnetic resonance imaging study.

An MRI study has been performed to determine the respiration induced motion of the kidneys. Under normal respiration conditions displacements of the left and right kidney varied from 2 to 24 mm and 4 to 35 mm, respectively. Under forced respiration conditions displacements were larger and ranged from 10 to 66 mm for the left kidney and 10 to 86 mm for the right kidney. The influence of kidney motion on the radiation dose was determined for patients irradiated on the total abdomen for ovarian cancer with shielding of the kidneys during part of the treatment. The kidney motion resulted in a larger fraction of the kidney volume receiving a dose between 20 and 22 Gy.

Short TI short TR inversion recovery imaging using reduced flip angles.

In this paper the effects of reducing the flip angle of the 90-degree observation pulse in inversion recovery imaging are described and analyzed. When incorporated in an IR sequence with a short inversion time (STIR), reduction to the 90-degree pulse allows a significant shortening of the repetition time without loss in contrast, although at the expense of some signal/noise. The generalized STIR sequence thus combines the previously reported advantages of a conventional STIR sequence--suppression of ghost artifacts from abdominal wall movement, suppression of chemical shift and boundary artifacts, additive effects of N(H), T1 and T2 on image contrast--with reduced power deposition and the advantages resulting from shorter repetition times, viz, single heart-beat triggering, increased number of signal averages for suppression of motion artifacts, acquisition of interleaved contiguous slices without cross-talk or considerable time savings when the number of required slices is limited. The proposed method is demonstrated and experimentally verified by imaging experiments on phantoms and human subjects. In principle the method is applicable to all cases where STIR imaging has been proven to be successful.

[Psychosocial consequences of screening for microalbuminuria and for some other risk factors]. / Psychosociale gevolgen van een screening op microalbuminurie en op enkele andere risicofactoren.

OBJECTIVE: Obtaining insight into the psychosocial consequences of a screening programme for the progression of heart, vessel and kidney damage. DESIGN: Questionnaire investigation. METHOD: This study addressed participants in the 'Prevention of renal and vascular end-stage disease' (PREVEND) study, which included about 40,000 inhabitants of Groningen, the Netherlands, aged 28-75 years, who were asked to send in a vial with morning urine in order to detect microalbuminuria. People with microalbuminuria were invited to a general practitioners' laboratory to determine the risk factors: urinary protein concentration, blood pressure and blood cholesterol level. A questionnaire was sent to 335 participants of the screening who had received the screening results two weeks before. RESULTS: The response rate was 75%. A minority of the respondents diagnosed with risk factors, expressed some concern. No influence on the wellbeing of this group of participants was established. Almost one-third of the respondents stated that they now 'lived according to healthier principles' because of the screening. On the other hand, there was a certain 'certificate of health effect': about half the smokers and the physically inactive saw the favourable screening result as a legitimation for their life style. An unfavourable screening result had led to additional medical consumption in almost half the respondents. The respondents appreciated the screening and especially the lower-educated had a very positive attitude towards early diagnosis in general. CONCLUSION: The screening positives showed no diminished wellbeing; their health behaviour improved due to the screening and they had a higher medical consumption. About half the screening negatives regarded the results as a legitimation of their unhealthy life style.

Psychosocial consequences of screening for albuminuria and certain other risk factors.

OBJECTIVE: To gain insight into the psychosocial consequences of a screening programme on the progression of heart, vascular and kidney damage. DESIGN: Over 85,000 people aged 28-75 were invited to participate in a screening for albuminuria. Nearly half of them sent in their morning urine of which almost 10,000 had a (slightly) elevated urinary albumin level. This latter group was invited to participate in a follow-up screening (24-hour urine samples, blood pressure, glucose, cholesterol) together with ±3,000 randomly selected subjects with a normal urinary albumin concentration. A questionnaire on the psychosocial consequences of the screening was sent to 335 participants of the screening programme each of whom had received their (positive or negative) screening results two weeks previously. RESULTS: The response rate was 75%. A minority of the respondents, diagnosed for risk factors, expressed some concern. No influence on the well-being of this group of participants could be established. Almost one third of the respondents claimed to follow a healthier lifestyle as a result of the screening. There are, however, also indications for a certain 'certificate of health effect': about half of the smokers and the physically inactive considered that the favourable screening results legitimated their unhealthy lifestyle. An unfavourable screening result led to additional medical consumption in almost half of the respondents. The respondents appreciated the screening and especially the less educated had a very positive attitude towards early diagnosis in general. CONCLUSIONS: Those screened positive showed no diminished well-being; their health behaviour improved because of the screening and their medical consumption increased. Many of those screened negative considered the test result a reason to continue their unhealthy lifestyle.

[The use of flocculation sludge in poultry feed. Chemical and microbiological composition]. / Het gebruik van vlokkingsslib in pluimveevoeders. Chemische en microbiologische samenstelling.

For the purpose of making inventories, the chemical and microbiological composition of samples of flocculated sludge of poultry, pig and cattle-stock slaughter-houses were examined. This was required to study the possibilities of using flocculated sludge as raw material in animal feed. Chemical studies showed that the dry matter (dm) levels of the various specimens of sludge varied markedly. (Broiler sludge 7.1% of dm, pig sludge 7.5%, cattle-stock sludge 5.5% and laying-hen sludge 13.3%). Broiler- and laying-hen sludge contained more crude fat than did the other samples of sludge. Measured by the concentrations of lysine, methionine and cystine, the sludge product was most similar to the protein of meal-and-bone meal and soy-bean meal. The iron content of almost all samples examined was very high. In view of the current standards for concentrations of metal in complete animal feeds, the concentrations of iron and lead will have to be taken into account in using this sludge product. The proportion of total polymers in the fat fractions of samples of sludge varied from 2.4% to 39.2%, less than 10% only being observed in two samples. The microbiological composition of broiler and pig sludge did not differ. Both the total aerobic bacterial count and the number of Enterobacteriaceae, Escherichia coli and Salmonella were found to be high. Species of Campylobacter were not isolated; however, a number of samples were found to be positive for adenovirus. Prior to deciding to use flocculated sludge in livestock feeding, the product will have to undergo thorough decontamination.

Hypertension and renal disease: role of microalbuminuria.

RISKS ASSOCIATED WITH HYPERTENSION: Hypertension is a risk factor for cardiovascular and possibly renal organ damage. Microalbuminuria is a newly recognized cardiovascular and renal risk factor in diabetic and non-diabetic subjects. The prevalence of microalbuminuria is enhanced in hypertensive subjects, in particular in those with blood pressure characteristics that are associated with enhanced cardiovascular risk, such as salt-sensitivity and an abnormal diurnal blood pressure rhythm. NEED FOR FURTHER TRIALS: Although microalbuminuria is more prevalent in hypertensives and is shown to be a strong and independent risk factor, the relation between microalbuminuria and hypertensive complications is unknown. Even more intriguing is the finding of elevated levels of microalbuminuria in normotensive children with one or two parents with hypertension. This suggests that microalbuminuria is linked to the pathogenesis of hypertension. However, the role and the cause(s) of microalbuminuria are uncertain. Microalbuminuria seems to link renal and cardiovascular organ damage. Microalbuminuria might be the consequence of (renal) organ damage induced by hypertension. Alternatively, microalbuminuria might be an independent marker of some process that occurs separately from diabetes, hypertension or dyslipidemia. Endothelial dysfunction has been suggested to underlie renal and/or cardiovascular organ damage in these diseases. More knowledge should be obtained on the cause and the natural course of microalbuminuria. CONCLUSION: Microalbuminuria possibly identifies at an early stage hypertensive patients with an enhanced risk of developing the well-known renal and cardiovascular hypertensive complications. For the patients at particular risk therapeutic measures than can be developed. If microalbuminuria identifies a specific underlying pathogenetic mechanism, these measures may intervene with such a mechanism. Alternatively, if microalbuminuria identifies enhanced risk then standard antihypertensive therapy can be intensified, since such measures also lower microalbuminuria.