Anesthesia for Bariatric Surgery

Question 1

There are syndromes that are associated with obesity, including …

Answer 1

leptin deficiency, Prader–Willi syndrome, and Lawrence–Moon–Biedl syndrome

Question 2

Clinical Criteria for Diagnosing Metabolic Syndrome

Answer 2

3 of the following:

• Central obesity:
  Waist circumference >102 cm in men
  Waist circumference >88 cm in women
• Triglycerides >150 mg/dL (1.7 mmol/L), or Specific treatment for this lipid abnormality
• High-density lipoprotein cholesterol <40 mg/dL (1.03 mmol/L) in men, or <50 mg/dL (1.29 mmol/L) in women, or
  Specific treatment for this lipid abnormality
• Blood pressure Systolic blood pressure ≥130 mm Hg, or Diastolic blood pressure ≥85 mm Hg, or Are taking blood pressure medications
• Fasting glucose ≥100 mg/dL (5.6 mmol/L), or Are taking glucose-lowering medications

Question 3

… used to treat human immunodeficiency virus (HIV) infection can induce metabolic syndrome secondary to insulin resistance

Answer 3

Protease inhibitors (Indinavir and Lopinavir/ritonavir)

Question 4

Metabolic syndrome is resolved by bariatric surgery in over …% of patients who achieve the expected weight loss

Answer 4

95

Question 5

Inflammatory processes appear to play an important role in the metabolic syndrome. Adipose tissue has two major functions: storage and release of … and secretion of proteins required for endocrine and autocrine regulation of energy metabolism.

Adipocytes exert their metabolic effects by release of …, whose release is enhanced by the presence of … .

Visceral adipose tissue has been identified as an important source of proinflammatory cytokines such as … , as well as anti-inflammatory cytokines such as … .

Answer 5

energy-rich fatty acids

free fatty acids

catecholamines, release of glucocorticoids, increased beta-receptor agonist activity, and reduction of lipid storage mediated by insulin

tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)

adiponectin

Question 6

Increased levels of proinflammatory cytokines likely contribute to the etiology of … primarily by obstructing insulin signaling and contributing to downregulation of peroxisomal proliferator-activated receptor-γ, which are fundamentally important regulators of adipocyte differentiation and control.

Answer 6

insulin resistance

Question 7

Proteins such as …, which are produced primarily by adipocytes, are classified as adipokines

Answer 7

leptin and adiponectin

Question 8

Explain the role of leptin in the physiopathology of obesity

Answer 8

Although leptin is primarily involved in appetite control, its immunologic effects include protection of T lymphocytes from apoptosis and regulation of T-cell activation and proliferation. Reduced leptin levels may increase appetite and slow metabolism, but may also increase susceptibility to the toxicity of proinflammatory stimuli, such as endotoxin and TNF-α. Elevated leptin levels are proinflammatory, and this likely plays an important role in the progression of heart disease and diabetes, especially in obese patients

Question 9

Serum levels of adiponectin correlate with … and … [do/do not] rise in obesity.

Significantly … [increased/reduced] adiponectin levels are found in patients having type 2 diabetes.

Adiponectin reduces both … production and activity. It also inhibits … production.

Answer 9

insulin sensitivity

do not

reduced

TNF-α

IL-6

Question 10

… , an adipokine that induces insulin resistance, is induced by endotoxin and cytokines.

… acts at the cellular level to upregulate production of proinflammatory cytokines, most likely through the … pathway.

It appears to present a molecular link between metabolic signaling, inflammatory processes, and the development of … disease.

Its levels have been associated with inflammatory markers apparently independent of … in humans.

Answer 10

Resistin

Resistin

nuclear factor κB (NFκB)

cardiovascular

BMI

Question 11

An obstructive apneic event is defined universally as …

Answer 11

the complete cessation of airflow during breathing lasting 10 seconds or longer despite maintenance of neuromuscular ventilatory effort

Question 12

The definition of an obstructive hypopneic event may vary depending on the criteria being used for scoring. The Centers for Medicare and Medicaid Services (CMS) defines a hypopneic event as … as opposed to the American Academy of Sleep Medicine (AASM), which accepts a …

Answer 12

the partial reduction of airflow of 30% or more lasting at least 10 seconds, accompanied by a decrease of at least 4% in the oxygen saturation (SpO2)

3% drop in SpO2 or a terminal cortical arousal.

Question 13

The severity of obstructive sleep apnea/hypopnea syndrome (OSAHS) is arbitrarily defined, but recommendations for disease classification are as follows:  

Answer 13

Mild Disease: AHI of 5 to 15 events per hour

Moderate Disease: AHI of 15 to 30 events per hour

Severe Disease: AHI of greater than 30 events per hour

Question 14

Numerous studies have confirmed that … is the greatest risk factor for OSAHS, with about …% of patients (up to …% of males and up to …% of females) with OSAHS being …

Answer 14

obesity

70

80

50

obese

Question 15

Describe the STOP-Bang Questionnaire

Answer 15

1) Snoring: Do you snore loudly (loud enough to be heard through closed doors)?

2) Tired: Do you often feel tired, fatigued, or sleepy during daytime?

3) Observed apnea: Has anyone observed you stop breathing during your sleep?

4) Pressure: Do you have or are you being treated for high blood pressure?

5) BMI more than 35kg/m2?

6) Age over 50 years old?

7) Neck circumference >40cm?

8) Gender: Male?

High risk of OSA: Yes to 3 or more questions.
Low risk of OSA: Yes to 2 or fewer questions.

Question 16

Levels of many different inflammatory mediators, including … are increased in patients with OSAHS

Answer 16

IL-6, high-sensitivity C-reactive protein (hs-CRP), leptin, TNF-α, IL-1, reactive oxygen species, and adhesion molecules, such as intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1),

Question 17

… [adaptive/native] immune responses act aberrantly in obese individuals.

… cell cytotoxic activity is depressed with obesity, as are plasma levels of cytokines such as … , and … known to regulate … cell function

Answer 17

Native

Natural killer (NK)

IL-12, IL-18

interferon-γ

NK

Question 18

… , which selectively inhibits intestinal cholesterol absorption, can be combined with statin therapy to further reduce LDL cholesterol by 15% to 20%.

… effectively decrease triglyceride levels while increasing HDL cholesterol. They lower LDL cholesterol levels mildly, but when combined with statin therapy, they may increase
the risk of myopathy.

… decrease triglyceride levels and improve insulin resistance in patients with metabolic syndrome. They are often used in combination therapy with other classes of the hypolipidemic drugs.

… is highly effective in raising HDL cholesterol levels in patients with metabolic syndrome. It decreases the concentration of small, dense LDL particles and also lowers serum levels of lipoprotein (a)

Answer 18

Ezetimibe

Fibrates

Omega-3 fatty acids

Nicotinic acid

Question 19

The AHA recommends that low-dose aspirin be used as a form of primary prevention in patients with metabolic syndrome whose 10-year risk for cardiovascular disease is …

Answer 19

10% or greater as determined by Framingham risk scoring

Question 20

Currently five drugs have FDA approval to be prescribed for long-term use for the specific indication of weight loss in adults: …

Answer 20

orlistat (Xenical, Alli),
phentermine–topiramate (Qsymia),
naltrexone–bupropion (Contrave),
liraglutide (Saxenda),
semaglutide (Wegovy).

Question 21

Orlistat mechanism of action and particularities

Answer 21

Orlistat, a lipase inhibitor, reversibly binds to lipase and prevents both absorption and digestion of certain dietary fats. Because orlistat also interferes with the absorption of fat-soluble vitamins, patients using this drug need to supplement fatsoluble vitamins A, D, E, and K. It has significant GI side effects including diarrhea, steatorrhea, flatulence, fecal incontinence, and oily rectal discharge

Question 22

Phentermine–topiramate mechanism of action and particularities

Answer 22

Phentermine–topiramate, an adrenergic reuptake inhibitor combined with an anticonvulsant, augments adrenergic signaling within the central nervous system and peripheral tissues. Phentermine decreases appetite and food intake and increases resting metabolic rate to promote weight loss. Its side effects include drowsiness, dry mouth, difficulty sleeping, tingling of the extremities, and constipation.

Question 23

Naltrexone–bupropion mechanism of action and particularities

Answer 23

Naltrexone–bupropion is a combination of an opioid receptor antagonist with a dopamine and norepinephrine reuptake inhibitor. Naltrexone is used to treat alcohol and drug dependence while bupropion is often used for depression and smoking cessation. This combination of medication is postulated to curb hunger and help control cravings by regulating feelings of pleasure when eating. Common side effects of naltrexone–bupropion include GI distress, dry mouth, hypertension, tachycardia, and possible increased risk of suicidal thoughts and actions

Question 24

Liraglutide and semaglutide mechanism pf action and particularities

Answer 24

Liraglutide and semaglutide are synthetic analogues of human glucagon-like peptide-1(GLP-1) and act as a GLP-1 receptor agonist. They both increase the production of insulin, inhibit glucagon secretion, and reduce food intake by lowering appetite and slowing down digestion in the stomach. Side effects can include GI distress, fatigue, and pancreatitis

Question 25

... (mounjaro) is a novel investigational once-weekly ... receptor agonist

Answer 25

Tirzepatide GIP (glucose-dependent insulinotropic polypeptide) receptor and GLP-1 (glucagon-like peptide-1)

Question 26

The only studies involving herbals that have consistently demonstrated weight loss involve combinations of ... . Pharmacologically, this is expected because ... , an adrenergic agonist, is known to be an appetite suppressant and a thermogenic agent. For this reason, ..., a natural source of the ... alkaloid, is added to most, if not all dietary supplements marketed for weight loss

Answer 26

ephedrine and caffeine ephedrine ma huang Ephedra

Question 27

The CDC defines children possessing BMIs in the ... percentiles as having “healthy weight.” Children whose BMI is in the ... percentile are "at risk for overweight,” while those having a BMI above the ... percentile are classified as “overweight.” These classifications were previously regarded as “overweight” and “obese,” respectively. This switch in terminology continues to be a source of confusion. Exceeding the ... percentile is referred to as extreme pediatric obesity.

Answer 27

5th to 85th 85th to 95th 95th 99th

Question 28

In recent years, the percentage of bariatric procedures represented by ... surgery performed has decreased from 35% in 2011 to approximately 3% in 2016. This decline in LGB operations is probably secondary to ... . Recently, the ... has become the most commonly performed surgery for obesity

Answer 28

laparoscopic gastric band only modest amount of weight loss and high rates of band revisions and adjustments required sleeve gastrectomy (SG)

Question 29

The sleeve gastrectomy has been shown to be safe and effective, with a mean excess weight loss of approximately ... %. The weight loss noted after a SG is not only due to the restrictive stomach, but also due to ...

Answer 29

65 the decrease in hormonal level of ghrelin that regulates appetite and food intake

Question 30

Today, ... and ... are the two most commonly performed malabsorptive operations, and both have achieved success in safety and efficacy. ... is more commonly performed, and it is considered the safer of the two malabsorption procedures

Answer 30

gastric bypass (GBP) biliary pancreatic diversion (BPD) GBP

Question 31

GBP surgery involves the creation of ... . This results in an element of gastric restriction. GBP also involves the creation of a ...

Answer 31

a small gastric pouch by stapling or banding the stomach Roux-en-Y anastomosis, in which the small gastric pouch is directly connected to the middle portion of the jejunum.

Question 32

The intragastric balloon is placed in the patient’s stomach endoscopically. It is then filled with saline to remove the stomach’s potential volume and to provide a sensation of fullness and satiety. Usage of such devices has also been shown to possibly decrease appetiteregulating hormones such as ... , thereby leading to decreased hunger and greater weight reduction. The device can be kept in the patient’s stomach for a maximum of ... and has been shown to decrease weight by an average of... %. Most common complications of the intragastric balloon are related to GI symptoms such as ... ; however, serious complications such as ... are possible

Answer 32

ghrelin 6 months 6.8 nausea, vomiting, halitosis, GERD, and abdominal discomfort balloon rupture, migration, and intestinal obstruction

Question 33

CPAP levels greater than ... imply a patient with the potential for difficult mask ventilation.

Answer 33

10

Question 34

Use of ... during preoxygenation of obese patients in the supine position resulted in a higher partial pressure of oxygen (PaO2) after intubation and decreased the amount of atelectasis that developed

Answer 34

10cm H2O CPAP

Question 34

The factors that may be considered contraindications for bariatric surgery include ...

Answer 34

unstable CAD, uncontrolled severe OSA, uncontrolled psychiatric disorder, intellectual disability (IQ <60), inability to understand the surgery, perceived inability to adhere to postoperative restrictions, continued drug abuse, and malignancy with a poor five-year survival prognosis

Question 35

In a study conducted to assess the relationship between patient positioning and development of hypoxemia in obese patients during apnea after anesthetic induction and intubation, patients were ventilated with a 50% oxygen/50% air mixture for 5 minutes before the ventilator circuit was disconnected. Apnea was continued until the SpO2 fell to 92%, at which time ventilation was resumed. Patients in the ... position reached the end point in 2 minutes, but it took 30 seconds longer if ... position with the ... was used and 1 minute longer if ... position was used. Use of ... position in obese patients undergoing bariatric surgery was also shown to reduce the alveolar-to-arterial oxygen difference, as well as increase total ventilatory compliance and reduce peak and plateau airway pressures when compared to ... position

Answer 35

supine supine back elevated 30 degrees 30-degree reverse Trendelenburg 30-degree reverse Trendelenburg supine

Question 36

Use of ...cm H2O PEEP has been demonstrated to have a greater effect in obese patients compared to normal subjects on improving ventilatory mechanics, increasing PaO2, and decreasing alveolar-to-arterial oxygen difference during general anesthesia with neuromuscular blockade. In addition to PEEP alone, use of a recruitment maneuver such as ... followed by application of PEEP has been demonstrated to prevent atelectasis from developing and to improve oxygenation, whereas neither PEEP nor a recruitment maneuver alone achieved the same degree of maintenance of pulmonary function

Answer 36

10 sustained lung inflation to 55cm H2O for 10 seconds

Question 37

Early Complications of Bariatric Surgery

Answer 37

Bleeding Infection Dehydration Peritonitis Leak from anastomotic site Bowel obstruction Perforation Pneumonia DVT/PE Death

Question 38

Late Complications of Bariatric Surgery

Answer 38

Anorexia Cholelithiasis/cholecystitis Pouch dilation or stricture Gastroesophageal reflux disease/dysphagia Herniation at surgical site Small bowel obstruction Marginal ulcer Pancreatitis Nutritional issues Fat-soluble vitamin deficiencies, especially vitamin B12

Question 39

A fraction of patients develop significant neurologic complications following GBP surgery. These are known to include ...

Answer 39

polyneuropathy, polyradiculoneuropathy, myelopathy, encephalopathy, and optic neuropathy.

Question 40

A study by Dindo and coworkers of 6336 patients did not find any difference in the incidence or severity of complications after elective general surgery, except ...

Answer 40

surgical site infections