Background
Normal physical and mental changes of ageing alter the way our bodies absorb, metabolise, distribute and eliminate medications. [10,11] Therefore, a clear understanding of physical and metabolic changes and their impact on the selection of drug therapy is important for the safe and effective management of symptoms for older adults with advanced illness. [10,11]
Establishing a sound management plan to alleviate physical symptoms is a crucial part of holistic palliative care. [5,6] Symptoms tend to increase as people approach the last days of their life and the complexity of managing these may increase as the body shuts down and functions such as swallowing and breathing become difficult. [5,6] Common symptoms at the end of life include fatigue, pain, nausea, vomiting, dyspnoea (difficulty breathing), noisy breathing, agitation and delirium. [1,2,4-6,8,9]
Respecting the severity of symptoms, medication is given by the most reliable route, the preferred route being orally i.e. by mouth. [5] A person may be unable to take medication orally because of dysphagia (difficulty swallowing), weakness, dry mouth, the inability to tolerate oral medication or malabsorption of oral medication. [5,6,11] In these instances, an alternate route is the subcutaneous route, which is the area between the dermis (skin) and muscle and is often the preferred option. [5-7,11] Continuous subcutaneous drug administration can be achieved by using a syringe driver. [2-5]
Evidence Summary
For older people at end of life, syringe drivers can be effective in managing common symptoms such as nausea, vomiting, pain, dyspnoea (difficulty breathing) and excessive secretions. [2,5,8,9] Subcutaneous infusion devices (syringe drivers) are commonly used to give comfort in palliative care to treat distressing symptoms when other routes are inappropriate or ineffective. [2-4,9] These devices are power-driven devices that can deliver a range of medications at a controlled rate, providing symptom control via continuous subcutaneous infusion (CSCI) of drugs. [2,3,5-8]
Common indications for use of syringe pumps in palliative care are: [1,7]
- dysphagia
- nausea
- vomiting
- poor enteral absorption of oral medications
- weakness or altered level of consciousness
Most commonly, the medication is delivered over a period of 24 hours [2-4,7] and the device can remain in place for up to 14 days. [2,4,5] How frequently the site is changed will be determined by how well it is tolerated by the person and the local healthcare service policy. [2] More research into 48-hour continuous subcutaneous infusion of medications is needed before it can be recommended for use within clinical practice. [12] Robust chemical and microbiology stability data is also needed for the more common drug combinations before such considerations can be made. [13]
In palliative care, the subcutaneous route is preferred to other parenteral routes (e.g. intravenous, intramuscular and suppositories) because it is less invasive and has less risk of causing infection. [2,11] Patients and carers can find a syringe driver convenient as it removes the need for repeated doses of oral medication or injections. Often two to three drugs are administered concurrently but it is important to respect local protocols and ensure that all drug combinations are compatible before administering an infusion. [2,5-7] Most of the symptoms at end-of-life can be controlled by the use of four types of drugs:
- analgesic
- sedative
- antiemetic
- anticholinergic. [4,11]
Before mixing drugs, it is important to check information about drug stability and for drug compatibility. [5] Drugs in solution may irreversibly degrade (be unstable) and consequently lose their therapeutic effect. [5] Drug incompatibility can result in a precipitation that may or may not be visible. There are many factors which influence the compatibility and stability of drugs administered in combinations using a syringe driver. It is therefore important that pH difference of drug combinations, exposure to light, appropriate diluent and temperature be carefully considered before mixing them. [5] Detailed information about commonly used medications, incompatibilities, contraindications, equipment and techniques are available in:
- the Therapeutic Guidelines (subscription required),
- The Syringe Driver: Continuous Subcutaneous Infusions in Palliative Care, 4th ed.,
- Syringe Driver Compatibility - Guidance document (689kb pdf),
- the Oxford Textbook of Palliative Medicine (subscription required),
- the Oxford Handbook of Palliative Care (subscription required),
- the Syringe Driver Survey Database (SDSD), and
- Syringe Driver Drug Compatibilities - Guide to Palliative Care Practice. [2,5-7,14,15]
The decision to commence a continuous subcutaneous infusion should be made after careful review by the treating doctor(s). [6] The decision should be personalised, clearly documented and include the person, their family and/or carer. [1,7] Evidence indicates that these devices are reliable, well accepted by patients and carers and can allow mobile patients to continue with their daily activities. [1,2,4,6] However, some people may perceive these devices as signalling a poor prognosis and they may be fearful of how to manage the device, to monitor the insertion site and to respond to an alarm. [2,4,5,7,8] Health professionals can help the experience of patients and carers with a syringe driver to be positive by providing good anticipatory care, a clear explanation of the benefits, and guidance and practical tips to maximise comfort and safety. [1,2,4,6]
A syringe driver can be used at home and maintained over extended periods. In community palliative care, a syringe driver is usually managed by a palliative care or nursing service. [2,9] Carers are asked to monitor for possible technical problems, adverse effects or requirements for breakthrough medication. [2] Patients and their families may be trained to operate the syringe driver so that the patient can stay in or return to their home community. [2] This may be of particular benefit to living in remote areas. Clear information for patients and carers (spoken, written, demonstrations and questions to check understanding) promotes safety and acceptance of the infusion device. [1-3] Access to 24-hour support and good anticipatory care can be associated with a positive experience. [1-3] The insertion site must be checked every 4 hours to prevent and identify any site-related complications (redness, tenderness, haematoma, leakage, and swelling). [1-4] There are multiple possible insertion sites available. [1,2] It is important to choose a site where the cannula is safely secured to prevent disconnection (care with agitated or restless clients or residents). [1,2] The most common adverse reactions in older people are: oedema, pain, inflammation, infection, abscesses and injection site reactions. [11]
There are some limitations and risks specific to the use of these devices such as technical problems (flat battery, kinks in the tubing, empty syringe) and skin reactions at the insertion site. [1-5] Insertion of the cannula may be inappropriate if a patient is very agitated. [5] When using continuous subcutaneous infusions with syringe drivers, two to three compatible drugs can be administered simultaneously. [2,5] It is important to refer to published information on drug compatibility or to a pharmacist to gauge if medications prescribed are appropriate to mix in a single syringe. Opioid for breakthrough pain may be given by a separate port. [2] Breakthrough medication is extra medication that may be required for symptoms that are not controlled by the medications prescribed for continuous delivery via the subcutaneous infusion device. [4] Depending on the infusion set used, breakthrough medication can be given. This is more appropriate than simply using the 'boost' facility on the syringe driver, particularly if multiple medicines are in the syringe.
There is a risk of potentially serious medication error if staff members are unfamiliar with the equipment, if different types of pumps or drivers are in use in the same setting, or if staff members use different ways to calculate infusion rates. [3] It is recommended that practitioners maintain their knowledge, practical skills and standardised equipment is available across the facility. [1] Regular maintenance of the device is important i.e. regular battery check and annual service. [1,2,4]
Quality Statement
The use of syringe drivers in palliative care is standard practice in Australia. [1,4] One literature review was retrieved [8] yet no systematic reviews on this subject were found. Specific to the use of syringe drivers in palliative care, one set of Australian guidelines (2010) was found with a related learning module (2014). [1,4] Two guidelines which refer to the use of syringe drivers in palliative care and a palliative care handbook and textbook were included. [2,6,7,9] Other sources were used to give context to this topic. [3,10-12,16]
Page updated 15 December 2021