Week 13 Handout Obesity

Question 1

What percentage of U.S. adults are classified as overweight or obese?

Answer 1

75% of U.S. adults are classified as overweight or obese.

Question 2

How much has obesity increased since 1994?

Answer 2

Obesity has increased by 19% since 1994 and has tripled since 1975.

Question 3

What is the increased risk of death for obese individuals?

Answer 3

Obese individuals have a 10–50% higher risk of death, including during surgery.

Question 4

What complications does obesity cause in anesthesia?

Answer 4

Obesity complicates airway, pharmacology, positioning, ventilation, and recovery.

Question 5

How is BMI calculated?

Answer 5

BMI = Weight (kg) / Height (m²)

Question 6

What are the BMI classifications for overweight and obesity?

Answer 6

Overweight: 25–29.9; Obese: ≥30; Severe Obesity: >40.

Question 7

What is Ideal Body Weight (IBW) used for?

Answer 7

IBW is used for drug dosing to prevent overdose.

Question 8

What is Lean Body Weight (LBW)?

Answer 8

LBW is fat-free mass; important for some drug calculations.

Question 9

What cardiopulmonary factors should be evaluated preoperatively?

Answer 9

Evaluate for HTN, angina, orthopnea, PND, JVD, edema, OSA.

Question 10

What should be documented in a preoperative assessment?

Answer 10

Document exercise tolerance, resting ECG for rate/rhythm/hypertrophy.

Question 11

What respiratory factors should be assessed preoperatively?

Answer 11

Assess for sputum, dyspnea, wheezing, desaturation in supine/recumbent position.

Question 12

What gastrointestinal risks are associated with obesity?

Answer 12

Risk of GERD, hiatal hernia, gallstones, pancreatitis, NAFLD, delayed gastric emptying.

Question 13

What endocrine factors should be considered preoperatively?

Answer 13

Consider underlying diabetes; verify last dose of weight loss medications.

Question 14

How does obesity affect aspiration risk?

Answer 14

Obesity increases risk for hiatal hernia, GERD, and aspiration.

Question 15

What is the significance of preoperative gastric ultrasound?

Answer 15

It may assess residual volume (<1.5L = no elevated risk).

Question 16

When should awake intubation be considered?

Answer 16

Consider awake intubation for BMI >50 or BMI <50 with large neck, OSA, or difficult airway predictors.

Question 17

What should be ensured for preoperative preparation?

Answer 17

Ensure availability of appropriate-sized BP cuffs and difficult airway cart.

Question 18

What EKG leads should be used for ischemia monitoring?

Answer 18

Use leads II and V5 for EKG ischemia monitoring.

Question 19

What is the recommendation for arterial line placement?

Answer 19

Place arterial line in moderate-to-severely obese patients.

Question 20

What are the airway management considerations for obese patients?

Answer 20

Thorough airway exam; high risk for difficult mask ventilation and intubation.

Question 21

What position should be avoided during intubation?

Answer 21

Avoid sniffing position; use head-elevated ramped position or reverse Trendelenburg.

Question 22

What are the intraoperative ventilation settings recommendations?

Answer 22

FiO₂ <0.8, recruitment maneuvers: 35–40 cm H₂O for 8–10 seconds, PEEP: 10–12 cm H₂O.

Question 23

How should tidal volume be calculated?

Answer 23

Tidal volume: 6–10 mL/kg ideal body weight.

Question 24

What is the recommended plateau pressure during ventilation?

Answer 24

Keep plateau pressure <30 cm H₂O.

Question 25

How does obesity alter drug distribution?

Answer 25

Obesity increases adipose tissue, CO, blood volume, LBW, renal clearance and decreases total body water.

Question 26

How should hydrophilic drugs be dosed?

Answer 26

Dose using IBW.

Question 27

How should lipophilic drugs be dosed?

Answer 27

Dose using TBW.

Question 28

What is the dosing recommendation for Propofol?

Answer 28

Induction by LBW, maintenance by TBW.

Question 29

What are the intraoperative positioning considerations?

Answer 29

Protect from nerve injury and prevent skin maceration.

Question 30

What are the postoperative respiratory risks?

Answer 30

OSA + opioids = high risk for respiratory depression.

Question 31

What is the risk of rhabdomyolysis in bariatric surgeries?

Answer 31

Seen in ~1.4% of bariatric surgeries; monitor CPK levels.

Question 32

What are the thromboembolism risks in bariatric surgery?

Answer 32

Leading cause of postop death; risk factors include BMI ≥60.

Question 33

What defines severe obesity? a. BMI 25-29 kg/m2 b. BMI greater than or equal to 30 kg/m2 c. >40 kg/m2 d. BMI above the 75th percentile of the general population

Answer 33

Answer: C Rationale: Severe obesity is defined as greater than 40 kg/m2. BMI 25-29 kg/m2 is the definition of overweight, while BMI greater than or equal to 30 kg/m2 is the definition of obesity (

Question 34

What medication should the anesthesia provider dose according to lean body weight? a. Succinylcholine b. Propofol c. Rocuronium d. Fentanyl

Answer 34

Answer: B Rationale: Propofol ought to be dosed according to lean body weight. Dosing according to total body weight in obese individuals would result in toxicity (Elisha, et al., 2022).

Question 35

What medication should the anesthesia provider dose according to ideal body weight (select 2) a. Rocuronium b. Succinylcholine c. Sugammadex d. Remifentanyl e. Propofol

Answer 35

Answer: a., d. Rationale: Rocuronium and remifentanil should be dosed according to ideal body weight to prevent toxicity in individuals with elevated BMI. Propofol should be dosed according to lean body weight. Succinylcholine, fentanyl, and sugammadex may be dosed according to total body weight (Elisha, et al., 2022).

Question 36

Which ventilation management strategies are helpful in oxygenating an individual with elevated BMI (select 2) a. Tidal volume 10 mL/kg total body weight b. FiO2 <0.8 c. Use PEEP of 10-12 cmH2O d. Place the bed in Trendelenburg position

Answer 36

Answer: b., c. Rationale: Recommendations for ventilating individuals with elevated BMI include a tidal volume of 6-10 mL/kg ideal body weight, FiO2 <0.8, PEEP 10-12 cmH2O, and reverse Trendelenburg position (Elisha, et al., 2022).

Question 37

Which option describes optimal positioning for intubation of patient with elevated BMI a. Sniffing position b. Tucked chin c. Ramped head and shoulders with sternal notch aligning with external auditory meatus d. Pt supine with bed in Trendelenburg position

Answer 37

Answer: c Rationale: Obese individuals are often harder to intubate when in sniffing position. A tucked chin would diminish view of the airway. The bed should be placed in reverse Trendelenburg position. Elevating the patient’s head and shoulders above the chest to the point where the sternal notch aligns with the external auditory meatus proves the most effective means of directly visualizing the airway (Elisha, et al., 2022).

Question 38

What is the best method for fluid management in obese populations a. Bolus one liter at the beginning of each case for obese patients excluding those with hypertension b. Administer fluid in response to the patient’s clinical parameters such as heart rate, blood pressure, and urine output c. Only give albumin intraoperatively d. Provide PRBCs when the patient’s hemoglobin falls below 5 g/dL as blood volume is diminished to 45-55 mL/kg actual body weight at baseline in extreme obesity

Answer 38

Answer: b Rationale: It is best to manage fluid status according to the patient’s clinical parameters in obese patients. Each patient has different needs at the beginning of surgery according to their condition and baseline fluid status. While albumin can be given intraoperatively to support oncotic pressure, it may be given in conjunction with other fluids. Blood volume is diminished to 45-55 mL/kg in severely obese patients, but the criteria for blood product replacement remains the same as normal-weight patients (El