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Management of diabetic emergencies

Diabetic ketoacidosis

In DKA, a relative lack of insulin results in hyperglycaemia as cells are unable to take up glucose – ‘starvation in the midst of plenty’. This causes cells to switch to a fatty acid metabolism, resulting in the production of acidic ketones.


  • Follow usual ABCDE approach 

2. Confirm diagnosis

  • Ensure you include VBG, capillary/urine ketones and glucose measurement
  • Confirm diagnosis (all of):
    • Glucose >11mmol/L (or known diabetes)
    • pH <7.3 or HCO3–  <15mmol/L
    • Capillary ketones >3mmol/L (or ++ urinary ketones)

Normal values (mmol/L)

  • Non-diabetic (random) = 4-7.8
  • Type 1 diabetic = 4-9
  • Type 2 diabetic = 4-8.5
  • Hyperglycaemia = >11
  • Hypoglycaemia = <4
  • Normal capillary ketones = <0.6

3. Intravenous fluids

NB: dehydration is more lethal than hyperglycaemia.

  • 1L saline over 1 hour (or faster if hypotensive) – without potassium
  • 1L saline over 2 hours
  • 1L saline over 2 hours
  • 1L saline over 4 hours
  • 1L saline over 4 hours
  • 1L saline over 6 hours
  • 1L saline over 6 hours

After the 1st litre, add potassium chloride to each litre depending on VBG results:

  • K+ > 5.5 = nil
  • K+ 3.5-5.5mmol/L = 40mmol KCl
  • K+ <3.5mmol/L = senior review as additional potassium required

4. Fixed rate insulin infusion

  • IV insulin infusion 0.1unit/kg/hour from 50 units human soluble rapid-acting insulin (e.g. Actrapid) in 50ml 0.9% saline
    • NB: maximum rate is 15 units per hour.                                               
  • When capillary glucose is <14mmol/L, give 10% IV glucose at 125ml/hour in addition to the 0.9% saline – but reduce the saline rate to account for extra fluid. Glucose is used so that insulin can continue to drive more glucose into cells to reduce ketosis and acid production.

5. Investigation to find cause

  • History
  • Top to tail examination (including looking diabetic foot exam)
  • Bloods (FBC, glucose, U&Es, LFTs, osmolality, CRP)
  • Blood culture
  • MSU
  • Chest X-ray
  • ECG

6. Other priorities

  • Treat the cause
  • Consider high dependancy unit admission if: ketones >6mmol/L, HCO3– <5mmol/L or pH <7.1, GCS <12, SBP <90mmHg, sats <92% on air, HR >100/<60bpm, potassium <3.5mmol/L on admission
  • Continue patient’s long-acting insulin throughout and start long-acting insulin (Lantus or Levemir 0.25 units/kg once daily s/c) if it is a new presentation
  • Check capillary glucose and ketones hourly and VBG at 1 hour, 2 hours, then 2-hourly to assess acid-base balance, potassium and glucose 
    • Aim to increase HCO3– by 3mmol/hour, reduce glucose by 3mmol/hour and reduce ketones by 0.5mmol/L/hour
    • Insulin can be increased by 1 unit/hour if target is not reached
  • When the acid-base abnormality is fully corrected (i.e. pH >7.3) and capillary ketones are <0.6mmol/L (should occur within 24 hours) and the patient is eating and drinking, restart their normal insulin regimen at a mealtime
  • If abnormal physiology is corrected but the patient is still not eating and drinking (or it is not a mealtime), start a variable rate insulin infusion
  • Ensure VTE prophylaxis is prescribed
  • Education and medication review

Hypermosmolar hyperglycaemic state

Hyperglycaemia develops slowly as a result of illness/dehydration and causes hyperosmolality in the intravascular compartment and severe cellular dehydration due to prolonged osmotic diuresis. Notably, there is no acidosis or ketosis because basal insulin levels allow sufficient cellular glucose uptake to prevent fatty acid metabolism. The main dangers are dehydration and a prothrombotic state. Serum osmolality (mainly determined by sodium and glucose) must be closely monitored to avoid over rapid correction, which carries a risk of osmotic demyelination syndrome.

Confirm diagnosis

  • Confirm diagnosis
    • Marked hyperglycaemia (≥30mmol/L) without acidosis or significant ketosis
    • Serum osmolality ≥320mmol/L
    • Hypovolaemia


  • Rehydrate with 0.9% saline (fluids given at a similar rate as in DKA initially)
  • Check serum osmolality (may be calculated by 2x sodium + glucose + urea) hourly initially – adjust fluid rate accordingly to avoid over rapid correction 
  • Start IV insulin infusion at 0.05units/kg/hour only if glucose is not falling with fluids alone or there is ketosis (but rehydrate first)
    • NB. fluid follows glucose due to osmosis. In hyperosmolar hyperglycaemic state, patients are extremely fluid deplete due to prolonged osmotic diuresis. If insulin is given prior to rehydration, glucose in the intravascular space is shifted into cells and fluid therefore will follow. This carries a risk of cardiovascular collapse due to rapid depletion of intravascular fluid volume. Hence, insulin can be dangerous in hyperosmolar hyperglycaemic state if patients are not adequately rehydrated first.
  • VTE prophylaxis (high risk of VTE)
  • Look for and treat cause 
  • Hold metformin for 2 days (it causes a metabolic acidosis)

Hyperglycaemia without DKA

  • Rehydrate if necessary
  • STAT dose of rapid-acting (e.g. Novorapid) or short-acting (e.g. Actrapid) insulin dose can be used 
    • Type 1: 1 unit decreases blood glucose by 3mmol/L (aim glucose <12mmol/L)
    • Type 2 (more insulin resistant): 0.1unit/kg (aim glucose <14mmol/L)
  • Identify and correct cause (and check patient has taken insulin normally)
  • Adjust normal insulin regimen as necessary
  • Recheck glucose in 1 hour and reassess


A dangerous medical emergency!

  • Unconscious
    • 200ml 10% glucose or 100ml 20% glucose IV STAT (repeat as necessary)
    • Glucagon 1mg IM if no IV access (once only)
  • Conscious but cannot swallow
    • 2 tubes 40% glucose gel around teeth if mild and patient conscious
  • Can swallow:
    • 15-20g fast-acting carbohydrate (e.g. 5 glucose/dextrose tablets, 200ml fruit juice/Lucozade, 3-4 teaspoons sugar)
    • AND long-acting carbohydrates
  • All:
    • Check capillary glucose 10 minutes later, repeat treatment as needed 
    • Give long-acting carbohydrate when able to swallow (e.g. biscuits, toast)
    • Determine and correct cause
    • Don’t omit insulin/tablets afterwards (risk of rebound hyperglycaemia) – reduce dose instead