Efficacy and safety of perioperative ketamine for the prevention of chronic postsurgical pain: A meta-analysis

STUDY OBJECTIVE

Assessment of the efficacy and safety of perioperative intravenous ketamine in reducing incidence and severity of chronic postsurgical pain.

STUDY DESIGN

A systematic review and meta-analysis of randomized controlled trials (RCTs).

DATA SOURCES

The following data sources were systematically searched: MEDLINE, CENTRAL, and EMBASE (till 02/2021).

PATIENTS

Adult patients undergoing any surgery.

INTERVENTIONS

Perioperative use of intravenous ketamine as an additive analgesic drug compared to placebo, no active control treatment, and other additive drugs.

MEASUREMENTS

Primary outcomes were number of patients with chronic postsurgical pain after 6 months and ketamine related adverse effects. Secondary outcomes were chronic postsurgical pain incidence after 3 and 12 months, chronic postsurgical neuropathic pain incidence, chronic postsurgical moderate to severe pain incidence, intensity of chronic postsurgical pain at rest, and during movement, oral morphine consumption after 3, 6, and 12 months and incidence of opioid-related adverse effects.

MAIN RESULTS

Thirty-six RCTs were included with a total of 3572 patients. Ketamine compared to placebo may result in no difference in the number of patients with chronic postsurgical pain after 6 months (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.71-1.05; I2  = 34%; 16 studies; low-certainty evidence). Ketamine may reduce the incidence of chronic postsurgical neuropathic pain after 3 months in comparison to placebo (RR 0.78, 95% CI 0.62-0.99, I2  = 31%, seven trials, low-certainty evidence). Ketamine compared to placebo may increase the risk for postoperative nystagmus (RR 9.04, 95% CI 1.15-70.90, I2 30%, two trials, low-certainty evidence) and postoperative visual disturbances (RR 2.29, 95% CI 1.05-4.99, I2 10%, seven trials, low-certainty evidence).

CONCLUSIONS

There is low-certainty evidence that perioperative ketamine has no effect on chronic postsurgical pain in adult patients. Low-certainty evidence suggests that ketamine compared to placebo may reduce incidence of chronic postsurgical neuropathic pain after 3 months. Questions like ideal dosing, treatment duration and more patient-related outcome measures remain unanswered, which warrants further studies.

PROTOCOL REGISTRATION

Prospero CRD42021223625, 07.01.2021.

Ketamine for postoperative pain treatment in spinal surgery: Systematic review with meta-analysis and trial sequential analysis

AIM

We aimed to assess the beneficial and harmful effects of perioperative pain treatment with ketamine in patients undergoing spinal surgery.

METHODS

We searched Medline, Embase, and CENTRAL from inception until 15 February 2023 for randomised clinical trials comparing ketamine with placebo or no intervention in patients undergoing spinal surgery. The primary outcomes were cumulative opioid consumption at 24 h postoperatively and serious adverse events. We adhered to recommendations of the Cochrane Collaboration and performed meta-analysis, Trial Sequential Analysis (TSA) to assess the risks of random errors, risk of bias assessment to evaluate the risks of systematic errors, and used the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

We included a total of 28 randomised clinical trials enrolling 2110 participants providing data for our pre-defined outcomes. Twenty-three trials enrolled adult participants and 5 trials enrolled paediatric participants. Three trials were at low risk of bias. Meta-analysis and TSA of trials including adults showed that ketamine versus placebo or no intervention seemed to reduce the cumulative 24-h opioid consumption (mean difference -17.57 mg; TSA-adjusted 95% confidence interval, -24.22 to -10.92; p < .01; low certainty of evidence), and there was no evidence of a difference of ketamine versus placebo or no intervention on the risk of serious adverse events (risk ratio 2.16; 96.7% confidence interval, 0.35 to 13.17; p = .36; very low certainty of evidence).

CONCLUSION

In adults undergoing spinal surgery, ketamine may reduce cumulative 24-h opioid consumption. Ketamine may increase the occurrence of serious adverse events, but the evidence was very uncertain.

The analgesic efficacy of ketamine for septorhinoplasty: a meta-analysis study

BACKGROUND

The analgesic efficacy of ketamine supplementation was not well-established for septorhinoplasty and this meta-analysis aimed to compare ketamine supplementation with placebo for the postoperative pain control of septorhinoplasty.

METHODS

We systematically searched several databases, including PubMed, EMbase, Web of science, EBSCO and Cochrane library databases, and included randomized controlled trials (RCTs) regarding the effect of ketamine supplementation versus placebo for pain control after septorhinoplasty. This meta-analysis was conducted by random effect model.

RESULTS

Five RCTs were included in this meta-analysis. In comparison with control group for septorhinoplasty, ketamine supplementation was associated with significantly decreased pain scores at 30 min (SMD = - 3.84; 95% CI = - 6.73 to - 0.96; P = 0.009), pain scores at 1 h (SMD = - 2.70; 95% CI = - 3.79 to - 1.61; P < 0.00001), pain scores at 2 h (SMD = - 1.83; 95% CI = - 3.01 to - 0.64; P = 0.003), rescue analgesics (OR = 0.08; 95% CI = 0.04 to 0.17; P < 0.00001), but unraveled no obvious impact on pain scores at 4 h (SMD = - 1.13; 95% CI = - 3.37 to 1.12; P = 0.32) or the incidence of nausea and vomiting (OR = 0.71; 95% CI = 0.30 to 1.72; P = 0.45).

CONCLUSIONS

Ketamine supplementation was effective to improve pain relief after septorhinoplasty.

Comparison of the Effect of Intravenous Fentanyl with Low-Dose Ketamine on Pain Relief in Patients Taking Methadone and Suffering from Limb Fractures

Background

Given the significance of pain control in addicted patients and the prominence of not using opioids due to patient's drug dependence, the present study aimed at comparing and evaluating the effect of intravenous fentanyl with low-dose ketamine on pain relief in patients taking methadone and suffering from limb fractures.

Materials and Methods

The present double-blind randomized clinical trial was performed on 100 patients taking methadone and suffering from limb fractures. The patients were divided into two groups receiving 1 μg/kg single dose of fentanyl and 0.3 mg/kg single dose of ketamine (low-dose ketamine). Patients' pain scores and the incidence rate of complications were recorded before the intervention, and 15, 30, and 60 min after drug administration and were then compared between the two groups.

Results

The mean pain score of patients 15 min after the intervention was significantly lower in the low-dose ketamine group with a mean of 2.50 ± 1.34 as compared with the fentanyl group with a mean of 7.10 ± 1.43 (P < 0.001). However, the mean pain score was not significantly different between the two groups 30 and 60 min after the intervention (P > 0.05). In addition, the incidence rate of complications was not significantly different between the two groups (P > 0.05).

Conclusion

According to the results of this study, low-dose ketamine as compared with fentanyl relieves pain in the mentioned patients with a faster effect and in a shorter time although no difference can be found between the pain scores of the two groups 30 and 60 min after the intervention.

Perioperative Low-Dose Ketamine for Postoperative Pain Management in Spine Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

Although low-dose ketamine has been shown to be generally beneficial in terms of pain control in a variety of major surgery, there is no consensus regarding the effectiveness of supplemental ketamine analgesic use exclusively in spine surgery. The objective of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to assess the efficacy and safety of perioperative low-dose ketamine for pain management and analgesic consumption in patients undergoing spine surgery.

Methods

A comprehensive literature search was performed for relevant studies using PubMed, EMBASE, Web of Science, and Cochrane Library. Patients who received perioperative low-dose ketamine were compared to the control group in terms of postoperative pain intensity, opioid consumption, and adverse events. Patients were further categorized by ages and administration times for subgroup analysis.

Results

A total of 30 RCTs comprising 1,865 patients undergoing elective spine surgery were included. Significantly lower pain intensity and less opioid consumption at 12 h, 24 h, and 48 h postoperatively and lower incidence of postoperative nausea and vomiting (PONV) were observed in the ketamine group (all P < 0.05). There was no significant difference of central nervous system (CNS) adverse events between groups. However, different efficacy of low-dose ketamine was detected when patients were categorized by ages and administration times.

Conclusion

Perioperative low-dose ketamine demonstrated analgesic and morphine-sparing effect with no increased adverse events after spine surgery. However, this effect was not significant in pediatric patients. Only postoperative or intraoperative and postoperative administration could prolong the analgesic time up to 48 h postoperatively. Further studies should focus on the optimal protocol of ketamine administration and its effect on old age participants.

Pharmacotherapy for the Prevention of Chronic Pain after Surgery in Adults: An Updated Systematic Review and Meta-analysis

BACKGROUND

Chronic postsurgical pain can severely impair patient health and quality of life. This systematic review update evaluated the effectiveness of systemic drugs to prevent chronic postsurgical pain.

METHODS

The authors included double-blind, placebo-controlled, randomized controlled trials including adults that evaluated perioperative systemic drugs. Studies that evaluated same drug(s) administered similarly were pooled. The primary outcome was the proportion reporting any pain at 3 or more months postsurgery.

RESULTS

The authors identified 70 new studies and 40 from 2013. Most evaluated ketamine, pregabalin, gabapentin, IV lidocaine, nonsteroidal anti-inflammatory drugs, and corticosteroids. Some meta-analyses showed statistically significant-but of unclear clinical relevance-reductions in chronic postsurgical pain prevalence after treatment with pregabalin, IV lidocaine, and nonsteroidal anti-inflammatory drugs. Meta-analyses with more than three studies and more than 500 participants showed no effect of ketamine on prevalence of any pain at 6 months when administered for 24 h or less (risk ratio, 0.62 [95% CI, 0.36 to 1.07]; prevalence, 0 to 88% ketamine; 0 to 94% placebo) or more than 24 h (risk ratio, 0.91 [95% CI, 0.74 to 1.12]; 6 to 71% ketamine; 5 to 78% placebo), no effect of pregabalin on prevalence of any pain at 3 months (risk ratio, 0.88 [95% CI, 0.70 to 1.10]; 4 to 88% pregabalin; 3 to 80% placebo) or 6 months (risk ratio, 0.78 [95% CI, 0.47 to 1.28]; 6 to 68% pregabalin; 4 to 69% placebo) when administered more than 24 h, and an effect of pregabalin on prevalence of moderate/severe pain at 3 months when administered more than 24 h (risk ratio, 0.47 [95% CI, 0.33 to 0.68]; 0 to 20% pregabalin; 4 to 34% placebo). However, the results should be interpreted with caution given small study sizes, variable surgical types, dosages, timing and method of outcome measurements in relation to the acute pain trajectory in question, and preoperative pain status.

CONCLUSIONS

Despite agreement that chronic postsurgical pain is an important topic, extremely little progress has been made since 2013, likely due to study designs being insufficient to address the complexities of this multifactorial problem.

EDITOR’S PERSPECTIVE

Perioperative Intravenous Low-Dose Ketamine Infusion to Minimize Pain for Septorhinoplasty: A Prospective, Randomized, Double-Blind Study

OBJECTIVES

Studies investigating the effects of intravenous (IV) ketamine in pain management after septorhinoplasty is limited. This study aims to evaluate the efficacy of low-dose IV infusion of ketamine on pain scores.

METHODS

This randomized, prospective, double-blind study was conducted with 48 patients who underwent septorhinoplasty. Intravenous ketamine bolus (0.5 mg/kg) was administered to the ketamine group (group K, n = 24) at anesthesia induction, and ketamine infusion was continued (0.25 mg/kg/h) during the surgery. In the control group (group C, n = 24), the same protocol was administered using saline instead of ketamine. Furthermore, 50-mg dexketoprofen trometamol was administered to both groups 30 minutes before the end of the surgery. Then it was repeated at the 12th and 24th hours postoperatively. Pain scores were evaluated with the visual analogue scale. Consumptions intraoperative of opioid and sevoflurane, rescue opioid requirement, patient satisfaction, and side effects were recorded.

RESULTS

Pain scores were significantly lower in group K at all postoperative periods (P < .05). There was no significant difference between the groups in terms of intraoperative sevoflurane and remifentanil consumptions (P > .05). Rescue opioid analgesic requirements were significantly lower in group K than group C (0/24 vs 6/24, respectively; P  = .022). Side effects were similar between the groups (P > .05).

CONCLUSION

We recommend the administration of low-dose ketamine infusion during septorhinoplasty surgery because it reduces the requirement for rescue opioid analgesia and postoperative pain scores.