Anesthetic Considerations for Obesity and Surgery Flashcards
What diseases are obese people at risk for?
CAD HTN CA Cerebrovascular dx Hyperlipidemia DM Gall bladder dx DJD OSA OHS Socioeconomic and psychological impairment
What BMI is low-risk for developing 1 or more comorbidity?
25-30 kg/m2
What BMI is high-risk for developing 1 or more comorbidity?
> 40 kg/m2
What is a major factor in anesthesia we consider with obesity?
difficult airway management
Majority of extubation or recovery claims were associated with _________, obesity, and/or ______.
difficult intubation on induction, OSA
What is Broca’s index?
most practical way to figure IBW
How can you calculate IBW for a male?
ht (cm) - 100
How can you calculate IBW for a female?
ht (cm) - 105
What are the NIH grades of obesity?
Grade I: BMI 26-29 kg/m2
Grade II: BMI 30-30.9 kg/m2
Grade III: BMI >40 kg/m2
What are the classifications of obesity?
Normal: 24-26 kg/m2 Mild: 27-30 kg/m2 Moderate: 31-35 kg/m2 Severe/morbid: >35 kg/m2 Super morbid: >55 kg/m2
What are some psychological impacts of obesity?
low self-esteen
distorted self image
depression
discrimination from public and healthcare providers
perpetuation of obesity from all the above
What are some characteristics of central/android/abdominal/”apple”?
- “at risk” waist/hip ratio: male>0.95, female >0.80
- > myocardial fat content
- increased incidence of ischemic CV disease, cerebrovascular disease, NIDDM, certain cancers, and death
- risks independent of total adipose mass
What are some characteristics of peripheral/gynecoid/gluteal femoral/”pear”?
- waist/hip ratio
With which gender is android fat distribution more common?
male
What does it mean when fat is metabolically active with regard to free fatty acid release (FFA)?
With high FFA levels delivered to liver, get stimulation of hepatic synthesis of very-low density lipoproteins (VLDL) and increased circulation of low density lipoproteins (LDL); hepatic exposure to high FFA levels causes glyconeogenesis and inhibition of insulin uptake causing NIDDM; increased myocardial fat content + decreased contractility correlates positively with higher waist-to-hip ratio and serum free fatty acid concentration
What are the myocardial changes with obese normotensive patients?
Increased preload = myocardial volume increases more than wall thickness (eccentric hypertrophy)
What are the myocardial changes with obese hypertensive patients?
Increased preload and afterload with periods of hypoxemia = LV dilation and wall stress leading to both eccentric and concentric hypertrophic changes, but concentric >eccentric
How much does your cardiac output increase per kg of body fat?
0.1 L/kg of body fat
What are myocardial changes with a lean hypertensive patient?
increased afterload = increased wall thickness + diminished volume (concentric hypertrophy)
What is the “bottom line” for obesity and cardiovascular diseasE?
obesity + hypoxia leads to heart disease and increased risk of sudden death
What are some pulmonary complications of obesity?
restrictive lung disease patterns asthma difficult airway OSA Pickwickian
What is obesity-hypoventilation system?
worsening severe sleep apnea which leads to loss of hypercarbic drive, hypersomnolence, increased DAW
What are the characteristics associated with Pickwickian syndrome?
hypercarbia, hypoxemia, polycythemia, hypersomnolence, pulmonary HTN, biventricular failure
What is metabolic syndrome?
characterized by obesity, hypertension, and diabetes; increased risk of CAD and stroke
