Ketamine-A Narrative Review of Its Uses in Medicine.

One of the most fascinating drugs in the anesthesiologist's armament is ketamine, an N-methyl-D-aspartate receptor antagonist with a myriad of uses. The drug is a dissociative anesthetic and has been used more often as an analgesic in numerous hospital units, outpatient pain clinics, and in the prehospital realm. It has been used to treat postoperative pain, chronic pain, complex regional pain syndrome, phantom limb pain, and other neuropathic conditions requiring analgesia. Research has also demonstrated its efficacy as an adjunct in psychotherapy, as a treatment for both depression and posttraumatic stress disorder, as a procedural sedative, and as a treatment for respiratory and neurologic conditions. Ketamine is not without its adverse effects, some of which can be mitigated with certain efforts. Such effects make it necessary for the clinician to use the drug only in situations where it will provide the greatest benefit with the fewest adverse effects. To the best of our knowledge, none of the reviews regarding ketamine have taken a comprehensive look at the drug's uses in all territories of medicine. This review will serve to touch on its chemical data, pharmacokinetics and pharmacodynamics, medical uses, and adverse effects while focusing specifically on the drugs usage in anesthesia and analgesia.

Role of ketamine in acute postoperative pain management: a narrative review.

OBJECTIVES: The objective of this narrative review was to examine the usage of ketamine as a postoperative analgesic agent across a wide variety of surgeries. DESIGN: A literature search was performed using the phrases "ketamine" and "postoperative pain." The authors analyzed the studies that involved testing ketamine's effectiveness at controlling postoperative pain. Effectiveness was assessed through various outcomes such as the amount of opiate consumption, visual analog scale (VAS) pain scores, and persistent postoperative pain at long-term follow-up. RESULTS: While many different administration protocols were evaluated, delivering ketamine both as a pre- or perioperative bolus and postoperative infusion for up to 48 hours appeared to be the most effective. These effects are dose-dependent. However, a number of studies analyzed showed no benefit in using ketamine versus placebo for controlling postoperative pain. While ketamine is a safe and well-tolerated drug, it does have adverse effects, and there are concerns for possible neurotoxicity and effects on memory. CONCLUSIONS: In a number of limited situations, ketamine has shown some efficacy in controlling postoperative pain and decreasing opioid consumption. More randomized controlled trials are necessary to determine the surgical procedures and administrations (i.e., intravenous, epidural) that ketamine is best suited for.

Development of phantom limb pain after femoral nerve block.

Historically, phantom limb pain (PLP) develops in 50-80% of amputees and may arise within days following an amputation for reasons presently not well understood. Our case involves a 29-year-old male with previous surgical amputation who develops PLP after the performance of a femoral nerve block. Although there have been documented cases of reactivation of PLP in amputees after neuraxial technique, there have been no reported events associated with femoral nerve blockade. We base our discussion on the theory that symptoms of phantom limb pain are of neuropathic origin and attempt to elaborate the link between regional anesthesia and PLP. Further investigation and understanding of PLP itself will hopefully uncover a relationship between peripheral nerve blocks targeting an affected limb and the subsequent development of this phenomenon, allowing physicians to take appropriate steps in prevention and treatment.