Pediatric Annals

Firm Rounds 

A 15-Year-Old Boy with Vomiting, Abdominal Distention

Robert Listernick, MD

Abstract

This 15-year-old boy was transferred because of vomiting and abdominal distention. Over the past year, he admitted to having had a 70-lb weight loss. However, 2 days before admission, he began feeling weak and had less energy. On the day of admission, his abdomen became “very big,” and he developed midepigastric abdominal pain. He had two episodes of “chocolaty” emesis, which prompted a visit to a local emergency room. Before coming to the hospital, he reportedly had normal oral intake and no other symptoms. At the outside hospital, he was noted to be hypotensive with a blood pressure of 80/40 and a heart rate of 80. There, he was found to have significant abdominal distension. He received 4 L of normal saline; a nasogastric tube drained “a large amount of dark brown fluid.” Computerized tomography (CT) scan of the chest, abdomen, and pelvis had “nonspecific findings.”

Abstract

This 15-year-old boy was transferred because of vomiting and abdominal distention. Over the past year, he admitted to having had a 70-lb weight loss. However, 2 days before admission, he began feeling weak and had less energy. On the day of admission, his abdomen became “very big,” and he developed midepigastric abdominal pain. He had two episodes of “chocolaty” emesis, which prompted a visit to a local emergency room. Before coming to the hospital, he reportedly had normal oral intake and no other symptoms. At the outside hospital, he was noted to be hypotensive with a blood pressure of 80/40 and a heart rate of 80. There, he was found to have significant abdominal distension. He received 4 L of normal saline; a nasogastric tube drained “a large amount of dark brown fluid.” Computerized tomography (CT) scan of the chest, abdomen, and pelvis had “nonspecific findings.”

Dr. Listernick is professor of pediatrics at Feinberg School of Medicine, Northwestern University, and director of the Diagnostic and Consultation Service, Division of General Academic Pediatrics, Children’s Memorial Hospital, Chicago, IL.

This 15-year-old boy was transferred because of vomiting and abdominal distention. Over the past year, he admitted to having had a 70-lb weight loss. However, 2 days before admission, he began feeling weak and had less energy. On the day of admission, his abdomen became “very big,” and he developed midepigastric abdominal pain. He had two episodes of “chocolaty” emesis, which prompted a visit to a local emergency room. Before coming to the hospital, he reportedly had normal oral intake and no other symptoms. At the outside hospital, he was noted to be hypotensive with a blood pressure of 80/40 and a heart rate of 80. There, he was found to have significant abdominal distension. He received 4 L of normal saline; a nasogastric tube drained “a large amount of dark brown fluid.” Computerized tomography (CT) scan of the chest, abdomen, and pelvis had “nonspecific findings.”

Initially, on review of systems, he admitted to the weight loss, which was said to be unintentional. There was no history of chronic fever, vomiting, diarrhea, abdominal pain, rashes, or other symptoms. He admitted to feeling weak and getting cold easily. Past medical history was unremarkable. He was taking no medications. He lives at home with his parents and his sister and reports having a good relationship with all of the family members.

He is a sophomore in high school who gets straight As. He has multiple friends and denies any bullying. He stated that he aspired to a career in sports management. Recently, he had been performing increasing amounts of exercise so that he could “get into shape.” He used a treadmill at home and did some weight lifting. He exercised one to two times each day, depending on his amount of homework. He denied smoking or drug abuse. Family history is unremarkable in detail.

On physical examination, he was a cachetic male with a flat affect. Resting pulse was 44, blood pressure 90/72, respiratory rate 16. Weight was 90 lb, and he was 5 ft 5 in tall. BMI was 14.8. HEENT examination was unremarkable. Neck was supple without significant adenopathy. Lungs were clear. There was sinus bradycardia. S1 and S2 were normal without murmurs. Lungs had bilateral crackles at the bases. The chest wall was normally shaped. Abdomen was flat and nondistended without hepatosplenomegaly. He was Tanner V and was uncircumcised. The extremities were normal without clubbing. He had dry, flaking skin most prominently on his abdomen.

Laboratory evaluation: sodium 135 mEq/L; potassium 4.9 mEq/L; chloride 109 mEq/L; bicarbonate 22 mEq/L; BUN 5 mg/dL; creatinine 0.5 mg/dL; total calcium 7 mg/dL; total protein 4.4 g/dL; albumin 2.7 g/dL; total bilirubin 1.4 mg/dL; ALT 1,148 IU/L; AST 1,038 IU/L; phosphorus 4.2 mg/dL; and magnesium 1.9 mg/dL. Amylase and lipase were normal. Hemoglobin was 11.2 g/dL; MCV 87; WBC 2,300/mm3 with 18% neutrophils; 19% immature neutrophils; 53% lymphocytes; 2% metamyelocytes; and platelet count 108,000/mm3. Vitamin D profile indicated moderate vitamin D deficiency; serum folate level was markedly low, as were serum vitamin E and vitamin A levels.

Robert Listernick, MD, moderator: There’s obviously a lot to talk about, given his degree of malnutrition. Any initial thoughts about his vomiting and abdominal distention?

Kevin Carney, MD, pediatric emergency room physician: Given his clinical presentation and the remarkable degree of weight loss, a reasonable assumption is that he has superior mesenteric artery (SMA) syndrome. This occurs due to compression of the transverse portion of the duodenum against the aorta by the superior mesenteric artery, which results in complete or partial duodenal obstruction. Presumably, the fat pad that normally prevents this obstruction from occurring normally is lost with malnutrition.

Dr. Listernick: In whom does this occur?

Dr. Carney: Most commonly in pediatrics, SMA syndrome is seen in children who have rapid weight loss secondary to anorexia nervosa. Occasionally, it’s seen in severely developmental delayed children with multiple medical problems and malnutrition. Although it’s a reported complication of scoliosis repair surgery, the critical care physicians tell me that they rarely see it.

Dr. Listernick: How is it diagnosed?

Dr. Carney: Usually, you can make the diagnosis based on the clinical presentation. If desired, barium study of the upper gastrointestinal tract will reveal dilatation of the first and second portion of the duodenum with an abrupt cutoff. Often, placing the child prone will allow the barium to pass as the obstruction is temporarily relieved.

Dr. Listernick: Treatment?

Dr. Carney: The treatment is supportive while attempting to achieve weight gain either through intravenous hyperalimentation or continuous nasojejeunal feedings, which bypass the obstruction.

Dr. Listernick: The diagnosis of SMA syndrome was made radiographically, and he was started on a combination of hyperalimentation and continuous nasojejeunal feedings. Before we discuss the etiology of his weight loss, let’s discuss potential complications that may occur as we attempt to correct his severe malnutrition.

Robert Tanz, MD, general academic pediatrician: Starvation is a catabolic state. Because of a lack of glucose necessary for energy generation, the body shifts to fat and protein catabolism to provide glucose and ketones for energy. Protein catabolism can lead to electrolyte depletion — particularly potassium, phosphorus and magnesium. This in turn may lead to poor myocardial contractility, gastrointestinal dysmotility, and decreased renal concentrating ability.

Dr. Listernick: What may happen when you start refeeding such patients?

Dr. Tanz: Anabolism starts and insulin levels increase, which lead to intracellular uptake of glucose, potassium, phosphorus, and magnesium, as well as decreased water and sodium excretion. The biggest concern is symptomatic hypophosphatemia, which may lead to muscle weakness, rhabdomyolysis, congestive heart failure, and sudden death. These patients have to be monitored very closely during the first several weeks of refeeding. These problems were initially recognized in World War II concentration camp survivors and prisoners of war during nutritional replenishment after prolonged starvation.

Dr. Listernick: He was treated with a combination of intravenous hyperalimentation and continuous nasojejeunal feedings. He required significant electrolyte repletion. Despite meticulous attention to his electrolytes, he developed profound hypophosphatemia with levels less than 0.5 mg/dL during the third week of refeeding.

Don Zimmerman, MD, pediatric endocrinologist: The endocrinologic aspects of refeeding syndrome are quite fascinating. Insulin and insulin-like growth factor have a profound effect on sodium reabsorption across a number of epithelial surfaces. This is seen in adults treated with growth hormone who develop edema and hypertension due to increased sodium reabsorption across the kidney. In children treated with growth hormone, a potential complication is pseudotumor cerebri due to increased sodium transport across the choroid plexus. When a person is deficient in insulin and insulin-like growth factor, the receptors have to become much more abundant because of the absence of the hormone. During refeeding, when insulin levels increase, massive fluid shifts may well take place.

Dr. Listernick: What about the “hypothyroidism” that is seen in these patients?

Dr. Zimmerman: It’s really miniature hibernation. Teleologically, the idea is that if your energy input is minimal, you want to diminish the necessity of energy expenditure as much as possible. You essentially turn down your production of heat, an important function of T4. As one starves, TSH levels may diminish but free T4 levels stay normal for a long time. However, levels of T3, the active thyroid hormone, plummet precipitously, and the patients become functionally hypothyroid.

Dr. Listernick: Did he have any arrhythmias?

Wayne Franklin, MD, pediatric cardiologist: Initially, he was having couplets of premature ventricular contractions, as well as profound bradycardia. He remained on cardiac telemetry during his first 4 weeks in the hospital. He also had significant hypomagnesemia and severe prolongation of the QTC interval, which placed him at major risk of torsades de pointes, ventricular fibrillation, and sudden death.

Dr. Listernick: We should say a word about his pancytopenia.

Elaine Morgan, MD, pediatric hematologist: Severe malnutrition, from whatever cause, may lead to bone marrow failure, even bone marrow necrosis. In addition, a number of the vitamin and trace element deficiencies may lead to bone marrow failure. He’s certainly at least folate deficient. His lack of red blood cell macrocytosis may be the result of concomitant iron deficiency.

Dr. Listernick: Moving forward, what was your psychiatric gestalt?

James MacKenzie, MD, child psychiatrist: Obviously, the initial thinking was that this was a child with an eating disorder. Once the language barrier was broken through, it became clear that several immediate family members also had psychiatric needs. It took a while to peel through the layers of his psyche and the social situation. About 18 months before this admission, he thought he was overweight because classmates were making fun of “his belly.” He admits to purposely starting to lose weight to get rid of this “belly.” His control of food and diet was pervasive throughout his entire household, and he took control of his diet from his parents. He bartered with his parents that “if you buy me a treadmill, I’ll stop losing all this weight.” Next, it was “if you just let me run on the treadmill for 1 hour each day and lift these weights here, then I’ll eat.” Of course, he never followed through on the promises and continued to exercise and not eat.

Dr. Listernick: Does this meet the definition of anorexia nervosa?

Dr. MacKenzie: The Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision, (DSM-IV-TR) divides anorexia nervosa into two types: restricting type and binge-eating purging type. Many patients have features of both disorders and can’t be easily classified. The definition of the restricting type includes:

  1. Refusal to maintain body weight at or above a minimally normal weight for age and height;

  2. Intense fear of gaining weight or becoming fat, even though underweight;

  3. Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or denial of the seriousness of the current low body weight; and

  4. amenorrhea (at least three consecutive cycles) in postmenarchal girls and women.

Dr. Listernick: Are boys any different?

Dr. MacKenzie: Girls with eating disorders outnumber boys 10 to 1. However, it does exist in boys. There appears to be a higher rate of comorbid substance abuse and psychiatric disorders in boys. In addition, although it is still somewhat controversial, many of the boys report themselves as being gay or bisexual. There’s a suggestion in the literature that, if this association exists, it is strongest in males with the binge-purging type.

Dr. Listernick: Interestingly, after the first week in the hospital and the initial psychiatric evaluation, he had a marked change in his mental status and became uncommunicative. He wouldn’t make eye contact with the examiner and would not respond to repeated questioning.

Dr. MacKenzie: He was exhibiting classic symptoms of hypoactive delirium, “quiet confusion.” Typically, these patients have an abrupt change in their mental status often felt by the caring physicians to represent depression. The patient is generally very calm and may go unrecognized as having a significant psychiatric disorder. Occasionally, these patients can convert to hyperactive delirium and present considerable management problems.

Leon Epstein, MD, pediatric neurologist: One thing to consider in malnourished patients who develop acute psychiatric disorders while refeeding is the possibility of temporal lobe seizures, particularly if the symptoms repeatedly abruptly start and stop.

Dr. Tanz: We found an article that indicated delirium can be seen in refeeding syndrome, particularly during the second or third week of hospitalization, which is exactly when our patient’s symptoms started. Moreover, the psychiatric symptoms appear to be related to significant hypophosphatemia, which is exactly what he experienced at that time.

Dr. Listernick: What’s the treatment of the delirium?

Dr. MacKenzie: Most importantly, you need to treat the underlying medical problem, which you did by giving lots of phosphate supplementation. The worst thing that you could do to this patient is to place him on an inpatient psychiatry unit without paying due attention to the medical issues. We used low doses of risperidone to help with his symptoms. As his nutritional status and electrolyte abnormalities improved, his psychiatric symptoms abated. He will participate in an intensive day program for eating disorders once discharged.

Dr. Tanz: He initially gained a great deal of weight, which turned out to be “water weight” that he lost during the second week in the hospital. During the third week, we began to see slow, steady, real weight gain. His bone marrow abnormalities improved. In addition, the marked transaminase elevation, which we presumed was secondary to a malnourished “fatty liver,” also improved.

Dr. Listernick: Thank you, everybody.

  1. Superior mesenteric artery (SMA) syndrome occurs due to compression of the transverse portion of the duodenum against the aorta by the superior mesenteric artery, which results in complete or partial duodenal obstruction leading to chronic vomiting. It is seen most commonly in children who have rapid weight loss secondary to anorexia nervosa.

  2. Refeeding syndrome is caused by symptomatic hypophosphatemia, which may lead to muscle weakness, rhabdomyolysis, congestive heart failure, and sudden death. Severe hypomagnesemia may also be seen leading to severe prolongation of the QTC interval, the development of torsades de pointes, ventricular fibrillation, and sudden death.

  3. The Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM IV-TR) divides anorexia nervosa into two types: restricting type and binge-eating purging type. The definition of the restricting type includes: 1) refusal to maintain body weight at or above a minimally normal weight for age and height; 2) intense fear of gaining weight or becoming fat, even though underweight; 3) disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or denial of the seriousness of the current low body weight; and 4) amenorrhea (at least three consecutive cycles) in postmenarchal girls and women.

Key Learning Points

Authors

Dr. Listernick is professor of pediatrics at Feinberg School of Medicine, Northwestern University, and director of the Diagnostic and Consultation Service, Division of General Academic Pediatrics, Children’s Memorial Hospital, Chicago, IL.

10.3928/00904481-20100922-07

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