The potential of intradialytic parenteral nutrition: A review

Revisiting Intradialytic Parenteral Nutrition: How Can We Apply the Evidence in Clinical Practice?

Intradialytic parenteral nutrition (IDPN) remains a controversial nutrition support practice in hemodialysis. Multiple reviews and evidence-based clinical practice guidelines have been published in the past 20 years. Despite essentially looking at the same evidence, conclusions and recommendations vary significantly, leading to widespread uncertainty among clinicians on the value of and indications for IDPN. This paper aims to bring a clinical perspective to the current state of evidence and clinical practice, recognizing the strengths and weaknesses of current evidence and the clinical questions that remain unanswered, as well as providing guidance for using IDPN in clinical practice. IDPN should be considered a strategy to complement spontaneous oral intake in clinically stable patients receiving maintenance hemodialysis or who have or are at risk of malnutrition and who have substantial but not adequate protein and/or energy intake. There is a clear need for robust randomized controlled trials evaluating the impact of IDPN in appropriately selected patients. Additionally, future trials should include patient-centered outcome measures such as appetite, spontaneous oral intake, quality of life, and reliable measures of nutritional status.

Red meat snacks for chronic hemodialysis patients: effect on inflammatory activity (a pilot study)

RATIONAL

Among the alternatives to reverse chronic hemodialysis protein-energy malnutrition is the enhancement of intradialytic oral nutritional therapy. Although foods of animal origin are a source of nutrients and represent a feasible diet, there is uncertainty about their health consequences.

OBJECTIVES

We assessed the relationship of intradialytic high-protein red meat snack supplementation with patient inflammatory status and protein losses (nitrogen) during this supplementation. Fourteen patients submitted to low-flux chronic hemodialysis for one month were divided into two groups receiving 2 g (group 1) and 29 g (group 2) of oral intradialytic protein during the initial phase, respectively. In the subsequent phase, group 1 was supplemented with 27 g protein (a red meat snack) for a total of 29 g per dialysis. Group 2 continued to receive 29 g protein. Nutritional status, total nitrogen losses through the dialysate and acute inflammatory phase protein (CRP) were assessed before and after dialysis. Reuse of the dialyzer was also determined on each occasion.

MAIN FINDINGS

Red meat supplementation did not interfere with CRP, nitrogen loss through the dialysate (18 ± 7 to 19 ± 4 g in group 1, ns, and 20 ± 7 to 21 ± 4 g in group 2, ns) or with nutritional status. However, the data showed a positive correlation between pre- and post-hemodialysis CRP values (r = 0.84, p < 0.01) in both groups, suggesting an increase of the values after ultrafiltration. Reuse of the dialyzer was not correlated with CRP values.

PRINCIPLE CONCLUSIONS

The results suggest that snacks were not acutely correlated with increased inflammatory levels and indicated that a protein-rich red meat snack may be beneficial for chronic hemodialysis patients.

Effect of intradialytic parenteral nutrition in patients with malnutrition–inflammation complex syndrome on body weight, inflammation, serum lipids and adipocytokines: results from a pilot study

OBJECTIVE

Evaluation of the influence of intradialytic parenteral nutrition (IDPN) in patients suffering from Malnutrition-Inflammation Complex Syndrome (MICS) on nutritional status, inflammation, adipocytokines and serum lipids.

SUBJECTS

Six patients with MICS were assigned to IDPN, whereas six patients matched for age, sex, body mass index (BMI) and co-morbidity without malnutrition served as controls. Patients were recruited from Outpatient Dialysis Unit, Medical University Innsbruck and from Dialysis Unit, Hospital Feldkirch.

RESULTS

In all patients with IDPN, dry body weight increased during the interventional period whereas body weight remained stable in patients without IDPN. Tumor necrosis factor (TNF)-alpha levels were higher in patients with MICS compared with controls at all time points. Total cholesterol, LDL- and HDL-levels significantly increased during dialysis at all time points in controls but not in patients with MICS. Albumin, C-reactive protein, interleukin-6 (IL-6), soluble interleukin-2 receptor (sIL-2R) and adipocytokines did not differ between patients and controls during the study period.

CONCLUSIONS

IDPN in patients with MICS increases body weight despite not influencing inflammatory status. Furthermore, IDPN does not induce a pro-atherogenic lipid composition enhancing the risk for atherosclerosis. Thus, IDPN is a safe and effective treatment of malnutrition in patients with MICS.

Malnutrition in Patients Undergoing Hemodialysis: Is Intradialytic Parenteral Nutrition the Answer?

Patients with end-stage renal disease often experience malnutrition as a result of decreased dietary intake; inadequate dialysis; loss of nutrients into the dialysate; abnormal protein, carbohydrate, and lipid metabolism; and concomitant diseases, which may contribute to an increase in morbidity and mortality. Intradialytic parenteral nutrition (IDPN) is being used to improve nutritional status, in conjunction with other methods of nutritional supplementation. The biggest advantage of IDPN is probably its convenience since it is administered during dialysis treatment and thus does not require additional clinic visits or prolonged dialysis time. Although IDPN has several disadvantages, its ability to improve nutritional status and reduce morbidity and mortality in patients with end-stage renal disease is promising. Well-designed, large-scale, prospective studies are required to confirm its beneficial effects.

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.

Intradialytic parenteral nutrition improves protein and energy homeostasis in chronic hemodialysis patients

Decreased dietary protein intake and hemodialysis-associated protein catabolism are among several factors that predispose chronic hemodialysis (CHD) patients to protein calorie malnutrition. Since attempts to increase protein intake by dietary counseling are usually ineffective, intradialytic parenteral nutrition (IDPN) has been proposed as a potential therapeutic approach in malnourished CHD patients. In this study, we examined protein and energy homeostasis during hemodialysis in seven CHD patients at two separate hemodialysis sessions, with and without IDPN administration. Patients were studied 2 hours before, during, and 2 hours following a hemodialysis session, using a primed constant infusion of L-(1-(13)C) leucine and L-(ring-(2)H(5)) phenylalanine. Our results showed that IPDN promoted a large increase in whole-body protein synthesis and a significant decrease in whole-body proteolysis, along with a significant increase in forearm muscle protein synthesis. The net result was a change from an essentially catabolic state to a highly positive protein balance, both in whole-body and forearm muscle compartments. We conclude that the provision of calories and amino acids during hemodialysis with IDPN acutely reverses the net negative whole-body and forearm muscle protein balances, demonstrating a need for long-term clinical trials evaluating IDPN in malnourished CHD patients.

Practical aspects of intradialytic nutritional support

A critical review of recent international literature related to the use of intradialytic parenteral nutrition is given. The role of intradialytic parenteral nutrition as a therapy in malnourished hemodialysis patients is established and the need for systematic monitoring of this population at high risk of malnutrition is emphasized.