Nutritional considerations after bariatric surgery

Malnutrition is a risk that is associated with all bariatric surgeries. Malnutrition is largely preventable after these surgeries if proper patient selection, thorough preoperative nutrition education, and postoperative nutritional follow-up take place along with patient compliance. Bariatric surgery is divided into 2 major categories: restrictive or malabsorptive (with or without the restrictive aspect). The more dramatic weight loss is generally associated with procedures that are malabsorptive in nature. There is an increased risk of specific nutritional deficiencies associated with these surgeries. With proper supplementation these deficiencies are largely avoidable. This article reviews the more common bariatric surgeries and the nutritional considerations associated specifically with each surgery. The article then summarizes the typical diet advancement schedule and reviews critical care nutrition in regards to total parenteral nutrition administration for the morbidly obese individual, following bariatric surgery.     

Comment repérer et traiter les carences en vitamines, minéraux et oligoéléments

Bariatric surgery leads to the risk of metabolic and nutritional complications. The nutritional deficiencies observed are most often associated with malabsorption caused by the surgical technique, but the reduction in food intake and nutritional imbalance generated by food restriction are also at play. The high prevalence of iron deficiency (about one third of gastroplasty patients and more than 50% of gastric bypass patients) calls for regular monitoring of blood levels. Dietary supplements in cases of nutritional deficiency are recommended following restrictive surgery and gastric bypass procedures (GBP). Women of childbearing age who have undergone GBP must discuss regular dietary supplementation (200 mg of iron a day) with their healthcare providers. Vitamin B12 deficiency is highly prevalent after GBP, but also occurs at a significant rate after restrictive surgery (4–10%). Dietary supplements after GBP are crucial, and oral administration is possible (1,000 μg a week at 500 μg a day). Folic acid deficiency occurs in about 40% of patients after GBP. A dose of 400 μg at 1 mg a day is necessary to correct this deficiency. This must always be administered when pregnancy has been planned. Increased parathyroid hormone levels stemming from vitamin D deficiency and reduced calcium absorption, with its consequences on bone, occur frequently after GBP. Calcium and vitamin D supplements must be administered in this case (1,000–1,500 mg a day of calcium (citrate), combined with 400–1,000 UI of cholecalciferol). Symptoms of thiamine (vitamin B1) deficiency, responsible for Wernicke’s encephalopathy, are usually triggered by glucose administration in deficient patients (vomiting). Zinc and selenium deficiencies affect 25–30% of patients. Dietary supplements of iron, vitamin B12, folic acid, calcium and vitamin D, as well as comprehensive monitoring of nutritional status, are necessary after bariatric surgery, especially following gastric bypass procedures. Patients should be informed of this necessity. The assessment of patient compliance is a factor to take into account when evaluating indications.     

Nutritional deficiencies in patients receiving cancer chemotherapy

Cancer often causes malnutrition and specific vitamin and protein deficiencies. Chemotherapy also causes deficiencies by promoting anorexia, stomatitis, and alimentary tract disturbances. Antimetabolite drugs in particular inhibit synthesis of essential vitamins, purines, and pyrimidines. Because vitamin levels in the blood are often nondiagnostic, nutritional deficiency is identified almost exclusively on the basis of clinical signs and symptoms and the patient's response to therapy. Signs and symptoms of cachexia and hypoalbuminemia are common in patients with advanced cancer. Deficiencies of vitamins B1, B2, and K and of niacin, folic acid, and thymine also may result from chemotherapy. Nutritional deficiencies are chemically correctable; however, the tumor must be eradicated to relieve cachexia.     

Perioperative nutrition and nutritional supplements.

Due to the combination of poor dietary habits and aging in the U.S. population, an increase in the incidence of chronic disease is occurring in this country. The prevalence of poor nutrition, obesity, diabetes, and other chronic diseases can have a significant impact on surgical outcome and complications. The number of patients with pre-existing nutritional deficiencies and health problems who are seeking cosmetic surgical procedures is growing. Nutritional intervention and supplements can have a beneficial effect on such patients who are undergoing surgery. Plastic surgeons performing aesthetic procedures may want to incorporate nutritional guidance and supplementation into their perioperative office regimen to mitigate complications and to optimize surgical outcome.     

Caring for patients after bariatric surgery

Bariatric surgery leads to sustainable long-term weight loss and may be curative for such obesity-related comorbidities as diabetes and obstructive sleep apnea in severely obese patients. The Roux-en-Y gastric bypass has become the most common procedure for patients undergoing bariatric surgery. The procedure carries a mortality risk of up to 1 percent and a serious complication risk of up to 10 percent. Indications include body mass index of 40 kg per m2 or greater, or 35 kg per m2 or greater with serious obesity-related comorbidities (e.g., diabetes, obstructive sleep apnea, coronary artery disease, debilitating arthritis). Pulmonary emboli, anastomotic leaks, and respiratory failure account for 80 percent of all deaths 30 days after bariatric surgery; therefore, appropriate prophylaxis for venous thrombo-embolism (including, in most cases, low-molecular-weight heparin) and awareness of the symptoms of common complications are important. Some of the common short-term complications of bariatric surgery are wound infection, stomal stenosis, marginal ulceration, and constipation. Symptomatic cholelithiasis, dumping syndrome, persistent vomiting, and nutritional deficiencies may present as long-term complications.     

Pregnancy following bariatric surgery

Gastric bypass surgery for morbid obesity is considered an appropriate intervention when other weight-loss measures have proven unsuccessful. Weight loss often brings about improvement in overall health by lessening the effects of obesity-related comorbidities such as chronic hypertension and diabetes. In fact, the ability to become pregnant is enhanced, as weight loss often allows for a normalization of sex hormones. However, the nutrition challenges brought about by the surgery may have a profound impact on maternal health and pregnancy outcome. Surgical procedures for morbid obesity may be classified according to the digestive aftereffects brought about by the particular procedure. These categories include the "restrictive" procedures, "restrictive-malabsorptive" procedures, and the less common "malabsorptive" procedures. Deficiencies in iron, vitamin B12, folate, and calcium can result in maternal complications, such as severe anemia, and in fetal complications, such as neural tube defect, intrauterine growth restriction, and failure to thrive. Nutrient supplementation following bariatric surgery and close supervision before, during, and after pregnancy can help prevent nutrition-related complications and improve maternal and fetal health.     

Hypovitaminosis D and morbid obesity

There is scarce and flawed data regarding vitamin D status in morbidly obese patients. More often than not, vitamin D deficits have been linked with bariatric surgery, not considering that the deficit may well precede surgery. Moreover, several pathophysiologic mechanism might explain, in part, vitamin D deficits. Conversely, the association between vitamin D deficits and secondary hyperparathyroidism in morbidly obese patients has been reported before and after bariatric surgery. Taking into account the elevated prevalence of vitamin D deficits in morbidly obese patients, its associated comorbidity, and the efficacy and low cost of its treatment to restore normal serum values of 25-OH-vitamin D, it seems advisable to recommend routine monitoring of serum calcium, phosphorus, and 25-OH-vitamin D levels in morbidly obese patients and to implement calcium and vitamin D supplementation whenever necessary.     

Perioperative management of the bariatric surgery patient: focus on cardiac and anesthesia considerations

Obesity is a major public health problem in developed nations worldwide. Currently, the only treatment for severe obesity (BMI > or = 35 kg/m2 with comorbidity) that provides long-term weight loss is bariatric surgery. Restrictive, malabsorptive, and combination procedures have been developed. Each type of procedure has its merits and unique set of risks and complications. Weight loss after bariatric surgery is accompanied by predictable improvement or resolution of obesity-related comorbidities and improved quality of life and life expectancy. Candidates for bariatric surgery are often at high risk for complications because of obesity-related comorbidities. Therefore, careful patient selection for bariatric surgery, together with well-designed strategies for preventing and managing complications, are keys to success. Close monitoring for nutritional deficiencies and short- and long-term complications is required to completely assess outcomes of these procedures.     

Nutritional consequences of weight-loss surgery

Nutritional deficiencies are already present in many morbidly obese patients before weight-loss surgery. Appropriate preoperative detection and correction is essential. The severity and pattern of deficiencies is dependent on the presence of preoperative uncorrected deficiency, the type of procedure performed varying with the degree of restriction or the length of bypassed small intestine, the modification of eating behavior, the development of complications, compliance with oral multivitamin and mineral supplementation, and compliance with follow-up. Rigorous control of fluids and electrolytes with establishment of adequate oral nutrition is important in the immediate postoperative period. Regular follow-up of the metabolic and nutritional status of the patient is essential, with life-long multivitamin and mineral supplementation.     

Nutritional concerns related to Roux-en-Y gastric bypass: what every clinician needs to know

Weight loss surgery, particularly the Roux-en-Y gastric bypass (REYGB), has become a popular treatment strategy for obesity. Often the only measure of success is the amount of weight lost following surgery. Unfortunately the nutritional adequacy of the postoperative diet has frequently been overlooked, and in the months to years that follow, nutritional deficiencies have become apparent, including protein-calorie malnutrition and various vitamin and mineral deficiencies contributing to medical illnesses and limiting optimal health. Therefore, patients require close monitoring following REYGB, with special regard to the rapidity of weight loss and vigilant screening for signs and symptoms of subclinical and clinical nutritional deficiencies. Several specific nutrients require close surveillance postoperatively to prevent life-threatening complications related to deficient states. This article addresses nutritional concerns associated with REYGB with fastidious focus on recognition and treatment of the nutritional deficiencies and promotion of nutritional health following REYGB. Recommendations regarding nutritional intake following REYGB are based on available scientific data, albeit limited. In cases where data do not exist, expert or consensus opinion is provided and recommendations for future research are given. Ultimately, clinical application of this information will contribute to the prevention of nutrition-related illness associated with REYGB.     

Vitamin therapy after heart transplantation

The need for routine nutritional supplementation with vitamins in most healthy individuals remains a matter of debate and current guidelines recommend that the need for these essential nutrients be met primarily through consuming an adequate diet. However, after heart transplantation, multiple factors, including the effects of prolonged debilitation prior to surgery and immunosuppression, may lead to physiological stress, which may justify consideration for vitamin supplementation. In general, clinical trials have not focused on vitamin supplementation after heart transplantation. There appears to be some limited clinical data to support the use of certain vitamins after heart transplantation. In particular, the putative antioxidant properties of vitamins C and E after heart transplantation may be beneficial as prophylaxis against cardiac allograft vasculopathy, and vitamin D, in conjunction with calcium, may help prevent post-transplant bone loss. Current guidelines only address the use of vitamin D after heart transplantation.     

Complications neurologiques périphériques après chirurgie bariatrique

Peripheral neuropathy is a rare but potentially very serious complications of bariatric surgery, which must be detected as early as possible, the axonal recovery seems to depend of care delay. Their frequency is estimated between 0.08 and 16%, they occur from 4 months to 14 years after surgery. The presentations are, in order of frequency; peripheral polyneuropathy because of micro-nutriment deficiencies (particularly vitamin B1 and B12, copper, and multiple deficiencies), and mono-neuropathy because of nerve compression with major and rapid weight loss, especially in diabetic patients. There is evidence to suggest a role for inflammation or an immunologic mechanism in neuropathy. Risk factors included amount of weight loss, prolonged gastrointestinal symptoms and postoperative surgical complications requiring hospitalization, not attending a nutritional support. Prognosis seems to depend of care delay. Routine monitoring of micronutrient levels and prompt recognition of neurological complications can reduce morbidity associated with these procedures and patients need to recognize alert symptoms as paresthesia, pain, and dizziness.     

Follow-up of nutritional and metabolic problems after bariatric surgery

Over the next several years, the number of patients who will have had bariatric surgery for morbid obesity will reach close to a million. Several well-described nutritional problems such as B12 and iron deficiency will be noted in these patients. Many of these patients will be lost to the original surgeon and will now be in the care of the "other physicians." These and other mineral and vitamin problems will need to be screened and treated. If these problems are left undiagnosed, severe and irreparable problems can result. Early problems, such as vomiting and dumping syndrome, will be easily recognized and treated, but other long-term problems, such as changes in bone metabolism, will need to be monitored. Again, if some of these long-term problems are not addressed in a timely fashion, then eventual treatment becomes much more difficult. This commentary will cover the common as well newer problems that are now developing in the patient who has had bariatric surgery. Patients who have undergone bariatric surgery require medical follow-up for reasons that are often determined by the type of surgical procedure performed. The majority of this review will deal with patients who have had the standard Roux-en-Y gastric bypass, which is a primarily restrictive procedure with a mild component of noncaloric malabsorption. At the end of this report, a short section will be devoted to the problems associated with the malabsorptive procedures.     

Presurgical evaluation and postoperative care for the bariatric patient

With the increasing number of bariatric surgeries being performed, multiple specialties encounter bariatric patients. This article gives an overview of the comprehensive evaluation and preoperative preparation of a bariatric patient. Medical, psychological, and behavioral evaluation is discussed. The role of routine preoperative endoscopy is controversial but can be very important and may alter the operation performed. Immediate postoperative care is also addressed. Undergoing bariatric surgery is a lifelong commitment, and frequent follow up with reinforcement and monitoring for nutritional deficiencies is extremely important.     

Nutritional support in critically ill patients with cancer

Nutritional depletion is a common problem seen in critically ill patients with cancer and is associated with increased morbidity and mortality. Infection and injury activate a cascade of metabolic events that leads to a poor nutritional state and wasteful energy consumption. The goals of nutritional support entail minimizing starvation, preventing nutrient deficiencies, supporting or improving immune function, and facilitating tissue repair and wound healing. Further understanding of the metabolic changes of illness will improve effective regulation of the inflammatory events occurring in critically ill patients. Multiple clinical parameters are available to assess the nutritional status in critically ill patients, but no standard recommendations can be made at this time. The use of these parameters can be appropriate, provided that their limitations are understood clearly. The development and standardization of objective parameters to identify patients at risk or with subclinical malnutrition are needed. Enteral and parenteral feedings are safe and effective methods to deliver nutrients to critically ill patients with cancer who are unable to ingest adequate amounts orally. Early nutritional support should be instituted in the appropriate clinical setting. Specialized nutritional solutions and supplements require careful consideration in patients with renal, hepatic, cardiac, or pulmonary disorders. The unselective use of nutritional support is not indicated in well-nourished patients with cancer undergoing surgery, chemotherapy, or radiotherapy in whom adequate oral intake is anticipated. Nutritional support remains an important adjunctive therapy in the overall management of critically ill patients. Continued clinical investigations in nutrition are necessary to identify other groups of patients who can benefit from nutritional interventions.     

Pharmacokinetics of methotrexate in Indian children and its relationship to nutritional status

Any significant change in the pharmacokinetics of an anticancer drug would have a bearing on its therapeutic efficacy and toxicity. Nutritional deficiencies have been shown to affect the pharmacokinetics of a drug. Since malnutrition and undernutrition are widely prevalent in India, the effect of initial nutritional status on the overall kinetics of methotrexate (MTX) administered to cancer patients appeared to be of practical importance. A study of 6 Indian children with malignancies was made to examine the pharmacokinetics of low dose MTX and its relationship to the nutritional status. The results indicate that the relative weight correlates well with the anthropometric parameters, nutritional parameters and dietary intake and may be used as a marker of nutritional status.     

The importance of nutritional care in HIV-infected children in resource-limited settings

Renewed efforts to provide proper nutritional care are essential for appropriate pediatric HIV management. Current studies support the use of vitamin A and macronutrients that increase caloric and protein intake. With additional research on key issues such as the needed composition and timing for nutritional supplementation, we can determine the best strategies to support the growth and development of HIV-infected children in resource-limited settings. Malnutrition among children is common in the resource-limited settings where HIV infection is most prevalent. While malnutrition is associated with higher morbidity and mortality for HIV-infected children, there is only limited evidence to guide the use of nutritional support for HIV-infected children. The best studied is vitamin A, which is associated with improved mortality and clinical outcomes. Zinc and multivitamin supplementation have not consistently been associated with clinical benefits. Limited research suggests macronutrient supplementation, which typically uses enriched formulas or foods, improves key anthropometrics for HIV-infected children, but the optimal composition of nutrients for supplementation has not been determined. More research is needed to understand the most efficient and sustainable ways to ensure adequate nutrition in this vulnerable population.     

炎症性肠病患者的营养支持治疗

溃疡性结肠炎和克罗恩病等炎症性肠病患者常伴有营养不良及生长发育障碍。营养支持治疗在炎症性肠病治疗中占有重要地位。应常规对炎症性肠病患者进行营养风险筛查,并采用适当方法进行营养评定,以便及时进行营养支持。肠内营养支持作为儿童克罗恩病患者诱导缓解和维持治疗的首选,在成人患者中作为药物的替代治疗。有多种营养制剂,不同患者对不同的营养制剂反应不同,需选择合适的制剂,进行个体化治疗,才能发挥营养制剂的最大效用。     

Syndromes carentiels sévères

The prevalence of vitamin deficiencies is underestimated. Risk factors for these deficiencies should be recognized in the intensive care unit. Some among these deficiencies can be fatal including Wernicke encephalopathy, shoshin beriberi, and scurvy; however they may recover dramatically with appropriate supplementation.