Renal consequences of parenteral nutrition

Urinary acid-base excretion deciphers high acid load from colonic bicarbonate loss in intestinal failure patients with ileocolonic anastomosis - Guidance for composition of parenteral support

BACKGROUND & AIMS

Acid-base disturbances are common in short bowel (SB) patients due to increased intestinal bicarbonate loss. However, the resulting systemic acid load has not been quantified. Base excess is used to monitor metabolic acid-base disturbances but inadequately reflects the acid load. Our aim was to investigate the systemic acid/base load in SB-patients to obtain quantitative estimates to guide the composition of parenteral support.

METHODS

We calculated total acid load in SB patients by summing 24-h urinary net acid excretion (NAE) and the provision of base equivalents in parenteral support. We then compared differences among anatomical SB-types: jejunostomy (SB-J), jejunocolostomy (SB-JC), and jejunoileostomy (SB-JIC). 47 urine samples from 34 SB patients were analyzed for bicarbonate (HCO3-), ammonium (NH4+), and titratable acid (TA) concentrations. NAE was calculated as (TA + NH4+) - HCO3-. Mixed-effects repeated-measures models were used to statistically examine differences between SB-types and associations with parenteral nutrition and NAE. A healthy cohort served as control.

RESULTS

In comparison to SB-J, SB-JC patients had a 4.1 mmoL/l lower base excess (95% CI: -6.3 to -1.8) and an 84.5 mmol/day higher total acid load (CI: 41.3 to 127.7). There were no significant differences between SB-JIC and SB-J regarding base excess, NAE, or total acid load. Higher amounts of infused acetate, sodium, and chloride, but not the acetate/chloride ratio, were associated with lower NAE and higher base excess.

CONCLUSIONS

Due to increased colonic bicarbonate loss, patients with SB-JC have a ∼4.4-fold higher acid load than healthy controls. The ion transport mechanisms mediating this bicarbonate loss from the remaining colon need further experimental investigation. NAE could be a useful tool to adjust base infusion in SB.

Early postnatal nutrition and renal consequences in preterm infants

Perinatal nutritional factors may lead to decreased nephron endowment, decreased kidney function, and long-term development of chronic kidney disease and non-communicable diseases. At the same time, optimal postnatal nutrition and catch-up growth are associated with better neurodevelopmental outcomes in preterm infants. Therefore, nutritional management of preterm infants is a major challenge for neonatologists. In this context, the Section of Nutrition, Gastroenterology and Metabolism reviewed the current knowledge on nutritional issues related to kidney function. This narrative review discusses the clinical impact of early postnatal nutrition on long-term kidney function. In preterm infants, data are largely lacking to determine the extent to which early nutrition contributes to nephrogenesis and nephron endowment. However, some nutritional principles may help clinicians better protect the developing kidney in preterm infants. IMPACT: Clinical data show that preterm infants are an emerging population at high risk for chronic kidney disease. Both undernutrition and overnutrition can alter long-term kidney function. In preterm infants, data are largely lacking to determine the extent to which early postnatal nutrition contributes to nephrogenesis, nephron endowment and increased risk for chronic kidney disease. Some nutritional principles may help clinicians better protect the developing kidney in preterm infants: avoiding extrauterine growth restriction; providing adequate protein and caloric intakes; limiting exposure to high and prolonged hyperglycaemia; avoiding micronutrient deficiencies and maintaining acid-base and electrolyte balance.

Children with Intestinal Failure Maintain Their Renal Function on Long-Term Parenteral Nutrition

BACKGROUND

Long-term parenteral nutrition (PN) has been associated with renal complications, including hypercalciuria, nephrocalcinosis, proteinuria and reduced glomerular filtration rate (GFR). Pediatric data are scarce and mostly short-term. Our study aimed to evaluate renal complications in children with intestinal failure (IF) receiving long-term PN.

METHODS

A cross-sectional study was performed in a tertiary pediatric IF clinic of patients receiving home-PN treatment for more than 1 year. Data regarding medical background, anthropometrics, laboratory investigations and abdominal sonography were retrieved.

RESULTS

Complete data were available for 15 children (67% males), with a median age of 6 (range 1.5-15) years and a median (IQR) PN duration of 4 (1.5-6) years. Low-grade proteinuria was identified in 61% and microalbuminuria in 30% of the cohort. Hypercalciuria and hyperoxaluria were present in 50% and 46%, respectively. One patient had nephrocalcinosis. The estimated GFR was normal in all but one patient who had pre-existing kidney disease.

CONCLUSIONS

Pediatric IF patients can present with preserved kidney function after years of PN treatment. Despite the high prevalence of hypercalciuria, nephrocalcinosis was not common. Base line and long-term monitoring of various aspects of renal function would be essential to characterize the effects of prolonged PN on kidney functions in pediatric patients.

Combined use of creatinine and cystatin C improves the detection of renal dysfunction in children undergoing home parenteral nutrition

BACKGROUND

Renal dysfunction can complicate home parenteral nutrition (HPN). The aims were, in the context of pediatric HPN, to assess renal function using the measured glomerular filtration rate (mGFR), determine the most accurate formula(s) to estimate GFR, and identify possible underlying mechanisms of renal impairment.

METHODS

A retrospective study was performed in 2 centers. Patients receiving HPN and aged 2-16 years without medical history of nephropathy were included. GFR was measured using iohexol clearance. Estimated GFR (eGFR) was calculated using creatinine, cystatin C-based, and combined (eGFR_cr+cyst ) Schwartz formulas.

RESULTS

A total of 36 patients (18 females) were included; they received HPN for 8 (2-16) years. The primary digestive disease was short-bowel syndrome for 16 (44%) patients, gastrointestinal motility disorder for 10 (28%), or congenital diarrhea for 10 (28%). The median (range) mGFR was 99 (33-136) ml/min/1.73 m² ; 9 (25%) patients had mildly decreased mGFR (<90 and ≥60 ml/min/1.73 m² ), and 2 (6%) had mildly to severely decreased mGFR (<60 ml/min/1.73 m² ). The eGFR_cr+cyst formula was the most accurate and precise to estimate GFR. A significant negative correlation between mGFR and PN duration was found for patients receiving PN for 6-7/7 days (P = .008). Activation of the renin-angiotensin system was identified in 15 of 36 (42%) patients.

CONCLUSION

Renal dysfunction was frequent and correlated with the duration of PN only for patients with the most severe intestinal failure. The use of eGFR_cr+cyst improves its detection in these patients. Chronic dehydration may be an underlying mechanism.

Energy and protein requirements for children with CKD stages 2-5 and on dialysis-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

Dietary management in pediatric chronic kidney disease (CKD) is an area fraught with uncertainties and wide variations in practice. Even in tertiary pediatric nephrology centers, expert dietetic input is often lacking. The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric renal dietitians and pediatric nephrologists, was established to develop clinical practice recommendations (CPRs) to address these challenges and to serve as a resource for nutritional care. We present CPRs for energy and protein requirements for children with CKD stages 2-5 and those on dialysis (CKD2-5D). We address energy requirements in the context of poor growth, obesity, and different levels of physical activity, together with the additional protein needs to compensate for dialysate losses. We describe how to achieve the dietary prescription for energy and protein using breastmilk, formulas, food, and dietary supplements, which can be incorporated into everyday practice. Statements with a low grade of evidence, or based on opinion, must be considered and adapted for the individual patient by the treating physician and dietitian according to their clinical judgment. Research recommendations have been suggested. The CPRs will be regularly audited and updated by the PRNT.

Monitoring of long-term parenteral nutrition in children with intestinal failure

Pediatric intestinal failure (IF) is a rare and complex condition associated with significant morbidity and mortality. It is defined as the reduction of gut mass or function below the minimal needed for absorption of nutrients and fluid to sustain life and growth. Since the advent of specialized multidisciplinary intestinal rehabilitation centers, IF management has considerably evolved in the last years, but serious complications of long-term parenteral nutrition (PN) can occur. Main complications include intestinal failure-associated liver disease, growth failure, body composition imbalance, central venous access complications, micronutrient deficiencies and toxicities, metabolic bone disease, small intestinal bacterial overgrowth, and renal disease. With improvement in survival rates of patients over the last 20 years, emphasis should be on limiting IF-related comorbidities and improving quality of life. Close monitoring is pivotal to ensuring quality of care of these patients. The care of children with chronic IF should involve a comprehensive monitoring plan with flexibility for individualization according to specific patient needs. Monitoring of children on long-term PN varies significantly across units and is mainly based on experience, although few guidelines exist. This narrative review summarizes the current knowledge and practices related to monitoring of children with IF. The authors also share their 20-year experience at the Royal Children's Hospital in Melbourne Australia on this topic.

Renal Function in Children on Long Term Home Parenteral Nutrition

Objectives: To assess renal function in pediatric intestinal failure (IF) patients on long term home parenteral nutrition (HPN). Methods: Children who received HPN for a minimum of 3 years between 2007 and 2017 were identified from the IF clinic of a large tertiary referral center. Estimated glomerular filtration rate (eGFR) was calculated using the Schwartz formula at discharge on HPN, after 6 months, 1, 2, and 3 years. Results: Twenty five patients (40% male) fulfilled the inclusion criteria. The indications for HPN were due to an underlying motility disorder in 56% (14/25), enteropathy in 24% (6/25), and short bowel syndrome in 20% (5/25). At the start of HPN 80% (20/25) had a normal eGFR. Four children (17%) had an abnormal eGFR. In the group of patients with normal eGFR at the start of HPN 30% (6/20) had at least one episode of decreased eGFR in the following 3 years, however there was no significant decline in eGFR at the end of the 3 year study period. Overall there was no statistically significant deterioration of eGFR in the study population (p = 0.7898). Conclusion: In our cohort of children on long term HPN no significant decline of eGFR could be demonstrated within 3 years of starting PN.

Intradialytic Parenteral Nutrition in Pediatrics

Children with end-stage renal disease (ESRD) on hemodialysis are at increased risk for malnutrition. Aggressive nutrition intervention such as intradialytic parenteral nutrition (IDPN) should be considered to prevent further co-morbidities and mortality associated with malnutrition when other interventions fail. IDPN is a non-invasive method of providing nutrition to malnourished hemodialysis (HD) patients via the HD access throughout the HD treatment. Although the evidence on the long-term benefits of IDPN is scant in pediatrics, there is evidence that it improves metabolic parameters and nutritional status. In this paper, therapy with IDPN including indications, goals of therapy, and elements to monitor will be described. In addition, a practice guideline for prescribing IDPN is provided.

When Is Parenteral Nutrition Appropriate?

Parenteral nutrition (PN) represents one of the most notable achievements of modern medicine, serving as a therapeutic modality for all age groups across the healthcare continuum. PN offers a life-sustaining option when intestinal failure prevents adequate oral or enteral nutrition. However, providing nutrients by vein is an expensive form of nutrition support, and serious adverse events can occur. In an effort to provide clinical guidance regarding PN therapy, the Board of Directors of the American Society for Parenteral and Enteral Nutrition (ASPEN) convened a task force to develop consensus recommendations regarding appropriate PN use. The recommendations contained in this document aim to delineate appropriate PN use and promote clinical benefits while minimizing the risks associated with the therapy. These consensus recommendations build on previous ASPEN clinical guidelines and consensus recommendations for PN safety. They are intended to guide evidence-based decisions regarding appropriate PN use for organizations and individual professionals, including physicians, nurses, dietitians, pharmacists, and other clinicians involved in providing PN. They not only support decisions related to initiating and managing PN but also serve as a guide for developing quality monitoring tools for PN and for identifying areas for further research. Finally, the recommendations contained within the document are also designed to inform decisions made by additional stakeholders, such as policy makers and third-party payers, by providing current perspectives regarding the use of PN in a variety of healthcare settings.

Anticoagulants for the prevention and treatment of catheter-related thrombosis in adults and children on parenteral nutrition: a systematic review and critical appraisal

BACKGROUND

Patients on parenteral nutrition require a central venous access and are at risk of catheter-related thrombosis, pulmonary embolism, and vena cava syndrome. Parenteral nutrition guidelines suggest anticoagulation for the primary prevention of catheter-related thrombosis during long-term parenteral nutrition. We conducted a systematic review of the efficacy, safety and feasibility of anticoagulant use for preventing and treating catheter-related thrombosis during parenteral nutrition.

MATERIALS AND METHODS

We searched for interventional and observational studies on adults and children receiving systemic anticoagulants during either short- or long-term parenteral nutrition delivered via central venous access. Primary outcomes were: objectively-confirmed catheter-related thrombosis, pulmonary embolism and bleeding. Secondary outcomes were: heparin-induced thrombocytopenia, prevalence of anticoagulation, and quality of International Normalised Ratio management in vitamin K antagonist-treated patients.

RESULTS

We identified 1,199 studies, of which 23 were included. Seven interventional studies of short-term parenteral nutrition (adult population, n=5) were classified as low-quality: in those, intravenous unfractionated heparin did not prevent catheter-related thrombosis if compared to saline. No interventional studies were conducted in patients on long-term parenteral nutrition. Observational data were sparse, rarely focusing on anticoagulation, and overall of low quality. The reported use of anticoagulants was between 22 and 66% in recent multicentre cohorts.

DISCUSSION

The amount and quality of data in this area are very suboptimal: most studies are outdated and involved heterogeneous populations. Currently, there is insufficient evidence to allow conclusions to be reached regarding the efficacy and safety of anticoagulants in this setting.

Advances in nutritional therapy in inflammatory bowel diseases: Review

Inflammatory bowel diseases (IBD), including ulcerative colitis and Crohn's disease are chronic, life-long, and relapsing diseases of the gastrointestinal tract. Currently, there are no complete cure possibilities, but combined pharmacological and nutritional therapy may induce remission of the disease. Malnutrition and specific nutritional deficiencies are frequent among IBD patients, so the majority of them need nutritional treatment, which not only improves the state of nutrition of the patients but has strong anti-inflammatory activity as well. Moreover, some nutrients, from early stages of life are suspected as triggering factors in the etiopathogenesis of IBD. Both parenteral and enteral nutrition is used in IBD therapy, but their practical utility in different populations and in different countries is not clearly established, and there are sometimes conflicting theories concerning the role of nutrition in IBD. This review presents the actual data from research studies on the influence of nutrition on the etiopathogenesis of IBD and the latest findings regarding its mechanisms of action. The use of both parenteral and enteral nutrition as therapeutic methods in induction and maintenance therapy in IBD treatment is also extensively discussed. Comparison of the latest research data, scientific theories concerning the role of nutrition in IBD, and different opinions about them are also presented and discussed. Additionally, some potential future perspectives for nutritional therapy are highlighted.