Obesity Flashcards
What is another name for the ideal body weight calculation?
Broca’s Index
Describe android obesity. State four other names for android obesity.
Android obesity is characterized by adipose tissue distribution predominantly in the upper body. A waist-to-hip ratio of 0.85 for males and 0.92 for females is consistent with android obesity. It is also known as central, abdominal, truncal, or “apple-shaped” obesity.
Describe gynecoid obesity. State 3 other names for gynecoid obesity.
In gynecoid obesity, adipose tissue is located mainly in the hips, buttocks, and thighs. It is also called peripheral, gluteal femoral, or “pear-shaped” obesity.
What pulmonary disease pattern is exhibited by morbidly obese patients?
Restrictive disease
Compared with the normal individual, what happens to chest wall compliance, lung compliance and FRC in the obese person?
Chest wall, lung parenchyma and pulmonary compliance decrease to 35% of predicted values. Decreased pulmonary compliance makes lung inflation more difficult causing decline in FRC to less than closing capacity.
What happens to closing capacity and FRC in the morbidly obese patient while upright, supine, or Trendelenburg?
In the upright position, FRC is decreased and closing capacity is increased. Closing capacity may be reached during tidal ventilation, meaning some airways close during tidal breathing. In the supine position, FRC decreases further and tidal breathing continue to occur with some airways closed. In the Trendelenburg position,, FRC is reduced to residual volume – there is no ERV — and is well below closing capacity.
Define apnea. What additional feature characterizes apnea as obstructive sleep apnea?
Apnea is the cessation of airflow at the nose and mouth for more than 10 seconds. Apnea is considered obstructive if there is continue respiratory effort despite airflow cessation.
What laboratory study provides the definitive diagnosis of OSA?
A polysomnography.
The results of a polysomnography are reported as the apnea/hypopnea index, which is graded into three levels of severity. How is the AHI calculated? List the 3 classifications of AHI.
The AHI is calculated as the total number of episodes of apnea and hypopnea divided by the total sleep time. Mild disease: AHI 5-15 events per hour; Moderate disease: AHI 15-30 events per hour; Severe disease: AHI > 30 events per hour.
List eight physiologic abnormalities that result from OSA?
1) hypoxemia (during apnea); 2) hypercarbia (during apnea); 3) pulmonary vasoconstriction; 4) systemic vasoconstriction; 5) cardiac arrhythmias; 6) secondary hypoxemia; 7) cognitive impairment; 8) daytime somnolence
Long-term OSA may lead to obesity hypoventilation (Pickwickian) syndrome (OHS), which is seen in 5-10% of morbidly obese patients. Describe the progression from OSA to OHS and the defining characteristics of OHS.
OHS is a combination of obesity and chronic hypoventilation that ultimately results in respiratory acidosis, pulmonary hypertension, right ventricular failure, and cor pulmonale. The presence of both obesity (BMI > 30) and AWAKE arterial hypercapnia in the absence of known causes of hypoventilation supports the diagnosis of OHS.
What is a metabolic syndrome?
Also known as syndrome X and insulin-resistance syndrome, it is a cluster of metabolic abnormalities associated with an increased risk of diabetes and cardiovascular events.
Metabolic syndrome is defined as the presence of 3 or more of 5 criteria. State the 5 criteria that define metabolic syndrome.
1) central obesity (increased waist circumference): > 40 inches in males and > 35 inches in females; 2) triglycerides > 150 mg/dL; 3) HDL < 40 mg/dL in males or < 50 in females; 4) Blood pressure > 130/85 or use of antihypertensives; 5) elevated fasting glucose > 100 mg/dL or use of antihyperglycemic agent.
What causes the prolonged responses of some medications given to a patient with morbid obesity?
Increased volume of distribution for lipid-soluble drugs.
For which IV anesthetic agents should dosing be based upon lean body weight in the obese patient?
Loading doses for thiopental and propofol, non-depolarizing neuromuscular blockers, remifentanil, fentanyl, and sufentanil,
