Obesity 2 Flashcards
Considerations for the cardiovascular effects of morbid obesity include: (select 2)
a. tachycardia
b. increased EKG voltage
c. diastolic dysfunction
d. increased venous return
c. diastolic dysfunction
d. increased venous return
__________ and _____________ place a higher workload on the myocardium for obese patients.
increased intravascular volume and a high cardiac output
The myocardium suffers ____________ with obese patients.
diastolic dysfunction; systolic dysfunction can progress to biventricular heart failure
Hypertension in obese patients results from
hyperinsulinemia
SNS + RAAS activation
increased cytokine concentrations in the plasma
Common EKG changes for obese patients include
axis deviation (right or left), low voltage, dysrhythmias (QT prolongation), & ischemia
Cardiac output increases by ___________ for every extra kg of fat.
100 mL/min.
What should you use to calculate perioperative fluid requirements for the obese patient?
lean body weight
The presence of _____________ on TEE may be the most useful confirmation of pulmonary hypertension in the obese patient.
tricuspid regurgitation
Why is cardiac output increased in the obese patient?
stroke volume increases
blood volume increases
In the obese patient, which factors are expected to increase? (select 2)
a. MAC
b. circulation time
c. volume of distribution of lipophilic drugs
d. volume of distribution of hydrophilic drugs
c. volume of distribution of liphophilic drugs
d. volume of distribution of hydrophilic drugs
As a general rule, water-soluble drug doses are calculated with _______, while lipid-soluble drug doses are calculated with _______. Obesity complicates things so you can’t rely on this oversimplified approach
IBW; TBW
_______ is not affected by obesity
MAC
Volatile agents are ________ so agents with _________ should be used in the obese patient.
liphophilic lowest blood:gas coefficients
______ is generally avoided in the obese patient because ___________
Nitrous oxide; restricts the maximum FiO2 that can be delivered
Obesity increases the volume of distribution for
lipid-soluble AND water-soluble drugs (lipid»_space;> water)
_________ should be used to calculate drug doses for the obese patient.
Lean body weight
The volume of distribution of a drug in the obese patient is altered by:
increased blood volume
increased cardiac output
altered plasma protein binding
lipid solubility of the drug
LBW can be estimated by
IBW x 1.3
The initial dose of which drugs should be based on total body weight? (select 2)
a. propofol
b. succinylcholine
c. remifentanil
d. midazolam
b. succinylcholine
d. midazolam
Lean body weight should be used to calculate the following drug doses for induction/loading doses:
propofol
rocuronium
vecuronium
remifentanil
Lean body weight should be used to calculate that following drug doses for maintenance doses of:
rocuronium
vecuronium
fentanyl
sufentanil
remifentanil
Total body weight should be used to calculate the induction/loading doses of
succinylcholine
cisatricurium
atracurium
fentanyl
sufentanil
midazolam (this does NOT include preoperative anxiolysis)
Total body weight should be used to calculate the maintenance doses of
propofol
cisatracurium
atracurium
midazolam
Engorgement of the epidural veins and increased epidural fat content will cause
a greater spread of local anesthetic in the epidural space
dose should be reduced 75% of the normal dose
