Ketamine and postoperative pain – a quantitative systematic review of randomised trials
Pain December 15, 2004 DOI: 10.1016/j.pain.2004.09.036 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Randomized Peer reviewed |
|---|---|
| Sample size | 2,839 |
| Population | Surgical patients from 25 countries |
| Intervention | Ketamine |
| Dose | 0.4 mg/kg (median), range 0.1-1.6 mg/kg |
| Topics | Ketamine Esketamine |
| Keywords | Anesthesia Premedication Morphine Adverse effect Analgesic Odds ratio Opioid Randomized controlled trial Placebo Surgery |
| Citations | 564 |
| Key findings | Prophylactic intravenous ketamine modestly reduces postoperative pain and morphine consumption but increases hallucination risk in awake or sedated patients not receiving benzodiazepine. |
Abstract
Ketamine, an N-methyl-D-aspartate receptor antagonist, is known to be analgesic and to induce psychomimetic effects. Benefits and risks of ketamine for the control of postoperative pain are not well understood. We systematically searched for randomised comparisons of ketamine with inactive controls in surgical patients, reporting on pain outcomes, opioid sparing, and adverse effects. Data were combined using a fixed effect model. Fifty-three trials (2839 patients) from 25 countries reported on a large variety of different ketamine regimens and surgical settings. Sixteen studies tested prophylactic intravenous ketamine (median dose 0.4 mg/kg, range (0.1-1.6)) in 850 adults. Weighted mean difference (WMD) for postoperative pain intensity (0-10 cm visual analogue scale) was -0.89 cm at 6 h, -0.42 at 12 h, -0.35 at 24 h and -0.27 at 48 h. Cumulative morphine consumption at 24 h was significantly decreased with ketamine (WMD -15.7 mg). There was no difference in morphine-related adverse effects. The other 37 trials tested in adults or children, prophylactic or therapeutic ketamine orally, intramuscularly, subcutaneously, intra-articulary, caudally, epidurally, transdermally, peripherally or added to a PCA device; meta-analyses were deemed inappropriate. The highest risk of hallucinations was in awake or sedated patients receiving ketamine without benzodiazepine; compared with controls, the odds ratio (OR) was 2.32 (95%CI, 1.09-4.92), number-needed-to-harm (NNH) 21. In patients undergoing general anaesthesia, the incidence of hallucinations was low and independent of benzodiazepine premedication; OR 1.49 (95%CI 0.18-12.6), NNH 286. Despite many published randomised trials, the role of ketamine, as a component of perioperative analgesia, remains unclear.
Comparable studies
Other systematic reviews and meta-analyses on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| The effect of a single dose of intravenous ketamine on suicidal ideation: a systematic review and individual participant data meta-analysis Depressed patients with suicidal ideation at baseline | 2017 | Systematic review and individual participant data meta-analysis | n = 167 |
| Ketamine use: a review Ketamine users | 2011 | Systematic review | |
| Ketamine and Other NMDA Antagonists: Early Clinical Trials and Possible Mechanisms in Depression Participants with major depression in placebo-controlled, double-blind, randomized... | 2015 | Systematic review and meta-analysis | |
| Side-effects associated with ketamine use in depression: a systematic review. Patients with depression | 2018 | Systematic review | |
| Use and efficacy of low-dose ketamine in the management of acute postoperative pain: a review of current techniques and outcomes | 1999 | Systematic review |
Citations in the library
Cited by 8
- Remifentanil-induced Postoperative Hyperalgesia and Its Prevention with Small-dose Ketamine Anesthesiology June 27, 2005
- Ketamine Safety and Tolerability in Clinical Trials for Treatment-Resistant Depression The Journal of Clinical Psychiatry September 2, 2014
- The Effect of Preprocedural Low-Dose Ketamine for Pain and Anxiety in Patients during Thoracic Epidural Catheterization. Medicina (Kaunas, Lithuania) April 22, 2024
- Intravenous Ketamine Infusion for Managing Chronic Postoperative Pain After Inguinal Herniorrhaphy: A Case Report. Journal of Pain & Palliative Care Pharmacotherapy April 30, 2025
- Ketamine disrupts gaze patterns during face viewing in the common marmoset bioRxiv Preprint Server February 16, 2021
and 3 more in the library