A 54–year–old female with metastatic ovarian cancer was admitted to the gynecologic oncology service with increasing abdominal girth, nausea, and vomiting. Her past medical history was significant for papillary serous adenocarcinoma with malignant pleural effusions and peritoneal carcinomatosis diagnosed six months ago. She had undergone neoadjuvant chemotherapy with carboplatin and paclitaxel, followed by an exploratory laparotomy, debulking, and total abdominal hysterectomy and bilateral salpingo–oophorectomy. Within the last month, she had been hospitalized for a small bowel obstruction and started on doxorubicin for disease progression. On this admission, her symptoms were attributed to rapidly accumulating malignant ascites and recurrent small bowel obstruction. She therefore underwent placement of a tunneled peritoneal catheter and a percutaneous endoscopic gastrostomy tube for decompression. During this time, she was kept NPO and maintained on D5 1/2 NS at 75 mL/h. Over the first week of hospitalization, her serum sodium rose from 129 to 162 mEq/L. The medicine team was informally called for help with fluid management. Per report, the patient denied any symptoms of hypernatremia but endorsed a persistently poor appetite. Her catheter continued to drain about 400 milliliters of ascitic fluid per day. However, her urine output had increased to six liters per day with a urine osmolality of 160 mOsm/L. Hypernatremia in the setting of dilute polyuria immediately raised concern for diabetes insipidus (DI), most likely central DI as metastases were seen on recent magnetic resonance imaging of the brain. Her intravenous fluids were switched to D5W at a rate that would lower her serum sodium by 0.5 mEq/L/h. She was ultimately started on desmopressin and treated with whole–brain irradiation for intracranial metastases. Her serum sodium trended down to 138 mEq/L, and her urine osmolality increased to over 600 mOsm/L, confirming the diagnosis of central DI.
This case illustrates several important points for hospitalists involved in consult medicine. Curbside consults are an integral part of our medical culture and promote learning and open communication across specialties. They can also be valuable for the hospitalist dealing with time constraints on a busy shift. While curbside consults are often straightforward, occasionally the question is of sufficient complexity that an informal discussion could compromise the quality of care. Hypernatremia in the hospitalized patient is nearly always related to restricted access to free water. However, in this instance it also signaled a rare condition, central DI, which happened to manifest for the first time under the care of the inpatient team.
When presented with a curbside consult, it is the responsibility of the hospitalist to assess the urgency and complexity of the case and recommend a formal consult if appropriate.