Ketamine Infusion Guidelines
Developed in 1963, ketamine is an N-methyl-D-aspartate (NMDA) receptor antagonist that is known to have analgesic and dissociative anaesthetic properties.
NMDA receptors are located in the spinal cord and are involved in the development of many types of pain, such as neuropathic and mixed pain conditions (i.e. post-herpetic neuralgia, phantom limb pain, post-operative pain, cancer pain).
Ketamine is also known to act on the kappa and mu-opioid receptor sites.
Ketamine infusions should be administered following standard hospital infusion guidelines. Such guidelines must include standing orders regarding the setup of the infusion and management of complications, such as excessive sedation, hallucinations/unpleasant dreams, and nausea and vomitting.
Titration of Ketamine Infusions
Intravenous ketamine is usually prescribed in the following way:
- Ketamine 500mg diluted in 500ml of normal saline
- The commencement dose is usually 5ml/hr (5mg/hr)
- The infusion dose is increased every 12 hours by 5ml/hr, to a maximum tolerated dose or 40ml/hr, whichever comes first.
Rarely, there may be elevation of liver enzymes that may lead to early cessation of treatment.
Also rarely, the cognitive side effects, namely unpleasant feelings or dreams, may be experienced.
- Fitzgibbon, EJ, Hall P, Schroder C, Seely J, Viola R. (2002) Low dose ketamine as an analgesic adjuvant in difficult pain syndromes: a strategy for conversion from parenteral to oral ketamine. Journal of Pain and Symptom Management. 23(2): 165-170.
- Hirota J. (1996) Ketamine: its mechanism(s) of action and unusual clinical uses. British Journal of Anaesthesia. 77(4): 441-4.
- Hocking G, Cousins M. (2003) Ketamine in chronic pain management: an evidence-based review. Anaesthesia and Analgesia. 97(6): 1730-9.
- Kosharskyy B, Almonte W, Shaparin N, Pappagallo M, Smith H. (2013) Intravenous infusions in chronic pain management. Pain Physician. 16(3): 231-49.
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