Tuesday, 5 November 2019

Hypoglycaemia


There are many causes of hypoglycaemia. Contrary to popular belief, hypoglycaemia is not caused by diabetes- hypoglycaemia is caused by the treatment of diabetes.
Definition
Whipple’s triad:
Symptoms of hypoglycaemia with abnormally low plasma glucose concentration, and relief of the symptoms after glucose concentrations normalise.

Pathogenesis
Overdose of insulin or oral hypoglycaemics
Drugs—ethanol, MAOIs, haloperidol, sulfonamides, salicylates
Insulinoma or islet cell hyperplasia
Adrenal insufficiency (Addison’s disease)
Hepatic failure, hypothermia and sometimes sepsis.
Increased exercise
Decreased calorie intake, or missed meals or snacks.

Signs and Symptoms
The signs and symptoms can be split into two categories – neuroglycopenia and adrenergic response. The adrenergic response is perhaps the one we are most familiar with, and precedes the neuroglycopaenic symptoms.

Adrenergic response
Catecholamines are released. How much catecholamine is released is inversely proportional to the sugar level, not the rate of drop. Symptoms include:
Sweating
Palpitations
Tremulousness
Anxiety
Hunger.

Neuroglycopenia
This occurs over 1–3 hours:
Headache, diplopia
Difficulty in concentrating, hallucinations
Confusion, irritability
Focal neurological deficits
Seizures
Coma


Lab Values
Hypoglycaemia is a blood sugar of less than 4.0mmol/L.
There is individual variation in the BGL required to produce symptoms, but it is generally regarded as <2.5 mmol/L.

Management
Eating + Drinking:            Sugary sweets like Percy Pigs or jelly babies. Chocolate is bad because the milk needs to be digested before it can be used to provide sugar. 10g of glucose is available from 55ml Lucozade, Ribena 19mL, Coca-Cola 100mL, 2 tsp sugar and 4 sugar lumps.
Once you have given a short acting sugar, remember to follow it up with some complicated carbohydrate like a sandwich.

Not Eating And Drinking:
Glucagon 1mg    IM injection        Glucagon causes transient insulin resistance for <2 hours, so BMs might rise. Glucagon may stimulate vomiting, so consider use of glucagon carefully.
IV Dextrose        20% IV dextrose is the treatment of choice. 50% dextrose is no longer available, as it causes a lot of inflammation. 5% dextrose is not helpful in treating hypoglycaemia. 10% glucose is acceptable.
Glucagon stimulates insulin secretion, and glycogenolysis so is less useful in type two diabetes. IV dextrose also stimulates insulin release, and can trigger rebound hypoglycaemia. Glucagon tends to produce a steady rise in glucose levels.

Incidents
Insulin is very dangerous, and a cause of many medical errors. Be aware of long and short acting insulins.


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