Severe Diabetic Ketoacidosis With Fatal Cerebral Edema in an Adult

Diabetic ketoacidosis (DKA) is a life-threatening complication of type 1 diabetes, and cerebral edema is well described in children; it is rare in adults and carries a high mortality. We present the case of a 47-year-old male with poorly controlled type 1 diabetes who was brought to the ED unresponsive. On arrival, he was obtunded, required intubation, and vasopressor support. Laboratory evaluation was consistent with severe DKA, including marked hyperglycemia, high anion gap metabolic acidosis, and ketonemia. He also presented with multiple electrolyte disturbances, including hyperkalemia, hyperphosphatemia, and acute kidney injury. He was started on standard DKA management; however, imaging revealed diffuse cerebral edema with signs concerning for herniation. Despite initiation of hypertonic therapy, his neurological status worsened, and repeat imaging showed progression of cerebral edema with findings suggestive of pseudo-subarachnoid hemorrhage. The patient died within 72 hours of admission. This case highlights the severe course that DKA can take when complicated by cerebral edema and emphasizes the importance of early recognition and close monitoring.