Week 1/2 - E - Complications of diabetes - D.K.A, H.H.S, Lactic acidosis, sick day rules

Question 1

What two complications of diabetes is IV insulin required in? (usually required in hypoglycaemia for sliding scale of insulin)

Answer 1

Diabetic ketoacidosis (DKA)

Hyperglycaemic hyperosmolar state (HHS)

Question 2

What is required for the biochemical diagnoses of DKA?

Answer 2

Glucose >11mmol/l

Ketones >3mmol/l or high on urine dipstick test (greater than 2 ++)

pH <7.3 or

Bicarbonate <15mmol/l

Question 3

Why is there total body depletion of potassium in DKA?

Answer 3

 Potassium usually above 5.5mmol/L -

In T1DM - beta cell destuction so insulin not there, in insulin deficiency glucose is still causing ATP and closure of potassium channels

In DKA - the glucose being lost via the urine causes an osmotic pull leading to extracellular potassium loss

Insulin then drives potassium into the cells but as the potassium has been lost, this means there will be a hypokalaemia as well as low potassium in the cells now

Question 4

When measuring the ketone level in blood, what is measured? When measuring the ketone level in urine, what is measured?

Answer 4

Blood - beta hydroxybutyrate

Urine - acetate

Question 5

What is the most common cause of diabetic ketoacidosis? What are three other causes?

Answer 5

Most common is non compliance with treatment

Infection

Newly diagnosed diabetes

Alcohol and drug use

Question 6

What is given to treat DKA? When should you continue insulin until?

Answer 6

• 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/

Question 7

What is the pathophysiology behind DKA?

Answer 7

Reduced insulin concentration and increased insulin counter-regulatory hormones, leads to hyperglycaemia, volume depletion and electrolyte imbalance 

Insulin deficiency leads to release of FFA from adipose tissue (lipolysis), hepatic fatty acid oxidation and formation of ketone bodies which causes ketonaemia and acidosis

Question 8

Disease less common than DKA but has a significantly higher mortality than DKA o Mainly occurs in T2DM and usually older patients What is this?

Answer 8

Hyperglycaemic hyperosmolar state (HHS)

Question 9

What is the most common predisposing factor of HHS? What are two drugs that cause this also?

Answer 9

Illness is most common factor

Steroids and thiazides is also make this more likely

Question 10

What is the other name for HHS?

Answer 10

Hyperglycaemic hyperosmolar non-ketotic coma

Question 11

What are the symptoms of HHS? (similar to DKA)

Answer 11

Polyuria, polydipsia, weight loss, Weakness, hypotension, dry mucous membranes, confusion, vomiting/abdo pain

Question 12

HHS is usually precipitated by an infection,myocardial infarction, stroke or another acute illness. How can eg an illness cause people with type 2 diabetes mellitus to enter a hyperglycaemic hyperosmolar state?

Answer 12

A relative insulin deficiency leads to a hyperglycaemia and a resulting high serum osmolarity.

This leads to excessive urination (more specifically an osmotic diuresis), which, in turn, leads to volume depletion and hemoconcentration that causes a further increase in blood glucose level

Question 13

Why is ketosis absent in HHS?

Answer 13

Ketosis is absent because the presence of some insulin inhibits hormone-sensitive lipase-mediated fat tissue breakdown.

(essentially there is enough insulin to inhibit fat breakdown and therefore ketosis, however there is not enough insulin to prevenet glycogenylosysis or gluconeogenesis)

Question 14

How is the osmolality calculated? What is the normal osmalality of blood and what is the osmolality level thought to be in HHS?

Answer 14

• Osmolality = 2x[Na+K] + Urea + glucose
• Normal osmolality 285-295msmol/kg

In HHS osmolality is thought to be greater than 320mosmol/kg (usually around 400)

Question 15

Restate the osmolality levels in HHS? What is the expected glucose levels in this condition? What is the expected pH in this condition?

Answer 15

Osmalality >320mosmol/kg (high serum glucose concentration)

Glucose levels >30mmol/;

No switch to ketone metabolism as there is insulin present so no ketonaemia and therefore pH>7.3

Question 16

How is HHS treated?

Answer 16

Similar treatment as DKA

Diet, insulin and fluid replacement

Potassium replacement may also be required once levels drop below 5.5mmol/l

Question 17

Lactate is the end product of anaerobic metabolism. Clearance requires hepatic uptake and aerobic conversion to pyruvate then glucose What are two causes of lactic acidosis?

Answer 17

Tissue hypoxaemia as requries aerobic respiration

Liver failure

Question 18

What percentage of DKA cases is associated with an increased lactate? (>5mmol/l) Which drug use to treat T2DM can cause lactic acidosis and therefore shouldnt be given to patients with chronic renal failure?

Answer 18

10% of cases

Metformin can cause lactic acidosis

Question 19

Microvascular disease – small vessels become sites of atherosclerosis and nerves receive a reduced oxygen supply and they become damaged and die off (prolonged high glucose can also be toxic to vessels) What are the three microvascualr disease in diabetes? which is most common?

Answer 19

Neuropathy - 60-70% of patients with diabetes will experience this

Nephropathy and retinopathy

Retinopathy is the most common microvascular diabetes complication

Question 20

What are three types of macrovascualr disease?

Answer 20

Stroke

IHD

Erectile dysfunction - occurs in at least 50% of all diabetic men – due to vascular and neuropathy – common side effect of antihypertensive drugs

Question 21

What are the four type of neuropathy?

Answer 21

Autonomic

Peripheral

Proximal

Focal

Question 22

Where is peripheral neuropathy located?

Answer 22

Numbness in hands and feet

Can be a burning pain

Question 23

What causes charcot’s foot?

Answer 23

Charcot foot is a condition causing weakening of the bones in the foot that can occur in people who have significant nerve damage (neuropathy).

The bones are weakened enough to fracture, and with continued walking the foot eventually changes shape.

Plantar sublaxation of the ruined bones

Question 24

What are the treatment options for charcot’s foot? Give three

Answer 24

Simple analgesics - paracetamol

Amitryptiline

Capsaicin cream - pain killer

Question 25

Diabetes is the commonest cause of kidney failure/dialysis What is used to screen for diabetic kidney disease

Answer 25

Use urinary albumin creatinine ratio (ACR) to screen for diabetic kidney disease

Question 26

What is a sign of late stage kidney disease?

Answer 26

Microalbuminuria

Macroalbuminria

Proteinuria

Question 27

What are the levells of microalbumin, macroalbumin and preoteinuria?

Answer 27

 Microalbuminuria: 30-300mg/ml 

Macroalbuminuria: >300mg/ml 

Proteinuria >500mg/ml

Question 28

What is the treatment of microalbuminuria?

Answer 28

• ACEI at highest tolerated dose!!

Question 29

What is the blood pressure targets for diabetic patients with and without microalbuminuria?

Answer 29

BP targets for diabetics without microalbuminuria is 140/80 and with microalbuminuria is 130/80

Question 30

Illness and infections cause your body to be more stressed. When you have diabetes your blood glucose levels often rise during illness especially if you have a fever When you have diabetes your blood glucose levels often rise during illness especially if you have a fever

What are the diabetic sick day rules? * monitoring glucose, * fluid intake, * struggling to ear * which oral hypoglycaemiic to avoid

Answer 30

The following are key messages that should be given to all patients with diabetes if they become unwell:

• * Increase frequency of blood glucose monitoring to four hourly or more frequently
• * Encourage fluid intake aiming for at least 3L / 24hrs
• * If unable / struggling to eat may need sugary drinks to maintain carbohydrate intake
• * AVOID SGLT2 inhibitors as they cause decreased glucose -re-absorption in the proximal renal tubules
• * Access to a mobile phone has been shown to reduce progression of ketosis to diabetic ketoacidosis