Diabetic Emergencies Flashcards
Why does hypoglycaemia occur?
As a result of an imbalance between injected insulin and the patient’s diet, exercise and basal requirement
When are the greatest times of risk for hypoglycaemia?
Before meals, through the night and during/after exercise
What are some factors which may precipitate hypoglycaemia?
Irregular eating habits, unusual exertion and alcohol excess
At what BG level do symptoms of hypoglycaemia develop?
< 3 mmol/l
How quickly do symptoms of hypoglycaemia occur?
Over a few minutes
What are some adrenergic symptoms of a diabetic hypo?
Sweating, tremor, pounding heartbeat
What are some physical signs of a diabetic hypo?
Pallor and cold sweat
Which diabetic patients may report a loss of warning signs of a hypo?
Those with longstanding type 1
What are some more behavioural features of a diabetic hypo?
Clumsy or inappropriate, irritable or aggressive
What are some options to reduce the risk of an overnight hypo?
Having a bedtime snack // Twice daily mixed insulin // Long acting insulin analogue at night // Infusion pump
What is the treatment for mild hypoglycaemia?
A form of rapidly absorbable carbohydrate such as Lucozade
What should patients be treated with in severe hypoglycaemia?
IM glucagon (1mg) or IV glucose (25-50ml of 50%), followed by a flush of 0.9% saline
DKA is a disordered metabolic state which usually occurs in the context of what?
Relative insulin deficiency and hence increased BG
If insulin is decreased in DKA, what hormones are increased?
Counter regulatory hormones like glucagon, adrenaline, cortisol and growth hormone
Which type of diabetes does DKA occur in?
Majority type 1, but can rarely occur in type 2
When does DKA usually occur?
In times of stress e.g. infection
In DKA, there is a lack of insulin and so glucose cannot get into cells to be used as energy. What is used instead? By what process are these formed?
Fatty acids from lipolysis
What happens in lipolysis?
Triglycerides are broken down into free fatty acids and glycerol
After lipolysis, fatty acids are turned into what? Where?
Ketone bodies, in the liver
What is the advantage and disadvantage of the production of ketones as an energy source?
Advantage: they can be used by the cells for energy // Disadvantage: they increase the acidity of blood
When does Kussmaul’s breathing occur?
When the blood is very acidic (acidosis)
What is Kussmaul’s breathing and what is its function?
Deep, laboured breathing which occurs as the body tries to blow off CO2 in order to decrease acidity
In the cell membranes, there is a H+/K+ co-transporter. What happens to these ion concentrations in DKA?
Since DKA is an acidosis, there is high H+ in the blood. As a result of this, H+ is taken into cells via these transporters, meaning that K+ is transported out of cells and into the blood
Under normal circumstances, insulin activates the Na/K ATPase pump. What does this do?
K+ into cells, Na+ out of cells
In DKA, the Na/K ATPase pump is not activated as there is not a lot of insulin. What is the result of this?
K+ remains in the ECF, which quickly gets into the blood
Due to actions of the H+/K+ co-transporter and the Na+/K+ ATPase pump, what happens to K+ levels in DKA?
Rise, giving hyperkalaemia
What will the anion gap be in DKA?
High
Ketone bodies break down into what? When this gets released via the lungs, what does it cause?
Acetone // When released from the lungs this gives the breath a sweet, fruity smell
With regards to ketones, what must a patient have to be diagnosed as in DKA?
> 3mmol/l in blood (or significant ketonuria i.e. ++)
With regards to blood glucose, what must a patient have to be diagnosed as DKA?
> 11mmol/l (or known diabetes)
With regards to bicarbonate, what must a patient have to be diagnosed as DKA?
< 15mmol/l (or venous pH < 7.5)
Blood ketones is the most effective way to measure ketones in DKA. What is measured when you test blood ketones?
Beta-Hydroxybutarate
What is the normal range of blood ketones?
< 0.6mmol/l
What is measured when you test urine ketones? Why is this not as effective a test as blood ketones?
Acetoacetate, this indicates the levels of ketones 2-4 hours earlier
What can the glucose range be in DKA?
10-100mmol/l (usually around 40)
What is usually the level of K+ in DKA? What do you need to be aware of?
> 5.5 // Must be aware of those with a low normal range, their elevated K+ may still be within the upper range of normal
What are some other markers which are often raised in DKA?
Creatinine, Na+, lactate, amylase and possible WCC
What are some common triggers of DKA?
Infection, drugs and alcohol, non-compliance with treatment, newly diagnosed patient
What are signs and symptoms of DKA that are osmotic related?
Thirst, polyuria, dehydration
What are some signs and symptoms of DKA that are related to the ketone bodies?
Flushing, vomiting, abdominal pain, dyspnoea (Kussmauls’)
What are some complications of DKA?
Aspiration, VF from hyperkalaemia, sepsis, thromboembolism, cerebral oedema
What is the commonest cause of DKA mortality in children?
Cerebral oedema
What are the 3 main treatments for DKA?
IV fluid 0.9% NaCl, insulin and K+
How much fluid should be given in DKA?
500ml bolus over 10-15 mins and then IV infusion once BP > 90
How is K+ given in DKA?
Include potassium chloride in fluids
Should established insulin therapy be continued in DKA?
Yes
When should glucose be given in DKA?
Once BG < 14mmol/l you should give glucose 10% IV infusion
HHS is mostly seen in which type of diabetes?
Type 2
What happens to plasma osmolarity in HHS?
Increased (dehydration)
In HHS, glucose in the blood is high. What does this lead to in terms of water balance?
Water moves out of cells to try and compensate which leads the cells shrivelled and dry
What happens in HHS once the vessels are full of water?
Increased urination and dehydration
Are ketonuria and acidosis features of HHS?
They can be, but not as severe as in DKA
HHS mainly occurs in which population? What is the exception to this?
Mainly in the older population, only seen in young patients in non-Caucasian groups
What has usually been taken before an episode of HHS?
Slowly absorbed (refined) carbohydrate
What are some risk factors for HHS?
Previous CV event, sepsis, medications (especially steroids and thiazides), fizzy drinks
What is HHS defined as?
Hypovolaemia and hyperglycaemia (> 50mmol/l) without significant acidosis and ketonuria
There will usually be impairment of what body system in patients with HHS?
Renal
In HHS, the value of osmolarity is often around what?
400mosmol/l
How is osmolarity worked out?
2 (Na+ / K+) + urea + glucose
What is the normal range of osmolarity?
285-295mosmol/l
What are the main treatments for HHS?
Fluids and insulin, cautiously and slowly
Rapid fluctuations in what ion should be avoided?
Na+
What should patients with HHS be screened for?
Silent vascular event
What medication should be given to all patients with HHS, unless it is contra-indicated?
LMWH
What is lactate?
The end product of anaerobic metabolism of glucose
Type A lactic acidosis is caused by what?
Tissue hypoxaemia
What is type B lactic acidosis caused by?
Liver disease, leukaemia, diabetes
When does lactic acidosis occur in diabetes?
DKA, or in severe illness/renal failure in patients on metformin
What are some clinical findings of lactic acidosis?
Hyperventilation, confusion, coma
How is lactic acidosis treated?
Treat the underlying condition and give fluids. Withdraw any offending medication
