There is an immense need for the invention of alternative non-opioid analgesics for the treatment of acute, chronic and refractory pain in the emergency department (ED).

Ketamine is a fast-acting non-opioid analgesic which is an N-methyl-d-aspartate (NMDA) receptor antagonist. It provides safe and effective analgesia. The low dose ketamine (LDK) (<1 mg/kg) produces sub-dissociative levels of analgesia, and it had been studied as an alternative and adjunct to opioid analgesics. A total of 11 studies were considered using LDK, used either alone or in combination with opioid analgesics in the ED. In these studies, Ketamine was shown to be effective in treating a variety of painful conditions. When it was given at sub dissociative doses, it favored the adverse effect profile. A comparison was also made between LDK and opioids in the ED. Comparison with other opioids indicated the non-superior analgesic effect of ketamine, but it was comparable to opioids. LDK causes less respiratory depression, and it had less widespread potential for abuse. Nursing protocols for the administration of LDK were also studied in the study.

It was inferred at last that LDK was highly safe and efficacious alternative and/or adjunct to opioid analgesics in the ED. However, there is a need for additional studies to expand and determine its optimal use.