Exam 1: Obesity Flashcards
BMI for obese, morbidly obese, and super-obese:
30+
40+
50+
WHO obesity classes and BMIs:
Class I: 30-34.9
Class II: 35-39.9
Class II: 40+
Four post-op DVT risk factors:
Venous stasis
BMI 60+
Truncal obesity
OSA/OHVS
Lung volume changes in obesity:
Decreased FRC
Decreased ERV
TV approaching closing capacity
Sequelae of decreased FRC r/t induction:
Less safe apnea time
Respiratory changes in ventilation:
Increased O2 consumption, CO2 production
High MV d/t inc RR
Dec chest wall compliance
Inc respiratory resistance/restrictive lung disease
PFT changes in obesity:
May remain normal until lung disease advances/pulmonary hypertension starts
Troublesome positions for obese pts:
Supine
Trendelenberg
Prone
% intubation difficulty at neck circumference of 40cm and 60cm:
5% and 35%
CO increases by ______ per each ______ of adipose tissue:
.01L/min per KG
Arterial HTN and CAD risk is _____ in obese pts:
Doubled
How does obesity lead to RH failure?
Increased blood volume and OSA/OHS leads to pulmonary hypertension
Increased CO and PHTN leads to increased RV workload and hypertrophy
How does obesity lead to LH failure?
Increased CO leads to increased LV workload,
Which, along with systemic HTN, leads to LV hypertrophy
Which, along with CAD, leads to LV failure
OSA characterized by:
Apnea > 10 seconds despite repiratory effort
Hypopnea episodes resulting in 4%+ drop in arterial O2
Mild/moderate/severe OSA:
Mild: 5-14 episodes/hr
Moderate: 15-30
Severe: 31+
OSA risk factors:
Middle age Male Obese ETOH use Drug sleep aids Abdominal fat Neck girth (16+ women, 17+ men)
Another name for obesity hypoventilation syndrome:
Pickwickian syndrome
OHS characterized by:
Loss of hypercarbic drive due to progressive desensitization of respiratory centers to nocturnal hypercarbia
Sudden death during sleep
GI effects of obesity:
GERD Hiatal hernia Increased gastric volume Increased intragastric pressure Increased gastric acidity
Thromboembolic effects of obesity:
DVT risk doubled
Polycythemia
Increased intra-abdominal pressure
Immobility
Gastric risk factors for aspiration pneumonitis:
Volumes > 25ml
pH < 2.5
Hepatic effects of obesity:
Fatty liver
Abnormal LFTs
Metabolic effects of obesity:
Insulin resistance
Adult onset DM
A fasting BG above _____ is a problem pre-op.
200
Reglan is contraindicated in what condition?
Bowel obstruction
What can reverse elevated LFTs due to obesity?
Weight loss
How do obesity-related elevatd LFTs affect clearance?
Normal clearance
Pre-op labs for obesity:
LFTs
Albumin level
Glucose
Clotting studies if risk factors
What position provides the longest safe apnea period for the obese pt?
Head-up Trendelenberg
Prone position for obese patients has these effects:
Increases intra-abd pressure
Worsens caval/aortic compression
Decreases FRC further
Aspiration prophylaxis for obese pts:
H2 antagonists
Bicitra
Reglan
Omeprazole
