Preoperative Evaluation of the Bariatric Surgery Patient

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Preoperative Evaluation of the Bariatric Surgery
Patient

• Eric I. Rosenberg, MD, MSPH, FACP

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Case 1

• . . . evaluate for metabolic disorder

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Super Super Morbid Obesity

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

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

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

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Prior Studies 8 months prior
Ca 9
141
106
25
TSH 3.7
84
3.8
0.7
28
11.9
Chest X-ray normal ECG normal
282
9.3
36
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Differential Dx for Severe Obesity

• Dietary
• Social/Behavioral
• Inactivity
• Iatrogenic
• Neuro-endocrine

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What would you do next?
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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?

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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?

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Severe Obesity BMI 40
NHLBI 2000
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Treatment Guidelines for Obesity
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Prevalence of Severe Obesity is Increasing
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Pharmacotherapy only 3 to 5 kg Average Weight
Loss
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Bariatric Surgery Reduces Obesity-Associated
Morbidity
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Surgery May Improve Longevity
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Ideal Bariatric Surgery Candidates
Cleve Clin J Med 200673(11).
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HMO/Medicare Payment for Bariatric Surgery

• BMI gt 40 for 2 to 5 years
• BMI gt 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

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Roux-en-Y Combines Restriction with Malabsorption
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Acute Complication Rates for Bariatric Surgery
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Long Term Complications

• Anastomotic Stricture
• Marginal ulcers
• Bowel obstruction
• Cholelithiasis
• Nutritional Deficiencies

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Nutritional Deficiencies are Common after
Malabsorptive Procedures

• Iron
• Vitamin B-12
• Calcium
• Vitamin D

Multitamins will not adequately treat iron and
B-12 deficiencies
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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?

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Possible Metabolic Causes of Obesity in Our
Patient

• Hypothyroidism
• Hypothalamic condition
• Cushings Syndrome
• Polycystic Ovarian Syndrome
• Pseudohypoparathyroidism

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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.
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But Could She Have Cushings Syndrome?

• Physical exam suggestive of hypercortisolism
• From severe obesity?
• From psychiatric distress?
• From alcoholism?
• No history of glucocorticoid use

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Prevalence of Clinical Features of Cushings
Syndrome

• Obesity (90)
• Neuropsychiatric (85)
• Hirsutism (75)
• Bruising (35)
• Hypertension (85)
• Diabetes (20)

Greenspans Basic and Clinical Endocrinology, 8th
Edition.
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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

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Accuracy of Screening Tests for Cushings Syndrome
J Clin Endocrinol Metab 882003.
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My Clinical Suspicion was High Enough to Screen
for Cushings

• RECOMMENDATIONS
• I ordered a midnight salivary cortisol test
  which is very sensitive and has high negative
  predictive value.

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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

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8 Months later

• Test 1 0.155 ug/dL (normal lt0.112)
• Test 2 quantity not sufficient
• Test 3 quantity not sufficient
• Test 4 quantity not sufficient
• Endocrine referral

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Dexamethasone Suppression Test Rules-Out Cushings

• 1mg Dexamethasone at 11PM to 12AM
• 8AM Cortisol level
• 1mcg/dL
• lt8 of patients with Cushings show suppression
  to lt 2 mcg/dL
• 100 sensitivity if suppress to less than 1.2
  mcg/dL

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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