Obesity Flashcards
1
Q
Definition of Overweight
Definition of obesity
A
- Overweight- increased body weight above a standard related to height
- Obesity- excessive body weight for the patients age, gender, and height
- body weight of 20% or more above ideal weight
- it is a disorder of energy balance
2
Q
Obesity stats
A
- 68% of US population overweight
- 33% obese
- 25% of children are obese
3
Q
Ideal body weight calculation for men
women
A
- men: IBW = 105 lb + 6 lb for each inch >5 ft
- women: IBW = 100lb = 5 lb for each inch >5 ft
- Brocca’s index:
- IBW (kg) = height (cm) -x
- x for men = 100, x for women = 105
- lean body weight is IBW + 20%
4
Q
How do you calculate BMI?
What is the problem with this measurement?
A
- MBI = weight in kg/ height2 (m)
- Does not clearly differentiate between overweight and overfat. Very muscular ppl will be designated overweight/obese even though they are not fat
5
Q
What are the different groupings of BMI?
A
- Overweight = BMI 25-29 kg/m2
- Obese = BMI >30
- Clinically severe Obese = BMI >40
- Super Obese = BMI >50
- Super-Super Obesity = MBI >60
- BMI >30 is associated with increased morbidity related to stroke, ischemic heart disease, HTN, and DM
6
Q
What is the impact of anatomic distribution?
A
- Android obesity- abdominal, central obesity
- more common in men
- higher incidence of metabolic disturbances, ischemic heart disease, stroke, dm, death
- Gynecoid obesity- fat around hips and buttocks
- more common in females
- Waist circumference is directly related to risk of pathophysiology
- >102 cm in men
- >88 cm in women
7
Q
What problems are associated with obesity?
A
- OSA
- RLD
- HTN
- CAD
- hyperlipidemia
- delayed gastric emptying/GERD
- Type II DM
- Gall bladder disease
- Cirrhosis/fatty liver disease
- venous stasis
- degenerative joint/disc disease
- increased breast, prostate, cervical, uterine, and colorectal cancer
8
Q
How does obesity alter the respiratory system?
A
- Reduces chest wall and lung compliance
- reduced FRC- 50%
- reduced ERV
- RV and CC not changed
- relationship btw FRC and CC is adversely effected
- FEV1 and FVC usually WNL
- Reduced TV- may fall into the range of closing capacity
- Increased pulmonary blood volume
- increased O2 consumption and CO2 production
- high MV, increased WOB
- As obesity worsens, you will see lung disease and PHTN but PFTs remain normal until this occurs
9
Q
How does obesity affect the respiratory system in different positions?
A
- Respiratory changes are all exaggerated in different positions
- Rapid desaturation may be seen when anesthesia is induced in recumbent/supine position
- Deviations in lung volumes lead to:
- VQ mismatch-
- hypoxemia
- increased right to left intrapulmonary shunt
- TV overlapping with closing capacity (the small airways will start to close during a normal tidal volume breath)
10
Q
What changes can you expect in securing an airway for an obese patinet?
A
- TMJ and atlanto-axial joint and cervical spine movement is limited by upper thoracic and low cervical fat pads
- Narrowed airway from extra tissue folds in mouth and pharynx
- Short, thick neck- measure it
- 40 cm = 5% incidence of difficult intubation
- 60 cm = 35% incidence of difficutl intubation
- Fat in suprasternal, presternal, posterior cervical and submental regions
- shortened distance between mandible and sternal fat pads
- OSA
- difficult to mask ventilate
- difficult to get a good view on laryngoscopy
11
Q
How is OSA characterized?
A
- Apnea > 10 seconds; total cessation of airflow despite respiratory effort against a closed glottis
- Hypopnea is 50% reduction in size or number of breaths that lasts at least 10 seconds compared to normal
- partial or intermittent collaps of pharyngeal airway during sleep
12
Q
What are the risk factors for OSA?
A
- middle age
- male
- obesity
- ETOH use
- drugs for sleep aids
- abdominal fat distribution
- neck girth 41 cm
- >17 inches for men
- >16 inches for women
13
Q
What problems can OSA lead to?
A
- chronic hypoxia, hypercapnia, pulmonary and systemic HTN
- snoring
- poor sleep leading to daytime somnolence
- impaired concentration
- morning HA
- Right heart failure
- polycythemia and increased blood volume
- respiratory acidosis
14
Q
How is OSA graded?
A
- Severity is graded by # of apnea or hyponeic episodes during 1 hour of observation
- mild = 5 -15/hour
- moderate = 15-30/hour
- severe >30/ hour
15
Q
What is Pickwickian syndrome?
How is it diagnosed?
A
- Obesity hypoventilation syndrome (OHS)
- Complication of extreme obesity/long term OSA
- hypercapnia, cyanosis induced polycythemia, somnolence and eventual right sided heart failure and PHTN
- Doagnosed by PCO2 >45 in an obese pt w/o significant COPD
- Clinically distince from OSA
- OSA you have nocturnal sleep disruption
- OHS you have nocturnal central apneic events (apnea without respiratory effort)