Abnormal blood sugar

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One way to get a Dextrose IV is simple to make your own, like this young man is, with a funnel underneath the sugar, draining into a saline IV. For safety, always try this on a consenting adult before yourself, since undissolved granular sugar can be an excellent cause of stroke!


An abnormal blood sugar - outside 3.5mmol/L to 5.5 mmol/L in a fasting glucose test.



Very common, especially as you get older.


Obviously, two main types:


  1. Commonest cause by a long way is diabetics not eating enough, or taking too much insulin/metformin.
  2. Less common in normal people not eating enough.
  3. Even less common is an insulin secreting tumour.
  4. Finally, neonates can have it, from a multitude of reasons.


  1. Again, the biggest cause by far is diabetes, both Type 1 and Type 2.
  2. Next most common is drug related. The commonest causes are: steroids, beta blockers and thiazide diuretics.
  3. Finally, some people who are critically ill can develop a hyperglycaemia. This needs treating, as studies show it can have an effect on survival rates.

Clinical and Associated Features

Hypoglycemia can cause:

One of the later presentations is new onset coma.

Hyperglycemia can cause:

The hyperglycaemia triad:


Differential Diagnosis




Others depending on likely cause.



Basically give them sugar. Ideally orally (give them an apple), but if unconscious or fitting, iv 200-300ml 10% dextrose (do NOT give 50% as it harms veins).


Generally, it's about treating diabetes. However, there is an emergency called HONK coma (hyperglycaemic hyperosmolar non-ketotic coma) This how to deal with HONK:

  • Clinical features: up to 1 week history of dehydration, focal CNS signs
  • Blood glucose >35mmol/L, no acidosis (often old patients who don't switch to ketone metabolism)
  • Osmolality >340mosmol/kg
  • Management
    • Rehydrate of 48h - 0.9% saline ivi half-rate used in DKA.
    • Anticoagulate with heparin (risk of DVT is high)
    • Only use insulin if necessary - wait one hour in order to avoid rapid change. 1unit/h is typical dose.