INTRODUCTION

A syringe driver is a small portable battery-operated device that administers medications continuously into the subcutaneous tissue continuously over long periods of time (over 12 or 24 hours) to manage symptoms effectively, when other routes of administration are ineffective, inappropriate or inaccessible.

Advantages

• Steady plasma concentration of medications can be maintained to achieve better control of symptoms
• Management of multiple symptoms through a single route of administration (avoids repeated injections or oral medications)
• More acceptable and convenient to patients when compared to other routes of administration e.g. intravenous, intramuscular and rectal
• Avoids restriction of mobility
• Promotes independence
• Simple technique and ease of administration

Indications

• Difficulty in swallowing
• Refusal to take oral medications
• Persistent nausea and vomiting
• Poor alimentary absorption
• Malignant bowel obstruction
• Last days of life – especially if sedated, unconscious or comatose

Contraindications

• Patient refusal
• Sites with compromised skin integrity – infection, inflammation, scars from previous injury, lymphoedema, irradiated areas

Adverse effects:

• Local (rare) – erythema, hematoma, pruritus, pain, leakage inflammation, and infection

ASSESSMENT

• Assess the stage of illness of patient
• Assess the patient/family for past use of syringe drivers and their experience
• Assess the concerns of patient and family about the syringe driver
• Assess the meaning of the use of syringe driver to the patient and family e.g. prognosis
• Inspect the site regularly for signs of local reactions (every 24 hours)
• Inspect the volume remaining in the syringe (every 24 hours)
• Inspect the patency of the tubing (every 24 hours)
• Assess the severity and control of the symptoms on a regular basis (every 24 hours)

MANAGEMENT

Recommendations

• Nurses, well trained in the use of syringe drivers are necessary
• Ensure that the dosage of medications is calculated according to the guidelines/protocols, when the syringe driver is set up
• Consider the following when prescribing medications through syringe driver and document the same
• Dose of medications are calculated for 24 hours
• Not more than three medications are combined in the syringe driver
• The medications used in the syringe driver are compatible (see Chart 1)
• Choice of diluent
• Suitable sites for placement of the include: the upper chest, scapula, deltoid area of upper arm, anterior abdomen and antero-lateral aspect of the thighs
• Consider placement over the scapula in disoriented/confused patients as it is less likely to be pulled out
• Site of placement of cannula should be changed every 3-5 days
• Ensure that regular assessment of site, volume remaining in the syringe, rate setting and patency of tubing are done at least twice a week and documented
• Syringe driver chart should be maintained and should include:
• Site inspection
• Rate setting
• Volume of fluid remaining in millimetres
• Any leakage
• Patency of tubing – clear, precipitation or crystallisation
• Battery – check the indicator light
• Document the severity and control of symptoms on regular basis
• Nurses should be trained well to train the family/caregiver to change the syringe
• Ensure that a spare battery is available
• Yearly maintenance of the Syringe driver should be done to maintain accurate delivery of medications

Education to patient/family

• Explain and educate the patient and family about the functions of the syringe driver and its advantages, disadvantages and safety aspects
• Explain and educate the possible adverse effects of syringe driver and to look for the same
• Explain and educate on the care of the syringe driver
• Explain to the patient and family on what to do and whom to call if the syringe driver does not function or symptoms are not effectively controlled
• Explain and educate how to incorporate the use of syringe driver into the activities of daily living e.g. showering
• Explain the necessity to administer rescue medications for the management of breakthrough symptoms and educate the patient/family
• Explain and educate the patient/family to assess the site of administration for inflammation, infection, haematoma, volume remaining in the syringe and the patency of the tubing
• Explain and educate the family on changing the syringe, batteries and simple trouble shooting

Medications

• Commonly used
• Morphine
• Haloperidol
• Hyoscine butyl bromide
• Midazolam
• Metoclopramide
• Dexamethasone
• Glycopyrronium
• Octreotide
• Ondansetron
• Contraindicated
• Prochlorperazine
• Diazepam
• Chlorpromazine

Diluents

• Sterile water
• Preferred as the chance of precipitation is negligible
• More compatibility data are available
• 0.9 % normal saline
• Incompatible with haloperidol >1 mg/mL
• Chance of precipitation are higher compared to sterile water

Technique

• Equipment
• Syringe driver, plastic cover and holster
• Key rate adjuster or paper clip
• 24G infusion cannula
• Extension tubing of short length
• Alkaline battery (appropriate volt) + spare battery
• Luerlock syringe – 10, 20mL
• Prescribed medications, sticky label, prescription chart
• Syringe driver chart
• Suitable diluent – sterile water is preferred
• Transparent occlusive dressing
• Preparation
• Explain the procedure to the patient and caregiver/family and ensure that the patient and caregiver/family understand the procedure
• Identify the site for insertion of 24G infusion cannula
• Insert the battery into the syringe driver and perform the safety checks to ensure that the syringe driver is working properly. Remove the battery until the time to start the infusion
• Two trained personnel should check the following steps to set the correct rate on the syringe driver
• Calculate the total volume before selecting the appropriate syringe
• Load the medications into the correct Luerlock syringe and draw sufficient quantity of diluent to make the calculated volume
• Label the syringe with the name of the medications/ dose and total volume when started but ensuring that the markings on the syringe are visible
• Measure the LENGTH of the fluid in the syringe in millimetres after the tubing has been primed
• Use a paper clip or key rate adjuster to set the rate of flow on the syringe driver
• Place the syringe into the slot on the syringe driver and secure the barrel of the syringe with the strap
• Wash hands
• Procedure
• Apply gloves
• Connect the 24G infusion cannula to the extension tubing
• Connect the 24G infusion cannula with tubing to the syringe and ensure that the connections are secure
• Prime the tubing and infusion cannula
• Prepare the insertion site using simple aseptic technique with spirit or alcohol swipe
• Pinch the skin fold on the site chosen, grasping the skin firmly
• Insert the 24G infusion cannula with tubing into the skin at an angle of 45 degrees, bevel up and release the skin fold; remove the stylet
• Loop the tubing once around the insertion site and secure the 24G infusion cannula with transparent occlusion dressing
• Ensure that the syringe driver is working properly
• Secure the syringe driver in the plastic bag and place inside the holster
• Ensure that adequate quantity of rescue medications is made available and necessary written and verbal instructions are given to ensure timely and proper administration
• Reloading the syringe
• Reassess and calculate the dosage of medications necessary for the next 24 hours and assess if any other medications are necessary and the required dosage
• Calculate the total volume and select the appropriate sized syringe
• Load the required medications along with the diluent into the syringe
• Measure the length of fluid in the new syringe at every replacement and replace the syringe
• Ensure that the rate of flow set on the syringe driver is correct and alter if necessary
• Replace the syringe and restart the syringe driver by pressing the start button
• If there are no problems, the same site may be used for several days
• Instruct the patient/family NOT to use the “boost button” if there is one

---

REFERENCES

• Twycross, R., Wilcock, A., Howard, P. (2014). Continuous subcutaneous drug infusions. Palliative Care Formulary 5. (pp. 844-860)
• Twycross, R., Wilcock, A., Howard, P. (2014). Appendix 3 – Compatibility charts. Palliative Care Formulary 5. (pp. 969-972)