Safer administration of insulin dr Helen Akester

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 requirements

• Body 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,anxiety

• Confirm BM reading

• Able 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