Hyperosmolar Hyperglycaemic State Flashcards
What characterises HHS?
Hyperglycaemia (glucose ≥30 mmol/L
Hyperosmolality (effective serum osmolality usually ≥320 mmol/kg
Volume depletion in the absence of significant ketoacidosis (pH ≥7.3 + bicarbonate ≥15 mmol/L
In which patients does HHS usually present?
Elderly with T2DM
Describe the pathophysiology of HHS
Hyperglycaemia leads to
Increased serum osmolality leads to
Osmotic diuresis leads to
Severe volume depletion
Lit 3 precipitating factors for HHS
Intercurrent illness
Dementia
Sedative drugs
How does HHS differ to DKA?
DKA presents within hours of onset, HHS comes on over many days, consequently, the dehydration + metabolic disturbances may be more extreme
List 3 symptoms arise as consequences of volume loss in HHS
Clinical signs of dehydration
Polyuria
Polydipsia
Name 2 systemic complications of HHS
Lethargy
N+V
Name 2 neurological S/S of HHS
Altered levels of consciousness
Focal neurological deficits
What haematological consequence may arise due to HHS?
Hyperviscosity
May result in MI, Stroke + Peripheral Arterial Thrombosis
List 5 features typically seen in HHS
Hypovolaemia
Marked hyperglycaemia >30 mmol/L
High serum osmolarity >320 mosmol/kg
No significant hyperketonaemia <3 mmol/L
No significant acidosis
What equation can be used to calculate serum osmolarity?
2 x (Na + glucose + urea)
What may cause acidosis in HHS?
Renal impairment secondary to dehydration
Lactic acidosis due to sepsis
What investigation distinguishes HHS from DKA?
Blood ketones
HHS: Low
DKA: High
What investigations should be performed in HHS?
Blood glucose
Blood ketones
VBG
U+Es + Creatinine
Serum osmolarity
FBC
ECG
What are the estimated fluid losses in HHS?
100 - 220 ml/kg
Describe management of HHS
Fluid replacement
+/- Insulin (in certain circumstances)
VTE prophylaxis
Describe fluid replacement in HHS
- IV 0.9% NaCl 1L over 1h
- IV 0.9% NaCl 0.5-1L/h
Why should caution be taken in the elderly with fluid replacement for HHS?
Too rapid rehydration may precipitate heart failure
Insufficient may fail to reverse AKI
How much potassium should be given alongside the IV fluids?
K+ >5.5: None
K+ 3.5-5.5: 40 mmol/L
K+ <3.5: Senior review
When is insulin indicated in management of HHS
If there is HHS + ketonaemia (3ß-hydroxybutyrate >1- ≤3 mmol/L or urine ketones < 2+) + not acidotic (pH >7.3 + bicarbonate >15 mmol/L)
Use 0.05 units/kg/h
OR
If significant ketonaemia (3ß-hydroxybutyrate >3 mmol/L) or ketonuria (≥ 2+) with a pH <7.3 + bicarbonate <15 mmol/L (i.e. mixed DKA + HHS)
Use DKA guidelines at 0.1 units/kg/h
How is hypoglycaemia avoided in management of HHS?
Aim to keep BG 10-15mmol/L in first 24h
If falls <14: start 5% dextrose at 125ml/h
What should the target fluid balance be in management of HHS?
At 6h: +ve fluid balance of 2-3L
At 12h: +ve fluid balance of 3-6L
What complication may arise due to HHS?
Vascular complications due to hyperviscosity e.g. MI, Stroke
