A girl with vomiting, abdominal pain, and increased thirst puzzles doctors
You are the resident on call overnight in the emergency department (ED). A 10-year-old girl with a history of abdominal migraines has just arrived, complaining of new-onset, nonbilious, nonbloody vomiting; abdominal pain; and increased thirst. She was wandering around the house aimlessly, which concerned her father enough to bring her to the hospital.
Her father states that she has had episodes of extreme abdominal pain since she was 6 years old. Looking through her medical record, you see that she has had a long history of gastrointestinal (GI) complaints, described as clusters of diffuse abdominal pain and vomiting every 2 to 3 weeks followed by 3- to 4-week periods without pain.
Since the onset of her symptoms, she has undergone an extensive evaluation of her intermittent abdominal pain. Blood tests have included a complete metabolic panel, complete blood count (CBC), liver function tests, tissue transglutaminase, thyroid studies, immunoglobulins, and Helicobacter pylori antibodies. Urine tests have included urinalysis, 5-hydroxyindoleacetic acid, and catecholamines. Stool tests have included culture and fecal occult blood.
She was last hospitalized 3 weeks ago for severe abdominal pain, diagnosed as constipation because her abdominal x-ray demonstrated impacted stool. Since that last admission, she has been without pain. Her father notes that the main difference now is that she has wanted to drink more water than usual in the past few days, just before her current symptoms began.
Emergency department examination and labs
The patient is a thin, tired-appearing girl who answers questions appropriately. Her initial vital signs are: temperature, 36.5°C; heart rate, 158 beats per minute; blood pressure, 8⅚4 mm Hg; respiratory rate, 18 breaths per minute; and oxygen saturation, 95% on room air. Although her extremities are warm, she has a capillary refill time of 4 seconds and mildly dry mucous membranes, so you give her a 20 mL/kg normal saline bolus and then maintenance normal saline to rehydrate her. She also has diffuse abdominal pain on palpation, with decreased bowel sounds but without guarding or rebound. The rest of the physical examination is unremarkable.
In the setting of her dehydration, in part because of her emesis, highest on the differential diagnosis are sepsis; hypovolemic shock; electrolyte imbalance, including glucose derangement; and urinary tract infection. Laboratory testing includes a chemistry panel, stat glucose, CBC, blood culture, venous blood gas (VBG), and urinalysis with urine culture. Results are: sodium, 140 mEq/L; potassium, 3.5 mEq/L; chloride, 99 mEq/L; bicarbonate, 18 mEq/dL; blood urea nitrogen, 23 mg/dL; creatinine, 1.03 mg/dL; and glucose, 305 mg/dL. The venous blood gas pH is 7.2, and the urinalysis is positive for urine ketones and glucose. The white cell count is elevated to 19,000/uL, with a left shift of 71% neutrophils and 15% bands.