Continuous subcutaneous infusions
As a patient approaches end of life, it is appropriate to discontinue unnecessary drugs and where possible convert those which must continue to subcutaneous injections or infusions.
Anticipatory prescribing at the end of life
It is good practice to prescribe certain injectable medications, to be administered in anticipation of symptoms. This avoids delays in patients receiving the treatment they need for symptom control. Prescribing anticipatory CSCIs, however, could potentially harm patients.
Prescribing CSCIs and patient safety
Before commencing or changing the dose of a drug in a CSCI, the patient must always be assessed by a skilled, competent and confident healthcare professional. This is no different to commencing or titrating an oral opioid. The patient must be assessed for the following:
- Are there any reversible causes to explain the patient’s deterioration, such as infection, metabolic disorder or drug side effect (including opioid toxicity)?
- Is the pain controlled?
- Is the pain opioid sensitive?
- How much opioid have then taken over 24 hours (on average)? Was it effective?
- What is the renal function?
- Is there any suggestion of opioid tolerance?
Sometimes a range of doses is prescribed, in anticipation of the patient needing dose adjustments. Never change the opioid dose without properly assessing the patient, whatever the route.
**You should only prescribe dose ranges if you are confident that the professional assessing the patient and actioning the change in dose is competent to do so. **
Wide dose ranges should not be prescribed. This reduces the risk of opioid-induced respiratory depression due to rapid dose titration.
Drug compatibility and stability
At the end of life it is common practice to combine 2 or more drugs in the same CSCI, to control symptoms and minimise discomfort for the patient. Mixing medicines in this way creates a new, unlicensed compound drug. However, these combinations are commonly used in practice, so they are supported by clinical expertise.
All professionals who prescribe and administer drugs via a CSCI must be aware of compatibility and stability issues. Most opioid guidelines contain compatibility charts. We have provided a link to the Scottish Palliative Care Guidelines, in case you do not have access to this information.
Cyclizine is incompatible with many drugs and should always be diluted if possible. Haloperidol in concentrations greater than 1mg/ml often causes compatibility issues.
Titrating doses via CSCI
The opioid dose is titrated following the same process as for oral opioids. It is not appropriate to titrate opioids via a CSCI for short-lived incident pain occurring in response to predicatable stimuli such as dressing changes, cars, swallowing or movement.
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