P0632 - Alphabet Soup: HHS, DKA, or both?

Introduction
Hyperosmolar hyperglycemic state (HHS) is commonly seen in adults, but can also occur in children and adolescents. Classifying hyperglycemic states correctly is essential to monitor for possible complications.

Case Description
15 year old male presented with confusion and vomiting. He had a sore throat for one week, then began having diffuse abdominal cramping and vomiting. On the night of presentation, he was confused and could not stand to ambulate. His mother noted he had been drinking approximately 30 bottles of water per day, urinating frequently, and had increased hunger. His Hgb A1c had been elevated at last PCP visit.

In the ED, patient was tachycardic, tachypneic, and disoriented. Exam also notable for acanthosis nigricans and BMI in the 99th percentile. Initial labs showed a glucose >1500, CO2 5, pH 7.01, beta hydroxybutyrate 13.6, lactate 3.5, and creatinine 2.38. His sodium when corrected for glucose was 154.4, and serum osmolality was 407. He was admitted to the PICU and initially treated per the institutional DKA protocol with 1L normal saline and initiation of an insulin drip. He also received mannitol for altered mental status (AMS).

Over the next 48 hours, the patient’s ketosis, acidosis and hyperglycemia improved, but he developed worsening hypernatremia, hyperchloremia, and acute kidney injury (AKI) with continued AMS. Brain MRI was normal. AKI work-up showed urinalysis with 2+ blood but no red blood cells. Creatinine kinase (CK) was 11,000. He was started on hyper-hydration and given multiple liters of lactated ringers, which slowly improved his CK and creatinine. However, his sodium and chloride and mental status did not improve until the initiation of hypotonic fluids on hospital day 4.

The patient was transferred to the floor, continued on hyper-hydration until CK fell below 5,000, and was discharged on 20 units of nightly insulin glargine with a diagnosis of likely type 2 diabetes. He was net positive 35 liters at discharge.

Discussion
Hyperosmotic hyperglycemic syndrome (HHS)is a common ED presentation in diabetic adults, but is now appearing more often in children/adolescents as type 2 diabetes rates rise in younger populations. HHS is characterized by markedly elevated blood glucose, minimal acidosis/ketosis, and markedly elevated serum osmolality, and AMS is most common presentation. HHS can exist in overlap with DKA, as with this patient, but DKA/HHS overlap is often missed in children. In HHS, it is crucial to expand intravascular volume. Estimated fluid deficits are significantly higher than in DKA. If a patient with HHS has persistent hypernatremia, hyperglycemia and hyperosmolality, rhabdomyolysis can develop.

Conclusion
Recognizing HHS and DKA/HHS overlap in all age groups is key to treating patients appropriately with adequate intravascular expansion and free water repletion to avoid complications such as severe electrolyte derangements and rhabdomyolysis.