Acute complications of diabetes

Question 1

Diabetic ketoacidosis: pathophysiology

Answer 1

Unchecked gluconeogenesis –> hyperglycaemia

Osmotic diuresis –> dehydration

Unchecked ketogenesis –> ketosis

Dissociation of ketone bodies into H+ and anions –> anion gap metabolic acidosis

Question 2

Adipose tissue- physiological effects of insulin deficiency

Answer 2

Increased lipolysis and reduced esterification of fat

FFA substrate for hepatic synthesis of ketone bodies

Muscle and brain can utilise ketones as main energy substrate

Ketoacidosis results when ketone body production exceeds rate of utilisation in peripheral tissues and renal clearance

Question 3

DKA- acidosis managed by

Answer 3

Intracellular buffereing - H+/K+ exchange

Respiratory compensation - hyperventilation

• H+ stimulates respiratory centres
• breathe off CO2

Renal excretion of H+ (slow response)

Question 4

DKA- electrolyte disturbances (renal losses)

Answer 4

Potassium depletion

Sodium depletion

Dehydration

Question 5

Extracellular [K]

Answer 5

4mmol/l

Question 6

Intracellular [K]

Answer 6

125mol/l

Question 7

DKA precipitating factors

Answer 7

Infections- pneumonia, urinary tract, viral illnesses, gastroenteritis

Error/ missed insulin administration

MI

Previously undiagnosed type 1 diabetes

Drugs: steroids

Question 8

Symptoms of DKA

Answer 8

Thirst and polyuria

Weakness and malaise

Drowsiness, confusion

Nausea and vomiting

Abdominal pain

Breathlessness

Question 9

Signs and symptoms of hyperglycaemia and dehydration

Answer 9

Symptoms

• thirst and polyuria
• weakness and malaise
• drowsiness, confusion

Signs

• dry mouth
• sunken eyes
• postural or supine hypotension
• hypothermia and coma

Question 10

Signs and symptoms of acidosis

Answer 10

Symptoms

• nausea and vomiting
• abdominal pain
• breathlessness

Signs

• facial flush
• hyperventilation
• smell of ketones on breath and ketonuria

Question 11

Clinical features of DKA

Answer 11

Age: mostly young T1DM

Cause: relative or absolute insulin deficiency

Serum sodium: normal or low

Blood glucose: usually <40mml/l

Serum HCO3-/pH: <14mmol/l / ph<7.3

Serum ketones: high

Mortality: 5% depending on age

Question 12

DKA 5 step plan

Answer 12

1. Confirm diagnosis and check for precipitating causes
2. Rehydrate and monitor fluid balance
   - IV fluids- saline with added potassium
   - consider urinary catheter
3. Lower glucose
   - intravenous insulin- fixed rate 0.1unit/kg/hr
4. Monitor electrolytes
   - potassium (and sodium)
5. Prevent clots
   - prophylactic low molecular weight heparin

Question 13

DKA other management factors

Answer 13

Is the patient conscious?
- assess GCS

At risk of aspiration
- consider NG tube

Monitor recovery
- glucose, ketones, pH, potassium hourly

Question 14

DKA recovery

Answer 14

pH normal, ketones <2+ (urine), vomiting settled

Resume normal diet

Switch from intravenous to normal subcutaneous insulin

Question 15

Hyperosmolar hyperglycaemic state clinical features

Answer 15

Age: usually .40

Precipitating causes: previously undiagnosed, steroids, diuretics, sugar

Serum sodium: usually high

Blood glucose: often >40mmol/l

Serum HCO3/ pH: normal/ pH 7.4

Serum ketones: 0

Mortality: 30%

Question 16

HHS management

Answer 16

Confirm diagnosis and check for precipitating causes

Rehydrate and monitor fluid balance

• IV fluids- saline with added potassium
• consider urinary catheter

Lower glucose (once glucose not improving with fluids)
- IV insulin fixed rate 0.05unit/kg/hr

Monitor electrolytes
- potassium (and sodium)

Prevent clots
- treatment low molecular weight heparin

Patients are often elderly and severely ill

Question 17

Hypoglycaemia

Answer 17

Blood sugar <4mmol/l

Asymptotic

• awake
• sleeping

Mild symptomatic (patient can treat themselves)

Severe symptomatic (help needed)

Coma and convulsions

Question 18

Autonomic symptoms of hypoglycaemia

Answer 18

Sweating, feeling hot

Trembling or skakiness

Anxiety

Palpitations

Question 19

Neuroglycopenic symptoms of hypoglycaemia

Answer 19

Dizziness, light headedness

Tiredness

Hunger, nausea

Headache

Inability to concentrate, confusion, difficulty speaking, poor coordination, behavioural changes, automatism

Coma and convulsions, hemiplegia

Question 20

Causes of hypoglycaemia

Answer 20

Insulin

• inappropriately excessive doses
• not eating, or insufficient carbohydrate

Sulfonylureas

Question 21

Hyperglycaemia- counter regulations

Answer 21

Glucagon, adrenaline, cortisol and GH all have anti insulin effect

Glucagon stimualtes glycogenolysis and gluconeogenesis (1)

Adrenaline increases glycogenolysis

GH and cortisol limit glucose disposal in peripheral tissues, takes several hours

Sympathetic nerves may directly activate hepatic glycogenolysis and stimulate glucagon secretion

Question 22

Treatment of minor episode of hypoglycaemia

Answer 22

20mg carbohydrate as sugary drink, fruit juice, glucose tablets, glucose gels followef by something starchy to eat

Glucose gels

Question 23

Treatment of hypoglycaemic coma

Answer 23

IM or IV glucagon 1mg

IV dextrose 25mg (150ml 10% glucose)