Adolescent girl is diagnosed with acute abdomen and shock

Key Points

The Case

You are the senior resident covering the pediatric intensive care unit (PICU) when you receive a call from the emergency department (ED) regarding a nearly 14-year-old Caucasian female patient with a diagnosis of "acute abdomen and suspected septic shock." Ten days before admission, she had had a lipoma removed from her back under general anesthesia. She had tolerated the procedure well and was sent home without complication. Several days later, she developed emesis and abdominal pain, without diarrhea or fever. The emesis subsequently resolved, but she has continued to have little oral intake, drinking only small amounts of water and soda daily. She complains of fatigue, as well as diffuse muscle pain in her extremities.

On the day of admission, the patient was brought to her pediatrician for evaluation. Because of her critically ill appearance (severe pallor, weakness, and cool skin), she was immediately transferred to the ED of our children's hospital, where her blood pressure (BP) was found to be 63/39 mmHg, her heart rate was 100 beats per minute, her respiratory rate was 20 breaths per minute, and her temperature 36.2° C. She was alert and coherent.

You find that she is in shock, pale and drowsy, but able to answer questions. Her temperature is 36.4° C, heart rate is 132 beats per minute, respiratory rate is 30 breaths per minute, BP is 76/40 mmHg, weight is 41 kg (15th percentile), and height is 157.5 cm (30th percentile). HEENT evaluation is normal, showing no rhinitis or pharyngitis. There is no nuchal rigidity. The patient is Tanner stage 4 for breast and genital development. Mucous membranes are dry; capillary refill is delayed at 4 seconds. Examination of the chest reveals mild subcostal retractions and rales and poor aeration bilaterally, more pronounced on the left. Abdominal examination reveals no tenderness or distention, with normal bowel sounds. The skin is pale, with no exanthems. A 4-cm healing surgical incision (with Steri-Strips in place) is noted on the midthoracic region of the back. The neurologic exam reveals generalized weakness, with no focal signs.

Laboratory tests reveal a white blood cell count of 11,000/mm³, hemoglobin 11.6 g/dL, hematocrit 32.9%, and platelet count 261,000/mm³. Serum chemistry tests reveal a sodium level of 119 mmol/L, potassium 7.4 mmol/L, chloride 87 mmol/L, bicarbonate 15 mmol/L, BUN 87 mg/dL, creatinine 1.6 mg/dL, and glucose 79 mg/dL. Urinalysis is normal; specific gravity is 1.020. Urine pregnancy test is negative. Venous blood gases reveal a pH of 7.36, pCO₂ 40, CO₂ 23, and base deficit -3.

Additional history

Because of the unexpected hyponatremia and hyperkalemia, you seek a more thorough history from the family. The patient has enjoyed good health, with no previous significant medical history. Menarche occurred at 13 years, 3 months of age. She does not use tampons. The parents report that during the preceding 2 years, the patient has developed a habit of significantly increased salt intake, characterized by consumption of an entire multiserving bag of potato chips or a full jar of pickles (including the juice) at 1 sitting. The parents also note that the patient always appears tan, with darker skin than other family members. Two weeks before admission, the parents had urged the patient to observe Lent by giving up addition of extra salt to her food.

Additional history obtained from her pediatrician reveals that the patient has lost approximately 10 pounds during the preceding 6 months. During the preceding year, her growth in length has dropped from the 50th to the 30th percentile; her weight has dropped from the 25th to the 15th percentile. The pediatrician had recommended a number of diagnostic tests, but the family had not followed through.

Based on her electrolyte abnormalities and this additional history, what could you be dealing with? Could this be adrenal insufficiency? Given the potentially lethal outcome if this diagnosis is not recognized, blood is drawn for cortisol level and other endocrine tests, and the patient is started on stress doses of hydrocortisone. Her BP and electrolytes stabilize over the next 24 hours, permitting you to taper off vasopressors. On her second day in the hospital, she develops increasing respiratory distress, necessitating bilateral thoracenteses to treat pleural effusions. Gram stain and cultures of pleural fluid are negative for bacteria, acid-fast bacilli, and fungi. The patient begins to improve, and you are able to wean her off oxygen by the sixth day.