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Eating Disorders - Bulimia Nervosa and Anorexia Nervosa

About half a percent of 15-19-year-olds have anorexia nervosa. Bulimia nervosa, it’s around 1-5%. But if you do surveys of self-induced vomiting in women, between 10 and 15% of women, depending on the sample, have had self-induced vomiting. Wrestlers, if you ask them - male wrestlers, not female wrestlers - you will find that a fair number of them will have self-induced vomiting to make weight. They’ve gotten around that by making the wrestlers weight mid-season and then right at competition.

So anorexia. That’s refusal to maintain body weight over minimal weight for age and height; 15% below expected, or failure to make expected weight gain during a period of growth leading to body weight below 15%. But that’s complicated. I’ll show you in a minute. Intense fear of gaining weight. You’ve all dealt with anorexics. They are horrified of gaining weight.

Two types of anorectics; those that restrict, which means that during anorexia nervosa they don’t binge or purge. One of the problems in looking at weight loss for teenagers is you are using the growth chart. What you do is you take a weight for height chart, find the height, the patient we are talking about is somewhere between 170 and 175 cm. You go down to what the 50^th percentile median weight for height is; that’s 55.5 I think, or is it 60? Okay, 60. Then you plot it.

From a GI standpoint; they get chipmunk cheeks. When you see adolescents who have anorexia nervosa, yet their cheeks look fairly broad - they look like they have mumps - it’s when you vomit a lot either through anorexia with purging or bulimia with purging, you get parotid hypertrophy. They are non-tender.

You can get esophagitis from acid going up, Mallory-Weiss tears from vomiting too often. You get streaks of blood. So a patient who all of a sudden has streaks of blood in their saliva from vomiting, think of bulimia. A perforation rupture of the stomach; almost unheard of, but that’s from eating too much.

Endocrine problems; growth retardation or short stature, delayed puberty. Of course amenorrhea. Low T-3 syndrome just means that what happens is T-3, if you measure it, is low but reverse T-3 is reversed. They really don’t have … they kind of look functionally hypothyroid but their TSH is normal. They develop a partial diabetes insipidus, as I said before. They lack the diurnal variation in ADH. Cortisol levels are really high. Growth hormone levels are really high. It’s stress. Your body is saying, "I want to do better."

Severe malnutrition; weight less than 75^th percentile of ideal body weight using weight-for-height charts not growth chart, dehydration, electrolyte disturbances, dysrhythmia and significant physiological instability. If you are not growing, you can actually prematurely close your epiphysis. Failure of outpatient treatment. If they are not eating at all, that’s a good reason to put them in the hospital. And uncontrolled bingeing and purging. Often patients with bulimia, unless you arrest the cycle, you can’t stop the process. So putting them in a day treatment program, they’ll just vomit all night, so they often need to go in the hospital.

Medical complications; seizures, syncope and such. Acute psychiatric emergency such as suicide ideation or psychosis, and comorbid diagnosis, particularly if they can’t live with their family. They can’t live with their family. Now what is the one thing that pediatricians miss, and that may show up on a Board question, and that’s hypophosphatemia. There have been several cases of death in anorectics if you re-feed them too fast. If you re-feed a TPN patient with short gut too fast you have hypophosphatemia. So you really must follow electrolytes as you are re-feeding. And the NPI in their eating disorder unit they’ll often start with 600 calories a day and slowly re-feed. What can happen? You can screw up your heart. You have altered RBC morphology, you can have liver dysfunction. Paralysis; patients don’t like that very much. Confusion, coma, cranial nerve palsy, sensory loss, Guillain-Barre syndrome.

So how do you avoid it? Know that it could happen. Re-feeding anybody who is emaciated. This is like the concentration camp survivors. Some died when they were re-fed too quickly. A Big Mac is not the best thing after being starved. Recognize who is at risk. Test and correct electrolyte abnormalities before initiating nutrition, restore circulatory volume, monitor pulse rate, increase calories slowly. Vitamins; monitor particularly phosphorus, potassium, magnesium. Glucose isn’t usually a problem, and I don’t do urinary electrolytes. The authors here say a little nutritional support is good, too much is lethal.