Morbid Obesity and Gastric Bypass

1. Morbid Obesity and Gastric Bypass Diego Gonzalez M.D. Metrohealth Medical Center Cleveland, Ohio November 4, 2002

2. Fun Facts • 61% of adults in US have BMI >25 in ’99 • 13% of children 6-11 • 14% of adolescents aged 12-19 • How many deaths in the US are associated with obesity? • Economic Cost? • National Institute of Health. Call to Action Report

3. Deaths and Cost • 300,000 deaths per year • BMI >30 have a 50%-100% increased risk of premature death. • 117 BILLION dollars in 2000 • National Institute of Health. Call to Action Report

4. More Fun Facts • More non-Hispanic white women(23%) are obese compared to non-Hispanic white men(21%) • Most affected-women are of low socioeconomic. • National Institute of Health. Call to Action Report

5. Taco Bell? • Mexican american boys tend to have higher prevalence of overweight. • National Institute of Health. Call to Action Report 1998

7. Heart Disease • Hypertension twice as common • Increased risk: MI, CHF, Sudden Death, Arrythmias.

8. Diabetes • A gain of 11-18 lbs increases the risk of developing Type 2 to twice that of normal individuals • Over 80% of people with DM type 2 are overweight or obese

9. Respiratory • Sleep Apnea • Obesity Hypoventilation Syndrome • Asthma • Decreased FRC • Increased risk of aspiration from GERD • Difficult airways (ventilate and intubate)

10. Other • Arthritis • Reproductive complications • Gallbladder disease. • Depression, Social Discrimination

11. What is BMI? • Body Mass Index • BMI=weight (kg) / height (m2) • BMI=pounds/inches 2 x 703 • Why BMI?

12. Classification • Healthy Weight 18.5-24.9 • Overweight 25.0-29.9 • Obesity • Class I 30.0-34.9 • Class II 35-39.9 • Class III >40

13. Limitations to BMI….really? • Overestimate body fat in persons who are very muscular i.e. body builders • Underestimate body fat in persons who have lost muscle mass i.e. elderly

14. Surgery Aspect • Indications • Types • Results • Complications

15. Indications • Age 18-60 • BMI > 40 • BMI > 35 with medical problems • Exhausted other venues of weight loss

16. Types of Surgery

17. How do they work? • Restrictive • Malabsorption • Behavioral modification

19. Results • Weight Loss- 66% at 1 to 2 years after surgery • 60% at 5 years • 50% at 10 years • African-american lose significantly less weight…why? • Improvement in comorbities

20. Complications • Akin to any surgery i.e. infection, DVT, wound deshicense, anastomotic leaks, etc. • Death 1%-2% after surgery, but higher with other comorbities. • Irritable bowel syndrome ….can lead to rectal problems

21. Anesthesia • Pre-Op • Intra-Op • Post-Op

22. Pre-Op/ History • History and Physical • ROS • Airway • Heart • Lungs • Eyes… eyes?… yes eyes • Previous anesthesia

23. Airway • Mallampati, mouth opening, tongue size, thyromental distance, sternomental distance, neck circumference • Predictibility of difficult intubation: neither obesity or BMI predicted problems with tracheal intubation… BUT HIGH MALLAMPATI SCORE >3 and LARGE NECK CIRCUMFERENCE MAY INCREASE THE POTENTIAL FOR DIFFICULT LARYNGOSCOPY AND INTUBATION • Anesthesia and Analgesia, Mar 2002. 732-736

24. Cardiovascular • HTN: multiple medications difficult to control • Cardiomyopathy, CHF, Ischemia, CVA, Pulmonary HT, DVT, PE, Hypercholesterolemia, Hypertriglyceridimia

25. Obesity Cardiomyopathy • Patients with severe and long standing obesity • LVH, left ventricle dilation and LV diastolic dysfunction. • Left Ventricle Failure and Right Ventricle Failure = Obesity Cardiomyopathy • Causes of death are CHF and sudden cardiac death

26. Lungs/ OSA • OSA- hypersomnolence, loud snoring, apnea and hypopnea during sleep • Physiologic changes: • Arterial hypoxemia • Polycythemia • Arterial Hypercarbia • HTN • Pulmonary hypertension

27. Lungs/ OSA • Risk Factors: • Male • Middle Age • Obesity • Alcohol • Drug Induced Sleep

28. Lungs/OHS • Obesity Hypoventilation Syndrome is defined as: • PaO2 < 70 • PaCO2 > 45 • BMI > 30 kg/m2 • No other respiratory disease of explaining the gas anomaly

29. Lungs/OHS • Why is there hypoventilation? • 1. High cost of work of respiration • 2. Dysfunction of the respiratory center • 3. Repeated episodes of nocturnal obstructive apnea

30. Lungs/OHS • Physiologic Changes: • Hypersomnolence (also OSA) • Arterial Hypoxemia (also OSA) • Polycythemia (also OSA) • Hypercarbia (also OSA) • Respiratory acidosis • Pulmonary hypertension (also OSA) • RV Failure (also OSA)

31. Lungs/OHS • Some say that OHS progress into OSA • Some say that they are different entities. • Who is right? • OHS are usually: • Older, more obese, more deranged daytime ABG values, more restricted lung volume, more severe desaturation during sleep. • Chest, 2001:120:336-339

32. Lungs/ OSA vrs OHS • Chicken or the egg? • A spectrum of the same disease?

33. Eyes • Hypoxia and hypercarbia as a sign of angiogenesis • Case Report , Elia J. Duh, AMA-Assn.org

34. Intra Operative • GA vrs TIVA • GA supplemented with regional • Fast onset and fast offset medication • Good muscle paralysis • Calculate drug doses according to IBW • Best choice of maintenance is….

35. NOT KNOWN

36. Post Op • Extubation • Post Op Pain • OSA and OHS • Cardiac

37. Post Op/Extubation • Fully awake • Recover in head up positioning • Monitoring very important if OSA or OHS

38. Post Op/Extubation Maximun decrease in PaO2 is 2-3 days post op. Mechanical weaning can be difficult b/c: 1. Increased work of breathing 2. Decresed lung volumes 3. V/Q mismatch

39. Pain Control and OSA • Pt with OSA have a exquist sensibility to narcotics, even when used in regional techniques. • Narcotics can have depressive effects up to 2-3 days post op

40. Post Op/ Others • Others: • DVT early ambulation/ heparin • Wound infection is twice as common • Guillain-Barre • Case Report: Chang; Obes Surg 2002 Aug; 12(4) 592-97

41. Daddies little girl…Ana Isabel