All in the Stream

A 67-year-old man presented to the emergency department with four days of nausea, vomiting, and chills. He was originally from the Philippines but lived in the United States for six years. His past medical history was notable for nephrolithiasis for which a ureteral stent had been placed and was subsequently removed three years prior. He reported no abdominal pain, diarrhea, dysuria, urinary frequency, hematuria, cough, headache, or fever. He was a retired high school teacher and a lifelong nonsmoker.

This patient presents with a nonspecific constellation of constitutional and gastrointestinal (GI) symptoms. A system-based approach may be helpful when considering the differential diagnosis. Chills most often suggest infection, especially in older patients. With regard to GI causes, acute gastroenteritis and other food-borne infections can cause nausea, vomiting, and chills, but these are typically accompanied by abdominal pain and diarrhea and often resolve in less than four days. Abdominal pain would also be expected with cholecystitis as well as more life-threatening causes of nausea such as acute pancreatitis, mesenteric ischemia, and bowel obstruction. In contrast, abdominal pain would not be expected with a central nervous system (CNS) infection such as a brain abscess, which may cause nausea from increased intracranial pressure. Headaches occur in a majority of these cases, making CNS etiologies of nausea less likely. Cardiovascular causes, including myocardial ischemia and infarction, may lead to nausea and vomiting, but these are less likely given the absence of chest pain. Genitourinary causes must be considered, especially given his history of both nephrolithiasis and instrumentation. A stricture or recurrence of nephrolithiasis could lead to acute pyelonephritis or perinephric abscess, although both commonly present with urinary tract symptoms. Uremia, possibly from obstructive uropathy given the patient’s history of nephrolithiasis, could also lead to this constellation of symptoms.

On examination, temperature was 101.6 °F, heart rate 126 beats per minute, respiratory rate 18 breaths per minute, blood pressure 120/76 mm Hg, and oxygen saturation 98% on room air. The oral mucosa was moist, heart sounds were normal without murmurs, lungs were clear to auscultation, and abdomen was soft, nontender, and nondistended. There was no flank tenderness, and penile, testicular, and prostate examination findings were normal.

Laboratory studies revealed a serum sodium of 126 mEq/L, potassium 5.0 mEq/L, chloride 98 mEq/L, bicarbonate 15 mEq/L, blood urea nitrogen 88 mg/dL, creatinine 9.0 mg/dL, calcium 8 mg/dL, glucose 110 mg/dL, and albumin 3.3 g/dL. One year prior, serum creatinine was 1.4 mg/dL. His white blood cell (WBC) count was 8.0 k/uL with normal differential, hemoglobin 11.4 g/dL with normal MCV, and platelet count was normal. Serum osmolality was 286 mOsm/kg and serum parathyroid hormone (PTH) level 63 pg/mL (normal, 10-65). The urinalysis revealed cloudy urine with a specific gravity 1.009, 54 red blood cells (RBC), 236 WBC, large leukocyte esterase, negative nitrite, trace protein, and no casts or dysmorphic RBCs. A random urine specimen revealed sodium of 86 mEq/L, potassium 16 mEq/L, chloride 80 mEq/L, and creatinine 70 mg/dL.