SAFER ADMINISTRATION OF INSULIN

Dr Helen Akester

Masham/Kirkby Malzeard Surgery

10th February 2011

NPSA (National Patient Safety Alert) issued in June 2010

• WHY?• In UK 4-5% population have diabetes,• 20-30% are treated with insulin• Insulin identified one of top 10 high risk

medications worldwide• Errors are very common-First national

audit >14,000 diabetic pts in England and Wales showed prescribing errors in 19.5% cases

Errors

• U.S study-up to 33% of medication errors related to Insulin. Errors twice as likely to cause harm as errors for other prescribed drugs.

• Insulin has narrow therapeutic range, requiring precise dosage adjustments with careful administration and monitoring. NPSA report shows that 62%insulin errors were around administration with prescribing the most common factor. 15,227 incidents inc 6 deaths relating to Insulin in E and W between 2003 and 2009. Many incidents unreported.

Variations

• Over 20 different types of insulin in use in various strengths and forms.

• Range of devices for delivery inc. insulin syringes ( from vials), insulin pens

(prefilled/reusable) and insulin pumps.

Aims

• Refresh your knowledge and understanding of insulin

• Outline differences in administering insulin

• Develop further understanding of range of available insulins and injection devices

• Review common side effects of insulin and how to effectively treat them

Insulins

• Available as treatment since the 1920s

• Most is genetically engineered (recombinant human insulins) to be more like the insulin the body makes

• Different insulin treatments available that have been genetically modified to have different absorption profiles-known as insulin analogues ( see MIMS)

PRESCRIPTION AND ADMINISTRATION OF INSULIN

• The right insulin

• The right dose

• The right time

• The right way

The Right Insulin

• All have a proprietary name eg Apidra, which must be stated when prescribing

• All have an approved name eg Insulin glulisine

• Can be easy to muddle eg Humalog,

Humalog 25 and Humalog 50

4 main insulin categories

Over 20 different types of insulin, classified according to their effect and action on the body:

Rapid Acting

Short Acting

Intermediate Acting

Long Acting

RAPID ACTING

• Works very quickly, <5-15mins

• Take just before eating

• Peaks between 30-90 mins

• Duration 3-5 hours

• Less likely to lead to hypoglycaemia than some other types of insulin

SHORT ACTING

• Works <30-60mins after injection

• Peaks at 2-3 hours

• Duration 5-8 hours

• Short lifespan, injected several times daily

INTERMEDIATE ACTING

• Longer lifespan, slower to work!

• Starts <2-4 hours

• Peaks 10-14 hours

• Remains working 16 hours

LONG ACTING

• Starts < 6 hours

• Continuous level of activity for up to 36 hours

• (sheet-fill in gaps)

• Choosing type of insulin depends on clinical need, personal choice and ability to self manage their insulin regime

Insulin Regime

• O.D regime-T2DM in combination with oral agents

• B.D regime-consisting of soluble, or soluble plus isophane or fixed formulations of a mixture of back ground insulin plus fast acting

eg Novomix 30, Humulin M

• Multiple injections-several times daily (4-5), mimic normal physiological profile. Inc. a SA or RA with meals and intermediate acting (basal) OD

• IV insulin-variable rate insulin infusion-hospital admission not eating/drinking- insulin half- life of 3-5mins

VARIABLE RATE INFUSION

• Prescribed with IV glucose• 24hrs expiry date from when prepared• Giving set-low absorption tubing, may

need to be primed• In T1DM discontinuation to coincide with

commencement of usual regime and meal time

• Cease 30 mins after Pts usual insulin commenced

STRENGTH OF INSULIN

Two strengths available:

• U100-more frequently used

• U500-eg Humulin R, unlicensed in UK

Soluble, 5x more concentrated than standard insulin, named pt basis by specialist, may be given by hospital pump

PRESCRIBING

• Ensure correct dose: inc. frequency of administration

• Check C.Is inc. allergies• Check other medications inc. OTC eg Gliclazide• Check illness not exacerbated by insulin• Informed consent-ensure aware of proposed tx

and effects, symptom relief, side-effects and mx, interactions with other meds inc. alcohol, need for monitoring, sick day rules, DVLA

WRITING PRESCRIPTIONS

• Computer generated prescriptions are common-but if writing (hospital, home visits) use indelible ink

• Do NOT abbreviate drug names: the word insulin should be used as well as brand name

• Do NOT use decimal places• Clearly state drug dose,strength,route,frequency• Draw line through any amendments and initial

change

WRITING PRESCRIPTIONS (CONT)

• Date prescription

• Sign and write contact details

• Write UNITS in full

• Write form of delivery eg disposable pen/vial

• Inc FULL name and address of patient

• <12 years –inc Age or DOB

THE RIGHT DOSE

• In UK most use 100units per ml (U100 Insulin)• A tiny drop can cause hypoglycaemia• Dose is crucial-different people have different

needs • e.g children, underwt, overwt, ill• 5u can make one person unconcious and have

no difference on another• Pts using SA insulin can adjust own dose to suit

diet, exercise and their blood glucose

THE RIGHT DOSE(CONT)

• Common errors:• Pen upside down eg 12 units instead of 21• 10 x overdose due to use of abbreviation eg ‘U’

instead of ‘UNITS’ eg 6U can be mistaken for 60 units

• Using ‘I.U’ as abbreviation for international units eg 6 iu can mistaken for 61 units

• Prescribing/administration wrong type of insulin due to incomplete name eg Humulin ?I or S

ADMINISTRATION ERRORS

• Selecting wrong vial or cartridge• Using syringe not designated for insulin use NB

Very concentrated so always use insulin syringe 100 units in 1ml ( or pen/pump)

• Usually insulin injected S.C with short needle eg 5mm. Given I.M it works very quickly and can cause hypoglycaemia.

• IV insulin always used diluted eg 50 units actrapid in 50ml 0.9% sodium chloride

INSULIN SYRINGES

• U100 syringe can hold 1ml/ 100 units insulin

• Other types-0.5ml 50 units

0.3ml 30 units

• 0.3ml syringe has half unit doses marked on if only small dose required

• 0.5ml syringe has single unit doses marked

PRELOADED PENS

• No need to insert cartridges

• Packs of 5-pt should be advised to order at end of 3rd pen

• Disposable needles-variety lengths-most common 5mm,6mm,8mm

• Use new needle for each injection

• Discard used needle in sharps container (safety clip device)

INSULIN PUMP

• Miniature pumping device worn outside body• Connected to catheter located under the

abdominal skin• Programmed to deliver insulin according to pt’s

daily regime• Delivers steady small doses of insulin, Pt gives

themselves bolus for meals/snacks• If disconnected-s/c insulin or variable rate

infusion according to Pts finger prick blood glucose

INSULIN INJECTION

Demands-dexterity, concentration, good vision, steady hand

Inject at 90o angle

Count to 10

Withdraw needle

INSULIN STORAGE

• Unopened vials/pens/cartridges-store in fridge• Check not vulnerable to freezing as will

deactivate insulin• Check individual products packages for length of

time can be used safely after opening e.g 4-6/52• Once open store at room temperature. Cold

injection painful and absorption profile different• Store cartridges in their original box as small and

be easily muddled• Do not leave exposed to direct sunlight• Never store pen with insulin pen needle intact

COMMUNITY SETTING• Self Mx /Empower Pt!• Unable to use pen/syringe involve health professional or carer• Pt safety: Obtain written consent Educate to ensure right insulin, right dose, right time, right way Correct procedure to reduce infection Correct storage of insulin Ensure f/u Raise awareness of risks of preloading insulin-DOH/MHRA advise

against predrawing insulin. If staff are asked to premix insulin the employing trust takes responsibility as this practice is not recommended

HYPOGLYCAEMIA

• Most common side effect of insulin• Most feared by those receiving insulin• ‘undersweet blood’: low levels of glucose in the

blood• Those with D.M on insulin a glucose <4mmol/l

indicates hypoglycaemia• Occurs when pharmacologically raised insulin

levels are not responsive to falling insulin requirementsBody usually has good neuroendocrine defence

system

HYPOGLYCAEMIA

• 2 separate effects:• ADRENERGIC-results in counter regulatory

process, adrenaline/ glucagon act to release glucose from liver, ‘fight and flight’ symptoms

• NEUROGLYCOPEANIC-brain has high energy requirements, relies almost entirely on glucose for fuel, cerebral function measurably impaired when glucose <3.5mmol/l-irrational behaviour/aggression/drowsiness/seizures and eventually coma

SYMPTOMS / TX

MILD Hunger, shakiness,nervousness,sweating,dizzy,

light headed,sleepy,confused, difficulty speaking,anxietyConfirm BM readingAble to swallow? 200ml non diet fizzy drink e.g coke, 200ml fruit

juice, 120ml lucozade,6 dextrose tablets or 3-4 teasp sugar

SYMPTOMS / TX

• Moderate:

• Conscious, confused or semi-conscious but able to swallow

• Tx

• Glucogel- 2 ampoules inserted into oral cavity-does not actually need to be swallowed

SYMPTOMS / TX

Severe:Unconscious, absent gag reflex

Tx: Give glucagon I.M, I.V 10-20% dextrose

Once alert rpt as for mild hypoglycaemia tx

Then once blood glucose risen give L/A carbohydrate eg cereal/bics

CAUSES

• Too much insulin/ too many tablets

• Unplanned/ strenuous activity

• Not enough food esp. carbohydrates e.g fasting/unwell

• Too much alcohol e.g limit to small amt-and always eat with it

• Delayed/missed meal

• Drug interaction

LIPOHYPERTROPHY

• Known as ‘fatty lumps’

• Can be large and unsightly

• Rarely troublesome, but tend to persist

• Must vary site of injection from day to day

• If insulin repeatedly injected into a fatty lump rate of absorption delayed

QUIZ

• BMJ ARTICLE