Obesity (Exam III) Flashcards
What is the #1 cause of medically-related preventable deaths?
Smoking
Obesity is #2.
What is an android body fat distribution associated with?
↑ O₂ consumption
CV disease
Gynoid body fat distributions are _____ metabolically active and not as associated with ______ disease.
less ; cardiovascular
Total blood volume is ______ in obesity.
increased
Obesity blood volume to weight ratio is typically lower than _____ mL/kg.
50 mL/kg
What occurs with cardiac output in obese patients?
CO will ↑ by 20-30 mL per kg of excess body fat.
CO increases due to LV dilation and ↑ stroke volume.
What causes cardiac dysrhythmias in the obese patient?
- Fatty infiltrates in the conduction system
- CAD
What EKG changes are typical of the obese patient?
- ↓ QRS voltage
- LV hypertrophy
- Left axis deviation
Increased levels of what coagulative factors are noted in obesity?
- Fibrinogen
- Factor VII
- Factor VIII
- Von Willebrand
Increased levels = hypercoagulability.
Why does endothelial dysfunction occur in the obese patient?
Due to ↑ factor VIII and von Willebrand.
Gastric ______ and _____ are increased in the obese patient.
Gastric volume and acidity are increased.
What intubation risk factors are present in an Obese patient due to changes in the GI system?
- Delayed gastric emptying
- ↑ chance of gastric volume > 25mL
- ↑ chance of pH < 2.5
What are the results of increased intragastric pressure secondary to obesity?
- LES relaxation
- Hiatal hernia formation
Glomerular _______ occurs with obesity due to increased renal blood flow.
hyperfiltration
What are the consequences of increased renal tubular absorption secondary to obesity?
- Impaired natriuresis
- RAAS activation
What are the endocrine effects of obesity?
- ↑ SNS activity
- Insulin resistance
- Enhanced NE and Ang II activity
- Na⁺ retention
- Thyroid hormone resistance
Metabolic syndrome diagnosis requires 3 of the following:
- Abdominal obesity
- ↓ HDLs
- ↑ Triglycerides
- Hyperinsulinemia
- Glucose intolerance
- Hypertension
- Inflammatory state
- Thrombotic state
What ethnicities are at higher risk for metabolic syndrome?
Hispanics and South Asians
What drugs may cause metabolic syndrome?
- Chronic corticosteroids
- Antidepressants
- Antipsychotics
- Protease inhibitors
Differentiate OSA and hypopnea.
- OSA: Complete cessation of breathing (5 times or more an hour)
- Hypopnea: Airflow reduction by ≥ 50% (15 times or more an hour)
What would a mild apnea/hypopnea index be?
5 - 15 events/hour
What would a moderate apnea/hypopnea index be?
15 - 30 events/hour
What would a severe apnea/hypopnea index be?
> 30 events/hour
CPAP is necessary for treatment of OSAHS (Obstructive sleep apnea and hypopnea syndrome) due to risk of what complications?
- Systemic/Pulmonary HTN
- LVH
- Dysrhythmias
- Cognitive impairment
What’s another name for Obesity Hypoventilation Syndrome?
Pickwickian Syndrome
What causes Pickwickian syndrome?
Long-term OSA
What does Pickwickian syndrome cause?
Pulm HTN and Cor Pulmonale
How is Pickwickian syndrome diagnosed?
- > 30 BMI
- Awake hypercapnia
What drug(s) classes are used to treat obesity?
- Phentermine
- Orlistat
- OTC Herbals
- GLP-1 Agonists
How does Phentermine work?
What are it’s side effects?
- Sympathomimetic that decreases appetite
- ↑HR, palpitations, HTN, dependence
How does Orlistat work?
What are the adverse effects associated with it?
- Orlistat blocks absorption of dietary fat
- Liquid, fatty stools, urgency, flatulence and cramping.
- Fat soluble vitamin deficiencies
How can Orlistat precipitate coagulopathy?
Possible Vit K deficiency → prolonged PT
Which herbals are pancreatic lipase inhibitors?
Caffeine
Green Tea
How do ginseng, ephedra, and sunflower oil “treat” obesity?
Appetite suppression
What berry is an OTC herbal energy stimulant?
Acai
What OTC Herbals regulate lipid metabolism?
- Soybean Oil
- Fish Oil
- Oolong tea
For patients taking a GLP-1 Agonist on a weekly basis, it is recommended to hold the dose for _____ prior to surgery.
1 week
How would a patient be treated if they forgot to hold their GLP-1 Agonist prior to surgery?
The patient is to be treated as a full stomach or gastric contents need to be evaluated by US.
CPAP pressures of > ______ cmH₂O are associated with difficult mask ventilation.
10 cmH₂O
How does closing capacity compare to tidal breathing in the morbidly obese patient?
Closing capacity ≈ Tidal breathing
Especially when recumbent/supine.
What is the most important respiratory/ventilatory intervention that can be done for the obese patient prior to intubation?
Preoxygenate.
What can possibly lead to renal failure when a morbidly obese patient is placed in the supine position?
Rhabdomyolysis of the gluteal muscles
Is prone or lateral decubitus positioning preferred in the obese patient?
Lateral decubitus
What oropharynx change occurs with obesity?
Oropharynx shape becomes elliptical w/ a short transverse and long AP axis.
Increased ________ ________ deposited into the airways can complicate airway management.
Adipose tissue
What is the relationship between degree of obesity and pharyngeal area?
Inverse relationship
More obese = Less pharyngeal area.
What predictors of difficult intubation are of particular import in the obese patient?
- BMI (though not all the time)
- Small mouth opening
- Large Teeth
- Limited neck mobility
- Retrognathia
What axes need to line up for intubation?
Laryngeal, Pharyngeal, and oropharyngeal
How quickly will a patient with a normal BMI desaturate from 100% to 90% SpO₂?
6 minutes
How quickly will a patient with a morbidly obese BMI desaturate from 100% to 90% SpO₂?
3 minutes or less
What is the best positioning on an OR table for recruitment in an obese patient?
- 30° Reverse Trendelenburg
- 25-30° with the head up
What measures should be take for alveolar recruitment to prevent atelectasis and desaturation in the obese patient?
- CPAP 10 cmH₂O during preoxygenation
- Positioning
- Recruiting maneuvers then PEEP 10cm
- Mechnical ventilation after induction
Which drug classes have exaggerated responses in obese patients (particularly those with OSA) ?
- Opioids
- Benzo’s
- Propofol
Which opioids are preferred in obese OSA patients?
Short-acting Opioids
- Remifentanil
- Fentanyl
______ is not a favored volatile in obese patients due to their greater O₂ demand.
N₂O
What drug class (in general) will diminish ventilatory response to CO₂?
VAA’s
Initial dosing of drugs in obese patients should be based on ______ _______.
Lipid solubility
Which common anesthetic drugs are dosed based on Ideal Body Weight (IBW)?
- Propofol
- Vecuronium
- Rocuronium
- Remifentanil
Which common anesthetic drugs are dosed based on Total Body Weight (IBW)?
- Midazolam
- Succinylcholine
- Cisatracurium
- Fentanyl
- Sufentanil
IV fluids requirements are ______ than what’s predicted in order to prevent acute tubular necrosis in the obese patient.
greater