Week 1/2 - B - Type 1 diabetes, DKA & hypoglycaemia

Question 1

Pancreatic beta cell destruction by T lymphocytes causing reduced insulin production resulting in hyperglycaemia What is this disease?

Answer 1

Type 1 diabetes mellitus

Question 2

HLA (human leucocyte antigen) is the human version of the major histocompatibility complex (MHC), a gene family that occurs in many species. In humans, the MHC complex consists of more than 200 genes located close together on chromosome 6.

What are the haplotypes in diabetes?

Answer 2

HLA-DR3 and HLA-DR4

Question 3

What are the types of antibodies the attack the islet cells of the pancreas?

Answer 3

Anti islet cell antibodies - mostly anti-GAD antibodies (anti-glutamic acid decarboxylase)

Question 4

Which is more common, type 1 or type 2 diabetes?

Answer 4

Around 10-15% are type I

Around 85-90% are type II

Question 5

Are children more likely to develop diabetes if their mother or father has it?

Answer 5

3 times more likely to develop diabetes if their father has it

Question 6

How common is diabetes in patients with cystic fibrosis? What other diseases is diabetes common in? (usually autoimmune diseases) (name 4)

Answer 6

25% of patients with cystic fibrosis have diabetes

Thyroid disease,

pernicious anaemia,

coeliac disease,

addison’s disease

Question 7

What is the diagnostic criteria for diabetes?

Answer 7

Venous plasma glucose tests

* Fasting glucose greater than 7mmol/l (fast for at least 8 hours)

* HbA1c greater than 48mmol/mol (6.5%)

* OGTT greater than 11.1mmol/l (measure 2 hours after 75g carboydrate load)

Random glucose - greater than 11.1mmol/l

Question 8

What are the two main of the diagnostic tests for diabetes?

Answer 8

The random glucose at 11.1mmol/l and the fasting glucose at 7mmol/l

If the patient is asymptomatic the above criteria apply but must be demonstrated on two separate occasions (if symptomatic, then only one occassion)

Question 9

What is the classic triad of clinical features associated with type 1 diabetes? What is the commonest presenting children in children?

Answer 9

Polyuria

Polydipsia

Weight loss

Secondary enuresis is the commonest symptom in children - (a child who has been trained and is dry in bed and has previously started wetting the bed then this is red flag of diabetes)

Question 10

How does the unopposed glucagon production further exacerbate the hyperglycaemia?

Answer 10

Glucagon will cause increased gluconeogensis, glycogenolysis and lioplysis increasing blood glucose

Question 11

What can increased glucose in the urinary system cause?

Answer 11

Can cause UTI infections as it provides a feeding source for bacteria

Question 12

What is a common presenting factor of young children due to the fact they have unopposed rising glucose as there is a lack of insulin and therefore skeletal and other tissues do not have any glucose stores giving them a need for energy

Answer 12

Diabetic ketoacidosis

Question 13

DKA often arises due to stress (ie infection) Stress causes increased hormonal levels of cortisol and adrenaline How does this cause increased serum ketones?

Answer 13

Cortisol cause stimulation of protein catabolism for gluconeogenesis and

adrenaline stimulates glucagon production causing increased lipolysis, gluconeogensis and glycogenolysis

The excess fatty acids causes is converted to ketones via the liver which causes the increased serum (and urine) ketones

Question 14

How does a patient with DKA present?

Answer 14

Kussmaul breathing (deep laboured breathing)

Vomiting and abdominal pain

Dehydration - due to the glucose in the blood

Can have polyuria

Question 15

What is the diagnostic criteria of diabetic ketoacidosis?

Answer 15

Diagnosis

• * Diabetes - hyperglycaemia >11.0mmol/l
• * Ketonaemia greater than 3mmol/l or 2+ on urine dipstick
• * Acidosis - venous blood pH <7.3

Question 16

How is diabetic ketoacidosis treated?

What does each treatment correct?

Answer 16

• Give 500ml NaCl 0.9% IV over 15 minutes
• Give IV human soluble insulin infusion of 50 units in 50ml NaCl 0.9% at 0.1units/kg/hour
• Give IV KCl in NaCl 0.9% bag once potassium <5.5mmol/l
• Give IV glucose 10% at 125ml/hour once glucose <14mmol/l
• Continue insulin until ketones 0.3mmol/l, ph > 7.3 and venous bicarb >15mmol/l

Question 17

How can a DKA cause depletion of body potassium levels?

Answer 17

High glucose levels in the blood spill over into the urine, taking water and solutes (such as sodium and potassium) along with it in a process known as osmotic diuresis

This can cause a depletion of potassium in the tissues however a hyperkalaemia

Question 18

How can the treatment of DKA lead to changes in potassium levels?

Answer 18

insulin decreases potassium levels in the blood by redistributing it into cells via increased sodium-potassium pump activity

Most of the extracellular potassium will have been lost due to the osmotic diuresis and therefore there will be a hypokalaemia which is dangerous

Question 19

What is the most common cause of death in the treatment of DKA?

Answer 19

Heart arrhythmia due to hypokalaemia ending in heart failure

Question 20

When is potassium given in DKA?

Answer 20

Monitor potassium and levels decrease to less than 5.5mmol/l in blood then give IV potassium

Question 21

When is glucose given in DKA?

Answer 21

Once the glucose levels decrease below 14mmol/l give IV glucose 10% glucose at 125ml/h to run alongside saline

Question 22

How long should the fixed rate insulin (0.1 unit/kg/hour) be continued for in the treatment of DKA? What should happen with the patients regular long acting doses?

Answer 22

Fixed rate insulin should be continued until ketones 7.3 and venous bicarb >15mmol/l.

Continue patients regular long-acting insulin doses throughout treatment (withhold the short acting (bolus) insulin doses)

Question 23

What is a child with dka at risk of when being treated?

Answer 23

At a high risk of cerebral oedema and therefore child should be treated with fluid replacement slowly and referred to paediatrics for management

Question 24

State how esach of the DKA treatments help

Answer 24

• Give 500ml NaCl 0.9% IV over 15 minutes (corrects dehydration and restores BP)
• Give IV human soluble insulin infusion of 50 units in 50ml NaCl 0.9% at 0.1units/kg/hour (decreases blood glucose however will also drive potassium into the cells causing a hypokalaemia)
• Give IV KCl in NaCl 0.9% bag once potassium <5.5mmol/l (prevents potassium from going dangeriously low causing potentially fatal arrhythmias)
• Give IV glucose 10% at 125ml/hour once glucose <14mmol/l (prevent hypoglycemia once blood glucose level begin to return to normal.)

Continue insulin until ketones 0.3mmol/l, ph > 7.3 and venous bicarb >15mmol/l

Question 25

How is newly diagnosed type 1 diabetes managed?

Answer 25

Lifelong insulin

Basal blous regime

Basal is once daily mimicking the background insulin production

Bolus is given with meals

Question 26

How much of the bodys isnulin is produced due to background insulin production?

Answer 26

50%

Question 27

What are the initial symptoms of hypoglycaemia?

Answer 27

• Pallor
• sweating,
• tremor,
• palpitations,
• confusion,
• nausea,
• hunger,
• weakness,
• fatigue,
• tachycardia

Question 28

What does severe hypoglycaemia lead to?

Answer 28

Leads to seizures, unconsciousness and the need for external assistance

Question 29

In a patient who is able to swallow and who is orientated (basically able to self manage), how should their hypoglycaemia be treated?

Answer 29

Give 15-20g fast acting carbohydrates eg 5 glucotabs or 90-120mls lucozade

Question 30

If glucose levels do not rise above 4mmol/l, how many times can the 15-20g fast acting carb be given?

Answer 30

Give upto 3 times

Question 31

If the patient is confused and aggressive however is till able to swallow, what should be given? How long after giving treatment for hypo should BG levels be checked?

Answer 31

Give 1.5-2tubes of glucogel into the buccal mucosa of the mouth

Recheck after 10-15 minutes

Question 32

If after trying 3 times, the patietns glucose does not rise above 4mmol/l either when the patinet was able to swallow or when the patient required the 1.5-2glucogel tubes, what is the next treatment?

Answer 32

Call doctor and give IM glucagon once only - can take up to 15 minutes to work or IV glucose

Question 33

If the patient is unconscious or having seizures, what should be given? What should be carried out before administrating medication?

Answer 33

Check ABC - firstly and switch off IV insulin

Then give IV glucose over 10 minutes:

75ml 20% glucose over 10 minutes or

150ml 10% glucose over 10 minutes

Question 34

If IV access is not able to be obtained or the patient is at home, what should be given?

Answer 34

1mg Glucagon IM once only

Question 35

How long can the glucagon take to work and when will it not be effective?

Answer 35

Can take up to 15 minutes to work and wont be as effective in undernourished or patients with liver disease

DO NOT administer if the hypo is due to oral hypoglycaemic induced agent hypoglycaemia

Question 36

What can occur in patients who have experienced multiple hypoglycaemic causing them not to have any symptoms?, this is dangerous

Answer 36

impaired hypoglycaemia awareness

Question 37

How should patients with type 1 diabetes be monitored?

Answer 37

Measuring HbA1c levels (measures levels of glucose over past 2-3 months)

Question 38

HbA1c depends on average blood glucose concentration and red blood cell (RBC) lifespan. The formation of the sugar-Hb linkage indicates the presence of excessive sugar in the bloodstream, often indicative of diabetes. A1C is of particular interest because it is easy to detect.

* What diseases can give falsely low HbA1c due to the decreased lifespan of red blood cells?

Answer 38

Sickle cell anaemia and other haemoglobinopathies can give falsely low HbA1c readings due the decreased lifespan of RBCs

Question 39

What factors contribute to hypoglycaemia? (how can alcohol induce this)

Answer 39

 Primary failure of hormones to raise glucose

• Hypopituitarism
• Adrenal cortical failure
• Isolated GH deficiency

Malabsorption deficiencies eg coeliac disease

Alcohol causes decreased liver gluconeogensis