1/3 of adult population >20 years old is overweight

27% of these are obese

What % of adults are either overweight or obese, according to Miller?

Obesity is second only to _____ in preventable causes of death.

65%

smoking

depression

diabetes

gallbladder disease

heart disease

hypertension

osteoarthritis

reflux esophagitis

sleep apena and other breathing problems

some forms of cancer

stroke

disorder of energy balance

"Net energy intake exceeds net energy expenditure over a prolonged period of time."

What does resting metabolic rate accounts for ___ % of total expenditure of energy?

What about activity?

60% of total expenditure of energy

Activity = 20%

- can be increased with exercise for up to 18 hrs

25 to 29.9 kg/m2

What is the BMI for an obese I person?

Wat is the BMI for obese II person?

>30-34.9 kg/m2

>35-39.9 kg/m2

What is the BMI for a morbidly obese person?

SUPERobese BMI?

Super superobese BMI?

35-40 kg/m2 IF have comorbidities 

>40-49.9 kg/m2 W/O comorbidities

>50-59.9 kg/m2 

>60 kg/m2

wt(kg)/ht2(m)

lbs/2.2 = kg

66in = 168cm = 1.68m = 2.82m2

Mechanisms of fat storage

Genetic

Psychological

(behavioral, cultural, socioeconomic)

underweight (<19)

overweight (>25.0)

Describe Class I, II, & III obesity & Superobese.

BMI

Risk of Health Problems Developing

Class I: 30.0-34.9 - high

Class II: 35.0-39.9 - very high

Class III: 40.0-49.9 - extremely high

Superobese: >50 - exceedingly high

Abdominal obesity

Atherogenic dyslipidemia

Elevated BP

Insulin resistance w/ or w/o glucose intolerance

Proinflammatory state

Prothrombotic state

etc...see slide 14 for more details

What is the clinical criteria for diagnosing metabolic syndrome?

How many of the criteria must be met for diagnosis?

Abdominal Obesity - waist >102cm/ men & >88cm/ women

Triglycerides >150 mg/dl

HDL cholesterol >40 mg/dl in men & >50 mg/dl in women

BP >130/85mmHg

Fasting glucose >110 mg/dl

*2 out of 4 or 3 of 5 criteria must be met depending on whether or not abd fat is included (books differ)*

Where in the body is lipoprotein lipase more active and less active?

What does this enzyme do besides store fat?

more active in abdominal fat

less active in hips, buttocks and thighs

produces cytokines, chemokines and steroid hormones

= chronic inflammatory state

What is increased M&M associated with?

(type of fat)

central/android fat "apple shaped" (which is more metaboliclly active)

peripheral/gynecoid fat "pear shaped"

Genetic factors

In past decades fat storage was a _____ , now storage of excess fat is _______ d/t sedentary lifestyles & increased consumption of calorie rich foods.

Survival Advantage

Maladaptive

obesity hypoventilation syndrome

decreased lung volumes & gas exchange

ischemic heart disease

systemic HTN

CHF

T/F. Obese patients may appear asymptomatic.

When will you note symptoms?

True - due to limited mobility

physical activity may cause exertional dyspnea and/or angina pectoris

ask patient specific activity questions to get a true picture of their health status

to avoid:

orthopnea

paroxysmal nocturnal dyspnea

How does added weight effect lung volumes?

D/t the added weight with these pts you must beware of which position?

It produces a restrictive defect d/t....

abdominal cage: added weight

impedance of diaphragm by abdominal weight

beware of supine position

What is increased small airway closure due to with obese pts?

What dose this cause?

declining FRC with increased BMI

causes V/Q mismatches, right to left shunt, & arterial hypoxemia

may decrease dramatically & rapidly on induction

-need high oxygen concentrations and make sure to thoroughly de-nitrogenate

PaCO2 remains normal as does ventilatory response to PCO2 (until OHS sets in)

-drugs that depress ventilation & supine position may quickly increase PaCO2 & depress response to PaCO2

How does obesity effect lung compliance & resistance?

Breathing pattern?

What position causes respiratory issues to be exaggerated?

increasing BMI leads to decreases in respiratory compliance and increase in resistance

rapid, shallow breathing pattern & increased WOB

exaggerated in supine position

What % of obese patients have systemic hypertension?

Why?

Each kg of fat contains ____ meters of blood vessels

Each kg of weight gained increses CO ____L/min

50-60% of obese patients have mild to mod. HTN

increased extracellular fluid volume causes hypervolemia and increased CO

each kg of fat contains 3000 meters of blood vessels

each kg of weight gained increses CO 0.1L/min

IE inc 20 kg = 2L more blood/min

What are cardiac dysrhythmias precipitated by in obese pts?

What predisposes obese pts to have dysrhythmias in response to the above?

arterial hypoxemia

hypercarbia

ischemic heart disease

obese hypoventilation syndrome

 fatty infiltrates of cardiac conduction sys.

What is common in the obese patient with central fat distribution?

What other diseases are common d/t this?

Ischemic Heart Disease

also common: HTN, diabetes, hypercholesterolemia

HTN

it causes left ventricular hypertrophy and an increasingly non-compliant left ventricle 

hypervolemia

increases demands on CV system

decreases cardiac reserve

limits exercise tolerance

-this progression becomes worse over time

Are obese at increased risk for aspiration?

What 4 risk factors do they have for aspiration?

ultimately yes

GERD 

Increased intra-abdominal pressure

Increased incidence of hiatal hernia

Larger gastric capacity, thus larger residual vol.

If an obese person does not have symptoms of reflux, so what?

Is it true that all obese ppl have delayed gastric emptying?

without symptoms of reflux, gastroesophageal sphincter tone is similar to non-obese in sitting & supine positions -- so not really a risk factor

No, even though they have more gastric volume their emptying may actually be more rapid

As weight increases, is there an increase in aspiration risk?

How should you induce an obese pt then?

most likely (for sure if have DM)

RSI with cricoid is usually done to be safe and for legal reasons per lec

How much higher is the incidence for diabetes in the obese patient?

Why?

Pts with NIDDM may require insulin with _____?

incidence is 7x greater in obese

peripheral tissues are resistant to insulin in obesity

NIDDM may require insulin with catabolic stress of surgery

abnormal liver function tests

fatty infiltrates of the liver

Do VIA's induce hepatic dysfunction more in obese patients?

T/F drug metabolism for obese pts is normal till their liver becomes cirrhotic?

no evidence of exaggerated inhalational agent induced hepatic dysfunction in obese

True per lec

What is the risk of gallbladder & biliary tract disease?

Why?

3x more than normal 

due to abnormal cholesterol metabolism

What is the risk of DVTs?

Why is this increased with obese pts?

2x greater than normal

because of increased venous stasis d/t

polycythemia

increased abdominal pressure

immobilization

Compression Devices

- placed before induction

Pharmacological Prophylaxis

- LMWH (dalteparin (Fragmin), enoxaparin (Lovenox), tinzaparin (Innohep), UFH (use total body weight)

Why is proper fitting of sequential or intermittent compression devices necessary?

proper fitting necessary to avoid injury to the patient and to enhance therapeutic value

What is a major complication that may lead to death with obese pts?

American Society of Bariatric Surgeons survey showed...

pulmonary embolism

48% of surgeons who responded had lost at least one patient to a fatal PE

esophagus, colon & rectum

liver, gallbladder, pancreas

kidney 

diet & behavoral modification

pharmacotherapy for weight loss

- Phenteramine, Sibutramine, & Orlistat

surgical techniques

restrictive - limits oral intake

malabsorptive - decreases the degree of absorption of nutrients

combination of the two

Vertical banded gastroplasty (VBG)

Gastric banding

Adjustable gastric banding (ABG)

Jejuno-ileal bypass

Biliopancreatic bypass

Roux-en-Y gastric bypass (RYGB)

Biliopancreatic diversion with duodenal switch

What is the most utilized surgical technique?

What type of procedure is it?

What is the surgical technique?

Approximately ___ % of all bariatric procedures performed in the US are this type.

Roux-en-Y gastric bypass

combination restrictive and malabsorptive procedure

performed via the laparoscopic technique

approximately 75% of all bariatric procedures performed in US

Roux-en-Y gastric bypass

What is bypassed for this procedure?

How is the gastric pouch formed, how big is it, what is it reconnected to?

Bypasses all of stomach and the entire duodenum

proximal gastric pouch is formed from stomach approximately 15 to 30 mL in volume

pouch anastomosed to the proximal jejunum

What is the adjustable gastric band?

What type of surgical approach is used?

Is this more or less complicated than Roux-en-Y?

adjustable inflatable ring placed completely around the proximal portion of the stomach - forms an "hourglass"

laparoscopic approach

significantly less involved than the Roux-en-Y"

How does the adjustable gastric band lead to weight loss?

This was approved by the FDA in ____

restricts oral intake 

2001

apnea for 10 seconds or more

5 times per hour of sleep

Tonsillar hypertrophy

craniofacial abnormalities

(retrognathia)

What causes a disordered night breathing pattern (aka OSA)?

associated with?

obstruction --- airway collapse leads to repetitive apneic episodes, poor sleep, daytime somnolence

associated with --- hypoxemia, polycythemia, HTN, R heart fx, pulm HTN, & eventual L heart fx 

family hx of OSAS

GERD

habitual snoring

male gender

obesity

middle age

evening alcohol consumption

drug-induced sleep

daytime somnolence, fatigue, and disrupted psychomotor vigilance

poor school and/or work performance

increased rates of industrial & traffic accidents

memory loss

large neck size

>17" in male >15" in female

What is Obesity Hypoventilation Syndrome? OHS

OSAS:

nocturnal apnea w/ correction of acidosis during awake hrs

during apnea there are respiratory efforts

OHS:

central apneic events - apnea with no respiratory efforts

progressive desensitization to hypercarbia

 Obesity

HTN

Arterial hypoxemia

Polycythemia

Pulmonary hypertension

Right ventricular failure

Hypercarbia

Respiratory acidosis

Daytime hypersomnolence

CPAP

Oral appliances (oral airway)

Sleep hygiene

Nocturnal oxygen therapy

Weight reduction:

diet

exercise

possibly bariatric surgery

1. avoid caffeine & alcoholic beverages prior to sleep

2. discontinue sleep medication & sedatives

3. encourage patients to sleep on their side rather than supine worse levels of collapse are usually seen in supine position

Hyoid suspension

Laser-assisted uvulopalatoplasty

Mandibular circular osteotomy

Maxillomandibular osteotomy & advancement

Radiofrequency ablation of the tongue

Septoplasty & inferior turbinate reduction

Tracheostomy

Uvulopalatopharyngoplasty

What position is uvulopalatopharyngoplasty performed in?

What med is likely to be used?

supine position - head elevated slightly to promote venous drainage

use of LA with epi is likely

What postop issues should you be aware of after a uvulopalatopharyngoplasty?

How do you help maintain airway postop?

CPAP?

How long should ventilation be monitored?

_____ for analgesia?

watch for acute airway obstruction!

leave nasopharyngeal airway in place

use CPAP & oxygen

monitor ventilation for 24 hours

Toradol for analgesia

Poor Mallampati classifications secondary to:

macroglossia

base of tongue hypertrophy

mandibular retrognathia

What blade should be used for obese patients?

stylet?

blanket stacking

HELP position - Troop elevation pillow

(head elevated laryngoscopy position)

What other tools can be used to intubate an obese person?

Which intubation technique is last resort?

1. image guided intubation with the assistance of  videolaryngoscopes

2. fiber optic intubation - available & ready for emergent use

3. awake fiberoptic intubation

4. awake tracheostomy - last resort

Why is airway management so important? (3 points)

Per graph on slide 56 on average you have ___ time as normal to intubate an obese pt before their sats drop?

most morbidly obese patients have poor pulmonary reserve

decompensate rapidly with delay in tracheal intubation

airway collapse may limit ability to ventilate (short, fat neck)

1/2 the normal time or less

What surgeries is a tracheostomy mandatory for?

Why may this be difficult?

for surgeries that involve base of tongue

difficult in obese patients with short necks

for mandibular and maxillomandibular surgeries

to permit occulsion of the teeth (intermaxillary fixation)

How do obese patients respond to CNS depressants?

What may even small doses cause?

Should you give CNS depressants pre-op?

sensitive to all

minimum dosages may cause apnea & upper airway collapse

pre-op "use bzd's & opioids sparingly if at all"

What agents are good for induction & maintenance?

Why may N2O not be that good even though it is short acting?

Use short acting agents

Sevo

Des

N2O?

Propofol

NDMR - Succs

N2O can cause pulm HTN & decreases amount of O2(%) you can supplement pt with

patient is fully awake

with intact upper airway reflexes

in a high Fowlers position

in monitored environment!

What is a major risk post-op for obese pts?

Why do you see this in the first 24hrs?

Why may this be seen up to 2-5 days post op?

arterial hypoxemia

1st 24 hours -- is d/t residual anesthetic/opioid

2-5 days post-op -- is d/t delay of redistribution of 3rd spaced fluid back into the vasculature

controversial

could increase duration of apnea by decreasing hypoxic arousal effect

For post-op pain control, how do obese patients respond to opioids?

What method of pain control is ideal for obese pt post op?

very sensitive to opioids

regional ideal

"good luck lol"

What NSAID can be given post op for pain control?

onset?

peak?

DOA?

Ketorolac (Toradol)15-30 mg IV loading dose

onset ~30 min

peak 1-2 hours

DOA 4-6 hours

Post Op

Surgical procedures for obese pts often are..?

Where should obese pts go after extensive surgery?

What do you do IF you are not sure about extubating?

surgeries often long with multiple procedures

patients with extensive surgery should go to ICU with oxygen, analgesics and pulse ox

when in doubt, do not extubate

List the pharmacokinetic changes of drugs.

Volume of distribution altered 

Delayed hepatic clearance

Increased renal elimination

What should you base the initial drug dose on?

___ for females

___ for males

ideal body weight

80kg for females

100kg for males 

When administering drugs to obese patients, you must _____ to response and watch for...?

Are recovery times different for obese & non-obese in 2-4 hr procedures?

titrate to response

watch for cumulative effects of repeated doses and prolonged responses

recovery times are often the same in obese and non-obese for 2-4 hour surgeries

*stolting sts that 2-4hrs is really not long enough for extra drug to deposit in an obese pt's fat stores b/c the blood flow to those tissues is so slow.

fat face and cheeks

short neck

large tongue

excessive palatial and pharyngeal soft tissue

restricted mouth opening

limited cervical and mandibular mobility

large breasts

makes it difficult

-consider leaving a bougie in place after extubation

During induction, knowing that your obese pt has a lower FRC than normal, what may you see?

What is most important during induction?

quicker decrease in PaO2 during laryngoscopy

maximize O2 content in lungs before laryngoscopy

What is the best anesthetic for maintenance with obese pts?

Which induction drugs have quicker wake-up times?

N2O would be useful but limits ______?

best choice unknown

sevo & des produce quicker wake-up times than iso or propofol gtt

N2O would be useful but limits O2%

Engorgement caused by increased abdominal pressure makes volume of epidural space less or decreased so you need to do what to LA dose?

How high will the sensory block be on obese pts?

LA dose 20% lower

sensory level is very difficult to predict

How should you manage ventilation?

TV?

PEEP?

What adverse effect can occur d/t large TV and PEEP?

use large TV to offset decreased FRC & PaO2

 PEEP should be considered

decrease in CO

Prone - unless cut out in bed

(risk for blindness)

Trendelenburg

not until fully recovered

recover in head-up to sitting position (hi Fowlers)

caution and careful monitoring with OSAS & HVS

What is a major concern of post op analgesia?

Which route of administration is unreliable in obese pts?

What method is common?

depression of respiration

IM unreliable

PCA common

What do you base your drug dosage on?

What form of postop analgesic drugs are very effective with this population?

T/F oral/IV antiinflammatory drugs are useful?

base dose on ideal body weight

neuraxial opioids effective

(continuous epidural with opioids and LA)

True

Postop Complications

T/F M&M rates are higher in obese than non-obese. 

VQ mismatches

Decreased lung volumes

Increased WOB

 typically occurs 2-3 days post op

*fluid

SSRI

SE: increased BP and HR

adrenergic and serotonergic reuptake inhibitor

SE: htn, increased HR, dry mouth

lipase inhibitor - prevents absorption & digestion of certain fats

comes in low fat?? pringles??/potato chips??

men = ht in cm - 100 

women = ht in cm - 105