Overview
Subdissociative ketamine (SDK) can be used to treat chronic pain in the ED.
Evidence for this indication is evolving.
Ketamine, Chronic Non-Cancer Pain
Indications
Chronic pain unrelieved by other modalities or in a patient who takes daily prescription opioids
Pain in a patient for whom opioids are contraindicated
The following types of pain or painful conditions, although not necessarily as first-line therapy:
- Axial skeletal pain1
- Chronic back pain
- Complex regional pain syndrome2
- Fibromyalgia2
- Gastroparesis
- Headache3,4
- Neuropathic pain2,3
- Postherpetic pain2
- Radiculopathies2,3
- Sickle cell disease5,6
- Trigeminal neuralgia3
Contraindications
Absolute: Allergy or hypersensitivity to ketamine
Relative: History of psychosis or psychiatric disease excluding depression
Use caution in patients with substance use disorders.3
Consider the same cautions and policies for treating chronic pain in the ED with either opioids or other medications with abuse potential.
Procedure & Administration
Intravenous
Dosing varies among studies.
There is significant heterogeneity between single dose, infusion, and route of administration.
Administer bolus at 0.1 to 0.3 mg/kg IV over 10 to 15 minutes.1,7
Avoid doses greater than 0.5 mg/kg in patients who have little or no experience with ketamine to prevent dissociation.
Infusion: 0.15 to 0.2 mg/kg per hour with or without bolus and titrate as required1,4,8
Duration of infusion: ranges from 5 to 45 minutes to multiple hours for pain that is difficult to control but is typically less than 1 hour, which is most applicable to the ED.2,7
Intranasal
Use when IV route is not desired.
0.5 to 1.0 mg/kg
Do not exceed more than 1 mL per naris.2,9
Use high-concentration formulation (50 mg/mL in children and 100 mg/mL in adults).
Complications
Dizziness3,7
Nausea/vomiting2
Special Considerations
Nursing staff might be unfamiliar with analgesic dosing.
Make it clear that significant emergence phenomena are generally not seen until high doses are reached and do not require cardiopulmonary monitoring.7,8
Institutional policies might dictate the advisability of pulse oximetry, cardiac monitoring, and nursing administration.
In this setting, SDK is intended and dosed for analgesia, not moderate or deep sedation. Specific sedation monitoring and safety requirements should not apply.
Discharge Procedure
Tell the patient that ketamine should reset the pain level lower.2-4
Otherwise, no special instructions are necessary.
Where to Learn More
References
- Pourmand A, Mazer-Amirshahi M, Royall C, et al. Low dose ketamine use in the emergency department: a new direction in pain management. Am J Emerg Med. 2017;35(6):918-921.
- Patil S, Anitescu M. Efficacy of outpatient ketamine infusions in refractory chronic pain syndromes: a 5-year retrospective analysis. Pain Med. 2012;13:263-269.
- Niesters M, Martini C, Dahan A. Ketamine for chronic pain: risks and benefits. Br J Pharmacol. 2013;77:357-367.
- Lauritsen C, Mazuera S, Lipton RB, et al. Intravenous ketamine for subacute treatment of refractory chronic migraine: a case series. J Headache Pain. 2016;17:106-111.
- Uprety D, Baber A, Foy M. Ketamine infusion for sickle cell pain crisis refractory to opioids: a case report and review of literature. Ann Hematol. 2014;93:769-771.
- Jennings CA, Bobb BT, Noreika DM, et al. Oral ketamine for sickle cell pain refractory to opioids. J Pain Palliat Care Pharmacother. 2013;27:150-154.
- Ahern TL, Herring AA, Miller S, et al. Low-dose ketamine infusion for emergency department patients with severe pain. Pain Med. 2015;16:1402-1409.
- Sheehy KA, Muller EA, Lippold C, et al. Subanesthetic ketamine infusions for the treatment of children and adolescents with chronic pain: a longitudinal study. BMC Pediatrics. 2015;15:198206.
- Andolfatto G, Willman E, Joo D, et al. Intranasal ketamine for analgesia in the emergency department: a prospective observational series. Acad Emerg Med. 2013;20:1050-1054.
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