HHS

Question 1

What are the characteristics of HHS?

Answer 1

• Hypovolaemia
• Hyperglycaemia (> 30 mmol/L)
• Mild or absent ketonaemia (blood ketones < 3 mmol/L)
• High osmolality (> 320 mOsm/kg)

Question 2

What pts normally will get HHS?

Answer 2

• elderly with multiple comorbidities
• T2DM

Question 4

What is the pathophysiology of HHS?

Answer 4

1. Relative lack of insulin
   
   • prevents inhibition of ketogenesis
   • but not enough to prevent hyperglycaemia
2. Rise in counter-regulatory hormones (e.g. cortisol, growth hormone, glucagon)
   
   • Increase gluconeogenesis
   • Increase glycogenolysis
3. 1+2 = Hyperglycaemia
   
   • proximal tubules reach max capacity for reabsorption of glucose
   • remaining glucose is passed through the renal nephron
   • osmotic diuresis occurs

Question 5

How many litres of fluid can HHS pt loss?

Answer 5

• 9L

Question 6

What are pt with HHS at risk of?

Answer 6

• Stroke
• DVT

Question 7

What are the causes of HHS?

Answer 7

• Infection
• High-dose steroids
• Myocardial infarction
• Vomiting
• Stroke
• Poor treatment concordance

Question 8

What are the clinical features of HHS?

Answer 8

• Polydipsia
• Polyuria
• Nausea
• Vomiting
• Muscle cramps
• Weakness
• Altered mental status
• Seizures
• Coma
• Dehydration (dry mucous membranes, sunken eyes, reduced capillary refill, decreased skin turgor)
• Hypotension
• Decreased urine output
• Decreased conscious level
• Coma
• Focal neurology signs
• Features of the precipitating cause

Question 9

What Ix would you order for HHS?

Answer 9

• Bedside tests
  
  • ECG
  • Urinalysis +/- MSU
  • Urinary pregnancy test
• Blood tests
  
  • FBC
  • U&Es
  • CRP
  • LFTs
  • Blood cultures
  • Troponin
  • Amylase
  • CK
• Imaging
  
  • Chest X-ray
  • CT head (if reduced GCS or focal neurology)

Question 10

Pt with HHS may require HDU if severe. What are the features to look for?

Answer 10

When 1 or more are present:

• osmolality >350 mosmol/kg
• sodium >160 mmol/L
• venous ⁄ arterial pH below 7.1
• hypokalaemia (less than 3.5 mmol/L) or hyperkalaemia (greater than 6 mmol/L) on admission
• Glasgow Coma Scale (GCS) less than 12 or abnormal
• AVPU (Alert, Voice, Pain, Unresponsive) scale
• oxygen saturation below 92% on air
• systolic blood pressure below 90 mmHg
• pulse over 100 or below 60 bpm
• urine output less than 0.5 ml/kg/hr
• serum creatinine >200 µmol/L
• hypothermia
• macrovascular event such as myocardial infarction or stroke
• other serious co-morbidity.

Question 11

What are the goals for HHS Mx?

Answer 11

• Normalise osmolality
• replace loss fluid and electrolyte
• normalise blood glucose

Question 12

What is the initial mx for HHS?

Answer 12

A-E assessment with

• Intravenous access (x2 large bore cannula)
• Blood / urinary ketones
• Capillary & plasma blood glucose
• FBC, U&Es, venous blood gas, plasma osmolality
• Blood cultures
• Urinalysis +/- MSU, Pregnancy test (as indicated)
• ECG
• CXR
• Urinary catheter
• Additional tests as indicated by the presentation/investigations (e.g. troponin, CT head)

Question 13

What is the fluid regimen like for HHS?

Answer 13

• First hr:
  
  • 0.9% saline solution. 1L in 1hr (quicker if hypotensive)
• Second-sixth hr:
  
  • 0.9% normal saline 0.5 – 1 L/hr
  • Target; 2-3 litres positive by 6 hours
• 6-12 hr:
  
  • Target: 3-6 litres positive by 12 hours
• 12-24 hr:
  
  • ​Continue fluid

Question 14

What is the electrolyte replacement like in HHS?

Answer 14

• monitor Na, K, Ph, Mg every 4hrs
• General rule for K:
  
  • Serum K+ > 5.5 mmol/L: Nil potassium replacement
  • Serum K+ 3.5-5.5 mmol/L: 40 mmol potassium replacement
  • Serum K+ < 3.5 mmol/L: Senior review for more invasive potassium replacement

Question 15

What is the insulin therapy like for HHS?

Answer 15

• commenced if there is evidence of
  
  • significant ketonaemia (> 1 mmol/L) or
  • ketonuria (2+ or more
• fixed rate intravenous insulin infusion (FRIII) at 0.05 units/kg/hr (half the dose used in DKA)
• Blood glucose maintained between 10-15 mmol/L in the first 24 hours
  
  • 5% or 10% dextrose if levels fall < 14 mmol/L.

Question 16

What are the metabolic treatment targets when mx HHS?

Answer 16

• Plasma osmolality: falling by 3-8 mOsm/kg/hr
• Blood glucose/l falling by at least 5 mmol/L/hr

Question 17

What are the cx of HHS?

Answer 17

• MI
• DVT
• PE
• Stroke
• Cerebral oedema

Question 18

What monitoring is required for HHS mx?

Answer 18

• Cardiac monitoring
• blood glucose, urea & electrolytes and plasma osmolality - every hr for 6hrs
• Monitoring can be reduced to 2 hrly > 4hrly > 12hrly
• UO measured hourly at all times