Preoperative Evaluation of the Bariatric Surgery Patient Eric I. Rosenberg, MD, MSPH, FACP

Case #1... evaluate for metabolic disorder

Super Super Morbid Obesity 53 year-old woman 399 lbs, 4 10, BMI 83.3 Bariatric surgeon notes central obesity, abdominal bruises, buffalo hump

History PMHx:Catatonic schizophrenia Bipolar Disorder PGynHx:G2 P2 Meds: Allergies: Fluoxetine, Risperidone Ø FH:Ø SH: ROS: Disabled; some EtOH Venous stasis, cellulitis

Exam BP 147/73, P 83 Flat affect Moon facies Buffalo hump No muscle wasting, no striae, no bruising

Prior Studies – 8 months prior TSH Ca + 9 Chest X-ray: normal ECG: normal

Differential Dx for Severe Obesity Dietary Social/Behavioral Inactivity Iatrogenic Neuro-endocrine

What would you do next?

Key Issues for Bariatric Pre-Operative Evaluation When should you suspect a non-lifestyle associated etiology for morbid obesity? What is the most efficient diagnostic strategy to evaluate for a neuro-hormonal cause? What are the most important medical risks to this patient if she undergoes bariatric surgery?

Key Issues for Bariatric Pre-Operative Evaluation When should you suspect a non-lifestyle associated etiology for morbid obesity? What is the most efficient diagnostic strategy to evaluate for a neuro-hormonal cause? What are the most important medical risks to this patient if she undergoes bariatric surgery?

Severe Obesity = BMI 40 NHLBI 2000

Treatment Guidelines for Obesity

Prevalence of Severe Obesity is Increasing

Pharmacotherapy: only 3 to 5 kg Average Weight Loss

Bariatric Surgery Reduces Obesity-Associated Morbidity

Surgery May Improve Longevity

Ideal Bariatric Surgery Candidates Cleve Clin J Med 2006;73(11).

HMO/Medicare Payment for Bariatric Surgery BMI > 40 for 2 to 5 years –BMI > 35 if CAD, DM, HTN, sleep apnea Repeated failures of supervised weight loss (6 months duration) Letter of medical necessity Treatable metabolic causes ruled out –Thyroid panel –adrenal disorders

Roux-en-Y Combines Restriction with Malabsorption

Acute Complication Rates for Bariatric Surgery

Long Term Complications Anastomotic Stricture Marginal ulcers Bowel obstruction Cholelithiasis Nutritional Deficiencies

Nutritional Deficiencies are Common after Malabsorptive Procedures Iron Vitamin B-12 Calcium Vitamin D Multitamins will not adequately treat iron and B-12 deficiencies

Key Issues for Bariatric Pre-Operative Evaluation When should you suspect a non-lifestyle associated etiology for morbid obesity? What is the most efficient diagnostic strategy to evaluate for a neuro-hormonal cause? What are the most important medical risks to this patient if she undergoes bariatric surgery?

Possible Metabolic Causes of Obesity in Our Patient Hypothyroidism Hypothalamic condition Cushings Syndrome Polycystic Ovarian Syndrome Pseudohypoparathyroidism

This was my non-clearance… IMPRESSION: A 53-year-old white female without any history of cardiopulmonary disease. Given her lifelong history of morbid obesity in association with and lack of history of diabetes and hypertension, I think it is unlikely that she has Cushing disease or other underlying metabolic disorder…. I think she is at high risk for perioperative delirium given her significant psychiatric history. I think that the surgical team will need to be cautious with administration of narcotics or hypnotics/sedatives.

But Could She Have Cushings Syndrome? Physical exam suggestive of hypercortisolism –From severe obesity? –From psychiatric distress? –From alcoholism? No history of glucocorticoid use

Prevalence of Clinical Features of Cushings Syndrome Obesity (90%) Neuropsychiatric (85%) Hirsutism (75%) Bruising (35%) Hypertension (85%) Diabetes (20%) Greenspans Basic and Clinical Endocrinology, 8 th Edition.

Validity of Standard Screening Tests for Cushings Syndrome Elevated midnight serum cortisol –96-100% sensitivity, 100% specificity Overnight Dexamethasone Suppression –90-100% sensitivity, 40% specificity Elevated 24-hour urinary cortisol excretion –100% sensitivity, 98% specificity

Accuracy of Screening Tests for Cushings Syndrome J Clin Endocrinol Metab 88:2003.

My Clinical Suspicion was High Enough to Screen for Cushings RECOMMENDATIONS: 1)I ordered a midnight salivary cortisol test which is very sensitive and has high negative predictive value.

Recommended Preoperative Testing for Bariatric Surgery Hematocrit Baseline Iron, B-12 levels TSH A1c (if diabetic control in doubt) Creatinine if appropriate Baseline ECG and other cardiopulmonary testing if suspect undiagnosed disease

8 Months later… Test #1: ug/dL (normal <0.112) Test #2: quantity not sufficient Test #3: quantity not sufficient Test #4: quantity not sufficient Endocrine referral

Dexamethasone Suppression Test Rules-Out Cushings 1mg Dexamethasone at 11PM to 12AM 8AM Cortisol level –1mcg/dL <8% of patients with Cushings show suppression to < 2 mcg/dL 100% sensitivity if suppress to less than 1.2 mcg/dL

Take-Home Points Severe Obesity is increasingly prevalent Bariatric Surgery will increase in popularity Prospective Bariatric Surgery Patients need careful risk assessment and long-term follow- up for complications Consider appropriate screening for secondary causes if patient presents with characteristic history, signs