Abnormal blood sugar

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!

Definition

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

Epidemiology

Very common, especially as you get older.

Pathophysiology

Obviously, two main types:

Hypoglycaemia

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.

Hyperglycaemia

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:

• Weakness
• Tremor or seizures
• Hunger
• Sweating
• Nervousness
• Palpitations

One of the later presentations is new onset coma.

Hyperglycemia can cause:

The hyperglycaemia triad:

• Polyuria Frequent urination
• Polydipsia - Excessive thirst
• Polyphagia - Excessive hunger

Also:

• Headache
• Blurry vision
• Confusion
• Fatigue
• Weight loss

Differential Diagnosis

Hypoglycaemia:

• Type 1 diabetes
• Type 2 diabetes
• Diabetic ketoacidosis
• Insulin excess, or oral hypoglycaemic agents.

Hyperglycaemia:

• Type 1 diabetes
• Type 2 diabetes
• Stress hyperglycaemia (e.g. corticosteroids, pregnancy)

Investigations

• Blood glucose
• U+Es

Others depending on likely cause.

Management

Hypoglycaemia

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).

Hyperglycaemia

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.