Fatal Diabetic Ketoacidosis and Suspected Non-occlusive Mesenteric Ischemia Induced by an Oral Glucose Tolerance Test: A Case Report.

Advances in insulin therapy have contributed to improved outcomes in diabetic ketoacidosis (DKA). However, severe cases requiring vasopressor support continue to carry a poor prognosis. A 47-year-old man without a prior diagnosis of diabetes developed polydipsia following increased carbohydrate intake. Despite symptoms suggestive of hyperglycemia, he underwent an oral glucose tolerance test (OGTT) without a prior plasma glucose measurement. Immediately afterward, he developed shock with altered mental status. His plasma glucose was 1,740 mg/dL; pH, 7.091; and total ketone bodies, 13,320 μmol/L - confirming severe DKA. Despite aggressive management, he developed persistent diarrhea, followed by septic shock. Repeat computed tomography at 36 hours revealed extensive intestinal pneumatosis, which was not present on admission, suggestive of non-occlusive mesenteric ischemia (NOMI). He progressed to multiple organ failure and died 76 hours after admission. This case highlights the potential for an OGTT to precipitate severe DKA in patients with undiagnosed diabetes. Concurrent septic shock further complicates fluid management and increases the risk of NOMI. This case underscores three critical lessons: (1) plasma glucose should be measured before performing an OGTT in patients suspected of having diabetes; (2) vigilant fluid management and infection control are essential in cases of severe DKA with shock; and (3) persistent diarrhea, despite appropriate DKA treatment, may represent an early sign of bowel ischemia in patients with altered consciousness.