Haematological aspects of life with an ileostomy

Nutritional management of high-output ileostomies in paediatric patients is vital and more evidence-based guidelines are needed

AIM

Paediatric patients with high-output ileostomies (HOI) face an elevated risk of complications. This study aimed to comprehensively review the existing literature and offer nutritional management recommendations for paediatric patients with an HOI.

METHODS

PubMed and Embase were searched for relevant English or French language papers up to 31 June 2022. The emphasis was placed on studies involving paediatric ileostomy patients, but insights were obtained from adult literature and other intestinal failure pathologies when these were lacking.

RESULTS

We identified 16 papers that addressed nutritional issues in paediatric ileostomy patients. Currently, no evidence supports a safe paediatric HOI threshold exceeding 20 mL/kg/day on two consecutive days. Paediatric HOI patients were at risk of dehydration, electrolyte disturbances, micronutrient deficiencies and growth failure. The primary dietary choice for neonates is bolus feeding with breastmilk. In older children, an enteral fluid restriction should be installed favouring isotonic or slightly hypotonic glucose-electrolyte solutions. A diet that is high in calories, complex carbohydrates and proteins, low in insoluble fibre and simple carbohydrates, and moderate in fat is recommended.

CONCLUSION

Adequate nutritional management is crucial to prevent complications in children with an HOI. Further research is needed to establish more evidence-based guidelines.

Vitamin B12 deficiency

Of the water-soluble vitamins, vitamin B12 (B12) has the lowest daily requirement. It also has several unique properties including a complex pathway for its absorption and assimilation requiring intact gastric and terminal small intestinal function, an enterohepatic pathway, and several dedicated binding proteins and chaperons. The many causes of B12 deficiency include malabsorption and defects in cellular delivery and uptake, as well as limited dietary intake. B12 is required as a cofactor for only two reactions in humans, the cytosolic methionine synthase reaction and the mitochondrial methymalonyl CoA mutase reaction. Disruption of either of these reactions gives rise to B12 deficiency. Although more common with advancing age, because of the higher prevalence of malabsorptive disorders in the elderly, B12 deficiency is widely distributed across all age groups particularly where food insecurity occurs. The consequences and severity of B12 deficiency are variable depending on the degree of deficiency and its duration. Major organ systems affected include the blood, bone marrow and nervous system. Megaloblastic anemia results from a defect in thymidine and therefore DNA synthesis in rapidly dividing cells. Nervous system involvement is varied, some of which results from defective myelin synthesis and repair. Cognitive impairment and psychosis may also occur. Diagnosis of B12 deficiency rests on clinical suspicion followed by laboratory testing, which consists of a panel of tests, that together provide clinically reliable predictive indices. B12 metabolism and deficiency is closely intertwined with folate, another B-vitamin. This chapter explores the various aspects of a unique and fascinating micronutrient.

Vitamin B12 deficiency in inflammatory bowel disease: a prospective observational pilot study

BACKGROUND AND AIM

Diagnostic and management guidelines for vitamin B12 (cobalamin, Cbl) deficiency in inflammatory bowel disease (IBD) are lacking. True deficiency is defined as Cbl concentrations below reference range combined with elevated methylmalonic acid (MMA) concentrations. Studies analyzing Cbl status in IBD use only Cbl concentrations without confirmatory MMA. This study aims to determine the proportion of IBD patients with Cbl concentrations below reference range and their predisposing clinical and genetic characteristics. We then compared this to the proportion with true deficiency.

PATIENTS AND METHODS

In a prospective observational pilot study of adult IBD outpatients, Cbl concentrations, MMA levels, and fucosyltransferase 2 mutations were measured at clinic visits.

RESULTS

A total of 66 Crohn's disease (CD) and 30 ulcerative colitis (UC) patients were recruited. Mean Cbl concentrations (pmol/l) in CD (253.7) were not significantly lower than UC (320.5, P=0.24). Serum Cbl below reference range (<148) was observed in 7.6 and 10% of CD and UC patients, respectively (P=0.70). True deficiency in CD and UC was 3 and 3.3%, respectively (P=1.0). Patients with ileal resections more than 30 cm had lower mean Cbl concentrations (177, P=0.02) and a trend toward higher proportions with Cbl levels below reference range (40%, P=0.06), but not increased deficiency rates (0%, P=1.0). Disease location, severity, and fucosyltransferase 2 mutations were not associated with altered Cbl status.

CONCLUSION

True Cbl deficiency was rare in IBD patients in this study. A disparity in Cbl status exists when confirmatory MMA levels are used compared with Cbl concentrations alone. Asymptomatic IBD patients with low serum Cbl require confirmatory tests to guide management and avoid unnecessary treatment.

Megaloblastic Anemias: Nutritional and Other Causes

Vitamin B₁₂ and folate deficiencies are major causes of megaloblastic anemia. Causes of B₁₂ deficiency include pernicious anemia, gastric surgery, intestinal disorders, dietary deficiency, and inherited disorders of B₁₂ transport or absorption. The prevalence of folate deficiency has decreased because of folate fortification, but deficiency still occurs from malabsorption and increased demand. Other causes include drugs and inborn metabolic errors. Clinical features of megaloblastic anemia include anemia, cytopenias, jaundice, and megaloblastic marrow morphology. Neurologic symptoms occur in B₁₂ deficiency, but not in folate deficiency. Management includes identifying any deficiency, establishing its cause, and replenishing B₁₂ or folate parenterally or orally.

Vitamin B12 deficiency in inflammatory bowel disease: prevalence, risk factors, evaluation, and management

BACKGROUND

Management of vitamin B(12) (cobalamin, Cbl) deficiency in inflammatory bowel disease (IBD) is often not evidenced-based because of uncertainty on whether it causes enough malabsorption to result in clinical disease. This systematic review examines whether IBD predisposes to Cbl deficiency. We provide an approach to the management of abnormal Cbl values in IBD based on current literature and consensus-based guidelines.

METHODS

An extensive search of the Ovid MEDLINE and EMBASE databases by independent reviewers identified 42 articles with a total of 3732 patients evaluating Cbl deficiency in IBD.

RESULTS

Crohn's disease without ileal resection, regardless of disease location in the ileum, did not increase the risk for Cbl deficiency. Ileal resections greater than 30 cm were associated with Cbl deficiency in Crohn's disease, whereas those less than 20 cm were not. The effects of 20 to 30 cm resections were inconsistent. Ulcerative colitis did not predispose to deficiency. All studies failed to use confirmatory biomarker testing as stipulated by diagnostic guidelines for Cbl deficiency.

CONCLUSIONS

This literature does not support an association of Crohn's disease in general, regardless of ileal involvement, with Cbl deficiency. Only ileal resections greater than 20 cm in Crohn's disease predispose to deficiency and warrant treatment. Based on these findings, we suggest a diagnostic and therapeutic algorithm. All findings and recommendations require verification in further studies using confirmatory biomarkers as per diagnostic guidelines for Cbl deficiency. Serum Cbl levels alone are likely insufficient to diagnose deficiency in asymptomatic patients.

Systematic review: managing anaemia in Crohn's disease

BACKGROUND

Anaemia is a serious complication of Crohn's disease that triggers hospitalization and, if not interfered with, may lead to death.

AIMS

To systematically summarize and compare the literature on anaemia in Crohn's disease.

METHODS

For this systematic review the literature was searched for English-language articles using anaemia, Crohn* and IBD as key words. 144 articles were identified and sorted according to the following topics: prevalence, aetiology, diagnostic tests and therapy.

RESULTS

The reported prevalence of anaemia varied between 6.2% and 73.7%, with higher reported frequencies in older studies and in in-patients. Iron deficiency is the most common underlying condition. Vitamin B12 deficiency is related to the extent of ileal resection but has rarely impact on anaemia. Diagnostic criteria are not established and treatment guidelines are missing. Oral iron supplementation seems effective for short periods but intolerance leads to discontinuation in up to 21%. Eleven of 11 studies show that oral iron enhances intestinal inflammation and colon carcinogenesis in animal models of colitis. Intravenous iron supplementation with iron sucrose has been tested in over 250 Crohn's disease patients, is safe, effective and does not carry such hazards.

CONCLUSIONS

As disease activity is determining the degree of anaemia in Crohn's disease, implementation of more effective therapy for Crohn's disease will lower its incidence. However, further studies regarding the safety and effectiveness of iron supplementation are needed.

Malnutrition and gastrointestinal disease

The recognition of several disease processes that cause or are associated with gastrointestinal malabsorption has led to extensive investigation into their pathogenesis, diagnosis, and treatment. This review of selected articles covers a range of subjects related to some of the more common malabsorptive disease. Selected topics including celiac disease, disaccharidase deficiencies, short bowel syndrome, and Crohn disease are discussed.

Intestinal absorption of different types of folate in healthy subjects with an ileostomy

Our knowledge on the absorption of folate is incomplete. The deconjugation process as a possible limiting factor in the absorption of folates was investigated. The study also attempted to validate the use of the area under the serum response curve (AUC) from food compared with folic acid as a proxy variable for food folate bioavailability. Folate absorption was determined in healthy ileostomy volunteers (n 11) using a single-dose short-term protocol. In a randomised crossover design, volunteers received spinach meals and a supplement. Based on analysis of test meals and ileostomy effluents, there was no difference in folate absorption between spinach with a mono-:polyglutamate ratio 40:60 and the same spinach with a 100:0 ratio. The absolute absorption of spinach folate (79 %) calculated from the difference between folate intake and folate content of ileostomy effluents was approximately equal to the relative absorption (81 %) calculated from the AUC after consumption of spinach meals in relation to the AUC after consumption of the folic acid supplement. We conclude that the deconjugation process is not a limiting factor in the absorption of spinach folates. Comparison of AUC of food folate v. folic acid in a short-term protocol may be suitable for assessing food folate bioavailability.

Malnutrition and gastrointestinal disease

The recognition of several disease processes that cause or are associated with gastrointestinal malabsorption has led to extensive investigation into their pathogenesis, diagnosis, and treatment. This review of selected articles covers a range of subjects related to some of the more common malabsorptive disease. Selected topics including celiac disease, disaccharidase deficiencies, short bowel syndrome, and Crohn disease are discussed.

Comparison of micronutrients in patients having had panproctocolectomy and either ileal pouch anal anastomosis or Brooke ileostomy for chronic ulcerative colitis (UC)

OBJECTIVE

Patients having panproctocolectomy undergo major metabolic changes. A recent study suggested that patients who have had a panproctocolectomy and ileal pouch-anal anastomosis (IPAA) may be trace element-deficient, while other recent evidence has suggested a gradual decrease in vitamin B12. This study was undertaken to compare patients who had a panproctocolectomy for UC in combination with either an IPAA or a Brooke ileostomy (BI), and to determine whether the type of surgery post-proctocolectomy influences the absorption of trace elements, as well as comparing the levels after both operations with the normal population values.

PATIENTS AND METHODS

One hundred randomly selected patients who had had a panproctocolectomy for UC (50 IPAA, 50 BI) were invited to take part in the study by letter. The patients who consented had blood taken for haemoglobin, serum iron, ferritin, serum folate, red cell folate, vitamin B12, insulin-like growth factor-1 (IGF-1), albumin, and the trace elements copper, magnesium, manganese, selenium, and zinc.

RESULTS

Of the 100 patients, 46 consented to participate in the study (23 IPAA, 23 BI). The age of the BI group was significantly higher than those of the IPAA group (mean age IPAA 44 years, BI 52 years, P < 0.05). There was no significant difference between the two groups with respect to time since operation, mean levels of haemoglobin, iron indices, albumin, serum and red cell folate, vitamin B12, or any of the trace elements examined. Plasma IGF-1 was higher in the IPAA group, but this was no longer significant when adjusted for age.

CONCLUSION

No difference was found in trace element status in patients who had had a panproctocolectomy for UC with either an IPAA or BI. Furthermore, no difference existed between these two groups.