|
|
|
|
|
|
 |
 |
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
|
Weighing the risks of a bariatric procedureEdward D. Huechtker, MPA, PA-CMr. Huechtker is Chair, Department of Critical Care, School of Health Related Professions, University of Alabama at Birmingham, and holds adjunct appointments at the Medical College of Georgia, Augusta, and Duke University School of Nursing, Durham, NC. The author has indicated no relationships to disclose relating to the content of this article.Weight-reduction surgery succeeds because it restricts how much the patient can eat—which, in turn, can lead to iron, folate, calcium, and vitamin B12 deficiencies, often within months of surgery. Patients who undergo weight-loss surgery usually work with a nutritionist or dietitian before and after surgery to develop and maintain a proper diet and supplement program to accommodate the new digestive configuration. Nevertheless, serious complications following these procedures are possible—including nutritional deficiencies that can lead to neurologic complications and altered mental status. Clinicians in primary care and emergency medicine should know when to include nutritional causes in the differential diagnosis of a patient who has had weight-loss surgery. The Roux-en-Y gastric bypass is currently the most commonly performed procedure, and it is both restrictive and malabsorptive. This surgery initially reduces the stomach from a normal capacity of approximately 32 oz to several tablespoons, although it can later stretch to hold up to 4 to 8 oz. The reduced capacity means that the patient eats less, a behavior that usually results in the desired weight loss but also in fewer nutrients consumed. Nutritional deficiencies can cause serious complications but are preventable in many patients (see "Avoiding vitamin and mineral deficiencies.") The opening between the stomach and small intestine is also reduced, which slows the emptying of the stomach, giving the patient an early feeling of satiety. In addition, less gastrin is available for digestion and for conversion of ferrous iron to the more absorbable form of ferric iron.1 The duodenal bypass prevents iron absorption in the duodenum, increasing the risk for iron deficiency anemia; many patients have a hypochromic microcytic anemia. Premenopausal women are even more prone to iron deficiency anemia and further suffer from vitamin B12 deficiency. In addition, malabsorption of calcium may contribute to osteoporosis. Nutritional considerationsFollowing the Roux-en-Y procedure, patients initially are restricted to clear liquids early after the surgery, drinking often to prevent dehydration. As the pouch stretches and the surgical site heals, the patient can begin to ingest other fluids, then pureed foods, and finally solid food. Patients should not drink while eating, which can result in the pouch filling too quickly with beverages that are not nutrient rich. The patient's diet progresses from clear liquids for the first 1 to 2 days to nutrient-rich meal replacement drinks such as Ensure, Sustacal, or Carnation Instant Breakfast, consumed until this diet is well tolerated, usually 1 to 2 weeks. The third stage is soft or pureed foods that are high in protein, such as scrambled eggs, low-fat cheese, small curd cottage cheese, and pureed meats. Some patients prefer baby food. Most patients can begin a regular gastric bypass diet, eating four to six small meals daily from all food groups, approximately 8 weeks after surgery. Nausea and vomiting are common initially but typically last only a day or so as the patient learns to eat slowly and chew food thoroughly. Vomiting can exacerbate protein and calorie deficiencies, causing the surgical site to heal slowly. Fats should be avoided because they are difficult to digest, as should high-fiber foods that tend to fill the pouch quickly and can block the smaller opening to the intestines. Carbonated beverages may be poorly tolerated. Foods that contain large amounts of sugar and fat are also high in calories; even small amounts of these calorie-dense foods can impede weight loss. In addition, too much sugar can cause the unpleasant dumping syndrome, a physiologic response to sugar characterized by sweating, shakiness, dizziness, rapid heart rate, and severe diarrhea. Experiencing the dumping syndrome often teaches the patient to avoid foods high in sugar. Avoiding vitamin and mineral deficienciesPoor nutrition can result if the patient does not consume foods that contain adequate amounts of necessary vitamins and minerals. Common problems, which can develop within months of surgery, include deficiencies of iron, folate, calcium, vitamin B12, and other vitamins and minerals. These deficiencies can cause anemia, osteoporosis, neurologic deficits, hair loss, and muscle wasting. Double vision, confusion, memory impairment, disorientation, and leg weakness have been reported as resulting from nutritional deficits following weight-loss surgery. Because the postsurgical diet does not provide adequate vitamins and minerals, one adult or two children's chewable multivitamin tablets are recommended, in addition to iron, calcium, and B12 supplementation. Women who become pregnant after weight-loss surgery have an additional reason to follow a good nutritional plan with appropriate vitamin and mineral supplementation. Some obstetric practices categorize pregnancy in women who have had gastric bypass surgery as high risk. Additional risks of bariatric surgery include possible follow-up surgery, such as an operation to correct an abdominal hernia following an open procedure or some other complication. Although the laparoscopic approach to bariatric surgery may avoid abdominal hernia, laparoscopy is often not appropriate for patients who weigh 350 lb or more or who have undergone previous abdominal surgery. Less common complications include breakdown of the staple line and stretched stomach outlets. In addition, some patients who have weight-loss surgery experience gallstones, which can develop following rapid or substantial weight loss, even in persons who have not undergone surgery. Taking supplemental bile salts for the first 6 months postoperatively can prevent gallstones.2 REFERENCES 1. Elliot K. Nutritional considerations after bariatric surgery. Crit Care Nurs Q. April-June 2003;26:133-138. 2. Gastrointestinal surgery for severe obesity. US Departmentof Health and Human Services, National Institutes of Health. December 2001. NIH publication 01-4006. Available at: http://www.niddk.nih.gov/health/nutrit/pubs/gastric/gastricsurgery.htm . Accessed March 12, 2004.
|
