Bariatric Flashcards
What is the definition of obesity?
A chronic, often progressive metabolic disease associated with increased morbidity and mortality
What is obesity a disorder of?
Body weight regulation
What subset of the population is least likely to be obese?
High income with the most education
What environmental factors can contribute to the prevalence of obesity?
Built environment - encourages or discourages physical activity
Food environment - encourages or discourages healthy eating
What health hazards are linked to obesity?
Type 2 diabetes mellitus
Heart disease
Stroke
Cancer
Osteoarthritis
Liver disease
Depression
What respiratory health hazards are linked to obesity?
Asthma
Obstructive sleep apnea
Obesity hypoventilation syndrome
Describe airway smooth muscle in lean people vs obese people
Lean = long and compliant
Obese = short and stiff
Which lung volume changes the most in the obese?
Expiratory reserve volume
How does obesity increase the work of breathing?
Chest wall is heavy and inhibits chest expansion
How is asthma in obese patients different in lean patients?
Asthma in obese patients is more difficult to treat
Patients with obesity have been shown to get decreased benefit from standard asthma treatment
Define obstructive sleep apnea
Repetitive episodes of apnea or reduced inspiratory airflow due to upper airway obstruction during sleep
What causes sleep apnea?
Loss of muscle tone with sleep
What are the characteristics of obstructive sleep apnea?
Loud snoring
Episodes of breathing cessation during sleep
Elbow sign
Abrupt awakenings accompanied by shortness of breath
Difficulty staying asleep
Frequent trips to the bathroom at night
Night sweats
What are some symptoms people with OSA may experience upon waking?
Dry mouth
Sore throat
Morning headache
Nausea
Excessive daytime sleepiness
What are the mental and psychological effects of sleep apnea?
Memory impairment
Difficulty concentrating
Moodiness or irritability
Intellectual and personality changes
Depression
Sexual impotence
What does OSA elevate the risk of?
Cardiovascular comorbidity and mortality
What are the three types of sleep apnea?
Obstructive
Central
Mixed
Define apnea
Cessation of airflow or aflow < 10% preevent baseline for duration of >10 seconds
Define hypopnea
Airflow decreased >30% of pre-event baseline for a duration of >10 seconds accompanied by >3% decline in SpO2 from pre-event baseline
What qualifies as mild, moderate and severe OSA?
Mild = 5-15 respiratory events per hour of sleep
Moderate = 15-30
Severe > 30
What are the treatment options for OSA?
Behavior modification
Positive airway pressure
Oral appliances
Surgery
Implantable upper airway stimulator
Describe obesity hypoventilation syndrome
An awake alveolar hypoventilation in an obese individual that cannot be attributed to other conditions associated with alveolar hypoventilation
When should you expect a patient to have obesity hypoventilation syndrome
BMI > 30
Bicarb > 27
PaCO2 > 45 mmHg
What other diseases are associated with obesity hypoventilation syndrome?
Pulmonary hypertension
Hypertension
Congestive heart failure
Insulin resistance
What procedures are complicated by a patient who is obese?
Bag mask ventilation
Difficult airway to intubate
Aspiration risk
What capacity is reduced in obese populations?
Functional reserve capacity
What practices should be included when mechanically ventilating an obese patient?
Target Vt to PBW
Maintain lung protective strategies
Increase PEEP to offset the weight of the chest
Elevate head of bed
Consider early extubation to NIV
Besides being difficult to intubate, what is another risk associated with intubating an obese patient?
They tend to desaturate faster
What is the relationship between obesity and clot formation?
Obese patients have an increased risk of DVT
Increased risk for DVT increases risk of pulmonary embolism
What are respiratory risks associated with surgical operations on obese patients?
Increased risk of V/Q mismatch
Increased risk of atelectasis
Delayed pulmonary recovery from surgery
What support do patients require prior to bariatric surgery?
Nutrition
Psychological counseling
Lifestyle modifications
Realistic expectations
Knowledge of risks
What are the 3 principles that must be considered for bariatric surgery?
Restriction
Malabsorption
Combination of restriction and malabsorption
What are the options for restricting caloric intake by reducing the stomach capacity?
Resect
Bypass
Create a proximal gastric outlet
Absorption function of small intestine remains intact
What are the options for limiting absorption?
Reduce the length of the functional small intestine
Bypass small bowel absorptive surface area
What are the most common bariatric surgeries?
Sleeve gastrectomy
Roux en y
What are the risks associated with malabsorption techniques?
Protein calorie malnutrition
Micronutrient deficiencies
Describe a sleeve gastrectomy
Majority of bariatric surgeries
Removes curvature of the stomach
Creates a tubular stomach
What are the hormonal effects of a sleeve gastrectomy?
Decrease hunger
Insulin resistance improves for better glycemic control
Describe the roux en y procedure
Combination of restriction and malabsorption
Decreases size of stomach
Reduces length of small intestine
