Condition
Bariatric Surgery in Adults
Editors: Kamran Samakar MD, MA, FACS, FASMBS; Roberto A. Martinez MD; Assar A. Rather MD, FACS, FASCRS; Fatima Cody Stanford MD, MPH, MPA, FAAP, FACP, FAHA, FTOS
Background Information
Description
- Bariatric operations alter the gastrointestinal tract and produce weight loss by restricting food intake and/or creating conditions for malabsorption.
- Bariatric surgery is usually reserved for patients with severe obesity for whom other treatments have failed and/or who have complications of severe obesity.
- Bariatric surgery can result in significant and durable weight loss and improvement or remission of comorbid conditions and survival.
Definitions
- Obesity is usually defined as a body mass index (BMI) of ≥ 30 kg/m2.
- 'BMI' is defined as weight in kg divided by the square of height in meters. See also a BMI calculator.
- 'Overweight' is defined as a BMI of 25-29.9 kg/m2.
- Obesity is categorized into 3 classes. Class 1 (mild) obesity is a BMI of 30-34.9 kg/m2, class 2 (moderate) obesity is a BMI of 35-39.9 kg/m2, and class 3 (severe) obesity, previously called morbid obesity, is a BMI of ≥ 40 kg/m2.
- Reference - Obes Res 1998 Sep;6 Suppl 2:51S, commentary can be found in Obes Res 1998 Nov;6(6):461
- Clinically severe obesity can also be defined as a BMI of ≥ 35 kg/m2 with comorbid conditions.
- Dumping syndrome is a complication of bariatric surgery characterized by symptoms such as nausea, flushing, sweating, light-headedness, and diarrhea after eating, particularly sweets or carbohydrates, due to the rapid emptying of the stomach contents into the small intestine (Dig Dis Sci 2016 Jan;61(1):11).
- 'Early' dumping occurs 30-60 minutes after eating (Dig Dis Sci 2016 Jan;61(1):11).
- 'Late' dumping occurs 1-3 hours after a meal (Dig Dis Sci 2016 Jan;61(1):11).
- Vertical sleeve gastrectomy may have a lower risk of dumping syndrome than Roux-en-Y gastric bypass (Mol Aspects Med 2013 Feb;34(1):84).
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DynaMed Levels of Evidence
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DynaMed provides easy-to-interpret Level of Evidence labels so users can quickly find and determine the quality of the best available evidence. Evidence may be labeled in one of three levels:
1Level 1 (likely reliable) Evidence
2Level 2 (mid-level) Evidence
3Level 3 (lacking direct) Evidence
Grades of Recommendation
Guideline producers are now frequently using classification approaches for their evidence and recommendations, and these classifications are recognized and requested by guideline users. When summarizing guideline recommendations for DynaMed users, the DynaMed Editors are using the guideline-specific classifications and providing guideline classification approach when this is done.
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