Test 2: Obesity (pt 1/3) Flashcards
The accepted measure of body habitus that describes adiposity normalized for height
Body Mass Index (BMI)
How to calculate BMI?
Patient’s actual body weight in kg divided by the square of the height in m
The risk of developing comorbid conditions ______ with higher BMIs.
Increases
What is the BMI Range for Normal Weight?
20 - 24.9
What is the BMI Range for Overweight?
25 - 29.9
What is the BMI Range for Obese (Class 1)
30 - 34.9
What is the BMI Range for Severely Obese (Class 2)?
35 - 39.9
What is the BMI Range for Extremely Obese (Class 3)?
> 40
What is the BMI Range for Super Obese?
> 50
The measurement of height and body mass that exhibits the lowest M&M for a given population
Ideal Body Weight (IBW)
Lean Body Weight (LBW) increases ____% with obesity secondary to increased muscle mass required to carry extra weight
30%
Formula for LBW based on IBW?
LBW = IBW x 1.3
How to calculate IBW for men?
Height in cm - 100
How to calculate IBW for women?
Height in cm - 105
Why is adipose tissue considered an endocrine organ?
It provides a reservoir of readily convertible & usable energy, and maintains heat insulation.
Obesity in childhood results in an increased ____ of fat cells
Number
Obesity in adulthood results in an increased ____ of fat cells
Size (hypertrophy of existing fat cells)
When does the number of fat cells stabilize?
Adolescence
Which type of obesity is associated with a higher risk of comorbidities?
Android (Apple Shape) aka Central aka Abdominal
Patients with Android obesity are at a higher risk of what comorbid conditions compared to those with Gynecoid obesity?
-Ischemic Heart Dz
-DM
-HTN
-HLD
-Death
-Higher risk of difficult airway and intubation
Patients with ____ obesity are at a higher risk of difficult airway and intubation
Android
Waist circumference >____ in males and >____ in females denotes an increased risk for comorbid conditions, higher risk for difficult airway and intubation, and establishes abdominal obesity.
> 40 in men and >35 in women
Which type of obesity is associated with an increased risk of varicose veins and joint disease?
Gynecoid (Pear Shape) aka Peripheral Gynecoid aka Gluteal Femoral Obesity
Which type of obesity has the most overall risk?
Android Obesity
Genetic predisposition, a primary factor in the development of obesity, explains ____% of the variance in body mass.
40%
What are factors that have led to the significant increase in the prevalence of obesity?
-Genetic
-Environmental (inc caloric intake and reduced physical activity)
-Inflammation (elevation of inflammatory mediators such as Angiotensinogen, TNF alpha, IL6, etc in morbidly obese patients)
In obese patients, compression of fat on the abdominal, diaphragmatic, and thoracic structures leads to a ________.
compromise of respiratory function.
In obese patients, chest wall, lung parenchyma, and pulmonary compliance are reduced to ____% of predicted values.
35%
Obese patients have premature airway closing, which causes what?
-Increased dead space (Vd)
-CO2 retention
-V/Q mismatch (Shunting)
-Hypoxemia
The rapid and shallow breathing pattern is characteristic of ____ Lung Disease
Restrictive
Why do obese patients have increased myocardial O2 consumption?
The metabolic needs of the fat organ and the greater mechanical work of breathing stimulate increased myocardial O2 consumption.
Obese patients have _____ CO2 production and retention, and _____ ventilation.
Increased; Decreased
True/False: Respiratory muscle dysfunction as well as the development of asthma-like symptoms are associated with obesity.
True (weight loss results in improvements in SOB)
Obese patients are predisposed to _____ _____, even in the setting of mild pulmonary or systematic insults.
Respiratory Failure.
Extreme obesity is associated with what alterations in spirometry values?
-Reduction in FRC
-Reduction in Expiratory Reserve Volume (ERV)
-Reduction in Total Lung Capacity (TLC)
Obese patients have a reduction in FRC. What does this mean for your clinical practice?
-Patient will not tolerate periods of apnea/hypoventilation
-Patient will desaturate quickly
-Patient needs full 3 minutes of pre-oxygenation
-Extubate them a little more awake than others
Repetitive upper airway collapses leading to cessation of breathing during sleep lasting 10 seconds or more.
Obstructive Sleep Apnea
What are symptoms that would make you suspect OSA?
Excessive daytime sleepiness, fatigue, and poor concentration.
OSA negatively affects quality of life, and can lead to what other major health disorders?
-CAD
-HTN
-HF
-CVA
What is the most prevalent sleep-breathing disorder?
OSA - it affects 9-25% of the general population.
Up to ____% of patients having bariatric surgery have OSA.
70%
What are anesthesia implications r/t OSA?
-Difficult Airway
-Increased sensitivity to anesthetic agents
-Increased post op complications
How do you diagnose OSA (officially)?
Polysomnography (PSG) using the Apnea-Hypopnea Index (AHI)
What does the Apnea-Hypopnea Index (AHI) Measure?
The number of abnormal respiratory events per hour of sleep.
What is the minimum diagnostic criteria for OSA?
An AHI of 10 + symptoms of excessive daytime sleepiness
How does the American Academy of Sleep define Mild, Moderate, and Severe OSA?
Mild - AHI between 5-15
Moderate - AHI between 15-30
Severe - AHI >30
Detail the STOP-BANG Questionnaire.
Snoring
Tiredness
Observed Apnea
High Blood Pressure
BMI (>35 kg/m2)
Age (>50 years)
Neck Circumference (>40 cm)
Gender (male)
What scores on the STOP-BANG questionnaire indicate intermediate and high risk for OSA?
Intermediate Risk: 3-4
High Risk: >5
What is the intervention for OSA that reduces the AHI score and attenuates symptoms such as daytime sleepiness, fatigue, poor concentration, and memory loss?
Positive Airway Pressure (PAP)
Long term use of PAP in patients with OSA is associated with a reduction in what comorbid condition?
CV morbidity and mortality
What are some strategies to reduce postop complications in patients with OSA?
-Regional Anesthesia when appropriate, or combined technique to limit opioids (multimodal anesthesia)
-Use of short-acting drugs
-Postoperative monitoring (espec SpO2) and use of PAP in PACU!
Approx. ____% of patients with Obesity Hypoventilation Syndrome (OHS) have OSA.
90%
What are the characteristics of Obesity Hypoventilation Syndrome (OHS)? (Also called Pickwickian Syndrome)
-Obesity (BMI > 30 kg/m2)
-OSA (90% have it)
-Hypercapnia (Daytime hypoventilation with awake PCO2 > 45 mm Hg)
-Respiratory Acidosis
-Daytime hypersomnolence
-Arterial Hypoxia (PaO2 < 70 mmHg)
-Polycythemia
-Pulmonary HTN
-R sided HF
-Sleep-disordered breathing in the absence of other causes of hypoventilation.
