Anorexia nervosa Flashcards
What is the definition of anorexia nervosa?
A psychiatric condition characterized by restriction of food intake in what has been termed the “relentless pursuit of thinness.”
Predmoninatly observed in girls and young women.
Males represent 5-10% of patients.
What are the types of anorexia nervosa?
Restricting type
Binge-eating/purging type
How is anorexia nervosa caused?
No underlying physical problems with food intake or absorption.
Abnormalities almost entirely attributable tot he following:
Starving or vomiting due to the use of emetics
Laxatives
Diuretics
How does food intake affect the nutritional aspects of AN?
Decreased food intake.
Restrictive AN eat proportionally fewer calories from fat.
Proportionally more calories eaten as carbohydrate.
Usual or higher proportion of calories taken as protein.
Absolute decreases in micronutrient intake.
How is absorption affected by AN?
Nutrient absorption expected to be normal.
Decreased ORAL glucose absorption.
How are serum carotene levels affected by AN and what does it suggest?
Elevated serum carotene levels.
Suggestive of decreased hepatic metabolism.
How is nutrition lost in AN?
D/t vomiting and the use of purgatives, laxatives, and diuretics
What is commonly lost in AN?
Water
Na, Cl, K, Mg
H+ (w/vomiting)
HCO3 (w/diarrhea)
What are the nutritional requirements of AN?
Lower metabolic rates than predicted.
Refeeding syndrome.
Protein restitution.
How many calories above maintenance is needed to increase weight 1kg?
5000 - 7500kcal
How many calories are required to restore body fat?
Requires up to 8000kcal/kg of fat
For whom should a focused assessment be conducted?
On all patients and should include:
Hx
Physical Examination
Lab tests
What should the history include in a focused assessment?
Weight Weight control Beliefs about food Frequency and duration of bingeing epidodes Purging behaviors
What should the physical exam include in a focused assessment?
Body measurements
Physical findings
When vomiting is a feature of illness (parotid enlargement, Russell’s sign)
Medical complications
What lab tests are included in a focused assessment?
Hematologic changes are common
Electrolyte disturbances
ECG abnormalities
What are the goals of therapy for AN?
Treatment of complications associated with condition.
Restoration of nutritional status to premorbid state.
Restore a normal body image so that normal nutritional status can be maintained.
How are AN patients managed?
Hospitalization
Multidisciplinary approach required
When are AN patients hospitalized?
Fluid and electrolyte abnormalities
Profound malnutrition
Rapid weight loss necessitating hospital admission
Other complications
What are multidisciplinary approaches?
Psychiatrists Internists Nutritionists Pharmacists Nurses Pediatricians
What weights are obtained in the history?
Current
Premorbid
Highest and lowest
Women
What weight controls are obtained in the history?
How patient lost weight Helps to characterize class of AN
What beliefs about food are included in the history?
Includes feelings about food allergies
Intolerances
What is recorded about frequency and duration of bingeing episodes in the history?
Foods usually consumed
What is recorded in the history for purging behaviors?
Use of emetics
Laxatives
What body measurements are recorded in physical examination?
Height
Weight
BMI
Anthropometric measurements
What physical findings are receorded in physical examinations?
Muscle mass
SQ tissues stores
What medical complications are recorded in a physical examination?
Volume depletion
Weakness
Dysrhythmias
What hematologic changes are common in laboratory tests?
Anemia
Neutropenia
Thrombocytopenia
What electrolyte imbalances are recorded in lab tests?
Hyponatremia
Hypochloremia
Hypokalemia
Metabolic alkalosis
What ECG abnormalities are recorded in lab tests?
Occur 60-70% of patients. Sinus bradycardia. Low amplitude QRS complexes. Nonspecific changes to ST and T waves U waves (hypokalemia) QT interval prolongation
What are the goals of therapy?
Treatment of complications associated with condition.
Restoration of nutritional status to premorbid state.
Restore a normal body image so that normal nutritional status can be maintained.
How is weight restoration achieved?
Consumption of a normal diet.
Avoidance of “artificial” means of nutrition support.
Slower rates of weight gain generally accepted.
What are artificial means of nutrition support?
Liquid supplements
Tube feeding
What topics are discussed for dietary counseling?
Types and quantities of foods eaten. Permitted to avoid only a limited number of foods. Important goal is to widen food choices. No hard guidelines on caloric intake. Frequent follow-up.
What is the recommended caloric intake for outpatients with AN?
1000-1500kcal/day.
Increase weekly by 250-500kcal/day.
Goal weekly weight gain of 1kg recommended.
What are the 3 phases of inpatient treatment?
Stabilization.
Fluid and electrolyte repletion.
Administration of micronutrients.
What is monitored for inpatient treatment?
CBC - weekly BMP - daily for 3 days then every 3 days ECG rPTT or INR Ca, Mg, PO4
Refeeding syndrome
Occassionally delayed for 24 hours. Monitoring extremely important. Begin by providing 20-25kcal/kg body weight. 1000-1500kcal/d to start. Modest calorie increases in first week.
When is it okay to administered parenterally?
When the gut is not intact.
Severe gastric retention.
Bowel obstruction from adhesions.
Crohn’s disease.
When is tube feeding essential?
Very malnourished patients.
When restoring body mass in patients incapable on their own.
Gastric retention/rupture.
Consider wastage by patient.
What is a common tendency with parenteral nutrition?
Push calories more than with enteral.
Cardiac and pulmonary decompensation.
What education should be given for AN?
Should be provided to both patient and caregiver.
Nutrition counseling is a key component of therapy.
Many educational aspects of therapy tend to be more behavioral.
Encourage patients to become knowledgeable about nutrition and effects of starvation.
