How would you calculate serum osmolarity?
2x(K+ + Na+) + Urea + Glucose
What are differences between HHS and DKA?
- More hyperglycaemic
- More Dehydrated
Why do people with HHS not normally develop ketones?
Still some insulin sensitivity, which suppresses lipolysis enough to stop ketone production
Why would you prophylactically anti-coagulate someone with HHS?
They are very dehydrated, meaning they are at significantly increased risk of developing DVTs and PEs
What is hyperosmolar hyperglycaemic state?
This condition, in which severe hyperglycaemia develops without significant ketosis, is the metabolic emergency characteristic of uncontrolled type 2 diabetes.
What can cause HHS in someone with diabetes?
Inadequate insulin/non compliance (21-41%)
- Infection (32-60%)
- Drugs - B-blockers, antipsychotics, steroids, immunosuppressants
What is the pathophysiology of HHS?
A relative insulin deficiency leads to a serum glucose that is usually higher than 33 mmol/L, and a resulting serum osmolarity that is greater than 320 mOsm. This leads to excessive urination (more specifically an osmotic diuresis), which, in turn, leads to volume depletion and hemoconcentration that causes a further increase in blood glucose level.
Ketosis is absent because the presence of some insulin inhibits hormone-sensitive lipase mediated fat tissue breakdown.
What are symptoms of HHS?
What are signs of HHS?
Signs of excessive dehydration
- Sunken eyes
- Dry mucus membranes
Evidence of occlusive events
Why can individuals with HHS present with reduced consciousness?
Increased plasma osmolarity
What plasma osmolarity is usually seen in HHS?
How hyperglycaemic are people who present with HHS?
What tests would you do in someone presenting with symptoms of HHS?
- Bedside - urine diptick, cap glucose/ketones, ECG
- Bloods - FBC, U+E's CRP, Serum osmolality, VBG/ABG, Cap and lab glucose, blood cultures
- Imaging - CXR
Why is serum sodium often low in HHS?
Hyperglycaemia induces osmotic movement of water from cells into intravascular space, causing dilution of sodium
Why would you perform a CXR in HHS?
Look for a precipitant
What are the principles to managing someone with HHS?
Basic principles as per DKA
- Rapid if shocked
- More gradual than DKA if not shocked
- I.V. insulin
Address underlying precipitant
What rate would you give insulin initially in HHS?
3 units/hr (0.05units/kg/hr)
What would you do within the first hour of managing someone with HHS?
- Initial investigations - FBC, U+E, VBG, Blood glucose, lactate
- Fluids - NaCl 0.9% 1L/hr
Consider Insulin - 3 units/hr
- Only if glucose is not coming down on fluid therapy alone
What would you reduce the hourly rate of fluids to in hours 2-4 in management of HHS?
500 mls/hr NaCl 0.9%
What would you do if BG did not decrease within the first couple of hours of insulin treatment in someone with HHS?
Increase insulin treatment
If blood glucose fell below 14 mmol/L when managing someone with HHS, what would you do?
10% dextrose + KCL at 100 ml/hr
When would you consider stopping IV insulin therapy?
When patient is stable and eating, and can digest antidiabetic medications
What are the main criteria for the diagnosis of HHS?
- Glucose > 11 mmol/L
- Plasma Osmolartiy >320 mOsm/L
- Absence of ketosis
Why should metformin be stopped in someone with HHS?
Can cause a metabolic acidosis
When would you consider starting someone on IV insulin in HHS?
If, after the first hour of management of HHS with fluids, blood glucose has not come down
How would you prophylactically manage risk of VTE in someone with HHS?