Morbid Obesity and Gastric Bypass

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

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

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 50% are more likely to be obese

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

Heart Disease Hypertension twice as common Increased risk: MI, CHF, Sudden Death, Arrythmias. BMI greater than 25.

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

Respiratory Sleep Apnea Obesity Hypoventilation Syndrome Asthma Decreased FRC Increased risk of aspiration from GERD Difficult airways (ventilate and intubate) Decreased FRC translates into quicker desaturation

Other Arthritis Reproductive complications Gallbladder disease. Depression, Social Discrimination

What is BMI? Body Mass Index BMI=weight (kg) / height (m2) BMI=pounds/inches 2 x 703 Why BMI? A panel convened by the NIH in 1998recommended that BMI be used to classify overweight and obesity. Simple rapid and cheap

Classification Healthy Weight 18.5-24.9 Overweight 25.0-29.9 Obesity Class II 35-39.9 Class III >40

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

Surgery Aspect Indications Types Results Complications

Indications Age 18-60 BMI > 40 BMI > 35 with medical problems Exhausted other venues of weight loss For example this beautifiul girls have NOT exhausted their venus to loss weight e.i. Excersice, diet, medications

Types of Surgery

How do they work? Restrictive Malabsorption Behavioral modification

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

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

Anesthesia Pre-Op Intra-Op Post-Op

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

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

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

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

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

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

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

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

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)

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

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

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

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….

NOT KNOWN

Post Op Extubation Post Op Pain OSA and OHS Cardiac

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

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

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

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