Syringe Driver and EOL medication

Paresh Parmar

Lead Stroke and Older Persons Pharmacist

Northwick Park Hospital

Oct 2019

1

What is the link?

‘alcolmeter’ aka breathalyser

Peak flow meter 1956

Plastic peak flow 2

What is the link?

Syringe driver for children with thalassaemia

‘alcolmeter’ aka breathalyser

Peak flow meter 1956

Plastic peak flow

Who is Wright?

3

Dr Martin Wright developed the portable syringe driver (1976)for children with thalassemia so they could be at home

(1912-2001)

4

Successful 1st use of CSCI for palliative patient 1979

Dr Martin’s GP, neighbor & friend who worked at

Michael Sobell House

5CSCI-continuous subcutaneous infusion

What is a syringe driver?• Small portable, battery operated device that

administers medicines subcutaneously over a selected period of time, usually 24 hours

• Medication is drawn up in a syringe and attached to a driver that depresses the plunger at an accurately controlled rate

• It can be used in patients who are ambulatory or bedbound

6

But why syringe driver?

• Persistent vomiting

• Reduced level of consciousness

• Weakness: resulting in difficulty swallowing medication, particularly in the last days of life

• Dysphagia-unable to take oral medication

• Poor compliance

• Poor absorption of oral medication

• Patient does not wish to take oral medication

• Repeated s/c doses inappropriate, ineffective or impractical

7

Goals of administering medication via syringe driver must be discussed with patient and family.

Syringe Drivers provides an alternative route for administering medication

Important to stress this when having discussions with patient/family

8

Initial issues:

• Millimetres (mm) of syringe length rather than millilitres (mL) of solution

• 2 types of syringe driver allowing injection at mm per hour (MS16 and MS16A) and another which could inject at mm per 24 hours (MS26).

• Confusion between the two types of syringe drivers which could result in inappropriate infusion rates leading to over-infusion and there had been patient deaths as a result.

• 1st January 2005 and 30th June 2010 there were 175 errors- eight deaths and 167 non-fatal reports

9

Thus, from a NPSA –Rapid Response Report 2010

Recommended that Syringe Drivers:• Rate in ml/hr

• Ability to stop infusion if required

• Alarm if syringe is removed before infusion is stopped

• Lock box/cover

• Internal memory to record

10

Commonest used mm/hr syringe driver

• The McKinley T34 is calibrated in millilitres per hour (mm/hr). The standard delivery period for a continuous subcutaneous infusion in palliative care is 24 hours.

• Can be used for adults and for children.

• Useful to manage symptoms of pain, nausea, anxiety and restlessness

11

12

To be discussed with patient/family

• Past experience with syringe driver?

• Address fears and anxiety of using syringe driver

• Stage of current illness & what how using a syringe driver affects future prognosis

• Reassurance that using syringe driver does not necessarily indicate that death is imminent

• Explain that syringe driver allows for symptomofdying to be managed, it does not speed up the dying process

13

What medication are prescribed to patients who are dying?4 Commonest anticipatory medication prescribed:

-Opioids for pain e.g morphine/oxycodone

-Antiemetics for nausea/vomiting e.g haloperidol, cyclizine

-Anxiolytics for anxiety/restlessness e.g midazolam

-Anticholinergics for secretions e.g glycopyrronium, hyoscine hydrobromide (XBBB)/ hyoscine butylbromide (≠XBBB)

Watch out:

Renal impairment (morphine/oxycodone),

Parkinsons (NO Metoclopramide/Haloperidol)

Most drugs administered s/c are UNLICENCED

14

Mary 92 years (46kg –NKDA, CrCl40ml/min) with large MCA stroke and midline shift -CT scan

15

All current medication has been deprescribed/rationalized.Mary has been prescribed -Morphine sulphate 10mg/ml 2.5-5mg q2 s/c prn (opioid naïve)-Midazolam 10mg/2ml 2.5-5mg q2 s/c prn-Haloperidol 0.5 -1.5mg q2 s/c prn-Glycopyrronium 200-400mcg q6-8 s/c prn

She has had 3 doses of the morphine 2.5mg and 2 doses of midazolam 2.5mg- in the last 24 hours

What would you prescribe in the syringe driver?

How many pharmacists check syringe driver prescriptions?

16

What do you check?

• Syringe driver- is it available/charged

• Medication available? (after hours/weekend/community)

• Prescription is correct? Diluent & volume specified?

• Drugs are compatible at prescribed doses?

• Duration indicated?

• Prescription signed and dated?

17

How to determine the dose in a syringe driver?

• Anticipatory medication s/c usage

• Determine total requirement over 24 hours

• Convert to CSCI dose in syringe driver per 24 hours

18

Back to the case…

• Mary has a CSCI :• Morphine sulphate 10mg

• Midazolam 5mg

• In sodium chloride 0.9%

• McKinley T34 syringe driver over 24 hours (rate automatically calculated)

• And PRN anticipatory medication

19

20

What diluent?• 2 main diluents used:

• Water for Injection (WFI) • Normal Saline (Sodium Chloride (NaCl) 0.9%)

• WFI is compatible with most medication (except ondansetron, levomepromazine, hyoscine butybromide& octreotide-use NaCl 0.9%)• WFI is hypotonic

• NaCl 0.9% also compatible with most medication (except cyclizine-use WFI)• Isotonic • Diluent of choice when drugs are compatible with more than

one solution • Closest to physiological tonicity, therefore less likely to cause

irritation

21

Incompatibility - a theoretically reversible physicochemical change that may result in precipitation or insolubility, which may not always be visible

– e.g. midazolam and dexamethasone

Instability - irreversible chemical degradation of the active compound, resulting in loss of potency

– e.g. glycopyrronium and dexamethasone

22

Compatibility of Medication

23

If more than 1 medication used, risk of physical or chemicalincompatibilityPhysical incompatibility = changes in solution e.g discolouration, clouding or precipitation of crystals or particlesChemical instability = higher concentrations, temperature, sunlightImportant to check compatibilities each time a syringe driver mixedChlorpromazine, diazepam and prochlorperazine not recommended to be given by subcutaneous infusion due to severe local reactions

Not more than 3 drugs in one syringe driver

Problems associated with the mixing of drugs-include:

• Degradation of the drug(s) which can in turn lead to decreased efficacy. The rate of degradation may be increased by other drugs which alter the pH of the mixture. Direct sunlight and heat can also cause degradation of the drugs.

• Crystallisation/precipitation. This can occur through formation of an insoluble product of drug interaction, or because a drug alters the pH of the solution rendering a 2nd drug insoluble, or because of an interaction between drug and diluent.

24

Resources: including local Policy

25

Example of compatibility grid

26

Size of Syringe

• Depends on quantity of medication used

• McKinley T34 automatically detects syringe size

• E.g. Mary’s CSCI prescription:• Morphine 10mg/ml –dose 10mg =1ml

• Midazolam 10mg/2ml –dose 5mg =1ml

• Therefore volume of NaCl 0.9% = 15ml

• Total 17ml in 20ml syringe

Can use 30ml and 50ml syringe for larger volumes

27

Labelling of Syringe:

Complete a subcutaneous infusion label, attach round the barrel of the syringe. The following details are required on the label:

• Patient name

• Hospital number/identification number

• Drug name(s)

• Dose of each drug

• Diluent name

• Total volume (ml)

• Date and time prepared

• Signature of nurse

28

Placing of s/c cannula Avoid the following sites:

• Oedematous areas including lymphoedematous arms (poor drug absorption and increased risk of infection/exacerbation of oedema)

• Bony prominences (poor absorption and discomfort)

• Irradiated sites (may have poor perfusion and hence poor drug absorption)

• Skin folds, sites near a joint and waistband area (movement may displace cannula;

discomfort)

• Broken skin.

29

Guidance on the key principles for healthcare professionals involved in the use of a syringe driver.

Checklist for prescribing (4 Ds):

• Drug Is the correct drug prescribed (eg, is this the correct opioid for a patient with renal impairment; can this drug be given via this route)• Dose Do I know the conversion ratio from oral to subcutaneous?• Diluent Do I know the correct diluent for use in the syringe driver?• Duration Over what period do I need to give this medicine (eg, 12 or 24 hours)

30

Checklists

Checklist for pharmacists (3 Ss):

• Stability Is the combination physically or chemically stable?• Safety Is the prescription clearly written and is the combination safe for use in this patient?• Suitability Is the drug suitable for the condition and for use via this route? Has the drug been converted correctly?

31

Checklist for administration (3 Cs):

• Compatibility Do I know if these drugs are compatible? Do I know whom to refer to for advice?• Clear instructions Have I set up the syringe driver for the correct duration and double-checked the calculation that I am inputting into the driver?• Clear solution Is the solution running clear and, on observation every four hours, is it still clear?

32

https://www.pharmaceutical-journal.com/news-and-analysis/improving-the-safety-of-syringe-drivers-through-a-multidisciplinary-approach/11088831.article

Check list on discharge:

• Provision on adequate quantities for anticipatory medication for PRN and syringe driver if appropriate

• Include diluent for syringe driver if patient discharged to home/NH

• Doctors to prescribe on separate drug chart/MARs sheet for community

33

Medication issues post discharge

• Medications in house but no prescription – District nurses cannot administer medications without the correct prescription in place. Prescriptions should ideally come from the GP but a hospital drug chart can also be used so if a patient is going home for end of life care, they should have a new drug chart with the injectable medications prescribed

• Medications prescribed but no range given so nurses are less able to adequately manage symptoms

• PRN dose does not reflect 24 hour dose (PRN should be 1/6 of 24 hour dose). This is seen especially when 24 hour dose is high

• Normal saline/WFI – often medications are in the house but normal saline has not been prescribed or dispensed – this can delay the setting up of syringe pump when needed

34

Cont…

• Education of relatives on what the medications are and how they are used / who administers them

• District nurses not being able to visit on time for re-priming syringe pumps (every 24 hours)

• Only injectable medications being prescribed as PRN’s when patient is still able to swallow (should have both PO and s/c preparation available)

• Needles, syringes and sharps boxes not being available

35