The Effects of Low-Dose Ketamine on Acute Pain in an Emergency Setting: A Systematic Review and Meta-Analysis

Abstract

ObjectivesCurrently 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.MethodsThe PubMed, EMBASE, and Cochrane Library databases were searched by two reviewers independently (last search performed on January 2016). Data were also extracted independently.ResultsA 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).ConclusionsThe 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.

A Systematic Review and Meta‐analysis of Ketamine as an Alternative to Opioids for Acute Pain in the Emergency Department

“…Of the four studies included, two showed a benefit in pain and distress with ketamine, while the others demonstrated either no difference between ketamine and fentanyl or ketamine and a placebo. In another meta‐analysis that also included trials we excluded, Lee and Lee included six trials and 438 patients and found ketamine to be either similar or superior to opioids and placebos. Ketamine was associated with a higher rate of neurologic and psychiatric adverse events (respectively, RR = 2.17, 95% CI = 1.37 to 3.42, p < 0.001, NNH = 9; RR = 13.86, 95% CI = 4.85 to 39.58, p < 0.001, NNH = 4), while opioids were associated with a higher risk of major cardiovascular events (RR = 0.22, 95% CI = 0.05–1.01, p = 0.05, NNH = 28), although the clinical significance of this is debatable.…”

“…As patients can still become dissociated or have psychiatric complaints, we shall instead refer to this as low‐dose ketamine (LDK). Two previously conducted reviews evaluating LDK in the ED suffered significant limitations by including pediatric trials, trials where ketamine was administered with other analgesics, and patients where ketamine was administered for procedural sedation leaving the independent effect of ketamine on acute pain control unresolved.…”

“…Our primary objective was to quantify the short‐term (≤60 minutes) analgesic efficacy of LDK, administered as an initial one‐dose, single‐agent IV bolus in adults between 18 and 65 years of age in the ED via a systematic review and meta‐analysis. The decision to impose strict requirements provides this review additional accuracy as compared with prior reviews that could neither isolate effects of different routes of administration or the potential biases of noncontrolled studies. The secondary objective was to quantify the risk of adverse effects attributable to ketamine used as an opioid alternative for ED analgesia.…”

Low Dose Ketamine Used for Acute Pain Management in the Emergency Department

“…If low dose ketamine is used in the emergency department as a pharmacological treatment for pain, it is important to take into consideration the risks and benefits, least effective and most effective uses. Low dose ketamine is an effective pharmacological treatment of pain by itself and as an adjunct to opioids [7] [30] because it is a non-competitive NMDA antagonist and it does not interfere with receptors used by opioids [7] [19] [30]. As an adjunct therapy, it is especially important to consider the dosing of opioids in order to prevent opioid-ketamine adverse reactions.…”

Hot Off the Press: A Systematic Review And Meta‐analysis of Ketamine as an Alternative to Opioids for Acute Pain in the Emergency Department

“…However, in recent years, an increased desire for alternatives has been prompted in an attempt to reduce opiate usage . Several studies have been performed evaluating low‐dose ketamine (LDK) for acute pain, with a variety of methodologic designs, time endpoints, and doses . This review attempts to determine the utility of LDK, alone, in comparison to opiates for acute pain in the ED.…”