9 Morbidly Obese Patient Flashcards
Obesity is defined as
WHO:
obese: BMI ≥30 kg/m2
morbidly obese: BMI ≥40 kg/m2
Asia-Pacific Guidlines:
obese: BMI ≥25 kg/m2
Diagnostic criteria for Obesity Hypoventilation Syndrome
BMI 30 kg/m2
Daytime PaCO2 >45 mm Hg
Associated sleep-related breathing disorder (OSA-hypopnea syndrome or sleep hypoventilation or both)
Absence of other known causes of hypoventilation
formula for weight estimation based on mid-arm circumference in school-age children
weight (kg) = (mid-arm circumference [cm] - 10) x 3
the standard adult blood pressure cuff is too short for patients with an arm circumference of
32 cm or larger
Patients who are overweight or obese will require cuffs larger in size
AHA recommendation of cuff widths when evaluating BP in obese
arm circuference 35-44 cm: 16 cm width
arm circumference 45-52 cm: 20 cm width
patients with short upper arm length: 16 cm width
Some common drugs that use ideal body weight in dosing
pencillins & cephalosporins
corticosteroids & H2-blockers
Digoxin & beta blockers
PROPOFOL
FENTANYL**
**MIDAZOLAM & *lorazepam
atracurium, vecuronium
phenytoin
linezolid
**initial dose still based on total body weight*
Some common drugs that use total body weight in dosing
ROCURONIUM
ENOXAPARIN
succinylcholine
unfractionated heparin
vancomycin
how to determine ideal body weight by *Devine formula**?
male weight = 50 kg + 2.3 kg (each inch >5 feet)
female weight = 45.5 kg + 2.3 kg (each inch >5 feet)
drugs whose initial dose should be based on total body weight but whose subsequent doses should be based on ideal body weight
Fentanyl and benzodiazepines
- lipophilic and have a prolonged half-life in obese patietns
remarks on femoral venous catheterization
in general, there is an increased incidence of infection and DVT when using the femoral approach.
If this proves to be the only option, then use this site.
remarks on internal jugular venous catheterization
the internal jugular vein can be accessed with equal success to the subclavian approach in patietns who are obese
the success rate might be increased with the head maintained in the neutral position, thereby reducing the risk of overlap of the IJV over the carotid artery
remarks on procedural sedation in the obese
Give procedural sedation drugs and pain medications cautiously. Select doses at the lower end of the range, and titrate to effect.
Local and regional anesthesia might be considered for complicated or prolonged procedures
characteristics that render obese patients more prone to aspiration during airway management
- increased intra-abdominal pressure
- increased incidence of hiatal hernia
- GERD
true or false:
Patients who are obese will desaturate more rapidly after preoxygenation than their lean counterparts.
TRUE
When no cervical spine injury is suspected, desaturation may be partially prevented by keeping the patient in a 25-degree head-up position during preoxygenation
maneuver recommended for opening airway in morbidly obese patients
Two-person bag-valve mask with a two-handed bilateral jaw thrust is recommended in patients who are morbidly obese.
true or false:
Obesity is a contraindication for rapid-sequence intubation (RSI)
FALSE
It is not.
Advance preparation is critical, and assessment for a potential difficult airway is of utmost importance
true or false:
The “sniffing” position results in optimal positioning for laryngoscopy in patients who are obese
FALSE
“Sniffing” position results in suboptimal view
and this my also confound results and falsely worsen graded views
The “ramping” position offers improved intubation condition in patients who are morbidly obese.
- achieved by placing multiple folded blankets under the upper body, head, and neck until the external auditory meatus and the sternal notch are horizontally aligned
Another option is intubating with the patient semi-upright
The relative benefits and risks of the awake intubation approach must be weighed against the merits of RSI, which are:
- reduction of risk of aspiration
- improved intubating conditions
- easier insertion of advanced and rescue airway devices
Until the proper size tracheostomy tube is located, a _________ ET tube passed through a cricothyroidotomy incision may serve as a temporizing measure
6-mm-inner-diameter ET tube
with respect to ventilator management, calculate tidal volume using
ideal body weight and begin with volumes of 6-8 mL/kg of ideal body weight
remarks on trauma in obese patients
MORE
rib fractures
pelvic fractures
pulmonary contusions
extremity fractures
risk of death
LESS
head injuries
liver injuries
remarks on trauma on mildly overweight patients
less prone to intra-abdominal injury because of the protective effect of the abdominal fat, known as “cushion effect”
