Ketamine Infusions for Chronic Pain Clinical Practice Guidelines (2018) (1)
American Society of Regional Anesthesia and Pain Medicine, American Academy of Pain Medicine, and American Society of Anesthesiologists
For spinal cord injury pain, there is weak evidence supporting ketamine infusions (0.42 mg/kg per hour to 0.4 mg/kg ranging from 17 minutes to 5 hours for 7 consecutive days) for short-term improvements in pain.
For complex regional pain syndrome (CRPS), there is moderate evidence supporting ketamine infusions (22 mg/h for 4 days or 0.35 mg/kg per hour over 4 hours daily for 10 days) to provide improvements in pain for up to 12 weeks.
For mixed neuropathic pain, phantom limb pain (PLP), postherpetic neuralgia (PHN), fibromyalgia, cancer pain, ischemic pain, migraine headache, and low-back pain, there is weak or no evidence supporting ketamine infusions for immediate improvements in pain. Excluding CRPS, there was no evidence supporting ketamine infusions for intermediate or long-term improvements in pain.
Ketamine should not be used in patients with poorly controlled cardiovascular disease and should be avoided in individuals with certain poorly controlled psychoses.
For hepatic dysfunction, it should be avoided in individuals with severe impairment but may be administered judiciously with proper monitoring in people with moderate disease.
In patients with elevated intracranial and intraocular pressure, there is grade C evidence that ketamine should not be used or used only in lower dosages with extreme caution.
Serial ketamine infusions should not be undertaken in patients with an active substance abuse problem and should be used along with universal precautions to monitor for abuse.
There is moderate evidence to support higher dosages of ketamine over longer time periods, and more frequent administration, for chronic pain. Similar to the strategy used for opioids and other analgesic drugs with significant adverse effect profiles, it is reasonable to start dosing with a single, outpatient infusion at a minimum dose of 80 mg lasting more than 2 hours and reassess before initiating further treatments, similar to what is widely recommended for epidural steroid injections...
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