Treatment of Vitamin B12 Deficiency after Gastric Surgery for Severe Obesity

Background: Vitamin B₁₂ deficiency after gastric surgery for obesity is due to a failure of separation of vitamin B₁₂ from protein foodstuffs and to a failure of absorption of crystalline vitamin B₁₂ in the presence of intrinsic factor. The purpose of this study was to determine which of four oral doses of crystalline vitamin B₁₂ was most effective in treating vitamin B₁₂ deficiency in 102 patients. Methods and Results: At time of entry into the study, the patients had a serum vitamin B₁₂ < 100 pmol L ⁻¹, were 29.9 ± 21.7 months post-op, were 37 ± 8 years old and had a body mass index of 30 ± 6 kg m⁻². Eight (8%) had had a vertical banded gastroplasty and 94 (92%) a gastric bypass. For the first 3 months all patients received 350 μg per day of crystalline vitamin B₁₂ and all increased their serum vitamin B₁₂ levels to over 100 pmol L⁻¹. The patients were then assigned to receive for a further 3 month period one of four oral doses of crystalline vitamin B₁₂-100 μg, 250 μg, 350 μg and 600 μg. Serum vitamin B₁₂ levels were greater than 150 pmol L⁻¹ after 6 months in 83.3% of patients who received 100 μg; 92.3% of patients who received 250 μg; 94.7% after 350 μg and 95.2% after 600 μg (p%0.525). Conclusion: At least 350 μg per day is the appropriate oral dose of crystalline vitamin B₁₂ after gastric surgery for obesity to correct low serum vitamin B₁₂ levels in 95% of patients.     

The role of parenteral nutrition

Patients with acute leukemia who undergo hematopoietic stem cell transplantation (HSCT) are susceptible to malnutrition caused by several factors including intensive cytotoxic therapy. This paper discusses the significance of malnutrition in these patients and provides an overview of nutrition therapy by the oral, enteral, and parenteral routes. The goal is to investigate whether the use of parenteral nutrition (PN) produces improved clinical outcomes in patients with acute leukemia and to identify criteria for the selection of patients most likely to benefit from this therapy. Although PN may be appropriate for patients suffering from complications such as graft-versus-host disease (GVHD) and mucositis, the data available at this time do not support PN as first-line therapy for all recipients of HSCT.     

Analysis of Estimation Methods for Resting Metabolic Rate in Critically Ill Adults

Background: Prediction of metabolic rate is an important part of the nutrition assessment of critically ill patients, yet there are limited data regarding the best equation to use to make this prediction. Methods: Standardized indirect calorimetry measurements were made in 202 ventilated, adult critical care patients, and resting metabolic rate was calculated using the following equations: Penn State equation, Faisy, Brandi, Swinamer, Ireton‐Jones, Mifflin, Mifflin × 1.25, Harris Benedict, Harris Benedict × 1.25, Harris Benedict using adjusted weight for obesity, and each of the adjusted weight versions of Harris Benedict × 1.25. The subjects were subgrouped by age and obesity status (young nonobese, young obese, elderly nonobese, elderly obese). Performance of each equation was assessed using bias, precision, and accuracy rate statistics. Results: Accuracy rates in the study population ranged from 67% for the Penn State equation to 18% for the weight‐adjusted Harris Benedict equation (without multiplication). Within subgroups, the highest accuracy rate was 77% in the elderly nonobese using the Penn State equation and the lowest was 0% for the weight‐adjusted Harris Benedict equation. The Penn State equation was the only equation that was unbiased and precise across all subgroups. The obese elderly group was the most difficult to predict. Therefore, a separate regression was computed for this group: Mifflin(0.71) + Tmax(85) + Ve(64) – 3085. Conclusions: The Penn State equation provides the most accurate assessment of metabolic rate in critically ill patients if indirect calorimetry is unavailable. An alternate form of this equation for elderly obese patients is presented, but has yet to be validated.     

Ghrelin Does Not Predict Adaptive Hyperphagia in Patients With Short Bowel Syndrome

Background: Adaptive hyperphagia is associated with reduced dependence on parenteral nutrition in patients with short bowel syndrome, but mechanisms have not been described. Ghrelin (GHR) has orexigenic effects, whereas peptide YY (PYY) reduces intake. GHR also acts as a hormone to control body fat stores. The authors evaluated whether GHR or PYY was related to caloric intake or absorption in patients with short bowel syndrome and whether GHR was associated with body mass index. Methods: Patients were admitted twice for nutrient balance. Height and body weight were obtained using standardized protocols. Energy intake >40 kcal/kg/day was defined as adaptive hyperphagia. Fasting plasma PYY and GHR were assayed in duplicate with Linco enzyme‐linked immunosorbent assay kits. Results: The median age of the 7 study participants was 62 (range, 45‐66) years, time with short bowel syndrome was 6.6 (range, 2‐29) years, and body mass index was 21.2 kg/m² (range, 19‐27.7). Five patients had adaptive hyperphagia. Neither GHR nor PYY was significantly related to energy intake or absorption (GHR: R = 0.22 and R = –0.233, PYY: R = 0.10 and R = –0.13). Body mass index trended toward an inverse association with GHR (GHR: R = –0.540, P = .211). Conclusion: The rigorous adaptive hyperphagia seen in these patients with short bowel syndrome was not related to fasting GHR or PYY, suggesting the need to explore other mechanisms.     

An Evaluation of the Neuroendocrine Response to Sleep in Pediatric Burn Patients

Introduction: Previous work demonstrated reduced stage 3+4 and rapid eye movement (REM) sleep following burn injury. This study evaluated the hormonal effects of drug intervention on measures of endocrine status. A secondary objective examined the relationship between hormones and sleep stage distribution. Methods: Forty patients 3–18 years of age with a mean percent total body surface area burn of 50.1 ± 2.9 were randomly assigned to zolpidem or haloperidol utilizing a blinded crossover design. Polysomnography was performed 6 nights, 3/week over 2 weeks. Each week's first night of monitoring was conducted without medication, serving as a baseline. Hormonal levels (epinephrine, norepinephrine, growth hormone, melatonin, dehydroepiandrosterone [DHEA], serotonin, cortisol) were obtained at 0600 h each study day. Results: Both drugs were associated with increased DHEA levels (P < .03); no other hormones were affected by medication. Significant inverse correlation was observed between REM sleep and epinephrine (r = –.34, P = .004) and norepinephrine levels (r = –.45, P = .02). A positive relationship existed between serotonin and sleep stage 3+4 (r = 0.24, P = .01) and REM (r = 0.48, P = .01). No other significant associations were identified between hormones and sleep. Conclusions: This work characterizes the relationship between sleep deprivation and select endocrine parameters postburn. Drug interventions utilized in this study were either ineffective or insufficient in modulating improved hormonal response. Significance of zolpidem's and haloperidol's effect on serum levels of DHEA is unclear. The inverse correlation of epinephrine with REM may suggest that hypermetabolism associated with burns is partly due to lack of REM sleep. Questions remain regarding the effects of sleep deprivation on metabolism and clinical outcome.     

Immunonutrition and enteral hyperalimentation of critically ill patients

Physicians need to be maximally aggressive in their use of total enteral nutrition (TEN) in the critically ill patient, due to its lower cost, better physiology, and lower complication rate when compared to parenteral therapy. Various components in TEN such as glutamine, arginine, RNA nucleotides, omega-3 fish oils, and fiber, may have important roles in immunonutrition by maintaining gut integrity, stimulating the immune system, and preventing bacterial translocation from the gut. For each patient, the physician must choose the optimal enteral formula for that particular disease or organ failure state to maximize nutrient substrate assimilation and tolerance. Total parenteral nutrition (TPN) should be used only when a true contraindication to enteral feedings exists or as adjunctive therapy when full nutritional requirements cannot be met by TEN alone.     

Anemia and Leukopenia in a Long‐Term Parenteral Nutrition Patient During a Shortage of Parenteral Trace Element Products in the United States

Recently, drug shortages in the United States have affected multiple components of the parenteral nutrition (PN) solution. A 62‐year‐old patient with systemic sclerosis who was dependent on home PN due to intestinal dysmotility developed anemia and leukopenia approximately 4 months after parenteral copper was withheld from her PN solution due to drug shortages. The patient was not able to tolerate a sufficient amount of oral multivitamins with trace elements due to severe dysphagia. Her serum copper and ceruloplasmin concentrations were undetectable, confirming the diagnosis of severe copper deficiency. The hematological abnormalities promptly resolved with copper supplementation. This report emphasizes the importance of close monitoring for nutrient deficiencies during drug shortages and supplementing with oral or enteral nutrition when feasible, particularly in high‐risk patients such as those with intestinal malabsorption or short bowel syndrome who are dependent on long‐term PN.