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Child Health Guideline Identifier

Pain - CRPS Ketamine Infusion

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Complex Regional Pain Syndrome (CRPS) is a form of chronic neuropathic pain that is often caused by fault or injury in the peripheral and central nervous system. A variety of studies have supported the use of Ketamine for the management of such pain. When given safely in a regular inpatient care unit, sub anaesthetic Ketamine, has been deemed useful for the management of acute and chronic pain. With Sheehy et al, (2015) finding children with CRPS to benefit from the intervention of a Ketamine infusion.

The following guideline has been modelled on the Ketamine infusion guideline that is used for management of acute pain. Modifications have been made to meet the criteria needed for CRPS management based on clinical experience for the targeted group of patients.


Standard in-patient ward.


Ketamine infusions for CRPS management will be prescribed and managed by the Complex Pain Service (CPS). After hours support will be provided by the acute anaesthetic/pain registrar on-call.

The pain nurse specialists can be contacted for advice for these patients during normal working hours, Monday to Friday.  Registered nurses that have attended the paediatric pain study day can care for a CRPS patient with a Ketamine infusion.


Ketamine infusions are charted on the intravenous analgesia preparation and prescription form (CR9003). Prescriptions may only be charted and altered by a complex pain consultant.

Details around the starting rate and time frame for increasing the rate will be clearly outlined in the patient clinical notes by the complex pain consultant. These instructions will also be detailed in the medication chart; this is not a medication order and should be used in partnership with the Intravenous analgesia preparation and prescription form (CR9003).

Indications for use

Children with CRPS or other appropriately identified complex pain conditions who are not responding to, or deteriorating on, individualised functional therapy rehabilitation programmes.

Exclusion criteria

Children where reduced emotional well-being or mental health is deemed the primary cause of poor response to functional therapy rehabilitation programmes or decline in condition.

Set-up and management

As per the set-up and management section of the Pain- Ketamine infusion guideline.


Infusion instructions

Commence infusion at 1ml/hr (60mcg/kg/hr) and increase by 1ml/hr every 6hours until a maximum dose of 4ml/hr (240 mcg/kg/hr) is reached. The maximum rate should be achieved by 18 hours from commencing infusion.

If the child has difficulty tolerating the increased rate changes at 6 hourly intervals this can be extended to 12 hour intervals, this decision will be made by the complex pain service. If the child is unable to tolerate 12 hour interval increases then the rate is maintained at the highest tolerable dose.

If the child shows a reasonable response from a lower rate than the recommended maximum of 4ml/hr, then the infusion is maintained at this lower dose. This decision will be made by the complex pain service.

Infusion maintenance

The effect, once the maximum rate tolerated or required is reached, is assessed after 24-hour. If the child is showing a response then the infusion is continued for 72-hours.

If the child has not had a response then the infusion is discontinued.

Response is a clinical decision but would normally be a reasonable decrease (3-point reduction or more) in self-reported pain intensity and/or reduction in flare episodes.


As per the observations section of the Pain - Ketamine infusion guideline. These details are also outlined on the intravenous Analgesia Preparation and Prescription form (CR9003).

Ceasing Ketamine infusion

The decision on when to discontinue the Ketamine infusion will be made by the complex pain service with majority of patients ceasing on day 4 post commencement. The complex pain service will document in the patients clinical notes when the infusion is to cease.


  1. Backonja M, et al. Response of chronic neuropathic pain syndromes to ketamine: A preliminary study. Pain 1994; 56:51-7
  2. Harbut RE and Correll GE. Successful treatment of a nine-year case of complex regional pain syndrome type-1 (reflex sympathetic dystrophy) with intravenous ketamine-infusion therapy in a warfarin-anticoagulated adult female patient. Pain Med 2002; 3:147-55 
  3. Wertli MM, et al. Rational pain management in complex regional pain syndrome 1 (CRPS 1) - A network meta-analysis. Pain Med 2014: 15;1575-89
  4. Connolly SB, et al. A systematic review of ketamine for complex regional pain syndrome. Pain Med 2015: 16:943-69
  5. Sheehy KA, et al. Subanesthetic ketamine infusions for the treatment of children and adolescents with chronic pain: a longitudinal study. BMC Pediatr 2015; 15:198-205
  6. Sheehy KA, et al. Subanesthetic ketamine for pain management in hospitalized children, adolescents, and young adults; a single-center cohort study. J Pain research 2017; 10:787-95

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Document Control

  • Date last published: 05 December 2017
  • Document type: Clinical Guideline
  • Services responsible: Paediatric Pain Service
  • Author(s): Ross Drake
  • Owner: Complex Pain Service
  • Editor: Greg Williams
  • Review frequency: 2 years

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