Predialysis Urea Research Articles

#5268 PREGNANCY OUTCOMES IN DIALYSIS PATIENTS: A TEN-YEAR SERIES FROM A TERTIARY CENTER

Abstract Background and Aims Pregnancy in dialysis patients was almost prohibited a decade ago, as fetal and maternal outcomes were very poor. In the last years, there has been a paradigm shift, as the introduction of intensive hemodialysis (HD) schedules has been associated with an impressive improvement on fetal outcomes, making motherhood a possibility in these women. Nevertheless, pregnancy in women on dialysis remains associated with a high incidence of complications and is extremely demanding for both patients and clinicians. We describe the maternal, obstetric, and perinatal outcomes of pregnancies in women on dialysis followed at the Nephro-Obstetric Clinic at Centro Hospitalar Universitário Lisboa Norte (CHULN). Method Retrospective analysis of pregnancies in women on dialysis and surveilled at the Nephro-Obstetric Clinic at CHULN from 2011 to 2022. Results We considered 17 pregnancies from 16 women. One of the women accounted was submitted to voluntary termination of pregnancy. Mean age was 31.5 ± 6.1 years; 70.6% were Black (n = 11) and 29.4% (n = 5) Caucasian; 58.8% were nulliparous (n = 10). All patients had chronic hypertension (HTN), although only 75.0% were under therapy (12/16). Additionally, 3/16 patients had diabetes and 2/16 hyperthyroidism. The mean of overall renal replacement therapy (RRT) duration was 9.1 ± 8.2 years (dialysis and renal transplantation time), being on dialysis program 43.7 ± 37.5 months before gestation. One patient was on peritoneal dialysis (PD) and two patients started HD during pregnancy. Five patients (31.2%) were exposed to teratogenic drugs during gestation. Pregnancy diagnosis occurred at 13.4 ± 5.6 weeks; 70.6% of the patients were on low dose acetylsalicylic acid (n = 12). HD mean time per week according to each trimester was 13.7 ± 2.8 hours/week, 24.5 ± 7.3 hours/week and 28.0 ± 8.0 hours/week during the 1st/2nd/3rd respectively. Mean pre-dialysis urea was 62.1 ± 28.0 mg/dL during gestation. Regarding maternal outcomes, worsening HTN occurred in 62.5% (n = 10) of patients during the 1st (4/10) and 2nd trimester (7/10) and pre- eclampsia (PE) occurred in 6/16 patients (1 with HELLP syndrome). One patient developed polyhydramnios and another one cholestasis of pregnancy. Premature rupture of membranes (PRM) occurred in 3 patients (at 17, 25 and 36 weeks); One patient asked for medical termination of pregnancy due to severe growth restriction and oligohydramnios at 20 weeks. Stillbirth occurred in 4 gestations (cervical insufficiency in a twin pregnancy, severe congenital fetal cardiopathy in a patient with PE, severe growth restriction and premature rupture of membranes (PRM). In the 2 patients with early PRM, the neonates died in the following week due to severe prematurity complications. Labor was induced in 9 patients, mainly due to PE (7/9). Cesarean was performed in 10/17 patients and mean gestation age at delivery was 29.8 ± 6.6 weeks. Extreme prematurity (<28 weeks) occurred in 3 pregnancies and there were three term babies. Mean birth weight was 1554.0±613.6 grams with 4 newborns having extremely low birth weight (<1000g) and 6 requiring neonatal care. Conclusion Our study reveals that pregnancy in women on dialysis is challenging and still associated with significant maternal, obstetric and perinatal complications. This population was highly heterogenous, with a significant number of patients living under unfavorable social conditions, and with significant comorbidities. The diagnosis of pregnancy took place mainly during the 2nd trimester, preventing early initiation of intensive dialysis schedules which could have significantly improved outcomes. Pregnancy planning, early diagnosis and management by a multidisciplinary experienced team are of paramount importance to improve outcomes and reduce complications.

A potential link between AQP3 and SLC14A1 gene expression level and clinical parameters of maintenance hemodialysis patients

BackgroundThe transport of water and urea through the erythrocyte membrane is facilitated by aquaporins such as aquaglyceroporin (AQP3), and type B urea transporters (UT-B). As they may play an important role in osmotic balance of maintenance hemodialysis (HD) patients, the aim of the present study was to determine whether any relationship exists between the expression of their genes and the biochemical / clinical parameters in HD patients.MethodsAQP3 and UT-B (SLC14A1) gene expression was evaluated using RT-qPCR analysis in 76 HD patients and 35 participants with no kidney failure.ResultsThe HD group demonstrated significantly higher median expression of AQP3 and UT-B (Z = 2.16; P = 0.03 and Z = 8.82; p < 0.0001, respectively) than controls. AQP3 negatively correlated with pre-dialysis urea serum concentration (R = -0.22; P = 0.049) and sodium gradient (R = -0.31; P = 0.04); however, no significant UT-B correlations were observed. Regarding the cause of end-stage kidney disease, AQP3 expression positively correlated with erythropoietin dosages in the chronic glomerulonephritis (GN) subgroup (R = 0.6; P = 0.003), but negatively in the diabetic nephropathy subgroup (R = -0.59; P = 0.004). UT-B positively correlated with inter-dialytic weight gain% in the GN subgroup (R = 0.47; P = 0.03).ConclusionMaintenance hemodialysis seems significantly modify AQP3 and UT-B expression but their link to clinical and biochemical parameters needs further large-scale evaluation.

Estimation of Urea Reduction Ratio in Dialysis Patients Per Session and Adequacy of Dialysis

Background: Chronic kidney disease is a condition in which the kidney is no more able to remove waste from the body. Through hemodialysis, the excess water and waste from the blood are removed such as urea and creatinine. The urea reduction ratio is a measure of the proportionate reduction in urea blood nitrogen throughout dialysis. It is an acceptable, easy and simple method globally to find dialysis adequacy that how much urea is removed from the body. Our study was aimed at assessing the targets to achieve the urea reduction ratio (URR), in chronic kidney disease patients who underwent hemodialysis. Methods: The pre-dialysis and post-dialysis blood samples were collected from 80 hemodialysis patients. A Performa was filled, blood pressure was monitored before mid and at the end of the session, weight was monitored and ultrafiltration for the adequacy of the dialysis. The urea reduction ratio (URR) was calculated by (pre dialysis urea – post-dialysis urea) divided by pre-dialysis urea and it is expressed in percentage. Results: The mean urea reduction rate (URR) was 74% (adequate URR is &gt;65%). The results of the pre-dialysis and post-dialysis serum urea levels. There was a significant reduction in these parameters, thus suggesting the adequacy of the dialysis. There was the achievement of the target goal. But the inadequacy was also seen at 54.7%. Conclusion: The targeted urea reduction ratio was achieved in the setup of Khyber teaching hospital, but for inadequacy, they need a lot of follow-up and supervision. Keywords: Urea reduction ratio, dialysis, hemodialysis, chronic kidney disease

MO929: Oxidative Stress in Hemodialysis Patients

Abstract BACKGROUND AND AIMS It is known that chronic kidney disease (CKD) is associated with complications such as anaemia, mineral bone disorders (CKD-MBD) or diselectrolytemia.Therefore, the diet of renal patients is restricted in different nutrients such as potassium or phosphorus, a fact that could potentially increase oxidative stress [1]. We investigated the relationship between an oxidative damage marker (malondialdehyde-MDA) on the one hand, and plasma antioxidant status (glutathione peroxidase-GPx) activity on the other hand with the nutritional status and with complications associated with CKD (anaemia, CKD-MBD). METHOD We conducted a single-centre cross-sectional study that included 58 CKD G5D patients (mean age of 60.39 ± 11.73 years; 33 males, 25 females; mean haemodialysis vintage of 6.43 ± 4.89 years). All patients have been assessed regarding dialysis status (medical history). We performed analysis before the dialysis session using standard methods blood biochemistry, complete blood count and using spectrophotometry (HPLC)-malondialdehyde and glutathione peroxidase. RESULTS The studied patients’ mean malondialdehyde was 1.41 ± 0.42 mcmol/L, while mean glutathione peroxidase was 58.65 ± 12.15 U/g Hg. The oxidative stress markers did not show any statistically significant correlation with age, gender, dialysis vintage or with predialysis urea and bicarbonate. Patients with a BMI &amp;gt; 30 kg/sqm (21 versus 37 patients) showed a significantly higher level of MDA 1.57 ± 0.51 mcmol/L versus 1.31 ± 0.33 mcmol/L, P = 0.02. We have also found a negative statistically significant correlation between MDA level and serum K (r = –0.29, P = 0.02) and serum phosphorus (r = –0.29, P = 0.03). Patients with predialysis K of higher then 5.5 mEq/L had a statistically significant lower MDA (1.29 ± 0.4 mcmol/L versus 1.54 ± 0.4 mcmol/L, P = 0.025) and a non-significant higher GPx (59.0 ± 12.58 U/g Hg versus 58.2 ± 11.87 U/g Hg, P = 0.8). We found a negative statistically significant correlation of the MDA level with haemoglobin (r = –0.39, P = 0.002) and with haematocrit (r = –0.35, P = 0.006). No statistically significant correlation of the plasma antioxidant GPx with the studied parameters of anaemia and CKD-MBD has been found. CONCLUSION In our study, we found that increased oxidative stress (expressed through the malondialdehyde level) is associated with obesity and more severe anaemia. The indirect relationship found with serum K and phosphorus could indicate the risk of oxidative stress, and therefore it could be useful to take into account the dietary antioxidants when recommending low potassium and low phosphorus diet.

Relationship between time-dependent variability in cardiometabolic risk factors and biochemical markers with cytokine and adipokine levels in hemodialysis patients

Hemodialysis patients (HP) are exposed to malnutrition, cardiometabolic and pro-inflammatory risk factors. However, limited knowledge of the variability of these risk factors remains a serious barrier to the proper clinical management of HP. From a longitudinal study, we investigated the relationship between time-dependent variability in cardiometabolic risk factors and biochemical markers with cytokine and adipokine circulating levels in HP. Thirty-eight HP (women = 15, men = 23) aged 54.13 ± 16.78 years old underwent three independent anthropometric, nutritional, biochemical and immunological assessments (1, 6 and 12 months). Patient’s characteristics (body mass, comorbidities, history of kidney disease and time on hemodialysis) were similar after sex stratification. From grouped data, 31.6–100.0% HP exhibited multiple malnutrition and cardiometabolic risk factors in all time-points evaluated. All anthropometric and nutritional results, and most biochemical markers were similar in 1, 6 and 12 months follow-up, indicating a marked time-dependent stability. Urea, creatinine, total proteins, albumin, adipokines (adiponectin, leptin and resistin) and cytokines (TNF, IL-6 and IL-10) levels were highly variable in 12 months follow-up. Direct correlations between leptin and fat mass, TNF and IL-6 with creatinine and pre-dialysis urea were observed in all time-points (1, 6 and 12 months). Creatinine and pre-dialysis urea were negatively correlated with IL-10 for the entire follow-up. Fat mass, creatinine and pre-dialysis urea were predictive markers of leptin, TNF, IL-6 and IL-10 variability. Our findings indicated that biochemical, nutritional and cardiovascular risk factors exhibit low time-dependent variability in HP under clinical and nutritional monitoring. However, adipokines and cytokines are highly variables, which can potentially be influenced by body adiposity, creatinine and urea clearance. Thus, these parameters can contribute to predict the inflammatory status in HP.

P1116IS DIALYSIS ADEQUACY AMELIORATED AFTER INCREASING DIALYSATE FLOW RATE IN CHRONIC HEMODIALYSIS? - ONE YEAR FOLLOW-UP

Abstract Background and Aims Hemodialysis (HD) adequacy, as measured by single pool (sp) Kt/V and urea reduction rate (URR), has been reported to be ameliorated after increasing dialysate flow rate (DFR). However, this is a matter of controversy as no benefit has been observed with dialyzers incorporating features to enhance dialysate flow distribution. We investigated the effect of increasing DFR on dialysis adequacy and on various laboratory parameters. Method Twenty-three patients, M/F=20/3, aged 65(44-89) years, dialyzed thrice weekly for 50(6-274) months, using polysulfone low flux dialyzers, participated in an annual randomized cross-over study. Patients were dialyzed with DFR of 500 ml/min and 700 ml/min for 6 consecutive months respectively, according to their usual dialysis prescription and with ultrafiltration volumes according to clinical need. Blood was sampled before and at the end of midweek sessions at the beginning of the first, 7th and 13rd month for urea, creatinine, potassium, sodium, albumin, total Ca and phosphate (sP). URR, spKt/V, corrected for albumin Ca(sCa) and sCa x sP product (CaxP) values were calculated. Results Under both 500 and 700 ml/min DFRs used, the expected post-dialysis alterations were found: decreased values in serum urea (respectively 161,5±38,0 to 49,9±20.1-p&amp;lt;0,001 and 140,3±30 to 56,0±20.4 mg/dl-p&amp;lt;0,001), creatinine (respectively 10,2±2 to 3.9±1,2-p&amp;lt;0,001 and 10,2±3,3 to 4,1±1,6 mg/dl-p&amp;lt;0,001), potassium (respectively 5,2±0,7 to 3,7±0,3 mM-p&amp;lt;0,001 and 5,3±0,6 to 3,9±0,3mM-p&amp;lt;0,001) and phosphate (respectively 5,4±1,7 to 2,9±0,6-p&amp;lt;0,001 and 5,7±1,6 to 2,6±0,6 mg/dl-p&amp;lt;0,001); increased values in serum albumin (respectively 4,3±0,4 to 4,7±0,4 g/dl-p=0,001 and 4,2±0,3 to 4,7±0,4 g/dl-p&amp;lt;0,001) and sCa (9,1±0,7 to 11,3±0,9 mg/dl-p&amp;lt;0,001 and 8,7±0,6 to 9,9±0,7 mg/dl-p&amp;lt;0,001). After increasing DFR from 500 to 700 ml/min we observed no reductions in pre-dialysis serum urea and creatinine levels or URR (68,6±8,1% to 69,9±7,9%-p=NS) and Kt/V (1,41±0,4 to 1,42±0,3-p=NS) values. However, under DFR of 700ml/min post-dialysis sCa, sP and sCa x sP product values were always lower compared with those under DFR of 500 ml/min (respectively 9,9±0.7 vs 10,8±0.8 mg/dl-p&amp;lt;0,001, 2,6±0,6 vs 2,9±0,6 mg/dl-p=0,02 and 25,6±6,2 vs 30,9±6,7 mg2/dl2-p&amp;lt;0,001). Conclusion DFR increase from 500 to 700 ml/min did not lead to favorable effects on dialysis adequacy but resulted in post-dialysis amelioration of serum calcium and phosphate levels and may be useful in cases of hypercalcemia, hyperphosphatemia and calcifications. DFR increase utility needs further investigation in patients with disorders of calcium-phosphate metabolism.

SAT-219 OUTCOMES OF PREGNANCY AMONG CHRONIC HEMODIALYSIS PATIENTS

Pregnancy in end stage renal disease (ESRD) women is uncommon and the risk for maternal - fetal complications is high. The rate of successful pregnancies in chronic hemodialysis (HD) patients has improved over the last decade up to 80%. Multidisciplinary team care and intensified hemodialysis regimens contributed in this substantial impact. We are reporting the outcomes of pregnancy in hemodialysis patients from single hemodialysis center in United Arab Emirates. A retrospective chart review study was conducted at Tawam hospital hemodialysis unit (capacity of 380 patients) over 10 years (Jan 2009 – June 2019). We included all cases of female HD patients get pregnant during study period. Demographic, clinical and laboratory data were collected as well as pregnancy outcomes, maternal and fetal complications were analyzed using descriptive analysis. we identified a total of 5 female ESRD patients on HD, with a total of 7 pregnancies. The mean age was 35.5 years. Three patients were expatriates. The causes of ESRD were type 1 diabetes (2), type 2 diabetes (1), systemic lupus erythematosus (1) and adult polycystic kidney disease (1). Other comorbid conditions were anemia of renal disease (5), hypertension (4), dyslipidemia (4), obesity (2), history of ischemic heart disease (IHD) (1) and peripheral vascular disease (PVD) (1). The average duration on hemodialysis at time of pregnancy was ranging from 3 months to 7 years and two patients were initiated on HD in the first 10 weeks of pregnancy. Three patients were multiparous prior to ESRD, with total number of children (11) and abortion/ fetal death (7). All the 5 patients had spontaneous pregnancies. The frequency of HD increased to 5-6 times per week with 4 hours duration with average pre-dialysis urea levels of 10.5 to 12 mmol/L Qutaiba Hussain*,. The maternal complications during pregnancy in our cohort including: urinary tract infection (1), diabetic foot infection (1), anemia required blood transfusion (3), renal cyst rupture (1), recurrent arteriovenous graft thrombosis (1), preeclampsia (3), premature preterm rapture of membrane (PPROM) and abruptio placenta (2). The successful outcomes of pregnancies were three live births required c sections for preterm delivery at 30 – 34 weeks (2 emergency c/sections for preeclampsia and abruptio placenta). A patient had advanced diabetic type 1 complications with IHD, PVD had a total of 3 pregnancies with poor outcomes due to uteroplacental insufficiency (one fetal death at 25 weeks, one severe intrauterine growth restriction (IUGR)/preeclampsia, and one with PPROM/ IUGR). The fetal complications identified were preterm delivery (3), fetal death (1), post-delivery death (2), severe IUGR (3), abortion (1) and fetal anomalies (2) [anhydramnios (1), membranous ventricular septal defect VSD (1)]. Pregnancy in chronic hemodialysis patients with advanced comorbid conditions has high risk for complications and need comprehensive care. We had a total of 7 pregnancies over 10 years with successful outcomes in three patients (42.8%).

Processed and ultra-processed food consumption are related to metabolic markers in hemodialysis subjects

ABSTRACT Objective To investigate the consumption of processed and ultra-processed foods and evaluate its relationship with the nutritional and metabolic status of hemodialysis patients in a single center in Brazil. Methods This cross-sectional study enrolled 73 individuals in hemodialysis (50 men and 23 women, 21-87 years-old). Clinical and lifestyle variables were assessed by a semi-structured questionnaire and dietary data by food frequency questionnaire. Anthropometric and metabolic data are collected from medical records. Results Processed and ultra-processed foods represented 11.0% of daily caloric intake, 53.0% of trans fatty acid, and 12.5% of salt consumed in the study sample. Individuals who had high intake of this food group (≥128.4g/day, median intake) had higher serum phosphorus and pre-dialysis urea values (p=0.038; p=0.013, respectively). Also, individual with higher consumption of processed meat, sausages and ready prepared food had higher pre-dialysis serum urea (p=0.021), while serum potassium was higher among the subjects who consumed more sauces and salt-based seasonings (p=0.002). Conclusion Higher consumption of processed and ultra-processed foods was associated with important biomarkers of metabolic control for hemodialysis subjects, probably due to non-health dietary composition. Nutritional guidelines and intervention strategies must be promoted to reduce consumption of these food-group in thisspecific population.

Pregnancy and dialysis.

ABSTRACTThe pregnancy rate of women on dialysis is still very low when compared to that of the remaining population. However, recent years have seen an increase in the success rates of these pregnancies. Among the main precautions that must be taken with pregnant women on dialysis are the maintenance of low levels of pre-dialysis urea, the adequacy of the tension profile, the control of anemia and care to avoid infections, nutritional deficits, changes in phosphorus-calcium metabolism and electrolytic fluctuations. It is also necessary to strictly monitor fetal growth and development. Pregnant women on dialysis have a higher probability of maternal and fetal complications; thus the importance of a multidisciplinary approach among nephrologists, obstetricians and pediatricians. The main objective of this study was to review the literature evidence available on pregnancy on dialysis, on the basic principles of the pathophysiology of pregnant women and their particularities in kidney disease. We will address available treatment options, benefits and risks, anticipating possible future challenges. At the end, we will present a clinical case to illustrate the topic.

Pathophysiology and implications of intradialytic hypertension.

Intradialytic hypertension occurs regularly in 10--15% of hemodialysis patients. A large observational study recently showed that intradialytic hypertension of any magnitude increased mortality risk comparable to the most severe degrees of intradialytic hypotension. The present review review discusses the most recent evidence underlying the pathophysiology of intradialytic hypertension and implications for its management. Patients with intradialytic hypertension typically have small interdialytic weight gains, but bioimpedance spectroscopy shows these patients have significant chronic extracellular volume excess. Intradialytic hypertension patients have lower albumin and predialysis urea nitrogen levels, which may contribute to small reductions in osmolarity that prevents blood pressure decreases. Intradialytic vascular resistance surges remain implicated as the driving force for blood pressure increases, but mediators other than endothelin-1 may be responsible. Beyond dry weight reduction, the only controlled intervention shown to interrupt the blood pressure increase is lowering dialysate sodium. Patients with recurrent intradialytic hypertension should be identified as high-risk patients. Dry weight should be re-evaluated, even if patients do not clinically appear volume overloaded. Antihypertensive drugs should be prescribed because of the persistently elevated ambulatory blood pressure. Dialysate sodium reduction should be considered, although the long term effects of this intervention are uncertain.

Determinants of survival in patients receiving dialysis in Libya

Maintenance dialysis is associated with reduced survival when compared with the general population. In Libya, information about outcomes on dialysis is scarce. This study, therefore, aimed to provide the first comprehensive analysis of survival in Libyan dialysis patients. This prospective multicenter study included all patients in Libya who had been receiving dialysis for >90 days in June 2009. Sociodemographic and clinical data were collected upon enrollment and survival status after 1 year was determined. Two thousand two hundred seventy-three patients in 38 dialysis centers were followed up for 1 year. The majority were receiving hemodialysis (98.8%). Sixty-seven patients were censored due to renal transplantation, and 46 patients were lost to follow-up. Thus, 2159 patients were followed up for 1 year. Four hundred fifty-eight deaths occurred, (crude annual mortality rate of 21.2%). Of these, 31% were due to ischemic heart disease, 16% cerebrovascular accidents, and 16% due to infection. Annual mortality rate was 0% to 70% in different dialysis centers. Best survival was in age group 25 to 34 years. Binary logistic regression analysis identified age at onset of dialysis, physical dependency, diabetes, and predialysis urea as independent determinants of increased mortality. Patients receiving dialysis in Libya have a crude 1-year mortality rate similar to most developed countries, but the mean age of the dialysis population is much lower, and this outcome is thus relatively poor. As in most countries, cardiovascular disease and infection were the most common causes of death. Variation in mortality rates between different centers suggests that survival could be improved by promoting standardization of best practice.

Pregnancy in women on chronic dialysis: a review.

The frequency of pregnancy in women on dialysis is extremely low, but the percentage of successful pregnancies in this context has increased over the years, with some studies placing the survival rate above 70%. These pregnancies are not exempt from both maternal and foetal complications, and so their management requires the joint efforts of nephrologists, gynaecologists, nurses, and nutritionists. Currently, we have been unable to establish consistent systematic treatment from both nephrological and gynaecological specialists in these patients. The main changes that need to be made are: increased time on dialysis, maintaining low levels of pre-dialysis urea, avoiding: maternal hypertension and hypotension, anaemia, urinary tract infections, and fluctuations in electrolytes. Adequate foetal monitoring is also necessary.

Breath ammonia and trimethylamine allow real-time monitoring of haemodialysis efficacy

Non-invasive monitoring of breath ammonia and trimethylamine using Selected-ion-flow-tube mass spectroscopy (SIFT-MS) could provide a real-time alternative to current invasive techniques. Breath ammonia and trimethylamine were monitored by SIFT-MS before, during and after haemodialysis in 20 patients. In 15 patients (41 sessions), breath was collected hourly into Tedlar bags and analysed immediately (group A). During multiple dialyses over 8 days, five patients breathed directly into the SIFT-MS analyser every 30 min (group B). Pre- and post-dialysis direct breath concentrations were compared with urea reduction, Kt/V and creatinine concentrations. Dialysis decreased breath ammonia, but a transient increase occurred mid treatment in some patients. Trimethylamine decreased more rapidly than reported previously. Pre-dialysis breath ammonia correlated with pre-dialysis urea in group B (r2 = 0.71) and with change in urea (group A, r2 = 0.24; group B, r2 = 0.74). In group B, ammonia correlated with change in creatinine (r2 = 0.35), weight (r2 = 0.52) and Kt/V (r2 = 0.30). The ammonia reduction ratio correlated with the urea reduction ratio (URR) (r2 = 0.42) and Kt/V (r2 = 0.38). Pre-dialysis trimethylamine correlated with Kt/V (r2 = 0.21), and the trimethylamine reduction ratio with URR (r2 = 0.49) and Kt/V (r2 = 0.36). Real-time breath analysis revealed previously unmeasurable differences in clearance kinetics of ammonia and trimethylamine. Breath ammonia is potentially useful in assessment of dialysis efficacy.

Standard Kt/Vurea: a method of calculation that includes effects of fluid removal and residual kidney clearance

Standard Kt/V(urea) (stdKt/V) is a hypothetical continuous clearance in patients treated with intermittent hemodialysis based on the generation rate of urea nitrogen and the average predialysis urea nitrogen. Previous equations to estimate stdKt/V were derived using a fixed-volume model. To determine the impact of fluid removal as well as residual urea clearance on stdKt/V, we modeled 245 hemodialysis sessions (including conventional 3/week, in-center 6/week, and at-home nocturnal 6/week) in 210 patients enrolled in the Frequent Hemodialysis Network Daily and Nocturnal clinical trials. To examine the role of fluid removal, modeled stdKt/V was compared to stdKt/V estimated from a previously published simplified equation. In a subgroup of 45 sessions with residual urea clearance over 1.5 ml/min, the contribution of residual urea clearance to stdKt/V was measured. For all dialysis schedules, the fixed-volume equation predicted stdKt/V well when both fluid removal and residual urea clearance were set to zero. When fluid removal was included, modeled stdKt/V was slightly underestimated for all three modes of hemodialysis. The shortfall correlated directly with weekly fluid removal and inversely with modeled urea volume. Modeled stdKt/V compressed residual urea clearance to about 70% of its measured value and the fractional downsizing significantly correlated inversely with treatment Kt/V. Our new equation predicted modeled stdKt/V with a high level of accuracy, even when substantial fluid removal and residual urea clearance were present.

Adequacy of hemodialysis in Nepalese patients undergoing maintenance hemodialysis

Inadequate dialysis accounts for the high mortality in patients with end stage renal disease (ESRD). In Nepal, due to various factors including financial and logistic limitations, hemodialysis is mostly performed twice-a-week. This study was undertaken to look at adequacy of dialysis in patients undergoing maintenance hemodialysis in Nepal where the patients profile, in terms of diet, body muscle mass, nutritional status etc are different from western world. In this cross sectional observational study, 40 patients on maintenance hemodialysis in the dialysis unit were evaluated and enrolled if patients were regularly undergoing twice-a-week hemodialysis in preceding 6 months with each session of dialysis prescription consisting of 4 hours (240 minutes). Patients were excluded if they were admitted in the hospital for some acute problems or had received acute hemodialysis in preceding 6 months. Only 14 patients fulfilled the inclusion criteria. Hemodialysis adequacy was measured using well established urea kinetic modeling. The mean age of the patients was 49 +/- 24 years. Mean predialysis urea and post dialysis urea were 163.7 +/- 60.05 mg/dL, and 73.7 mg/dL +/- 30.55 respectively. Mean URR was 65.3%. Mean Kt/v as assessed by Jindals equation was 0.99. Our study showed that twice-a-week of maintenance hemodialysis did not achieve recommended adequacy of hemodialysis in our patients.

Goodpasture's syndrome, haemodialysis and pregnancy

A 29-year-old Caucasian woman had been diagnosed with Goodpasture's syndrome 12 months previously. Her renal function did not recover, she required haemodialysis and was put on the transplant list. She developed amenorrhoea on haemodialysis. She was seen at 22 weeks gestation in her second pregnancy. She was counselled regarding the high risk of fetal and maternal complications. She was offered medical termination of pregnancy but decided to continue. management plan was devised aiming to maintain the health of the mother, allow growth of the fetus and to support the patient and her partner. The plan included referral to a specialist obstetric unit. All drugs were evaluated and potentially dangerous medication, i.e. losartan, was stopped. Her haemodialysis was increased to six times a week (at least 24 h/week) to maintain a pre-dialysis urea of less than 16 mmol/litre. Her dialysate bicarbonate levels were reduced to prevent the usual post-dialysis alkalosis and avoid pre-dialysis acidosis. Intradialystic hypotension was avoided by careful fluid balance assessment and low ultrafiltration rates on dialysis, and post-dialysis hypercalcaemia was avoided by adjusting the dialysate calcium concentration. Hypocalcaemia was avoided by close monitoring of calcium and vitamin D levels and ensuring adequate doses of calcium and alfacalcidol. Hypertension was controlled with a safe antihypertensive (methyldopa), her haemoglobin was maintained between 10 and 11 g/dl with iron and erythropoietin and adequate nutrition with increased calorie and protein intake, water-soluble vitamins (B and C), and folic acid. Fetal growth and liquor volumes were monitored by regular ultrasound scanning. At 24 weeks methyldopa 250 mg twice a day was started to control her blood pressure. Her growth scan at 24 and 26 weeks was satisfactory. At 27 weeks and 2 days she was admitted with severe epigastric pain. There were no other features of pre-eclampsia. She was given a course of betamethasone for fetal lung maturity. Two days later tests revealed a low platelet count (67×109/litre; normal value 150–400×109/litre) and high alanine aminotransferase (ALT) levels (113 iu/litre; 0–40 iu/litre). The next day a repeat test showed platelet count of 47×109/litre and an ALT level of 415 iu/litre. A working diagnosis of HELLP (haemolysis, elevated liver enzyme and low platelet) syndrome was made. The multidisciplinary team decided to deliver her electively by caesarean section the next day. A healthy baby boy weighing 540 g was delivered without any difficulty. She recovered well after the operation and was back on haemodialysis three times a week. The baby was doing well at 6 months of age.

A HAEMODIALYSIS NUTRITIONAL SCREENING TOOL FOR NURSES ‐ A PILOT STUDY

The purpose of the study was to pilot a nurse-performed nutritional screening tool (NST) for dialysis patients in order to identify nutritionally at-risk patients. Haemodialysis (HD) patients are at risk of nutritional-related problems. Nutritional screening by nurses may assist in the early recognition of and response to these problems. An NST was developed using 9 screening parameters. (BMI, weight change, poor appetite, GI symptoms, albumin, pre-dialysis urea, K+, PO4++, HbA1c). The NST was compared with Standard Dietitian Assessment (SDA). 44 HD patients were screened with the NST and then with SDA. The tool showed sensitivity of 0.7 (95%CI+/- 0.21) and a specificity of 0.77 (95%CI+/-0.16). Reliability was low (alpha = .18). Alpha increased to 0.32 if pre-dialysis urea was removed from the tool and increased to 0.48 if weight loss, appetite, K+ and PO4++ were used alone. The pilot study showed a low reliability of the NST compared with SDA. With further analysis and modifications, the NST has the potential to assist nutritional screening by nurses in dialysis centres that have limited dietetic access.

Nocturnal hemodialysis is associated with restoration of impaired endothelial progenitor cell biology in end-stage renal disease

Cardiovascular disease is the principal cause of death in end-stage renal disease (ESRD) patients. Endothelial progenitor cells (EPCs) play a critical role in vascular repair, and improving EPC biology represents a novel therapeutic target. Three groups of age- and gender-matched patients were studied: 1) 10 healthy control, 2) 12 conventional hemodialysis (CHD) patients, and 3) 10 nocturnal hemodialysis (NHD) patients. EPC number and migratory function were assessed. Left ventricular mass index (LVMI) was derived, and correlations between EPC biology, uremic clearance, and LVMI were made. Compared with controls, EPC number and function were markedly impaired in CHD patients [(3.48 +/- 1.2 vs. 0.86 +/- 0.20%/50,000 cells, P < 0.05) and (18.8 +/- 2.64 vs. 3.75 +/- 0.34 cells/high-power field, P < 0.05), respectively]. In contrast, EPC number and function were normal in NHD patients [(3.48 +/- 1.17 vs. 3.83 +/- 0.77%/50,000 cells) and (18.8 +/- 2.6 vs. 22.2 +/- 2.4 cells/high-power field), respectively]. Among ESRD patients, EPC number and function inversely correlated with predialysis urea concentration (r = -0.40; r = -0.57), LVMI (r = -0.41; -0.46) and systolic BP (r = -0.58; r = -0.44). We demonstrate that NHD is associated with restoration of abnormal EPC biology in ESRD. Given the increasing importance of EPCs in the repair and restoration of cardiovascular function, these data have important clinical implications for vascular risk in ESRD patients.

Seasonal Variations of Clinical and Biochemical Parameters in Chronic Haemodialysis

Introduction: Seasonal variations in clinical and laboratory variables occur commonly among chronic haemodialysis patients. In order to demonstrate seasonal differences, we prospectively compared biochemical and clinical parameters in a group of chronically haemodialysed patients living in South Croatia, a region with a Mediterranean climate. Materials and Methods: Data were processed on 135 single dialysis treatments involving a group of 34 anuric chronic haemodialysis (HD) patients. Outcomes were measured at 3-month intervals, in March, June, September and December. Results: The seasonal differences were found in phosphorus (P = 0.001), creatinine before HD (P &lt;0.001), creatinine after HD (P = 0.005), alkaline phosphatase (P = 0.012), alanine aminotransferase (P = 0.042), urea before HD (P = 0.039), albumins (P &lt;0.001), total cholesterol (P &lt;0.001), low-density lipoprotein (LDL) cholesterol (P &lt;0.001), high-density lipoprotein (HDL) cholesterol (P &lt;0.001), glucose (P = 0.033), and ultrafiltration per HD (P = 0.037). When the data were grouped into cold (March and December) and mild (June and September) months, we found differences in phosphorus (1.48 ± 0.47 versus 1.72 ± 0.51, P = 0.005), alkaline phosphatase (119.46 ± 69.03 versus 169.78 ± 107.98, P = 0.002), urea before HD (27.13 ± 5.35 versus 24.40 ± 5.99, P = 0.006), albumins (37.92 ± 5.17 versus 40.58 ± 5.69, P = 0.006), total cholesterol (4.93 ± 0.93 versus 5.30 ± 0.93, P = 0.023), LDL cholesterol (2.85 ± 1.04 versus 3.23 ± 0.87, P = 0.046), glucose (4.62 ± 1.15 versus 5.57 ± 1.46, P = 0.004), and ultrafiltration per HD (3.57 ± 1.18 versus 2.97 ± 1.20, P = 0.004). Conclusion: In Mediterranean climates, seasonal differences in predialysis urea concentration and ultrafiltration rate per dialysis could be attributed to different food and water intake. The seasonal differences in blood concentration of phosphorus, alkaline phosphatase, total cholesterol, LDL cholesterol, and glucose might be the results of neurohormonal influences. This climate has no impact on haemoglobin and blood pressure levels.

Acute effect of hemodialysis on serum levels of the proinflammatory cytokines.

Chronic inflammation is a common feature of end-stage renal disease, which carries a heightened risk of atherosclerosis and other co-morbid conditions. Dialysis treatment per se can bring additional risk factors for inflammation, such as increased risk of local graft and fistula infections, impure dialysate or bio-incompatible membranes. Our study was designed to determine whether a hemodialysis session leads to an acute substantial alteration in the plasma levels of the proinflammatory cytokines interleukin (IL)-6, IL-1beta and tumor necrosis factor (TNF)-alpha, the T-lymphocyte activation factor soluble IL-2 receptor (sIL-2R), and an inflammation mediator and chemotactic granulocyte factor, IL-8, in end-stage renal disease patients receiving chronic intermittent HD. In this study, 21 (12 male/nine female) patients undergoing chronic hemodialysis were enrolled. The acute effect of a hemodialysis session on serum cytokine concentrations was assessed by comparison of pre-hemodialysis and post-hemodialysis determinations. Serum IL-1beta, sIL-2R, IL-6, IL-8 and TNF-alpha levels were determined with chemiluminescence enzyme immunometric assays. A significant difference was not observed for IL-1beta, IL-6, TNF-alpha, and sIL-2R concentrations in pre-hemodialysis and post-hemodialysis specimens (p>0.05). Serum median (25th-75th percentiles) IL-8 concentration was 69.4 (34.9-110.3) pg/ml before hemodialysis, and decreased to 31.5 (18.0-78.8) pg/ml following hemodialysis (p: 0.006). Clearance of IL-8 increased by 0.47+/-0.08 pg/ml for each unit increase in pre-dialysis IL-8 (p<0.001) and decreased by 5.63+/-2.59 pg/ml for each unit increase in pre-dialysis urea mmol/l (p<0.05). In conclusion, the results of our study demonstrate that a hemodialysis session markedly decreases IL-8 concentration, which is significantly affected by pre-dialysis concentrations, indicating that removal of IL-8 is a concentration gradient-dependent action, but does not change the serum levels of IL-1beta, sIL-2R, IL-6, and TNF-alpha, underlining importance of the structural characteristics of the molecules.