Substance misuse: acute pain management
The aim of the analgesic management of these patients is to:
- Provide safe and effective analgesia.
- Prevent withdrawal.
- Liaise with the community drugs team throughout the duration of their hospital stay and early discharge planning.
- Offer drug management referral if needed.
Key principles:
- Treat all patients with empathy and reassure them that their pain will be managed. Illicit opioid users are often scared of withdrawing and have had previous bad experiences with health care providers.
- Detoxification is not appropriate in the peri-operative period.
- Patients on long term opioids are at risk of opioid tolerance and opioid induced hyperalgesia.
- Inadequate acute pain management will not only hamper recovery but increases the risk of relapse of illicit drug use.
- Sedation/overdose when tolerance to opioids is uncertain especially when patients are using additional centrally active medications. They are still at risk of opioid induced side effects including ventilatory impairment (OIVI) so careful monitoring is needed.
- Diversion and misuse of drugs prescribed for acute pain is a risk but should not prevent adequate analgesia.
- Early and continued liaison with their community drugs team (CDT), community pharmacist and general practitioner is important.
- Multimodal analgesia is key to their pain management.
- Regional analgesia can be very useful if appropriate, it can avoid or reduce opioid need.
- Have a clear plan for dose tapering as acute pain subsides.
Patients on opioid substitution therapy (OST)
- Confirm the dose with CDT / community pharmacist.
- OST should be continued if reliably taken in the last three days and there is no sign of opioid overdose.
Methadone
- If struggling with pain split the dose into a bd/tds dose
- Multimodal analgesia titrated to effective analgesia
Buprenorphine sublingually
- If struggling with pain split the dose into a bd/tds dose
- Multimodal analgesia titrated to effective analgesia
SC buprenorphine
- This can be given weekly or monthly as a depot
- Acute pain management maybe problematic
- Multimodal analgesia with regional anaesthesia techniques where appropriate
- If listed for elective surgery careful planning is needed in liaison with the patients CDT. This may include the conversion of the OST to s/l daily buprenorphine or oral methadone until the acute pain has settled
Patients using illicit opioids not on OST
- Quality of illicit opioids is variable.
- Score opioid withdrawal using Clinical Opioid Withdrawal Score (COWS) COWS Score for Opiate Withdrawal (mdcalc.com)
- Dose OST as per the COWS score- one example of how to do this is from Oxford University Hospitals (Dr Jane Quinlan)