Week 1/2 - E - Complications of diabetes - D.K.A, H.H.S, Lactic acidosis, sick day rules Flashcards
What two complications of diabetes is IV insulin required in? (usually required in hypoglycaemia for sliding scale of insulin)
Diabetic ketoacidosis (DKA)
Hyperglycaemic hyperosmolar state (HHS)
What is required for the biochemical diagnoses of DKA?
Glucose >11mmol/l
Ketones >3mmol/l or high on urine dipstick test (greater than 2 ++)
pH <7.3 or
Bicarbonate <15mmol/l
Why is there total body depletion of potassium in DKA?
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
When measuring the ketone level in blood, what is measured? When measuring the ketone level in urine, what is measured?
Blood - beta hydroxybutyrate
Urine - acetate
What is the most common cause of diabetic ketoacidosis? What are three other causes?
Most common is non compliance with treatment
Infection
Newly diagnosed diabetes
Alcohol and drug use
What is given to treat DKA? When should you continue insulin until?
- 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/
What is the pathophysiology behind DKA?
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
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?
Hyperglycaemic hyperosmolar state (HHS)
What is the most common predisposing factor of HHS? What are two drugs that cause this also?
Illness is most common factor
Steroids and thiazides is also make this more likely
What is the other name for HHS?
Hyperglycaemic hyperosmolar non-ketotic coma
What are the symptoms of HHS? (similar to DKA)
Polyuria, polydipsia, weight loss, Weakness, hypotension, dry mucous membranes, confusion, vomiting/abdo pain
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?
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
Why is ketosis absent in HHS?
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)
How is the osmolality calculated? What is the normal osmalality of blood and what is the osmolality level thought to be in HHS?
- 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)
Restate the osmolality levels in HHS? What is the expected glucose levels in this condition? What is the expected pH in this condition?
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
How is HHS treated?
Similar treatment as DKA
Diet, insulin and fluid replacement
Potassium replacement may also be required once levels drop below 5.5mmol/l
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?
Tissue hypoxaemia as requries aerobic respiration
Liver failure
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?
10% of cases
Metformin can cause lactic acidosis
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?
Neuropathy - 60-70% of patients with diabetes will experience this
Nephropathy and retinopathy
Retinopathy is the most common microvascular diabetes complication
What are three types of macrovascualr disease?
Stroke
IHD
Erectile dysfunction - occurs in at least 50% of all diabetic men – due to vascular and neuropathy – common side effect of antihypertensive drugs
What are the four type of neuropathy?
Autonomic
Peripheral
Proximal
Focal
Where is peripheral neuropathy located?
Numbness in hands and feet
Can be a burning pain
What causes charcot’s foot?
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
What are the treatment options for charcot’s foot? Give three
Simple analgesics - paracetamol
Amitryptiline
Capsaicin cream - pain killer
Diabetes is the commonest cause of kidney failure/dialysis What is used to screen for diabetic kidney disease
Use urinary albumin creatinine ratio (ACR) to screen for diabetic kidney disease
What is a sign of late stage kidney disease?
Microalbuminuria
Macroalbuminria
Proteinuria
What are the levells of microalbumin, macroalbumin and preoteinuria?
Microalbuminuria: 30-300mg/ml
Macroalbuminuria: >300mg/ml
Proteinuria >500mg/ml
What is the treatment of microalbuminuria?
• ACEI at highest tolerated dose!!
What is the blood pressure targets for diabetic patients with and without microalbuminuria?
BP targets for diabetics without microalbuminuria is 140/80 and with microalbuminuria is 130/80
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
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
