Hyperosmolar hyperglycaemic state

Question 1

What is meant by “hyperosmolar hyperglycaemic state”?

Answer 1

• Characterised by profound hyperglycaemia (>30), hyperosmolality (>320), and volume depletion (dehydration) in the absence of significant ketoacidosis
• May be initial presentation of T2DM
• In HHS there are still small amounts of insulin being secreted by the pancreas, hence DKA is prevented

Question 2

Describe the epidemiology of HHS

Answer 2

Most commonly occurs in older people with type 2 diabetes

Question 3

What are the risk factors for HHS?

Answer 3

• Infection (most commonly pneumonia or UTI)
• surgery
• inadequate insulin therapy
• acute illness (MI, sepsis, stroke)
• non-adherence to diabetes medications

Question 4

What are the presenting symptoms/ signs of HHS?

Answer 4

• Acute Cognitive Impairment → may be recorded via GCS (due to hypernatraemia)
• Polyuria, Polydipsia, Weight Loss, N&V
• Dry Mucous Membranes & Decreased Skin Turgor → signs of volume depletion
• More insidious onset (over days)
• (DKA DISTINGUISHING FEATURES → rapid onset, abdominal pain, fruity breath odour, kussmaul respirations)

Question 5

What investigations are used to diagnose/ monitor HHS?

Answer 5

1. Hypovolaemia
2. Blood Glucose → markedly raised (>30 mmol/L) without ketonaemia/acidosis
3. Blood Ketones → negative (distiguish DKA vs HHS)
4. Serum Osmolality → significantly raised (normal in DKA) = KEY PARAMETER TO MONITOR
   - Estimated Serum Osmolality = 2(Na+K) + Glucose + Urea
5. Severe Hyperglycaemia (>30) + Hypotension + Hyperosmolality (>320)

Question 6

How is HHS managed?

Answer 6

1. Fluid Resuscitation (IV Fluids) → Isotonic Saline solution (0.9% NaCl)
   - Excessive infusion of NaCl ⇒ can cause hyperchloraemic acidosis (hence hartmann’s solution may be preffered when large volumes of fluid are to be administered). Excessive infusion of any IV fluid can cause pulmonary oedema and potentially cardiac failure.
2. Electrolyte Repletion (if needed) → add potassium (KCl) to infusion
3. IV Insulin (0.05 units/kg/hr) → not given first, as can result in cerebral oedema due to quick shift in glucose.
   - If Glucose falls → 5% Dextrose
4. First correct hypotension and electrolyte abnormalities. Then correct hyperglycaemia (partially achieved with fluid therapy).  
5. VTE Prophylaxis→ patients at high risk due to dehydration