Patient Overview
A 40-year-old man presented with fever and headache for three days, vomiting for two days, and seizures for one day. The seizures were generalized tonic-clonic in nature, associated with loss of consciousness, and lasted for approximately 10 minutes.
He had no prior history of diabetes mellitus, hypertension, or epilepsy. There was no history of blurred vision, limb weakness, or bowel or bladder disturbances.
Clinical Presentation
On examination, the patient appeared dehydrated with a Glasgow Coma Scale (GCS) score of 13. His vital signs were as follows: temperature 100°F, pulse rate 90/min with low volume, respiratory rate 24/min, blood pressure 88/50 mmHg, and capillary refill time of 3 seconds.
Central nervous system examination revealed normal pupils, with no cranial nerve involvement or hypertonia of the limbs. Examination of other systems was unremarkable.
Capillary blood glucose (CBG) was markedly elevated at greater than 600 mg/dL.
Diagnostic Evaluation
The patient was initially diagnosed with hyperglycemia and diabetic ketoacidosis (DKA) precipitated by an acute febrile illness. Other differential diagnoses included hyperosmolar hyperglycemic state (HHS), uremia, and dyselectrolytemias.
Urine examination was negative for ketone bodies. Arterial blood gas analysis showed a pH of 7.3 and serum bicarbonate of 21 mEq/L.
The diagnostic criteria for DKA include blood glucose greater than 250 mg/dL, arterial pH less than 7.3, serum bicarbonate less than 15 mEq/L, and the presence of ketonemia or ketonuria. These criteria were not met in this case.
Based on these findings, the diagnosis was revised to HHS according to American Diabetes Association (ADA) criteria, with associated acute kidney injury (AKI).
Management
The patient was initially treated with an intravenous normal saline fluid bolus.
Intravenous insulin infusion with regular insulin was started at 50 units per hour and increased to 70 units per hour until blood glucose reached 250 mg/dL. The infusion rate was then reduced to 30 units per hour and titrated to maintain target blood glucose levels between 140 and 180 mg/dL.
Antibiotic therapy with piperacillin plus tazobactam was initiated. Antiepileptic therapy with levetiracetam and thiamine 100 mg was also administered.
At 24 hours, blood glucose levels ranged between 350 and 550 mg/dL, and by 36 hours, the level decreased to 241 mg/dL. After 36 hours, subcutaneous insulin therapy was initiated with regular insulin 8 units every 6 hours along with basal insulin 12 units at night.
The patient’s sensorium gradually improved, and oral intake was resumed. On the seventh day of admission, insulin therapy was discontinued, and oral antidiabetic therapy with glimepiride 1 mg once daily and metformin 500 mg twice daily was started.
Follow-Up
The patient was diagnosed with diabetes mellitus with initial presentation as HHS and was treated with intravenous fluids and insulin therapy.
Due to social issues, regular follow-up was not maintained. After three months, the patient presented with a headache and was found to have hypoglycemia, with CBG of 34 mg/dL. A second hypoglycemic episode occurred one week later, following which oral antidiabetic drugs were discontinued.
Subsequent follow-up showed that blood glucose levels remained within normal range without antidiabetic therapy. However, persistent elevation of serum urea and creatinine levels was noted.
Glycated hemoglobin (HbA1c) increased to 5.9%, consistent with prediabetes. Renal biopsy revealed acute tubulointerstitial nephritis (ATIN).
