Obesity Flashcards
When does adipose tissue become pathologic?
When it starts releasing FFAs and cytokines.
Visceral fat releases the most of that, which is why android obesity carries highest health risk.
Diagnosis of metabolic syndrome
Must have three of these
1) Large waist size (>40 inches for men or 35 for women)
2) TG > 150
3) HDL 130/85
5) Fasting BG > 100
Respiratory effects of obesity
Restrictive lung disease pattern!
FRC reduced
VC reduced
TLC reduced
ERV reduced
CC normal
Prone to hypoxemia because of decreased FRC and increased O2 consumption
Formula for BMI
(kg)/(m2)
Appropriate TV for morbidly obese patient
6-8mL/kg
Larger volumes only improve oxygenation minimally and may cause sheer stress to the lungs
Maneuver for recruiting alveoli
PPV to 40cmH2O and hold for 10 seconds
How should minute ventilation be increased?
Using RR rather than TV
What is the main cause of CV complications in obesity?
Expansion of intravascular volume and a high cardiac output state
Excess adipose tissue requires more vasculature to support their growth. More work for the heart, and the heart dilates to accommodate the extra volume.
CO increases 100mL/min for every extra kg of fat. HR is usually unchanged, so this is accomplished by increases in SV.
Why are obese people prone to dysrhythmias?
Cardiac hypertrophy, CAD, and fatty infiltration o the conduction system.
Weight based dosing for normal weight people and obese people
Water soluble drugs calculated on IDEAL BODY WEIGHT
Lipophilic drugs are calculated by TOTAL BODY WEIGHT
In the obese, Vd for both lipophilic and hydrophilic drugs increase, but lipophilic way more so.
Problem with this dosing is that IBW dosing may under-dose them, and TBW dosing may overdose them (fat is less vascular than other tissue)!
- Dosing based on LEAN body weight solves this issue!!!
Pseudocholinesterase activity in the obese
Increased.
Sux is dosed on TBW because of increased hydrophilic Vd as well as increased activity of pseudocholinesterase!
AHI scores and OSA
Mild = 5-15 episodes/hr Moderate = 15-30 episodes/hr Severe = >30 episodes/hr
This is the most sensitive sign of an anastomotic leak follow gastric bypass
Unexplained tachycardia***
Fever and abdominal also frequently seen
Estimated Blood Volume of obese patients
50mL/kg
This is because adipose tissue isn’t as vascular as lean tissue
Fluid management in the obese population should be based on this weight
LBW
