Diabetes - Clinical presentation, diagnosis & investigation Flashcards
What does Polyuria mean and why is it a common symptom of diabetes mellitus?
Polyuria is excessive or an abnormally large production or passage of urine. It is due to osmotic diuresis when blood glucose exceed renal threshold.
What does Polydipsia mean and why is it a common symptom of diabetes mellitus?
Polydipsia is abnormally great thirst. It is due to resulting fluid and electrolyte loss
Why is weight loss a common symptom of diabetes mellitus?
It is due to fluid depletion and increased breakdown of fat and muscle.
Why is fatigue a common symptom of diabetes mellitus?
It is due to body inability to get glucose from blood into cells to meet energy needs
Why is blurred vision a common symptom of diabetes mellitus?
It is due to glucose induced changes in refraction
What is diabetic ketoacidosis (DKA)?
- DKA develops when your body doesn’t have enough insulin to allow blood sugar into your cells for use as energy.
- Instead, your liver breaks down fat for fuel, a process that produces acids called ketones.
- When too many ketones are produced too fast, they can build up to dangerous levels in your body.
Is Diabetic Ketoacidosis (DKA) a medical emergency?
Yes
What the symptoms of DKA?
- Hyperventilation
- Nausea & Vomiting
- Dehydration
- Weakness
- Ketone breath
- Reduced consciousness
- Potentially fatal
- Blood glucose increases —> Osmotic diuresis & dehydration —> HYPOTENSION
- Ketone bodies increases —> Metabolic acidosis (“air hunger” + ketone breath)
- Hyperosmolality
- Potassium loss
- Muscle catabolism & generalised weakness
Which type of diabetes does DKA affect?
Type 1
When can DKA be presented/identified?
- Can be first presentation if diagnosis was not made from common symptoms
OR - Interruption of insulin supple in a diagnosed Type 1 diabetic
OR - Intercurrent illness in a diagnosed Type 1 diabetic e.g. infection, diarrhoea (or excess alcohol)
What does intercurrent illness mean?
A disease that intervenes during the course of another disease.
What are the 6 clinical manifestations of Type 2 diabetes?
- Often insidious onset with few or none of the classical symptoms
- May only be detected as part of routine investigation
- Chronic skin infections
- Pruritis (severe itching) & Candida infection of vagina
- Can be present first as the complications - e.g. retinopathy, neuropathy, foot ulcers, nephropathy
- Hyperosmolar non-ketotic syndrome (HONK) - MEDICAL EMERGENCY
What does clinical manifestation mean?
A clinical manifestation is the physical result of some type of illness or infection
What is Hyperosmolar non-ketotic syndrome (HONK)?
HONK is a life-threatening complication of uncontrolled diabetes mellitus. Hepatic glycogenolysis & gluconeogenesis occur.
How is HONK different to DKA?
With HONK there is no significant ketosis and no acidosis due to endogenous insulin levels being sufficient to inhibit hepatic ketogenesis unlike DKA.
Is Hyperosmolar non-ketotic syndrome (HONK)? a medical emergency?
Yes
What is normal blood glucose levels?
3.4-5.8 mmol/l (4-6 mmol/l)
What are the symptoms for diabetes mellitus from the WHO diagnostic criteria 2006?
- Random venous plasma glucose > 11.1 mmol/l
- Fasting venous plasma glucose > 7.0 mmol/l
- Plasma glucose > 11.1 mmol/l 2hrs after 75g anhydrous glucose in an oral glucose tolerance test (GTT) - ONLY USED FOR BORDERLINE CASES AND DIAGNOSIS OF GESTATIONAL DIABETES.
How to diagnose and investigate diabetes mellitus if no symptoms are present?
- Two separate measurements of either random > 11.1 mmol/l or fasting > 7.0 mmol/l or from 2hrs post GTT
- If fasting or random are not diagnostic, the GTT value should be used
Can Glycated/glycosylated Haemoglobin- HbA1c levels be used as part of diagnosis of DM in Type 2 diabetes mellitus?
Yes
- >48 mmol/ml (6.5%)
What biochemical results can be used to diagnose/investigate DKA and HONK?
- Glucose
- Urea, creatinine, eGFR
- Electrolytes
- Arterial pH, PO2 and PCO2
