Exploring the use of continuous subcutaneous infusions in palliative care – indications, advantages and factors to consider with regards to patient selection

Although the oral route should be maintained for as long as possible in a palliative care setting, there are a variety of circumstances where commencing a continuous subcutaneous infusion (CSCI) may be beneficial. This may be temporary (for example, to manage significant vomiting, then once symptoms are under control, the patient may be converted back to oral medications if appropriate), or the CSCI may be ongoing as part of end-of-life care.

Indications for CSCI use include:

• Where oral administration is problematic – for example, with significant nausea and vomiting, a severely dry mouth, dysphagia (particularly in cases such as mouth, throat or oesophageal cancer), poor oral absorption, if the patient is too weak to swallow oral formulations, or they are unconscious
• Where rectal administration is problematic – for example, significant diarrhoea or a bowel obstruction
• Where IV administration is problematic – for example, due to the risk of infection and the level of invasiveness in a palliative care setting
• Where IM administration is problematic – many patients find IM injections to be uncomfortable (particularly if they are cachectic, which is common in a palliative care setting)
• If the patient requests to switch to a CSCI – for example, to minimise their tablet burden or if they are requiring repeated bolus subcutaneous injections per day
• Intractable pain may or may not be an indication for CSCI use, as there are differing viewpoints as to whether CSCIs provide superior analgesia compared to other routes of administration. There is a lack of studies in this area due to the difficulty assessing patient-reported symptom relief in end-of-life care; however a recent small study did find CSCIs did provide superior analgesia.

There are a number of advantages of CSCI use which include:

• Giving medications via CSCI rather than bolus subcutaneous injections decreases the number of injections for a patient. This is more comfortable for them and is more convenient (for patients, nursing staff, or family/carers if in a home setting) as a CSCI is normally only changed every 24 hours
• CSCIs may allow a combination of medications to be given in the one syringe driver (taking into account drug compatibility)
• If a CSCI is used at the patient’s home (versus in hospital/hospice care), it may allow them to remain at home for end-of-life care which may align better with their preferences and goals of care
• The use of a CSCI may result in more stable plasma levels of medications, thereby minimising fluctuating/withdrawal symptoms and resulting in improved symptom control. Also, noting that in a hospital or hospice setting, there are often delays to patients receiving bolus subcutaneous doses in a timely manner – in other words, this is another way the use of a CSCI may improve symptom control
• If patients are still ambulant, the use of CSCI can help to maintain their mobility rather than leaving them bed-bound

In terms of considerations around patient selection:

• If the CSCI is to be used in a home setting, there are a number of factors to consider in terms of an ‘appropriate’ patient to receive a CSCI:
  – That the home environment is suitable/safe for palliative care staff to attend the house to change the CSCI (normally once daily) and to review the patient
  – Ideally, there would be a family member/carer at home who would be willing and able to administer subcutaneous ‘prn’ breakthrough doses. This person(s) should receive appropriate education regarding the correct administration and disposal of medications. Patients or their family members should also be able to manage ‘technical problems’, for example knowing how to change the batteries if necessary, or how to manage a leaking infusion
• A CSCI may be difficult to connect and change for some patients, for example, those who are highly agitated, although placement of the cannula around the scapula may be helpful in this regard
• A CSCI may not function optimally in patients with impaired lymphatic drainage (for example, patients with significant oedema)
• Some patients feel that the use of a CSCI takes away their sense of control of their medications – again, to consider the individual patient’s preferences and goals of care

A final consideration with regards to patient selection is that patients and their families should have clear education provided with regards to the role of a CSCI, as well as its advantages/disadvantages for that specific patient. An open discussion between patients, their family and members of the palliative care team will give patients and their family the opportunity to ask any further questions prior to commencing a CSCI, and can help to dispel some myths surrounding CSCI use (for example, that their use may hasten death.