Abstract
Background and Aims:
Ketamine is being proposed for the prevention of rebound pain. This meta-analysis systematically reviews evidence from randomised controlled trials on the efficacy of ketamine (intravenous or perineural) in preventing rebound pain in adults undergoing surgery under regional nerve block.
Methods:
A systematic search for randomised controlled trials evaluating ketamine/esketamine (perineural or intravenous) for preventing rebound pain was conducted across databases up to March 2025. Adults receiving regional nerve block with or without ketamine/esketamine were included. The primary outcome was the incidence of rebound pain. Secondary outcomes included onset time and severity of rebound pain, patient satisfaction, and adverse effects.
Results:
Six trials enroling 890 patients were included. Ketamine/esketamine significantly reduced the incidence of rebound pain [odds ratio (OR) 0.43, 95% confidence interval (CI) 0.32 to 0.59; P < 0.00001; I² = 39%]. The intravenous subgroup showed a significant reduction (OR 0.48, 95% CI 0.34 to 0.68; P < 0.00001; I² = 21%). The esketamine-versus-control subgroup also favoured active treatment (OR 0.37, 95% CI 0.22 to 0.64; P = 0.0004; I² = 51%). Hallucinations were significantly more frequent with active treatment (OR 12.73, 95% CI 2.98 to 54.41; P = 0.0006; I² = 0%).
Conclusion:
Current evidence suggests that intravenous and perineural ketamine/esketamine reduce the incidence of rebound pain after a peripheral regional nerve block.
Keywords: Esketamine, ketamine, peripheral nerve block, postoperative pain, rebound pain, regional anaesthesia
INTRODUCTION
Regional analgesia (RA) has transformed modern anaesthesia practice and postoperative pain management.[1] In addition to reducing opioid consumption, RA facilitates early ambulation and functional recovery.[2] However, a notable and emerging concern with this technique is rebound pain (RP)—a phenomenon increasingly referred to as the ‘dark side’ of single-injection nerve blocks. RP is characterised by a sudden escalation from well-controlled pain (scale ≤ 3) to severe pain (≥ 7) within 24 hours following the resolution of a regional nerve block. Its incidence has been reported to be approximately 49.6%.[3] Several causes have been hypothesised, such as inadequate preemptive analgesia, increased central sensitisation, and inter-individual variability in the modulation of endogenous pain pathways.[4] This abrupt increase in pain intensity can negate many benefits of RA by increasing opioid consumption, delaying mobilisation, and reducing patient satisfaction. Hence, current research is actively exploring prophylactic strategies to prevent RP, including the use of adjuncts such as dexamethasone, ketamine, and dexmedetomidine.[5,6]
Ketamine prevents RP by inhibiting central sensitisation and hyperalgesia through N-methyl-D-aspartate (NMDA) receptor antagonism and modulation of multiple neurotransmitter systems. Its S-enantiomer, esketamine, has demonstrated even greater potency in this regard, positioning both agents as promising candidates for RP prevention.[7] However, existing studies examining the use of ketamine for RP have yielded mixed results.[8,9] Hence, to evaluate the efficacy and safety of ketamine [intravenous (IV) or perineural] in preventing RP, we conducted this meta-analysis.
METHODS
The meta-analysis was registered with the International Prospective Register of Systematic Reviews (PROSPERO; registration number CRD42024528309), and the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were used for methodology and study selection. The Population, Intervention, Comparators, Outcomes, Timing, and Settings (PICOTS) criteria were used for the conduct of the review. The literature search covered the period from database inception to March 2025, and the included trials were published between 2020 and 2025. Patients: adult patients undergoing surgical procedures under regional nerve block, either alone or in combination with general anaesthesia. Intervention: the addition of ketamine/esketamine (perineural or IV) to a local anaesthetic for a regional nerve block. Comparator: patients receiving regional nerve block without ketamine. Outcomes: the primary outcome was the incidence of RP (as defined by the study authors). Secondary outcomes included the time to onset of RP, severity of RP, patient satisfaction with pain control, and adverse effects, including nausea, vomiting, dizziness, hallucination, and nightmares.
Exclusion criteria were trials enroling patients under 18 years of age, trials comparing routes of ketamine administration without a control arm, and those without randomisation. Studies that compared various routes of ketamine administration and included a control group, with data reported separately for each treatment arm, were considered as separate trials.
Search strategy
We searched PubMed, MEDLINE, Embase, and Scopus databases from inception to March 2025 using terms covering the topics ‘ketamine’ OR ‘esketamine’ OR ‘S-ketamine’ AND ‘rebound pain’ AND ‘block’, without imposing any language restriction. Controlled vocabulary, such as Medical Subject Headings (MeSH), was used when available. The bibliographies of relevant publications were screened for additional articles. Supplementary Appendix 1 outlines the search strategy. Two authors independently performed full-text screening after shortlisting the eligible abstracts. Any disagreement regarding trial eligibility was resolved by consulting a third author.
Data extraction
Two reviewers independently extracted data from the included trials on the first author, journal name, year of publication, and country. The reviewers then tabulated information on the number of groups and patients analysed in each, type of surgery, block technique, drugs used, and the dose and route of ketamine administered, and the incidence and severity of RP. Finally, data on adverse effects in the form of hallucinations, sleep disturbance, nightmare, delirium, and postoperative nausea and vomiting (PONV) were recorded.
Outcome measurements
Outcome data were extracted as mean and standard deviation (SD) for continuous variables and as proportions for dichotomous outcomes. Data provided as the median and interquartile range were converted to mean and SD using Hozo’s formula.[10]
Risk of bias assessment of individual trials
Two authors independently judged the risk of bias (ROB) using the Cochrane Collaboration (RoB 2) criteria.[11] Overall ROB was expressed as low risk, some concerns, or high risk. A trial was considered to have a low ROB only if all domains were judged to be at low risk.
Certainty of evidence across trials
Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines were used to assess the overall certainty of evidence across pooled outcomes.[12]
Data analysis
We performed the statistical analysis of the pooled data using Review Manager (RevMan) version 5.4 (Cochrane Collaboration). Dichotomous outcomes were expressed as odds ratios (ORs) and continuous outcomes as mean differences (MDs) with 95% confidence intervals (CIs). Trial inconsistency was measured using the I² statistic and was considered significant if it exceeded 50%.
Forest plots were created to display and evaluate treatment effects. All reported P values were considered two-sided, with P < 0.05 deemed statistically significant. The number needed to treat (NNT) was calculated using available pooled numbers in the control and intervention groups. To assess potential publication bias, we used a funnel plot. We also performed two subgroup analyses: one including only trials with IV administration, and another comparing esketamine to control groups.
Trial sequential analysis (TSA) was performed for the primary outcome to account for cumulative type I error. The required information size (RIS) was calculated assuming a control event rate of 39.6%, a relative risk reduction of 35%, a two-sided alpha of 0.05, and 80% power, with an O’Brien-Fleming alpha-spending function.
RESULTS
Study selection and characteristics of included trials
Our literature search revealed 55 trials. Figure 1 shows the PRISMA diagram delineating the study inclusion/exclusion process. Six trials enroling 890 patients were included in this systematic review.[13,14,15,16,17,18] Characteristics of the included trials are shown in Table 1. Of the 890 patients enroled across six randomised controlled trials (RCTs), 458 received ketamine/esketamine (IV in 358, perineural in 100), and 432 patients were in the control group. The trial conducted by Touil and colleagues evaluated ketamine, while the remaining studies investigated esketamine.[17] The trial conducted by Zhu and colleagues (2020) included three treatment arms comparing IV and perineural administration, with both compared to a control group.[14] Accordingly, we labelled these arms as Zhu A and Zhu B.[14] The trials were published between 2020 and 2025. Regional blocks administered included axillary, sciatic, adductor canal, paravertebral, and brachial plexus blocks. Patients in one study received spinal anaesthesia along with the regional block,[16] and in two studies, general anaesthesia was administered after the block.[16,18] Block was the only modality of anaesthesia in the remaining trials.[13,15,17] Doses of local anaesthetic were variable. Ketamine doses ranged from 0.3 to 0.5 mg/kg (or a fixed dose of 40 mg).
Figure 1.
PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram of included randomised controlled trials
Table 1.
Characteristics of the included trials
| Author, year | Block (local anaesthetic) | Surgery | Included treatment arms (n) | Postoperative analgesia | Definition of rebound pain | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Chen and colleagues, 2024[15] | Single nerve block | Upper-limb surgery | Esketamine + sufentanil (40); sufentanil (40) | Sufentanil PCA | Sudden transition from no pain to severe pain, NRS ≥7 | |||||
| Li and colleagues, 2025[16] | USG-guided distal adductor canal block (0.375% ropivacaine) with spinal anaesthesia and a periarticular mixture (100 mg ropivacaine + 2 mg betamethasone) | Total knee arthroplasty | Esketamine IV (178); control (178) | Esketamine group: IV infusion of S-ketamine hydrochloride in 0.9% saline to 20 mL at 0.12 mL/kg/h (0.30 mg/kg/h; total 0.5 mg/kg). Control group: continuous infusion of 0.9% saline. Rescue: celecoxib 200 mg PO, sufentanil PCA, butorphanol, acetaminophen PRN, oxycodone PRN, meperidine. | Transition from well-controlled pain (NRS <3) to severe pain (NRS ≥7) after block resolution | |||||
| Touil and colleagues, 2022[17] | Axillary plexus block | Upper-limb orthopaedic surgery | Ketamine IV (54); control (55) | Ketamine 0.3 mg/kg IV diluted in 10 mL saline. Control group: equivalent volume of 0.9% saline after completion of the axillary plexus block. Rescue: tramadol. | Severe pain (NRS >7) after block resolution | |||||
| Zeng and colleagues, 2024[18] | Transthoracic paravertebral block (15 mL of 0.25% ropivacaine) | Thoracoscopic lobectomy | Esketamine IV (60); control (60) | Bolus of esketamine 0.5 mg/kg IV during anaesthesia induction and a further bolus of 0.3 mg/kg half an hour before the end of surgery. Control group: saline. Rescue: sufentanil PCA. | Severe pain (NRS > 7) after block resolution | |||||
| Zhu and colleagues, 2020[14] | Sciatic nerve block combined with femoral nerve block (0.375% ropivacaine) | Anterior cruciate ligament reconstruction | Ketamine IV (26); ketamine PN (25); control (25) | Control: 40 mL of 0.375% ropivacaine. Ketamine PN: 40 mg ketamine mixed with 0.375% ropivacaine in 40 mL. Ketamine IV: 40 mL of 0.375% ropivacaine plus 40 mg ketamine IV after incision. Rescue: sufentanil PCA, flurbiprofen. | Highest pain score in the first 12 h after the block wore off minus the lowest pain score in the first 12 h before it wore off | |||||
| Zhu and colleagues, 2024[13] | Brachial plexus block (0.75% ropivacaine) | Upper-limb orthopaedic surgery | Esketamine PN (75); control (74) | Esketamine group: 30 mL of 0.375% ropivacaine + 0.5 mg/kg esketamine. Control group: 30 mL of 0.375% ropivacaine. Rescue: sufentanil PCA. | Severe pain (NRS >7) |
IV: Intravenous; NRS: Numeric Rating Scale; PCA: Patient-controlled analgesia; PN: Perineural; PO: Oral; PRN: As required; USG: Ultrasonography
Risk of bias and publication bias
The ROB assessment for each study is presented in Figure 2. Overall, four of the six RCTs were deemed at low ROB,[13,16,17,18] two had some concerns,[14,15] and none was at high risk. Publication bias was not estimated as fewer than ten studies were included in this meta-analysis.
Figure 2.
Risk-of-bias summary of included studies according to Cochrane Collaboration guidelines. Green, red, and yellow circles indicate low risk, high risk, and some concerns, respectively
Incidence of rebound pain
Five studies (814 patients; ketamine 407, control 407) reported the number of patients experiencing RP, providing sufficient data for statistical pooling.[13,15,16,17,18] Of these, 90 patients in the ketamine group and 161 in the control group reported RP in the postoperative period. Ketamine/esketamine significantly reduced the incidence of RP (OR 0.43, 95% CI 0.32 to 0.59; P < 0.00001; I² =39%) [Figure 3a]. This resulted in a NNT of approximately 6 for preventing RP; that is, for every six patients receiving the active modality, one additional occurrence of RP would be prevented compared with the control group. The overall strength of evidence was moderate. The subgroup analysis of trials using IV administration alone showed a significant reduction (OR 0.48, 95% CI 0.34 to 0.68; P < 0.00001; I² =21%) [Figure 3b]. Similarly, the subgroup analysis of studies comparing esketamine with a control group demonstrated a beneficial effect of the active treatment (OR 0.37, 95% CI 0.22 to 0.64; P = 0.0004; I² =51%) [Figure 3c].
Figure 3.
Forest plot of pooled data showing (a) incidence of rebound pain with ketamine/esketamine versus control; (b) subgroup analysis of trials evaluating intravenous ketamine versus control; (c) subgroup analysis of trials evaluating esketamine versus control
The power of the present meta-analysis (with an alpha of <5%) was found to be >95%, indicating that the pooled sample size was sufficient to draw valid conclusions [Figure 4]. The GRADE evidence profile for all pooled outcomes is presented in Table 2. TSA demonstrated that the accrued sample of 814 patients exceeded the required information size of 176 patients (assuming a control event rate of 39.6%, a relative risk reduction of 35%, alpha = 0.05, power = 80%) by more than fourfold. The cumulative Z-curve crossed the O’Brien-Fleming boundary and remained beyond it, confirming that the observed benefit is unlikely to represent a false-positive finding [Figure 5].
Figure 4.
Power analysis of the pooled data for the incidence of rebound pain, with power on the x-axis and effect size on the y-axis
Table 2.
GRADE evidence profile—ketamine/esketamine for prevention of rebound pain after regional nerve block
| Outcome (no. of participants) | No. of studies | Study design | Risk of bias | Inconsistency | Indirectness | Imprecision | Publication bias | Certainty of evidence | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Incidence of rebound pain (n=814) | 5 | RCT | Not serious | Not serious (I²=39%, P=0.16) | Not serious | Not serious | Undetected | ⊕⊕⊕○ MODERATE | ||||||||
| Severity of rebound pain—NRS (continuous; 3 studies) | 3 | RCT | Not serious | Serious (not pooled)* | Not serious | Serious (few studies) | Undetected | ⊕⊕○○ LOW | ||||||||
| Hallucinations (n=577) | 4 | RCT | Not serious | Not serious (I²=0%) | Not serious | Serious† | Undetected | ⊕⊕⊕○ MODERATE | ||||||||
| Delirium (n=476) | 2 | RCT | Not serious | Not serious (I²=0%) | Not serious | Serious (2 studies only) | Undetected | ⊕⊕○○ LOW | ||||||||
| PONV (n=725) | 5 | RCT | Not serious | Not serious (I²=0%) | Not serious | Not serious | Undetected | ⊕⊕⊕○ MODERATE |
GRADE certainty symbols: ⊕⊕⊕⊕ High; ⊕⊕⊕○ Moderate; ⊕⊕○○ Low; ⊕○○○ Very low. *Scoring systems were heterogeneous across trials; meta-analysis not performed. †Downgraded one level for imprecision: zero events in the control arm inflate the OR estimate and widen the CI. NRS=Numerical Rating Scale; PONV=Postoperative nausea and vomiting; RCT=Randomised controlled trial; I²=Index of heterogeneity; GRADE=Grading of Recommendations Assessment, Development and Evaluation
Figure 5.
Trial sequential analysis for the incidence of rebound pain
Patient satisfaction score
Patient satisfaction was reported in three trials; however, data could not be pooled for analysis owing to the use of different scoring systems.[13,14,16]
Adverse effects
Individual trial data for all adverse effects are summarised in Table 3.
Table 3.
Adverse-effects summary—ketamine/esketamine versus control by individual trial
| Study (Author, year) | Agent | Route | N (K/C) | Hallucinations n (K/C) | Delirium n (K/C) | Nightmares n (K/C) | Sleep dist. n (K/C) | PONV n (K/C) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chen 2024[15] | Esketamine | IV | 40/40 | NR | NR | NR | NR | NR | ||||||||
| Li 2025[16] | Esketamine | IV | 178/178 | 11/0 | 10/8 | 6/3 | NR | 34/32 | ||||||||
| Touil 2022[17] | Ketamine | IV | 54/55 | NR | NR | NR | NR | NR | ||||||||
| Zeng 2024[18] | Esketamine | IV | 60/60 | 1/0 | 9/9 | 1/1 | NR | 9/7 | ||||||||
| Zhu 2020 (A)[14] | Ketamine | IV | 26/25 | 8/0 | NR | NR | 14/6 | 3/2 | ||||||||
| Zhu 2020 (B)[14] | Ketamine | PN | 25/25 | 1/0 | NR | NR | 5/6 | 2/2 | ||||||||
| Zhu 2024[13] | Esketamine | PN | 75/74 | NR | NR | NR | NR | 1/2 | ||||||||
| Pooled (studies reporting data) | — | — | — | 21/0 (4 arms) | 19/17 (2 trials) | — | — | 49/45 (5 arms) |
n=Number of patients with the event; N=Total number of patients analysed in the group; K=Ketamine/esketamine group; C=Control group; IV=Intravenous; PN=Perineural; NR=Not reported in the trial; dist.=Disturbance (sleep disturbance); PONV=Postoperative nausea and vomiting. The total N varies per adverse-effect outcome, as not all studies reported each outcome. The pooled row presents event counts from the arms contributing data to each outcome pool. Hallucination data were pooled from four arms across three trials (Li 2025, Zeng 2024, Zhu 2020 A and B); delirium from two trials (Li 2025, Zeng 2024); and PONV from five arms across four trials
Hallucinations
Data for this outcome were pooled from four study arms across three trials (577 patients; 289 in the ketamine group and 288 in the control group).[14,16,18] Twenty-one patients in the ketamine group and no patients in the control group experienced hallucinations. The incidence of hallucinations was significantly greater in the active group (OR 12.73, 95% CI 2.98 to 54.41; P = 0.0006; I² = 0%) than in the control group [Figure 6a].
Figure 6.
Forest plot of pooled data showing (a) incidence of hallucinations with ketamine/esketamine versus control; (b) incidence of delirium with ketamine/esketamine versus control; (c) incidence of PONV with ketamine/esketamine versus control. CI:Confidence interval; PONV: Postoperative nausea and vomiting
Delirium
Data were pooled from two trials comprising 476 patients (238 in the ketamine group and 238 in the control group).[16,18] No significant difference in the incidence of delirium was observed between the two groups (OR 0.88, 95% CI 0.44 to 1.76; P = 0.73; I² = 0%) [Figure 6b].
Postoperative nausea and vomiting
Data were pooled from five study arms across four RCTs comprising 725 patients (363 in the ketamine group and 362 in the control group).[13,14,16,18] No significant difference in PONV incidence was observed between the two groups (OR 0.90, 95% CI 0.58 to 1.41; P = 0.65; I² = 0%) [Figure 6c].
DISCUSSION
We conducted this systematic review and meta-analysis to evaluate the prophylactic efficacy of ketamine and its S-enantiomer in reducing RP following RA. Our pooled analysis indicates that ketamine, particularly when administered intravenously, is associated with a reduced incidence of RP. The certainty of evidence was moderate. The benefit persisted in a subgroup analysis of esketamine. The statistical power of this meta-analysis indicates that the sample size was sufficient to detect clinically relevant differences. However, the incidence of hallucinations was significantly higher with ketamine/esketamine.
RP is characterised by a marked increase in pain intensity upon resolution of a regional block, representing a significant clinical challenge. It can adversely impact postoperative outcomes by increasing opioid consumption, impairing sleep quality, and diminishing overall patient satisfaction with regional anaesthesia.[13] The pathophysiology of RP is complex and multifactorial. During regional anaesthesia, nociceptive input is temporarily suppressed, but surgical tissue injury and inflammation persist. This sensory mismatch may contribute to a phenomenon known as latent sensitisation—a priming of the central nervous system that can evolve into central sensitisation once the block wears off. This process is primarily mediated by NMDA receptors in the dorsal horn of the spinal cord.
Ketamine is a non-selective NMDA receptor inhibitor with well-established analgesic, anti-hyperalgesic, and anti-inflammatory properties. Our analysis indicates that ketamine or its analogue offers significant protective effects against RP.[19] The route of ketamine administration appears to play an important role in its efficacy. IV ketamine, whether delivered as a bolus or infusion during the perioperative period, consistently demonstrated effectiveness across the included studies in the current systematic review and meta-analysis. This route facilitates systemic distribution and allows for central modulation of nociceptive pathways. On the other hand, perineural administration of ketamine—direct application near the nerve with local anaesthetics—is a less commonly studied route. While theoretically advantageous owing to its potential for local NMDA receptor blockade, reduced postoperative sleep disturbance,[20] and prolonged peripheral analgesia, evidence remains limited, and concerns regarding neurotoxicity at the site of administration persist. Further high-quality studies are needed to determine the safety and efficacy of perineural ketamine in clinical practice.
While the analgesic, anti-inflammatory, and anti-hyperalgesic benefits of ketamine are promising,[19] the drug’s adverse-effect profile warrants careful consideration. The most notable side effect observed in this meta-analysis was the occurrence of hallucinations, which were significantly more frequent in the ketamine group. This finding highlights the psychomimetic potential of ketamine, even at the sub-anaesthetic doses commonly used for analgesia. Although these side effects are often transient and self-limiting, they may cause distress to patients and require pharmacological management (e.g., with benzodiazepines) or additional monitoring in the postoperative setting. The clinical significance of this adverse effect depends on the setting and the patient’s psychological profile; thus, a risk–benefit assessment is crucial before routine use.
Other adjuncts have also been investigated for the prevention of RP. Dexmedetomidine, an alpha-2 adrenergic agonist, has been studied both perineurally and intravenously and may prolong block duration and attenuate RP.[5,6] Dexamethasone appears to offer a favourable safety profile, in addition to demonstrating a significant reduction in RP,[5,6] positioning it as a potentially safer alternative to ketamine in perioperative settings. However, no direct head-to-head clinical trials comparing the efficacy and safety of ketamine, dexmedetomidine, and dexamethasone have been conducted to date. Accordingly, further high-quality RCTs are needed to evaluate and directly compare these agents, which would help guide evidence-based clinical decision-making.
The heterogeneity across studies in our review was generally low, suggesting that the findings are robust. However, variability persists in dosing regimens, routes of administration (IV vs. perineural), and definitions of RP across studies. There is also a relative lack of data regarding perineural ketamine. Whether IV or perineural ketamine is superior for the prevention of RP cannot be answered from the current evidence base. The IV subgroup (four studies; 332 ketamine, 333 control patients) showed a consistent, low-heterogeneity reduction in RP (OR 0.48, 95% CI 0.34 to 0.68; P < 0.0001; I² = 21%). The perineural route was represented by only one arm each from two trials,[13,14] making any firm conclusion premature. Preservative-related neurotoxicity concerns compound the uncertainty for perineural use. Head-to-head trials comparing both routes against a common control are warranted.
Our meta-analysis also has several limitations. The types of regional anaesthesia and surgery in the included studies were not uniform. Different dosages and isomer formulations of ketamine were used, which might have influenced the results. None of the trials reported whether preservative-free formulations were used—a clinically relevant omission for the perineural route, given documented neurotoxicity concerns with benzalkonium chloride. The included trials employed heterogeneous postoperative analgesic rescue protocols, and differences in background analgesia may have independently influenced the incidence and severity of RP, representing residual confounding. The pooling of racemic ketamine and esketamine without pharmacokinetic dose adjustment represents a source of heterogeneity that limits direct cross-trial comparison.
CONCLUSION
Ketamine appears to be effective in reducing the incidence and severity of RP after regional nerve block, particularly when used intravenously. Nevertheless, its use is associated with a significantly increased risk of hallucinations, necessitating careful patient selection and monitoring.
Author contributions
NPS, JKM, PMS: Concept. JKM, NPS, BJKK: Manuscript writing. NPS, PMS: Statistical analysis. JKM, NPS, BJKK: Data collection.
Presentation at conferences/CMEs and abstract publication
None.
Study data availability
The data used in this meta-analysis is available and will be shared by the authors (email to the corresponding author) with a reasonable request.
Disclosure of use of artificial intelligence (AI)-assistive or generative tools
None.
Declaration of use of permitted tools
None.
Supplementary material
This article has supplementary material and can be accessed at this link. Supplementary Material at https://links.lww.com/IJOA/A82.
Conflicts of interest
There are no conflicts of interest.
Acknowledgement
None.
SUPPLEMENTARY MATERIAL: SEARCH STRATEGY (SUPPLEMENTARY APPENDIX 1)
PubMed- 11
Search: ((((ketamine) OR (Esketamine)) OR (Sketamine)) AND (rebound pain)) AND (block)
("esketamine"[Supplementary Concept] OR "esketamine"[All Fields] OR "ketamine"[All Fields] OR "ketamine"[MeSH Terms] OR "ketamin"[All Fields] OR "ketamine s"[All Fields] OR "ketamines"[All Fields] OR ("esketamine"[Supplementary Concept] OR "esketamine"[All Fields] OR "esketamine"[All Fields]) OR "Sketamine"[All Fields]) AND (("rebound"[All Fields] OR "rebounded"[All Fields] OR "rebounder"[All Fields] OR "rebounders"[All Fields] OR "rebounding"[All Fields] OR "rebounds"[All Fields]) AND ("pain"[MeSH Terms] OR "pain"[All Fields])) AND ("block"[All Fields] OR "blocked"[All Fields] OR "blocking"[All Fields] OR "blockings"[All Fields] OR "blocks"[All Fields])
Translations
ketamine: "Esketamine"[Supplementary Concept] OR "Esketamine"[All Fields] OR "ketamine"[All Fields] OR "ketamine"[MeSH Terms] OR "ketamin"[All Fields] OR "ketamine's"[All Fields] OR "ketamines"[All Fields]
Esketamine: "Esketamine"[Supplementary Concept] OR "Esketamine"[All Fields] OR "esketamine"[All Fields]
rebound: "rebound"[All Fields] OR "rebounded"[All Fields] OR "rebounder"[All Fields] OR "rebounders"[All Fields] OR "rebounding"[All Fields] OR "rebounds"[All Fields]
pain: "pain"[MeSH Terms] OR "pain"[All Fields]
block: "block"[All Fields] OR "blocked"[All Fields] OR "blocking"[All Fields] OR "blockings"[All Fields] OR "blocks"[All Fields]
COCHRANE-15
((ketamine or esketamine or S-ketamine) and rebound pain and block).mp. [mp=title, original title, abstract, floating sub-heading word, mesh headings, heading words, keyword]
EMBASE-11
((ketamine or esketamine or S-ketamine) and rebound pain and block).mp. [mp=title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword heading word, floating subheading word, candidate term word]
SCOPUS- 18
ketamine OR esketamine OR s-ketamine AND rebound AND pain AND block
Funding Statement
Nil.
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