Hemodialysis prognostic nutrition index as a predictor for morbidity and mortality in hemodialysis patients and its correlation to adequacy of dialysis. Council on Renal Nutrition National Research Question Collaborative Study Group

Slipping Through the Pores: Hypoalbuminemia and Albumin Loss During Hemodialysis

Hypoalbuminemia results when compensatory mechanisms are unable to keep pace with derangements in catabolism/loss and/or decreased synthesis of albumin. Across many disease states, including chronic kidney disease (CKD), hypoalbuminemia is a well-established, independent risk factor for adverse outcomes, including mortality. In the setting of CKD, reduced serum albumin concentrations are often a manifestation of protein-energy wasting, a state of metabolic and nutritional alterations resulting in reduced protein and energy stores. The progression of CKD to kidney failure and the initiation of maintenance hemodialysis (HD) further predisposes an already at-risk population toward hypoalbuminemia such that approximately 60% of HD patients have albumin concentrations <4.0 g/dl. Albumin loss into the dialysate through the dialyzer appears to be a potentially modifiable cause of hypoalbuminemia in some patients. A group of newer dialyzers for maintenance HD-sometimes termed protein-leaking or medium cut-off membranes-aim to improve clearance of middle molecules (vs high flux dialyzers) but are associated with increased albumin losses. In this article, we will examine the impact of dialyzer selection on albumin losses during conventional HD, including the clinical relevance of such losses on serum albumin levels. Data on the clinical relevance of albumin losses during dialysis and current gaps in the evidence base are also discussed.

Using a web-based nutrition algorithm in hemodialysis patients

OBJECTIVES

The purpose of this study was to test the ability of a newly developed nutrition algorithm on (1) clinical utility and (2) ability to capture patient outcomes.

RESEARCH DESIGN

This was a prospective observational study, using a practice based research network structure, involving renal dietitians and hemodialysis [HD] patients.

SETTING

This study took place in HD outpatient units in five different countries.

SUBJECTS

Hundred chronic HD patients were included in this study. To select subjects, dietitians screened and consented patients in their facilities until 4 patients "at nutrition risk" based on the algorithm screening tool were identified. Inclusion criteria were patients aged older than 19 years, not on hospice or equivalent, able to read the informed consent and ask questions, and receiving HD.

MAIN OUTCOME MEASURE

The ability of the algorithm screening tool is to identify patients at nutrition risk, to guide clinicians in logical renal-modified nutrition care process chains including follow-up on relevant parameters, and capture change in outcomes over 3 months. Statistics were performed using SPSS version 20.0 and significance was set at P < .05.

RESULTS

One hundred patients on HD, enrolled by 29 dietitians, were included in this analysis. The average number of out-of-range screening parameters per patient was 3.7 (standard deviation 1.5, range 1-7), and the most prevalent risk factors were elevated parathyroid hormone (PTH; 62.8%) and low serum cholesterol (56.5%). At the initial screening step, 8 of the 14 factors led to chains with nonrandom selection patterns (by χ(2) test with P < .05). In the subsequent diagnosis step, patients diagnosed within the insufficient protein group (n = 38), increased protein intake by 0.11 g/kg/day (P = .022). In patients with a diagnosis in the high PTH group, PTH decreased by a mean of 176.85 pg/mL (n = 19, P = .011) and in those with a diagnosis in the high phosphorous group, serum phosphorous decreased by a mean of 0.91 mg/dL (n = 33, P = .006). Finally, the relative likelihood of each assessment being completed after making the related diagnosis at the previous visit compared with those for whom that diagnosis was not made was assessed, including the likelihood of a patient's protein intake assessed after a diagnosis in the insufficient protein group was made (odds ratio = 4.08, P < .05).

CONCLUSIONS

This study demonstrates the clinical utility of a web-based HD-specific nutrition algorithm, including the ability to track changes in outcomes over time. There is potential for future research to use this tool and investigate the comparative impact of nutrition interventions.

Nutritional predictors of postoperative outcome in pancreatic cancer

BACKGROUND

Nutritional status plays an important role in the incidence of postoperative complications and the prognosis of various tumours. The prognostic value of preoperative nutritional factors in patients with pancreatic cancer is not known.

METHODS

This retrospective study included 268 patients who underwent resection for adenocarcinoma of the pancreas. The predictive value of preoperative nutritional status for postoperative outcome (survival, complications) was assessed. Nutritional factors included the three constitutional indices, serum albumin and Onodera's prognostic nutrition index (PNI), calculated as 10 × serum albumin (g/dl) + 0·005× total lymphocyte count (per mm(3)).

RESULTS

In multivariable analysis preoperative low PNI (but not low albumin) was an independent prognostic factor for poor survival: hazard ratio (HR) 1·73 (95 per cent confidence interval (c.i.) 1·21 to 2·47). The accuracy of a PNI value of less than 45 as cut-off for clinically significant preoperative malnutrition in predicting 1- or 2-year survival after surgery was, however, limited (66·4 and 56·3 per cent respectively). Low preoperative albumin concentration and PNI were significantly associated with postoperative complications: odds ratio 1·98 (95 per cent c.i. 1·18 to 3·32) and 2·14 (1·23 to 3·73) respectively. Low PNI and low body mass index were independently associated with pancreatic fistula: HR 2·52 (1·37 to 4·63) and 0·40 (0·17 to 0·93) respectively.

CONCLUSION

The PNI is associated with overall survival and postoperative complications, in particular pancreatic fistula, in patients with pancreatic cancer. The moderate accuracy of PNI as a predictor of survival limits its clinical use.

Malnutrition-inflammation complex syndrome in dialysis patients: causes and consequences

Protein-energy malnutrition (PEM) and inflammation are common and usually concurrent in maintenance dialysis patients. Many factors that appear to lead to these 2 conditions overlap, as do assessment tools and such criteria for detecting them as hypoalbuminemia. Both these conditions are related to poor dialysis outcome. Low appetite and a hypercatabolic state are among common features. PEM in dialysis patients has been suggested to be secondary to inflammation; however, the evidence is not conclusive, and an equicausal status or even opposite causal direction is possible. Hence, malnutrition-inflammation complex syndrome (MICS) is an appropriate term. Possible causes of MICS include comorbid illnesses, oxidative and carbonyl stress, nutrient loss through dialysis, anorexia and low nutrient intake, uremic toxins, decreased clearance of inflammatory cytokines, volume overload, and dialysis-related factors. MICS is believed to be the main cause of erythropoietin hyporesponsiveness, high rate of cardiovascular atherosclerotic disease, decreased quality of life, and increased mortality and hospitalization in dialysis patients. Because MICS leads to a low body mass index, hypocholesterolemia, hypocreatininemia, and hypohomocysteinemia, a "reverse epidemiology" of cardiovascular risks can occur in dialysis patients. Therefore, obesity, hypercholesterolemia, and increased blood levels of creatinine and homocysteine appear to be protective and paradoxically associated with a better outcome. There is no consensus about how to determine the degree of severity of MICS or how to manage it. Several diagnostic tools and treatment modalities are discussed. Successful management of MICS may ameliorate the cardiovascular epidemic and poor outcome in dialysis patients. Clinical trials focusing on MICS and its possible causes and consequences are urgently required to improve poor clinical outcome in dialysis patients.

Estimation of delivered dialysis dose by on-line monitoring of the ultraviolet absorbance in the spent dialysate

BACKGROUND

Several methods are available to determine Kt/V, from predialysis and postdialysis blood samples to using on-line dialysate urea monitors or to ionic dialysance using a conductivity method. The aim of this study is to compare Kt/V calculated from the slope of the logarithmic on-line ultraviolet (UV) absorbance measurements, blood urea Kt/V, dialysate urea Kt/V, and Kt/V from the Urea Monitor 1000 (UM; Baxter Healthcare Corp, Deerfield, IL).

METHODS

Thirteen uremic patients on chronic thrice-weekly hemodialysis therapy were included in the study. The method uses absorption of UV radiation by means of a spectrophotometric set-up. Measurements were performed on-line with the spectrophotometer connected to the fluid outlet of the dialysis machine; all spent dialysate passed through a specially designed cuvette for optical single-wavelength measurements. UV absorbance measurements were compared with those calculated using blood urea and dialysate urea, and, in a subset of treatments, the UM.

RESULTS

Equilibrated Kt/V (eKt/V) obtained with UV absorbance (eKt/Va) was 1.19 +/- 0.23; blood urea (eKt/Vb), 1.30 +/- 0.20, and dialysate urea (eKt/Vd), 1.26 +/- 0.21, and Kt/V in a subset measured by the UM (UM Kt/V) was 1.24 +/- 0.18. The difference between eKt/Vb and eKt/Va was 0.10 +/- 0.11, showing a variation similar to the difference between eKt/Vb and eKt/Vd (0.03 +/- 0.10) and in a subset between eKt/Vb and UM Kt/V (-0.02 +/- 0.11).

CONCLUSION

The study suggests that urea Kt/V can be estimated by on-line measurement of UV absorption in the spent dialysate.

Relative contributions of nutrition and inflammation to clinical outcome in dialysis patients

Protein-energy malnutrition (PEM) is a common phenomenon in maintenance dialysis (MD) patients and a risk factor for poor quality of life and increased morbidity and mortality, including cardiovascular death, in these individuals. The association between undernutrition and adverse outcome in MD patients, which stands in contrast to that seen in the general population, has been referred to as reverse epidemiology. Measures of food intake, body composition tools, nutritional scoring systems, and laboratory values are used to assess the degree of severity of PEM, but no uniform approach is available for rating the overall severity of PEM. Epidemiologic studies suggest that inflammation is a missing link between PEM and poor clinical outcome in MD patients, and the existence of a malnutrition inflammation complex syndrome is suggested in these patients. Inflammation may be due to subclinical and clinically apparent illnesses. Some investigators suggest that PEM may predispose to illness and inflammation. There is a paucity of information concerning the effect of nutritional therapy on morbidity and mortality in MD patients. Interventional studies of the effect of nutritional support on outcome often are difficult to interpret because of small sample sizes, short duration of study, and other limitations. Large-scale, randomized, clinical trials of the effects of nutritional intake, nutritional status, and inflammation on clinical outcome are needed to define better the relationships between these factors in MD patients.

Infections in patients with end-stage renal disease. An overview

One of the best kept secrets in medicine is the problem of infections in patients with end-stage renal disease. The prescription of chronic hemodialysis has not reduced the problem of infection; it has only changed the paradigm. Dialysis superimposes myriad new problems onto patients with relentless deterioration from underlying multisystem disease and poor wound healing. All end-stage renal disease and transplant programs require the input from an individual with the specialized knowledge of laboratory diagnosis, pharmacokinetics of antibiotics, antibiotic choice, antimicrobial resistance, infection control, and infection prevention. This article gives an overview of some of the complexities of infectious problems experienced by this unique biological model.

History of the professional councils of the National Kidney Foundation

As the Councils move toward the new millennium, efforts to improve outcomes for patients with renal disease will be at the forefront. Each council has established a commitment to improving the quality of life for these individuals. Toward this goal, the CNNT, the CRN, and the CNSW will each propose programs to the NKF for improving the knowledge and skills of the professionals within these councils, promoting research within the respective scope of these professions, and working together to bring a better understanding of the issues confronted by the patients and the professionals as well. As an example of the combined effort of the Councils, the first joint project of the century will be to bring the communications packages of each council under a common framework by joining the newsletters of each council. It is an exciting time to be part of the NKF. As a professional in the renal community, being a part of the CNNT, the CRN, or the CNSW offers a professional enrichment and opportunities to participate in making lives better for those with renal disease.