title: The Effects of Low-Dose Ketamine on Acute Pain in an Emergency Setting: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  Currently ketamine is not used often as an analgesic in the emergency department (ED). Nonetheless, it can increase the efficiency of opioids and decrease their side effects. The purpose of this systematic review and meta-analysis was to evaluate whether low-dose ketamine in the ED provides better analgesia with fewer adverse effects.
  
  
  METHODS
  The PubMed, EMBASE, and Cochrane Library databases were searched by two reviewers independently (last search performed on January 2016). Data were also extracted independently.
  
  
  RESULTS
  A total of 6 trials involving 438 patients were included in the current analysis. Our subgroup analysis of pain reduction indicates that the favorable effects of ketamine were similar or superior to those of placebo or opioids, although these effects were heterogeneous. However, low-dose ketamine was associated with a higher risk of neurological (relative risk [RR] = 2.17, 95% confidence interval [CI] = 1.37-3.42, P < 0.001) and psychological events (RR = 13.86, 95% CI = 4.85-39.58, P < 0.001). In contrast, the opioid group had a higher risk of major cardiopulmonary events (RR = 0.22, 95% CI = 0.05-1.01, P = 0.05).
  
  
  CONCLUSIONS
  The efficiency of ketamine varies depending on the pain site, but low-dose ketamine may be a key agent for pain control in the ED, as it has no side effects. It may also help to reduce the side effects of opioids.
authors: Department of Nursing, Dong-A University, Daesin Gonwon-Ro, Seo-Gu, Busan, South Korea.
authors: Eun Nam
authors: EN
authors: Lee
authors: Department of Emergency Medicine, Dong-A university College of Medicine, Daesin Gonwon-Ro, Seo-Gu, Busan, South Korea.
authors: Jae Hoon
authors: http://orcid.org/0000-0002-5815-6994
authors: JH
authors: Lee
mesh_terms: D059787:Acute Pain / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004632:Emergency Medical Services / Q000379:methods*; D006801:Humans; D007649:Ketamine / Q000009:adverse effects / Q000494:pharmacology* / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D007649:Ketamine