Recognizing Starvation Ketoacidosis in Acute Care Surgery: A Case Report and Literature Review.

Starvation ketoacidosis is an underrecognized metabolic complication in non-diabetic surgical patients who experience prolonged fasting. While commonly associated with diabetic ketoacidosis, high anion gap metabolic acidosis can occur in patients without diabetes following several days of inadequate oral intake, particularly when combined with surgical stress.  A 71-year-old Hispanic woman with a history of open ventral hernia repair in Mexico six weeks prior presented to the emergency department with abdominal pain following a fall. Computed tomography revealed concern for small bowel perforation. She underwent emergent exploratory laparotomy with abdominal washout, small bowel resection (10 cm distal jejunum), and temporary wound vacuum-assisted closure, followed by re-exploratory laparotomy with small bowel anastomosis and abdominal closure the following day. On postoperative day 3, the patient developed respiratory distress and altered mental status. Arterial blood gas analysis revealed severe metabolic acidosis with pH 7.045, pCO2 12.7 mmHg, HCO3 11.0 mEq/L, and base excess -25.1 mEq/L. Lactate was normal. Given the clinical context of prolonged poor oral intake and the severity of acidosis disproportionate to the lactate level despite lack of a diagnosis of diabetes, serum ketone bodies were measured and found to be markedly elevated at 6.8 mmol/L. The patient was diagnosed with starvation ketoacidosis and, given the patient's inability to tolerate enteral intake and ongoing postoperative status, was immediately treated with total parenteral nutrition and intravenous sodium bicarbonate to provide continuous carbohydrate delivery. Within several hours, the anion gap normalized, and the patient's clinical status improved dramatically. This case emphasizes the importance of maintaining a high index of suspicion for starvation ketoacidosis in acute care surgery patients presenting after prolonged periods of inadequate oral intake, particularly those with complex surgical histories requiring multiple operations.