Ketamine, a dissociative anesthetic medication first synthesized in 1962, has been used extensively in emergency departments for analgesia and sedation in children. Over the last several decades, Ketamine has been used in adults about to undergo painful or delicate procedures, creating a favorable dissociative, amnestic state. These procedures include fracture reductions and repair of disfiguring or extensive lacerations in frightened children. As a result, Ketamine is the anesthetic of choice for pediatric analgesia and sedation in the ED.
Most recently, Ketamine Infusion Therapy, the administration of intravenous low-dose Ketamine, has been surprisingly effective in rapidly improving the symptoms of depression, posttraumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), and other mental health conditions as well as chronic pain syndromes. This effect is supported by countless studies conducted at reputable research centers from 2000 to the present.
Treating Mental Health Disorders
Ketamine has been shown to improve symptoms of depression in as little as several hours after the first treatment. This lifting of the depressive symptoms seems to last anywhere from several days to weeks or months and typically lasts the longest after a series of six infusions over two weeks. In addition, single-dose “booster” treatments for two weeks to months after the initial infusion have been shown to prolong the antidepressant effect of the medication in many patients.
In 2014, Thomas Insel, former Director of the National Institute of Mental Health, stated, “Recent data suggest that ketamine, given intravenously, might be the most important breakthrough in antidepressant treatment in decades.”
Treating Chronic Pain
Traditionally, many patients with chronic pain are treated with opioid analgesics. Opioids bind to neuronal opiate receptors causing decreased activation of the neuronal pathways involved in pain perception. Unfortunately, these effects are short-lived, and over a relatively short time, the neurons involved respond by the overexpression of the opiate receptors, leading to decreased responsiveness and effectiveness to these medications.
Consequently, many people who are started on opioid analgesics, despite initial improvement in their daily pain levels, frequently require the need escalating doses, increased frequency of dosing, and the use of more potent opioids to control their pain over time. The use of opioids to manage chronic pain is, therefore, a treatment with diminishing returns, as the side effects and lack of efficacy rapidly overwhelm the benefits of this class of medications. Medication tolerance, dependence, and addiction are often the result.
Ketamine Infusion Therapy has been shown to rapidly provide up to a 50% decrease in patient-reported pain levels in patients that respond to these treatments. Ketamine is particularly effective for many chronic pain syndromes, particularly neuropathic pain syndromes, such as chronic regional pain syndrome (CRPS). Ketamine is thought to improve chronic pain in a novel way by blocking the N-methyl-D-aspartate (NMDA) receptor. This NMDA blockade is believed to allow the pain pathways in the brain and spine to “reset,” allowing a more typical response to pain signals from the body’s nerves. This resetting of the pain pathways may last for weeks to months and can be maintained with occasional booster treatments, as needed. Ketamine, which blocks these hyperstimulated pain pathways, allows a decrease in painful symptoms and a decrease in the need for opioid medications.
In addition, many patients suffering from chronic pain disorders have a proven overlay of depressive symptoms and chronic anxiety. Ketamine’s ability to decrease the symptoms of depression and anxiety can also lessen the compounding effect these conditions have on the patient’s pain level.