What is the preoperative workup for bariatric (bariatric surgery) surgery?

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From the Guidelines

A comprehensive bariatric surgery workup is essential to ensure patient safety and optimize outcomes, and should include a thorough medical assessment, cardiac evaluation, pulmonary function testing, psychological evaluation, nutritional counseling, and gastrointestinal evaluation, as recommended by the most recent guidelines 1.

Key Components of Bariatric Surgery Workup

  • Medical assessment: complete blood count, comprehensive metabolic panel, lipid profile, hemoglobin A1c, thyroid function tests, coagulation studies, and nutritional panels (including vitamin D, B12, folate, and iron studies) should be performed to identify any underlying conditions that may impact surgery outcomes 1.
  • Cardiac evaluation: an ECG and possibly stress testing or echocardiogram is necessary for patients with cardiac risk factors, as recommended by the American Heart Association 1.
  • Pulmonary function testing and sleep studies: recommended for those with respiratory symptoms or suspected sleep apnea to identify any potential respiratory complications.
  • Psychological evaluation: mandatory to assess understanding of the procedure, commitment to lifestyle changes, and to identify any eating disorders or mental health conditions that could impact outcomes.
  • Nutritional counseling: should occur over 3-6 months, with education on pre-operative diet (typically a 2-week very low-calorie diet of 800-1000 calories daily before surgery) and post-operative dietary progression, as recommended by the ERAS society 1.
  • Gastrointestinal evaluation: upper endoscopy is often performed to rule out pathology like H. pylori infection, which should be treated before surgery.

Preoperative Weight Loss

  • A 2-4 week period of low-calorie diet (1000-1200 kcal/d) or very low-calorie diet (800 kcal/d) is usually recommended prior to bariatric surgery to reduce liver volume and improve surgical outcomes 1.
  • Preoperative weight loss has been associated with reduced postoperative complications and improved postoperative weight loss, although the optimal composition of preoperative low-calorie diet is yet to be determined.

Importance of Comprehensive Workup

  • A comprehensive bariatric surgery workup helps identify contraindications, reduces surgical risks, and prepares patients for the significant lifestyle changes required for long-term success after bariatric surgery.
  • The workup should be tailored to the individual patient's needs and risk factors, and should be performed by a multidisciplinary team of healthcare professionals, including a specialist dietitian, as recommended by the British Obesity and Metabolic Surgery Society 1.

From the Research

Bariatric Surgery Workup

  • Bariatric surgery is a safe and effective treatment for morbid obesity and related metabolic diseases, but it requires careful selection, extensive evaluation, and optimization of patients to achieve optimal outcomes 2.
  • A multidisciplinary, comprehensive, and timely assessment preoperatively is crucial due to the unique and challenging issues in this patient population, including medical, psychiatric, and psychological comorbidities 2, 3.
  • The preoperative evaluation should include:
    • Comprehensive patient education about surgical outcomes and postoperative behavioral regimen 4.
    • Complete medical evaluation, including cardiovascular, pulmonary, and gastrointestinal systems, as well as metabolic status assessment 4.
    • Nutritional assessment, preoperative weight loss efforts, and diet education regarding postoperative eating behaviors 4.
    • Psychological evaluation to assess psychosocial factors that impact long-term outcomes, including adherence to recommended postoperative lifestyle regimen, emotional adjustment, and weight loss outcomes 4, 3.
    • Preoperative abdominal ultrasound to assess for biliary tract pathology, steatosis, fibrosis, and presence of nonalcoholic steatohepatitis 4.
    • Routine preoperative esophagogastroduodenoscopy to evaluate common gastrointestinal disorders associated with obesity 4.
  • Preoperative weight loss should be strongly encouraged 4.
  • Patients at high risk for hepatic failure after bariatric surgery should be better evaluated preoperatively, and a tailor-made approach should be applied to avoid disastrous complications 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

A focus on surgical preoperative evaluation of the bariatric patient--the Cleveland Clinic protocol and review of the literature.

The surgeon : journal of the Royal Colleges of Surgeons of Edinburgh and Ireland, 2011

Research

Preoperative Evaluation in Bariatric Surgery.

Journal of laparoendoscopic & advanced surgical techniques. Part A, 2018

Research

Bariatric surgery: blessing or sometimes curse for the liver?

Przeglad menopauzalny = Menopause review, 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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