Blood Glucose

Public summary: 

Learn about diabetes and try using a handheld blood glucose meter.

Useful information
Kit List: 

Blood glucose meter
Test strips (these are expensive, use with care!)
100mM stock glucose solution
20ml universal tubes
Plastic dropper pipettes

Frequency of use: 

In a nutshell:
Use the handheld glucose meter to test the glucose concentration of different solutions (in place of blood). Many children will know someone who has diabetes but may not have had the chance to look at the equipment they use. Use this opportunity to let them investigate, and talk about the different types of diabetes and how it affects lifestyle.
How to set up the experiment:
Make up bottles of a variety of glucose concentrations using the syringes to measure out 100mM stock solution for dilution. Aim for solutions with concentrations of approximately 2 (hypoglycaemic), 5 (normal fasting), 7(normal post-meal, diabetic fasting), 12 (diabetic post-meal) and 25 (approaching ketoacidosis). I normally only use two different solutions though to conserve the testing strips (a normal one and a diabetic one). You may then wish to hide the numbers on the bottles, depending on how you wish to demonstrate!
Talk about diabetes in general. Use the charts to explain how blood glucose varies throughout the day and how this differs in diabetes. You could then get the children to choose one glucose solution and test the concentration, then work out what situation this reading is likely to have arisen in. You could also talk about the pancreas, its role in regulating glucose levels, and the actions of insulin and glucagon (this may also lead on to a discussion about hormones).
*USING THE METER* - this is very simple. Press the large on button and insert a new single-use test strip. Apply a tiny drop of solution to the end of the strip – not on top of the flat part, but poking the thin end into the droplet so it can be drawn in to the capillary. It may be easiest to do this by placing a small droplet of the solution onto the child’s (clean – this isn’t going to work if they’re covered in chocolate) finger/back of hand and then poking the test strip in to it as if it were a real drop of blood.

Background information:

Diabetes Mellitus (from Wikipedia)
Diabetes mellitus, or simply diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the pancreas does not produce enough insulin, or because cells do not respond to the insulin that is produced. This high blood sugar produces the classical symptoms of polyuria (frequent urination), polydipsia (increased thirst) and polyphagia (increased hunger). The cause of the polyuria is simply osmotic diuresis – the glucose content of the blood is so high that it cannot all be reabsorbed by the renal tubules and thus glucose is excreted in the urine. This increases osmotic pressure in the tubule, causing retention of water and thus high volumes of urine.
There are three main types of diabetes mellitus (DM).
Type 1 DM results from the body's failure to produce insulin, and currently requires the person to inject insulin or wear an insulin pump. This form was previously referred to as "insulin-dependent diabetes mellitus" (IDDM) or "juvenile diabetes".
Type 2 DM results from insulin resistance, a condition in which cells fail to use insulin properly, sometimes combined with an absolute insulin deficiency. This form was previously referred to as non insulin-dependent diabetes mellitus (NIDDM) or "adult-onset diabetes".
The third main form, gestational diabetes occurs when pregnant women without a previous diagnosis of diabetes develop a high blood glucose level. It may precede development of type 2 DM.

Type 1 diabetes
Type 1 diabetes mellitus is characterized by loss of the insulin-producing beta cells of the islets of Langerhans in the pancreas, leading to insulin deficiency. This type can be further classified as immune-mediated or idiopathic. The majority of type 1 diabetes is of the immune-mediated nature, in which beta cell loss is a T-cell-mediated autoimmune attack. There is no known preventive measure against type 1 diabetes, which causes approximately 10% of diabetes mellitus cases in North America and Europe. Most affected people are otherwise healthy and of a healthy weight when onset occurs. Sensitivity and responsiveness to insulin are usually normal, especially in the early stages. Type 1 diabetes can affect children or adults, but was traditionally termed "juvenile diabetes" because a majority of these diabetes cases were in children.

Type 2 diabetes
Type 2 diabetes mellitus is characterized by insulin resistance, which may be combined with relatively reduced insulin secretion. The defective responsiveness of body tissues to insulin is believed to involve the insulin receptor. However, the specific defects are not known. Diabetes mellitus cases due to a known defect are classified separately. Type 2 diabetes is the most common type. Type 2 diabetes is a risk factor associated with 'lifestyle' problems such as obesity.

Diabetic Emergencies
People (usually with type 1 diabetes) may also present with diabetic ketoacidosis, a state of metabolic dysregulation characterized by the smell of acetone, a rapid, deep breathing known as Kussmaul breathing, nausea, vomiting and abdominal pain, and altered states of consciousness. It occurs when the body breaks down lots of fat to fuel cells as glucose cannot enter them. In ketoacidosis the pH of the blood rapidly drops which affects a variety of bodily functions.

Fasting plasma glucose level ≥ 7.0 mmol/l (126 mg/dl)
Plasma glucose ≥ 11.1 mmol/l (200 mg/dL) two hours after a 75 g oral glucose load as in a glucose tolerance test
Symptoms of hyperglycemia and casual plasma glucose ≥ 11.1 mmol/l (200 mg/dl)

The pancreas is a glandular organ in the digestive system and endocrine system of vertebrates. It is an endocrine gland producing several important hormones, including insulin and glucagon which circulate in the blood. Insulin is a peptide hormone, produced by beta cells of the pancreas, and is central to regulating carbohydrate and fat metabolism in the body. It causes cells in the liver, skeletal muscles, and fat tissue to absorb glucose from the blood (thus lowering blood glucose levels). Glucagon is a peptide hormone secreted by the pancreas that raises blood glucose levels. Its effect is opposite that of insulin.

Treatment (from Insulin is used to treat type 1 diabetes, and only used in type 2 diabetes when other, non insulin based treatments, have failed.
There are six main types of insulin:
• Rapid-acting analogues can be injected just before, with or after food and have a peak action at between 0 and three hours. They tend to last between two and five hours and only last long enough for the meal at which they are taken. They are clear in appearance.
• Long-acting analogues tend to be injected once a day to provide background insulin lasting approximately 24 hours. They don't need to be taken with food because they don't have a peak action. They are clear in appearance.
• Short-acting insulins should be injected 15–30 minutes before a meal to cover the rise in blood glucose levels that occurs after eating. They have a peak action of two–six hours and can last for up to eight hours. They are clear in appearance.
• Medium- and long-acting insulins are taken once or twice a day to provide background insulin or in combination with short-acting insulins/rapid-acting analogues. Their peak activity is between four and 12 hours and can last up to 30 hours. They are cloudy in appearance.
• Mixed insulin – a combination of medium- and short-acting insulin.
• Mixed analogue – a combination of medium-acting insulin and rapid-acting analogue.
Historically, people would have taken two doses of short-acting insulin and had to tailor their diet around it, eating specific quantities of food at specific times. Now, most people take a long-acting insulin once per day and then rapid acting insulin every time they eat, calculating the dose against the amount of carbohydrate in their food. This means more injections, but much greater freedom in eating.

What about insulin pumps?
These are increasing in popularity. They are small electronic pumps which are clipped to the waistband and have a narrow tube with a small plastic cannula inserted into the subcutaneous tissue in the abdomen (this set is changed every few days). They allow a constant infusion of insulin with ‘boluses’ added at the press of a button on eating. They allow freedom in choice and timing of food, but some people find them restrictive because of the tubing and the device clipped to the belt.

Is this the same as an ‘artificial pancreas’?
Not quite – it’s sort of half of one! The aim of an ‘artificial pancreas’ is to monitor blood glucose levels and respond to this by alteration of insulin infusion – i.e. a closed unit where the user does not have to have any input themselves and without having to do finger-prick blood glucose tests. One of the major difficulties in this is devising a way of monitoring glucose levels in the body.

Can’t we test real blood?
No! Good opportunity to talk about blood-borne diseases, blood and sharps safety.

Risk Assessment
Date risk assesment last checked: 
Sun, 26/01/2020
Risk assesment checked by: 
Date risk assesment double checked: 
Mon, 27/01/2020
Risk assesment double-checked by: 
Beatrix Huissoon
Risk Assessment: 

Using a hand-held glucose meter to test the concentration of water and glucose solutions.

Hazard Risk Likelihood Severity Overall Mitigation Likelihood Severity Overall
Spillages Slip hazard. 2 2 4 All spills should be cleared up immediately. Call first aider in case of injury. Use wet floor sign if necessary. 1 2 2
Fake blood Feeling faint at sight of fake blood. 1 3 3 In case of faintness make sit or lie down and remove fake blood from there line of sight, in case of injury call first aider. 1 2 2