Type 1 Diabetes Treatment Flashcards
Devices available to administer subcutaneous insulin?
Syringe
Disposable pen (for self-administration)
Reusable cartridge pen (for self-administration)
Continuous subcutaneous insulin infusion pump (for self-administration)
Principles of treatment of T1DM?
Prevent hyperglycaemia
Avoid hypoglycaemia
Reduce chronic complications
Symptoms and signs of hyperglycaemia?
Thirst, tiredness, blurred vision, weight loss, polyuria, nocturia and fungal infections (e.g: thrush)
Cognitive, mood state, information processing, working memory
Risks with hyperglycaemia?
Potential risk of DKA
Symptoms of hypoglycaemia?
Pallor, sweating, tremor, palpitations, confusion, nausea and hunger
Congitive signs inc. tense-tiredness, information processing, working memory or coma
Complications of T1DM?
Microvascular disease, macrovascular disease, acute metabolic comps. (e.g: DKA, SHG) and reduced psychosocial morbidity
Describe normal insulin phsyiological release
Insulin is secreted at a low basal rate, accounting for 50% of the insulin that is produced
Post-prandial insulin is secreted in relation to post-meal glucose
Types of administered insulin and the onset and duration fo action?
Rapid-acting analogues (0-5 hours), e.g: Humalog (insulin lispro)
Short-acting (0-8 hours), e.g: Humulin S (human insulin)
Intermediate acting - isophase - (0-20 hours), e.g: Humulin I (isophane human)
Long-acting analogue, e.g: lantus (0-24 hours; these are the smoothest acting) or levemir (0-24 hours but less smooth)
Rapid-acting analogue-intermediate mixture (0-4 hours rapid-acting superimposed on 0-22 hours intermediate-acting?), e.g: Humalog Mix25/Mix50
Short-acting intermediate mixture (0-8 hours short-acting superimposed on 0-20 hours intermediate acting), e.g: Humulin M3
What is the best insulin regimen (to mimic endogenous insulin production)?
Basal bolus insulin
Different patterns of insulin injections?
Twice daily insulin (BD) - less flexible but most commonly used
Once daily insulin
These can use:
• Rapid-acting analogue-intermediate mixture
• Short-acting intermediate mixture
• Intermediate-acting (isophane)
Main treatment methods of T1DM?
Most people should be treated with Multiple Daily Injections (MDI), 3-4 injections per day OR Continuous Subcutaneous Insulin Infusion (CSII)
Educate patients in how to match prandial insulin dose to carb intake, pre-meal glucose and anticipated activity
Most people should use insulin analogues to reduce hypoglycaemia risk
How to calculate units of insulin pre-meals?
……..
Target glucose levels?
Pre-meal: 3.9-7.2 mmol/l
1-2 hours after beginning a meal: <10 mmol/l
Examples of prandial insulins?
Insulin analogues, e.g: Insulin aspart (NovoRapid), lispro (Humalog) - onset of action is within 10-15 mins and peak action is at 60-90 mins; duration of action of 4-5 hours
Soluble insulin, e.g: Actrapid, Humulin - onset of action is within 30-60 mins and peak action is at 2-4 hours; duration of action is 5-8 hours
Examples of basal insulins?
Isophane “basal” insulins, e.g: Insulatard, Humulin I - intermediate/long-acting; peak of activity is 4-6 hours after administration
Analogue basal insulins, e.g: Lantus, Levemir - longer duration of action but less peak activity (flatter profile); can be given once/twice a day
What type of basal insulin should most T1DM patients be on?
Analogue basal insulin
What is advanced carbohydrate counting?
Synchronising the amount of insulin taken to the amount of carbohydrate consumed
Who is advanced carbohydrate counting suitable for?
For those on MDIs OR for people on CSII pumps
Components of advanced carbohydrate counting?
- Insulin to carbohydrate ration (ICR)
* Insulin sensitivity factor, AKA correction factor (CF)
General rules with carbohydrate counting?
Rapid-acting insulin can be altered according to the amount and type of food intake; the patient eats different amounts of carbs at each meal and requires different amounts of rapid-acting insulin at meals, e.g: 1 unit per 10g of carbohydrate
Blood glucose is checked 2 hours after the meal; general rule is that if it is >2 mmol/ above pre-meal level on 2 consecutive days, insulin may need to be increased to carbohydrate ratio
Blood glucose level aims with carbohydrate counting?
Fasting BG 4-7 mmol/l with basal long-acting insulin adjustment
Prandial BG 4-8 mmol/l with appropriate food intake and adjustment of rapid-acting insulin
How is the amount of carbohydrate estimated in food?
Food measurement, e.g: weight, volume
Food composition tables and labels
There are always hidden sources of carbohydrates
How is carbohydrate counting used to calculate insulin doses?
Rate of insulin : CHO
e.g: 1 unit of insulin per 10g CHO = 6.5 units of insulin
What is an insulin pump?
Allows continuous administration of short-acting insulin subcutaneously
Background insulin is dictated by the basal rate; these can be programmed in advance and may be set to different rates at different times of the day
It delivers manually activated bolus’ of insulin to cover meals (covered by CHO counting)
Insulin regimen with a insulin pump (CSII)?
Breakfast bolus
Lunch bolus
Supper bolus
Examples of different meal bolus profiles with an insulin pump?
Standard Dual Multiple Short extended Long extended
How can metabolic control be evaluated?
Home blood glucose monitoring
Urine testing (glucose/ketones)
Glycated haemoglobin (HbA1C)
Continuous glucose monitor (not funded on NHS unless special circumstances)
Limitations of blood glucose monitoring?
Finger prick tests only provide a “snapshot” at any given moment; continuous blood glucose monitoring is much better
What is HbA1c?
Glycated haemoglobin is the largest component of the glycated haemoglobins (60-80%); it is formed by non-enzymatic glycation of haemoglobin on exposure to glucose
Increases in a predictable way in response to prevailing glucose and it can be used as a measure of average blood glucose over a longer period of time (6-8 hours)
Target HbA1c?
48 mmol/mol
Limitations of insulin injections/pump?
Injected into subcutaneous tissue rather than directly released into the portal blood
The peak is too slow to prevent post-meal hyperglycaemic spike and it has slow clearance; endogenous insulin rapidly prevents post-meal hyperglycaemia and is also rapidly cleared
Factors affecting insulin absorption/action?
- Pen accuracy and any leakage
- Temperature
- Injection site and depth
- Exercise
Steps to reduce risk with insulin injections?
Check injection sites for lipohypertrophy (lumps) - these can form due to injection into the same site, so encourage rotation; if people inject into these, no effect so they rotate site but also increase insulin and then become hypoglycaemia
Check new needle usage each time
Ensure equipment is in good working order
No sharing of needles
Top safety issues with insulin?
Wrong dose, insulin omission and wrong insulin product (names are similar, e.g: Humulin S, Humulin I and Humulin M3)
“Rights” of prescribing insulin?
Right patient, medicine, dose, route, time
Insulin prescribing requires:
• Right documentation, monitoring and storage (in-use devices are stable at room temp for 28 days; unopened vials, pen devices and cartridges should be stored in medicine fridge)
Principles of insulin dose adjustment?
Review glycaemic control and adjust the routine insulin proactively to optimise control
Adjust insulin dose prescribed prior to any problems; remember that reactive insulin adjustment can precipitate hypoglycaemia
DO NOT OMIT INSULIN IF HYPOGLYCAEMIC; TREAT THIS AND ADMINISTER INSULIN AS USUAL
Why are there so many errors with insulin?
Patient vary widely in their physiological response to insulin
Many different types of insulin are available, varying in composition and delivery mechanism
Similar-sounding names and numbers are used to describe composition (can be confused for dose)
Insulin syringes have ml on them, not units, e.g: 0.6 ml does not = 6 units; this is 60 units
How to ensure mistakes with insulin administration are avoided?
- Verify the amount and type of insulin with the patient if possible BEFORE administering it
- Only use specific insulin syringes for administration of insulin from a vial and ensure you know how to use these correctly
- ALWAYS ensure a second independent check of insulin doses prior to administration
- Glucose should be used for all intravenous insulin infusions except for patients admitted with diabetic ketoacidosis
Guidelines for a Mx of a patient that presents with ketoacidosis?
ADD PICTURE
Uses of IV insulin?
- DKA
- Hyperosmolar hyperglycaemia state (HHS)
- Acute illness
- Fasting patients who are unable to tolerate oral intake
Monitoring for IV insulin Mx?
Hourly BG monitoring (aim is 5-12 mmol/l)
Free of hypoglycaemia
Check ketones if the BG is >12 mmol/l
Check U&Es daily (at least)
Ensure safe transition from IV to subcutaneous insulin
Other insulin formulations?
Inhaled insulin - too many complications, e.g: lung inflammatory conditions and potential for lung carcinoma
Oral insulin - little absorption due to metabolism
Non-insulin adjunct therapy, e.g: metformin, leptin, GLP-1 - have some use
Types of pancreas transplantation?
Whole pancreas transplantation (usually alongside a kidney transplant)
Islet autotransplantation
Indications for pancreas transplantation?
- Imminent or ESRD due to receive/with kidney transplant
- Severe hypoglycaemia/metabolic complications
- Incapacitation with clinical/emotional problems
- Uncontrolled diabetes despite maximal treatment
- Severe and progressive long-term complications despite maximal therapy
Aim of islet transplantation?
Replace only the endocrine component of the pancreas with the aim of restoring physiological glucose homeostasis in individuals with T1DM
4 key steps inv. with islet transplantation?
- Pancreas donation and retrieval
- Islet isolation
- Islet culture
- Islet transplantation
Potential outcomes of islet transplantation?
- Insulin dependence
- Reduction in severe hypoglycaemia
- Improved glycaemic control
