Bulimia Nervosa

Overview

Definition

Bulimia nervosa is an eating disorder characterized by recurrent episodes of binge eating Binge eating Binge eating is defined as consuming an amount of food in a specified amount of time (e.g., 1 hour) that greatly exceeds what most people would consume in that same amount of time. Binge Eating Disorder (consuming a larger-than-appropriate amount of food in a set period of time) accompanied by inappropriate compensatory behavior Compensatory behavior Binge Eating Disorder (purging).

Epidemiology

• Lifetime prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency: 1%
• Women aged 18–35 most commonly affected
• More prevalent in women
• Later onset in adolescence than in anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa nervosa

Pathophysiology

• No consensus on pathophysiology
• May be related to abnormal functioning of corticolimbic circuits (involved in appetite) 
• Efficacy of antidepressants as well as established link between serotonin Serotonin A biochemical messenger and regulator, synthesized from the essential amino acid l-tryptophan. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Receptors and Neurotransmitters of the CNS and satiety suggest the involvement of serotonin Serotonin A biochemical messenger and regulator, synthesized from the essential amino acid l-tryptophan. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Receptors and Neurotransmitters of the CNS and norepinephrine Norepinephrine Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the locus ceruleus. Receptors and Neurotransmitters of the CNS in the pathophysiology of bulimia.

Diagnosis

History

• Diagnosis is clinical, based on specific criteria:
  • Recurrent episodic binge eating Binge eating Binge eating is defined as consuming an amount of food in a specified amount of time (e.g., 1 hour) that greatly exceeds what most people would consume in that same amount of time. Binge Eating Disorder followed by feelings of disgust and guilt
  • Recurrent inappropriate compensatory behaviors to prevent weight gain, including:
    • Use of laxatives Laxatives Laxatives are medications used to promote defecation. Most often, laxatives are used to treat constipation or for bowel preparation for certain procedures. There are 4 main classes of laxatives: bulk-forming, stimulant, osmotic, and emollient. Laxatives or diuretics Diuretics Agents that promote the excretion of urine through their effects on kidney function. Heart Failure and Angina Medication
    • Self-induced vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
    • Fasting
    • Excessive exercise
  • Excessive emphasis on body shape or weight
• At least 2 episodes per week for 3 months
• Binge eating Binge eating Binge eating is defined as consuming an amount of food in a specified amount of time (e.g., 1 hour) that greatly exceeds what most people would consume in that same amount of time. Binge Eating Disorder and compensatory behavior Compensatory behavior Binge Eating Disorder do not occur exclusively during episodes of anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa nervosa.

Physical exam

Specific exam findings can be suggestive of eating disorders:

• BMI BMI An indicator of body density as determined by the relationship of body weight to body height. Bmi=weight (kg)/height squared (m2). Bmi correlates with body fat (adipose tissue). Their relationship varies with age and gender. For adults, bmi falls into these categories: below 18. 5 (underweight); 18. 5-24. 9 (normal); 25. 0-29. 9 (overweight); 30. 0 and above (obese). Obesity > 18.5 kg/m²
• Easy fatigability 
• Orthostatic hypotension Orthostatic hypotension A significant drop in blood pressure after assuming a standing position. Orthostatic hypotension is a finding, and defined as a 20-mm hg decrease in systolic pressure or a 10-mm hg decrease in diastolic pressure 3 minutes after the person has risen from supine to standing. Symptoms generally include dizziness, blurred vision, and syncope. Hypotension
• Physical signs consistent with self-induced vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia:
  • Swelling Swelling Inflammation of the salivary glands Salivary glands The salivary glands are exocrine glands positioned in and around the oral cavity. These glands are responsible for secreting saliva into the mouth, which aids in digestion. There are 3 major paired salivary glands: the sublingual, submandibular, and parotid glands. Salivary Glands: Anatomy
  • Dental caries
  • Scars or calluses on the hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy from contact with the teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth: Anatomy ( Russell sign Russell sign Anorexia Nervosa)
• Dehydration Dehydration The condition that results from excessive loss of water from a living organism. Volume Depletion and Dehydration
• Menstrual irregularities
• Mallory-Weiss syndrome Mallory-Weiss Syndrome Mallory-Weiss syndrome (MWS) is defined by the presence of longitudinal mucosal lacerations in the distal esophagus and proximal stomach, which are usually associated with any action that provokes a sudden rise in intraluminal esophageal pressure, such as forceful or recurrent retching, vomiting, coughing, or straining. Mallory-Weiss Syndrome (Mallory-Weiss Tear)
• Bloating Bloating Constipation
• Constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation

Lab findings

Though not diagnostic, certain lab findings are suggestive of bulimia: 

• Increased serum amylase Amylase A group of amylolytic enzymes that cleave starch, glycogen, and related alpha-1, 4-glucans. Digestion and Absorption due to parotid gland Parotid gland The largest of the three pairs of salivary glands. They lie on the sides of the face immediately below and in front of the ear. Salivary Glands: Anatomy hypertrophy Hypertrophy General increase in bulk of a part or organ due to cell enlargement and accumulation of fluids and secretions, not due to tumor formation, nor to an increase in the number of cells (hyperplasia). Cellular Adaptation
• Electrolyte abnormalities ( hypokalemia Hypokalemia Hypokalemia is defined as plasma potassium (K+) concentration < 3.5 mEq/L. Homeostatic mechanisms maintain plasma concentration between 3.5-5.2 mEq/L despite marked variation in dietary intake. Hypokalemia can be due to renal losses, GI losses, transcellular shifts, or poor dietary intake. Hypokalemia, hypochloremia Hypochloremia Electrolytes), which occur due to vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia and excessive renal loss of potassium Potassium An element in the alkali group of metals with an atomic symbol k, atomic number 19, and atomic weight 39. 10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance. Hyperkalemia
• Metabolic alkalosis Alkalosis A pathological condition that removes acid or adds base to the body fluids. Respiratory Alkalosis (due to recurrent acid loss in vomitus)

Management

Management

The 1st-line treatment is a combination of psychotherapy Psychotherapy Psychotherapy is interpersonal treatment based on the understanding of psychological principles and mechanisms of mental disease. The treatment approach is often individualized, depending on the psychiatric condition(s) or circumstance. Psychotherapy and pharmacotherapy. 

• Psychotherapy Psychotherapy Psychotherapy is interpersonal treatment based on the understanding of psychological principles and mechanisms of mental disease. The treatment approach is often individualized, depending on the psychiatric condition(s) or circumstance. Psychotherapy:
  • The mainstay of treatment is CBT.
  • Goal is to normalize patient’s eating behavior and avoid destructive binge-eating episodes.
  • CBT alone results in better outcomes than medications alone.
• Pharmacotherapy:
  • Selective serotonin reuptake inhibitors Selective Serotonin Reuptake Inhibitors Serotonin Reuptake Inhibitors and Similar Antidepressants ( SSRIs SSRIs Serotonin Reuptake Inhibitors and Similar Antidepressants; e.g., fluoxetine Fluoxetine The first highly specific serotonin uptake inhibitor. It is used as an antidepressant and often has a more acceptable side-effects profile than traditional antidepressants. Serotonin Reuptake Inhibitors and Similar Antidepressants) are preferred.
  • Other options:
    • Tricyclic antidepressants Tricyclic antidepressants Tricyclic antidepressants (TCAs) are a class of medications used in the management of mood disorders, primarily depression. These agents, named after their 3-ring chemical structure, act via reuptake inhibition of neurotransmitters (particularly norepinephrine and serotonin) in the brain. Tricyclic Antidepressants
    • Monoamine oxidase Oxidase Neisseria inhibitors
    • Mood stabilizers
  • Bupropion Bupropion A propiophenone-derived antidepressant and antismoking agent that inhibits the uptake of dopamine. Other Antidepressants is contraindicated in bulimia nervosa (may induce seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures). 
• Adjunct therapy:
  • Nutritional rehabilitation: need a nutritionist as a guide to help replace nutritional stores
• Hospitalization Hospitalization The confinement of a patient in a hospital. Delirium may be necessary in cases of:
  • Failure of outpatient treatment
  • Self-injuring behavior 
  • Increased risk of suicidal tendencies
  • Severe electrolyte or metabolic abnormality

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

• Higher rates of remission Remission A spontaneous diminution or abatement of a disease over time, without formal treatment. Cluster Headaches and recovery than in anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa nervosa
• Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with comorbid substance use generally have worse outcomes. 

Differential Diagnosis

• Anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa nervosa: an eating disorder characterized by intense fear of gaining weight, restricted dietary habits, and distorted body image. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship affected by anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa nervosa are usually underweight and reluctant to seek medical help. Treatment involves CBT with antidepressant Antidepressant Antidepressants encompass several drug classes and are used to treat individuals with depression, anxiety, and psychiatric conditions, as well as those with chronic pain and symptoms of menopause. Antidepressants include selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and many other drugs in a class of their own. Serotonin Reuptake Inhibitors and Similar Antidepressants medication as an adjunct. Extreme cases may require hospitalization Hospitalization The confinement of a patient in a hospital. Delirium.
• Binge-eating disorder: an eating disorder marked by recurrent episodes of binge eating Binge eating Binge eating is defined as consuming an amount of food in a specified amount of time (e.g., 1 hour) that greatly exceeds what most people would consume in that same amount of time. Binge Eating Disorder without inappropriate compensatory behavior Compensatory behavior Binge Eating Disorder, resulting in fluctuating body weight. Episodes occur at least once a week for 3 months. Treatment consists of a combination of psychotherapy Psychotherapy Psychotherapy is interpersonal treatment based on the understanding of psychological principles and mechanisms of mental disease. The treatment approach is often individualized, depending on the psychiatric condition(s) or circumstance. Psychotherapy and pharmacotherapy.
• Rumination Rumination Regurgitation and re-chewing of previously swallowed food in ruminants. Rumination Disorder disorder: repeated regurgitation Regurgitation Gastroesophageal Reflux Disease (GERD) of food, which may be re-chewed, re-swallowed, or spit out, and which is not due to a general medical condition (e.g., GERD GERD Gastroesophageal reflux disease (GERD) occurs when the stomach acid frequently flows back into the esophagus. This backwash (acid reflux) can irritate the lining of the esophagus, causing symptoms such as retrosternal burning pain (heartburn). Gastroesophageal Reflux Disease (GERD)). Treatment involves multiple CBT techniques, including biofeedback Biofeedback The therapy technique of providing the status of one’s own autonomic nervous system function (e.g., skin temperature, heartbeats, brain waves) as visual or auditory feedback in order to self-control related conditions (e.g., hypertension, migraine headaches). Psychotherapy psychotherapy Psychotherapy Psychotherapy is interpersonal treatment based on the understanding of psychological principles and mechanisms of mental disease. The treatment approach is often individualized, depending on the psychiatric condition(s) or circumstance. Psychotherapy, as well as medication when appropriate (e.g., proton pump Pump ACES and RUSH: Resuscitation Ultrasound Protocols inhibitors).
• Kleine-Levin syndrome (KLS): also known as “sleeping beauty syndrome,” a very rare sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep disorder that includes recurrent episodes of hypersomnia Hypersomnia Disorders characterized by hypersomnolence during normal waking hours that may impair cognitive functioning. Subtypes include primary hypersomnia disorders (e.g., idiopathic hypersomnolence; narcolepsy; and kleine-levin syndrome) and secondary hypersomnia disorders where excessive somnolence can be attributed to a known cause (e.g., drug affect, mental disorders, and sleep apnea syndrome). Whipple’s Disease that presents with behavioral or cognitive abnormalities, including compulsive eating and hypersexuality. Ptients with KLS do not have a crippling fear of weight gain or place a great deal of self-worth on their body weight and shape, unlike patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with bulimia nervosa.