PM12 2021: Ketamine infusion for chronic non-cancer pain

Ethics:

“Off label”

· Different age group

· Different sex

· Different indication

· Different dose

· Different route

“Conditional”

· Quality of evidence is not strong, but:

o Use is justified (e.g. severe disease, failed treatment)

o Benefits > risks

· Conditions:

o Protocol

o Data collection to gather evidence

Upshot

· Use of ketamine in CNCP is both off-label and conditional

· Hence must obtain written informed consent

Rationale	· Intrinsic analgesic effect · Reversal of central sensitisation of nociception · Facilitate reduction in opioid use
Efficacy	· No consensus on protocol (dose, duration) · No consensus on outcomes
Adverse effects	· Cardiovascular: tachycardia, hypertension · Neurological: psychosis, unconsciousness (especially if bolus) · Psychological: addiction · Hepatotoxicity
Questions	· Improvement in pain? · Improvement in function? · Duration of effect? · Prevent relapse of opioid misuse? · Optimal regimen? · Comparison to controlled opioid reduction? · Does oral ketamine work?

Assessment

· Biological

· Psychological

· Social

Eligibility

· Central sensitisation

· Opioid failure / side effects / dependence

Goals

· Reduce opioid use

· Improve quality of life

· Improve pain

Location	· Inpatient hospital
Preparation	· Standard concentration · Dedicated line · Locked pump · No bolus option
Infusion	· Induction 0.05-0.1mg/kg/h · Max 0.5mg/kg/h · Weaning over 12-24 hours
Other drugs	· One opioid only · Plan for weaning
Monitoring	· Regular observations · Daily review by pain specialist or delegate · No leaving the ward · Observation 4 hours before discharge · Q48h LFTs?
Discharge	· Plan in case of relapse · Phone call 24-48h · Communicate with GP