HHS Flashcards
How would you calculate serum osmolarity?
2x(K+ + Na+) + Urea + Glucose
What are differences between HHS and DKA?
- More hyperglycaemic
- More Dehydrated
HHS happens gradually (gradual dehydration), DKA more rapid
Delerium more common in HHS
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%)
Acute illness
- Infection (32-60%)
- CVA
- MI
- Pancreatitis
Others
- Endocrine
- Drugs - B-blockers, antipsychotics, steroids, immunosuppressants
What is the pathophysiology of HHS?
https://www.youtube.com/watch?v=QRLZwXL6w1c
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?
- Thirst
- Polyuria
- Polydipsia
- Stupor/Coma
What are signs of HHS?
Signs of excessive dehydration
- Tachycardia
- Hypotension
- Sunken eyes
- Dry mucus membranes
Reduced consciousness
Evidence of occlusive events
Why can individuals with HHS present with reduced consciousness?
Increased plasma osmolality
What plasma osmolality is usually seen in HHS?
>320 mOsm/kg
How hypoglycaemic are people who present with HHS?
>30 mmol/L
What tests would you do in someone presenting with symptoms of HHS?
- Bloods - FBC, U+E’s CRP, Serum osmolality, VBG/ABG
- ECG
- CXR
- Cap and lab glucose
- Blood Cultures
Why is serum sodium often low in HHS?
Hyperglycaemia induces osmotic movement of water from cells into intravascular space, causing dilution of sodium
Aims of treatment in HHS
Normalise osmolaloty, replace fluid and electrolye losses, normalise blood glucose
While preventing… arterial venous thomrbosis, cerebral oedema, foot ulceration
What are the principles to managing someone with HHS?
Basic principles as per DKA
-
I.V. fluids
- Rapid if shocked
- More gradual than DKA if not shocked
- I.V. insulin
- Potassium
Address underlying precipitant
DVT prophylaxis
What rate would you give insulin initially in HHS?
3 units/hr
Remember that insulin drives K back into cells so watch for hypokalaemia
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
- Insulin - 3 units/hr
- Monitoring
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
