Case 5 - Hyperosmolar hyperglycaemic syndrome

Question 1

Reasons err message comes up on CBG machine

Answer 1

• Test strip problem - removed too early, wet, damaged
• Blood sample problem - not enoough blood
• Hardware error
• Extremely high glucose reading

Question 2

What glucose level does blood need to be to give a reading of ‘HI’?

Answer 2

More than 30mmol/L

Question 3

If repeated error messages are received on CBG monitor, how else can we measure glucose?

Answer 3

• ABG or VBG

Question 4

Test to do after hyperglycaemia is confirmed

Answer 4

Urine dip for ketones
Blood test for ketones

Question 5

What happens to osmolarity in HHS?

Answer 5

High - very concentrated

Question 6

Diagnosis of HHS needs…

Answer 6

• High osmolarity usually more than 320
• Absence of acidosis and ketones
• Hyperglycaemia (often more than 30mmol/L)
• Hypovolaemia

Question 7

Initial treatment of HHS

Answer 7

1. IV 1L 0.9% saline over 1hr (more rapid if sys les 90)
2. Only commence insulin IV if ketonaemia
3. LMWH
4. Find cause
5. Replace K+ if 3.5-5.5 if less senior review

Question 8

Aim of reducing osmolarity

Answer 8

• 3-8mosmol/kg/hr
• After initial 1L give another if able to depending on assessment or 500mls
• Target is to achieve +ve fluid balance of 2-3L by 6hrs
• 3-6L by 12hrs

Often done as 1L over 1hr x 2, then 1L over 4hrs x 2, then 1L over 6hrs x2

Question 9

Complications of HHS

Answer 9

• Cerebral oedema
• Aspiration pneumonia
• Hypokalaemia
• Hypomagnesaemia
• Hypophosphataemia
• Thromboembolism