Medical Management Of Anorexia Nervosa And Bulimia Nervosa

Note: This chapter is written to benefit both professional and nonprofessional readers and is geared specifically to anorexia nervosa and bulimia nervosa. The reader is referred to other sources for information on binge eating disorder. An overview of the general medical concerns of these eating disorders is provided, as well as guidelines for a thorough medical assessment, including laboratory tests that must be performed. An in-depth discussion of the problems related to amenorrhea and bone density has also been added to this most recent edition.

Of the entire gamut of psychological disorders treated by clinicians, anorexia nervosa and bulimia nervosa are the ones most frequently punctuated by accompanying medical complications. Although many of these are more annoying than serious, a distinct number of them are indeed potentially life threatening. The mortality rate for these disorders exceeds that found in any other psychiatric illness and approaches 20 percent in the advanced stages of anorexia nervosa. Thus, a clinician cannot simply assume that the physical symptoms associated with these eating disorders are just functional in origin. Physical complaints must be judiciously investigated and organic disease systematically excluded by appropriate tests. Conversely, it is important, from a treatment vantage point, to avoid subjecting the patient to expensive, unnecessary, and potentially invasive tests.

Competent and comprehensive care of eating disorders must involve understanding the medical aspects of these illnesses, not just for physicians but for any clinician treating them, regardless of discipline or orientation. A therapist must know what to look for, what certain symptoms might mean, and when to send a patient for an initial medical evaluation as well as for follow-up. A dietitian will likely be the team member who performs the nutrition evaluation, instead of the physician, and must have adequate knowledge of all medical/nutritional aspects of eating disorders. A psychiatrist may prescribe medication for an underlying mood or thought disorder and must coordinate this with the rest of the treatment.

The medical complications that arise vary with each individual. Two persons with the same behaviors may develop completely different physical symptoms or the same symptoms within different time frames. Some patients who self-induce vomiting have low electrolytes and a bleeding esophagus; others can vomit for years without ever developing these symptoms. People have died from ingesting ipecac or excessive pressure on their diaphragms from a binge, while others have performed these same behaviors with no evidence of medical complications. It is critical to keep this in mind. A bulimic woman who binges and vomits eighteen times a day or a 79-pound anorexic can both have normal lab results. It is necessary to have a well-trained and experienced physician as part of the treatment of an eating disordered patient. Not only do these physicians have to treat symptoms that they find, but they have to anticipate what is to come, and discuss what is not revealed by medical lab data.

A physician treating a patient with an eating disorder needs to know what to look for and what laboratory or other tests to perform. The physician must have some empathy and understanding of the overall picture involved in an eating disorder to avoid minimizing symptoms, misunderstanding, or giving conflicting advice. Unfortunately, physicians with special training and/or experience in diagnosing and treating eating disorders are not very common, and furthermore, patients who seek psychotherapy for an eating disorder often have their own family doctors they may prefer to use rather than one the therapist refers them to. Physicians not trained in eating disorders may overlook or disregard certain findings to the detriment of the patient. In fact, eating disorders often go undetected for long periods of time even when the individual has been to a physician. Weight loss of unknown origin, failure to grow at a normal rate, unexplained amenorrhea, hypothyroid or high cholesterol can all be signs of undiagnosed anorexia nervosa that physicians too often fail to act on or attribute to other causes. Patients have been known to have loss of dental enamel, parotid gland enlargement, damaged esophagi, high serum amylase levels, and scars on the back of the hand from self-induced vomiting, and yet still be undiagnosed with bulimia nervosa!

Although there is clearly a continuum in the spectrum of physical illnesses encountered in anorexia and bulimia, with much clinical overlap, the discussions of anorexia and bulimia and their unique medical complications are also useful.

ANOREXIA NERVOSA

Most medical complications in anorexia are a direct result of weight loss. There are a number of easily observable skin abnormalities that are seen including brittle nails, thinning hair, yellow-tinged skin, and a fine downy growth of hair on the face, back, and arms, which is referred to as lanugo hair. All of these changes revert to normal with weight restoration. There are other, more serious complications involving a variety of systems in the body.

Most anorexics can be treated as outpatients. Inpatient hospitalization is recommended for patients whose weight loss is rapidly progressive or whose weight loss is greater than 30 percent of ideal body weight, as well as for those with cardiac arrhythmias or symptoms of inadequate blood flow to the brain.

GASTROINTESTINAL SYSTEM

The gastrointestinal tract is affected by the weight loss inherent to anorexia nervosa. There are two main issues in this regard.

Complaints of early satiety and abdominal pain. It has been shown by well-performed studies that the transit time of food out of the stomach and through the digestive tract is significantly slowed in individuals with anorexia nervosa. This, in turn, can produce complaints of early satiety (fullness) and abdominal pain. Although it is clearly logical to surmise that such a complaint in this population may be part of the illness and represent an attempt to avoid the psychological pain of beginning to once again eat normally, there may clearly be an organic basis to this concern. A quality, thorough physical examination and evaluation will be able to define the correct source of these complaints. If the complaints are truly organic and no metabolic cause is found to explain them, treatment with an agent that speeds emptying of the stomach should afford the patient relief; reducing the caloric load and rate of refeeding (beginning to eat normally after self-induced starvation) will also be therapeutic. These problems resolve with weight gain.

Complaints of constipation. Many anorexics are troubled by constipation, particularly early on in the refeeding process. This is in part attributable to the slowed gastrointestinal transit time described above. In addition, there is a poor reflex functioning of the colon secondary to a history of inadequate food intake. It is important to keep in mind that complaints of constipation are frequently due to a patient's false perception of what causes constipation. It is important to forewarn these patients from the outset that it normally may take three to six days for food to pass through the digestive system. Thus, it may be impractical to expect a bowel movement the first day after beginning to increase daily caloric intake. In addition to forewarning, it is important to educate patients about intake of adequate liquids and fiber as well as a judicious amount of walking, because the bowel becomes sluggish when an individual is sedentary. An extensive medical workup for constipation is generally unnecessary unless a series of abdominal examinations confirms obstruction and progressive distention (bloating).

CARDIOVASCULAR SYSTEM

Just as the other body systems are affected by weight loss, the cardiovascular system is also not spared. Severe weight loss causes thinning of the heart muscle fibers and a resultant diminished cardiac volume. As a result of this process, there is a reduction in maximal work capacity and aerobic capacity. A slowed heart rate (40 to 60 beats/minute) and low blood pressure (systolics of 70 to 90 mm Hg) are commonly found in these patients. These changes are not dangerous unless there is coexisting evidence of heart failure or an arrhythmia (irregular heartbeat). There is also an increased prevalence of a heart valve abnormality known as mitral valve prolapse. While generally benign and reversible with weight gain, it can produce palpitations, chest pain, and even arrhythmias.

One other cardiac concern is known as the refeeding syndrome. All malnourished patients are at risk for the refeeding syndrome when nutritional repletion is initiated. This syndrome was first des-cribed in survivors of concentration camps after World War II. There are multiple causes for this syndrome. The potential for starvation-induced low blood levels of phosphorus following intake of foods high in calories or glucose is one of the main causes of this sobering syndrome. Phosphorous depletion produces widespread abnormalities in the cardiorespiratory system, which can be fatal. In addition to phosphorous, the refeeding syndrome also evolves due to changes in potassium and magnesium levels. Further, abrupt blood volume expansion and inappropriately aggressive nutritional intake may place excessive strain on the shrunken heart and cause the inability of the heart to maintain adequate circulation.

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The crucial issue when refeeding anorexic patients is to identify beforehand which patients may be at risk. Generally speaking, it is the severely emaciated, malnourished patient with prolonged starvation who is at risk for refeeding syndrome. However, in some cases, patients who have been deprived of nutrition for seven to ten days are potentially in this category. There are general guidelines to follow to avoid these problems. The overall general rule in adding calories is "Start low, go slow." It is of extreme importance to monitor electrolytes during the refeeding period and to ensure that they are normal prior to the beginning of refeeding. In severe cases, particularly patients requiring hospitalization or tube feeding, checking electrolytes every two to three days for the first two weeks and then, if stable, decreasing the frequency seems wise. A supplement may be indicated to help avoid phosphorous depletion. From a clinical standpoint, following the pulse and respiratory rates for unexpected increases from the baseline as well as checking for fluid retention are a crucial part of the treatment plan in avoiding refeeding syndrome.

EKG abnormalities are also common in anorexia, such as sinus brachycardia (slow heart rate), which is usually not dangerous. However, some cardiac irregularities can be dangerous, for example, prolonged QT intervals (measurement of electrical impulses) and ventricular dysrhythmia (abnormal heart rhythms). Some have opined that a baseline EKG is therefore indicated to screen for these findings.

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By Carolyn Costin, M.A., M.Ed., MFCC and Philip S. Mehler, M.D. - Medical Reference from "The Eating Disorders Sourcebook"

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