From the Guidelines
HHS stands for Hyperosmolar Hyperglycemic State, a serious acute complication of diabetes characterized by extremely high blood glucose levels, severe dehydration, and altered mental status without significant ketoacidosis. This condition is a medical emergency that requires prompt recognition and treatment to prevent serious complications and death.
Key Characteristics of HHS
- Extremely high blood glucose levels (typically >600 mg/dL)
- Severe dehydration
- Altered mental status without significant ketoacidosis
- Occurs predominantly in older adults with type 2 diabetes
- Has a higher mortality rate than diabetic ketoacidosis (DKA)
Treatment of HHS
- Aggressive fluid replacement with normal saline
- Insulin therapy (typically IV insulin at 0.1 units/kg/hr after an initial bolus)
- Electrolyte monitoring and replacement (particularly potassium, magnesium, and phosphate)
- Addressing the underlying trigger such as infection, medication non-compliance, or acute illness
- Close monitoring of glucose levels, electrolytes, and mental status is essential during treatment 1. Unlike DKA, HHS develops more gradually over days to weeks, allowing for extreme dehydration to occur, which makes prompt recognition and treatment crucial to prevent serious complications including thrombosis, seizures, and death.
Important Considerations
- Recent studies have reported that the administration of a low dose of basal insulin analog in addition to intravenous insulin infusion may prevent rebound hyperglycemia without increased risk of hypoglycemia 1.
- There is no significant difference in outcomes for intravenous human regular insulin versus subcutaneous rapid-acting analogs when combined with aggressive fluid management for treating mild or moderate DKA 1.
- The use of bicarbonate in people with DKA made no difference in the resolution of acidosis or time to discharge, and its use is generally not recommended 1.
From the Research
Definition of HHS
Characteristics of HHS
- HHS is a serious acute complication of diabetes decompensation, especially in type 2 diabetes (T2DM), and has a critical prognosis 2.
- Primary characteristics of HHS include:
- Extreme hyperglycemia
- Severe dehydration (with prerenal hyperazotaemia)
- Plasma hyperosmolarity
- Frequent disorders of consciousness
- Absent or minimum ketoacidosis (with higher values, only found in combined forms) 2.
Clinical Features of HHS
- Clinical features of HHS include:
- Marked hypovolaemia
- Osmolality ≥320 mOsm/kg
- Marked hyperglycaemia ≥30 mmol/L
- Without significant ketonaemia (≤3.0 mmol/L)
- Without significant acidosis (pH >7.3) and bicarbonate ≥15 mmol/L 3.
Treatment of HHS
- The aims of therapy are to improve clinical status/replace fluid losses by 24 h, gradual decline in osmolality, blood glucose 10-15 mmol/L in the first 24 h, prevent hypoglycaemia/hypokalaemia and prevent harm 3.
- Interventions include:
- Intravenous (IV) 0.9% sodium chloride to restore circulating volume
- Fixed rate intravenous insulin infusion (FRIII) should be commenced once osmolality stops falling with fluid replacement unless there is ketonaemia
- Glucose infusion (5% or 10%) should be started once glucose <14 mmol/L
- Potassium replacement according to potassium levels 3.