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Seminars in Arthritis and Rheumatism Aug 2021To assess how patient characteristics and study design influence the effectiveness of control interventions in hand OA trials. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To assess how patient characteristics and study design influence the effectiveness of control interventions in hand OA trials.
METHODS
The study protocol was registered in PROSPERO (CRD42020163473). Two authors independently searched four electronic databases from their inception to December 31, 2019. Randomized and non-randomized controlled hand OA trials were included if pain intensity was assessed using a validated scale. We allocated control groups into one of the following: placebo, add-on treatment, no treatment, or active treatment. The standardized mean differences (d) of pain, as well as subjective function and hand strength, were pooled with 95% confidence intervals (CI) and 90% prediction intervals using random-effects models. Meta-regression and post-hoc subgroup analyses were performed to investigate which factors potentially impacted placebo analgesia and between-study heterogeneity.
RESULTS
Thirty-one placebo, 11 add-on, 12 no-treatment, and 10 active-treatment controls were included in meta-analyses. Effective pain relief was observed in placebo (d = -0.50, 95% CI -0.63 to -0.37), add-on (d = -0.35, 95% CI -0.59 to -0.12), and active-treatment (d = -0.92, 95% CI -1.35 to -0.48) groups. In subjective function, these treatments had smaller but beneficial effects; hand strength, contrastingly, was not improved. Placebo effects were larger when flare designs were used (d = -0.96) and more homogeneous when minimum pain thresholds were set (d = -0.46, 90% prediction intervals -0.79 to -0.14).
CONCLUSION
Placebo, add-on, and active control treatments were more effective than the no treatment control in relieving hand pain and improving subjective function. By choosing minimum pain thresholds and flare requirements at patient enrollment, moderate pain relief may be replicated among control participants in future randomized placebo-controlled trials.
Topics: Control Groups; Hand; Humans; Osteoarthritis; Pain; Randomized Controlled Trials as Topic
PubMed: 34146952
DOI: 10.1016/j.semarthrit.2021.04.006 -
The Cochrane Database of Systematic... Apr 2016This is the third updated version of a Cochrane review first published in Issue 4, 2003 of The Cochrane Library and first updated in 2007. Morphine has been used for... (Review)
Review
BACKGROUND
This is the third updated version of a Cochrane review first published in Issue 4, 2003 of The Cochrane Library and first updated in 2007. Morphine has been used for many years to relieve pain. Oral morphine in either immediate release or modified release form remains the analgesic of choice for moderate or severe cancer pain.
OBJECTIVES
To determine the efficacy of oral morphine in relieving cancer pain, and to assess the incidence and severity of adverse events.
SEARCH METHODS
We searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 9); MEDLINE (1966 to October 2015); and EMBASE (1974 to October 2015). We also searched ClinicalTrials.gov (1 October 2015).
SELECTION CRITERIA
Published randomised controlled trials (RCTs) using placebo or active comparators reporting on the analgesic effect of oral morphine in adults and children with cancer pain. We excluded trials with fewer than 10 participants.
DATA COLLECTION AND ANALYSIS
One review author extracted data, which were checked by another review author. There were insufficient comparable data for meta-analysis to be undertaken or to produce numbers needed to treat (NNTs) for the analgesic effect. We extracted any available data on the number or proportion of participants with 'no worse than mild pain' or treatment success (very satisfied, or very good or excellent on patient global impression scales).
MAIN RESULTS
We identified seven new studies in this update. We excluded six, and one study is ongoing so also not included in this update. This review contains a total of 62 included studies, with 4241 participants. Thirty-six studies used a cross-over design ranging from one to 15 days, with the greatest number (11) for seven days for each arm of the trial. Overall we judged the included studies to be at high risk of bias because the methods of randomisation and allocation concealment were poorly reported. The primary outcomes for this review were participant-reported pain and pain relief.Fifteen studies compared oral morphine modified release (Mm/r) preparations with morphine immediate release (MIR). Fourteen studies compared Mm/r in different strengths; six of these included 24-hour modified release products. Fifteen studies compared Mm/r with other opioids. Six studies compared MIR with other opioids. Two studies compared oral Mm/r with rectal Mm/r. Three studies compared MIR with MIR by a different route of administration. Two studies compared Mm/r with Mm/r at different times and two compared MIR with MIR given at a different time. One study was found comparing each of the following: Mm/r tablet with Mm/r suspension; Mm/r with non-opioids; MIR with non-opioids; and oral morphine with epidural morphine.In the previous update, a standard of 'no worse than mild pain' was set, equivalent to a score of 30/100 mm or less on a visual analogue pain intensity scale (VAS), or the equivalent in other pain scales. Eighteen studies achieved this level of pain relief on average, and no study reported that good levels of pain relief were not attained. Where results were reported for individual participants in 17 studies, 'no worse than mild pain' was achieved by 96% of participants (362/377), and an outcome equivalent to treatment success in 63% (400/638).Morphine is an effective analgesic for cancer pain. Pain relief did not differ between Mm/r and MIR. Modified release versions of morphine were effective for 12- or 24-hour dosing depending on the formulation. Daily doses in studies ranged from 25 mg to 2000 mg with an average of between 100 mg and 250 mg. Dose titration was undertaken with both instant release and modified release products. A small number of participants did not achieve adequate analgesia with morphine. Adverse events were common, predictable, and approximately 6% of participants discontinued treatment with morphine because of intolerable adverse events.The quality of the evidence is generally poor. Studies are old, often small, and were largely carried out for registration purposes and therefore were only designed to show equivalence between different formulations.
AUTHORS' CONCLUSIONS
The conclusions have not changed for this update. The effectiveness of oral morphine has stood the test of time, but the randomised trial literature for morphine is small given the importance of this medicine. Most trials recruited fewer than 100 participants and did not provide appropriate data for meta-analysis. Only a few reported how many people had good pain relief, but where it was reported, over 90% had no worse than mild pain within a reasonably short time period. The review demonstrates the wide dose range of morphine used in studies, and that a small percentage of participants are unable to tolerate oral morphine. The review also shows the wide range of study designs, and inconsistency in cross-over designs. Trial design was frequently based on titration of morphine or comparator to achieve adequate analgesia, then crossing participants over in cross-over design studies. It was not clear if these trials were sufficiently powered to detect any clinical differences between formulations or comparator drugs. New studies added to the review for the previous update reinforced the view that it is possible to use modified release morphine to titrate to analgesic effect. There is qualitative evidence that oral morphine has much the same efficacy as other available opioids.
Topics: Administration, Oral; Adult; Analgesics, Opioid; Child; Humans; Morphine; Neoplasms; Pain; Randomized Controlled Trials as Topic
PubMed: 27105021
DOI: 10.1002/14651858.CD003868.pub4 -
BMC Anesthesiology Feb 2023Dexmedetomidine (DEX) has been thought to be an effective adjuvant to local anesthetics (LAs) in erector spinae plane block (ESPB), however, this method of use is not... (Meta-Analysis)
Meta-Analysis
The effect and safety of dexmedetomidine as an adjuvant to local anesthetics in erector spinae plane block: a systematic review and meta-analysis of randomized controlled trials.
BACKGROUND
Dexmedetomidine (DEX) has been thought to be an effective adjuvant to local anesthetics (LAs) in erector spinae plane block (ESPB), however, this method of use is not recorded in the drug instructions. Hence, our meta-analysis will evaluate its efficacy and safety for the first time.
METHODS
A systematic search of published articles was conducted in the PubMed, Embase, Web of science, and Cochrane Library databases up to July 17, 2022, using specific keywords related to our aims. The time first to request rescue analgesia, number of patient controlled intravenous analgesia (PCIA) presses, rate of rescue analgesia use, postoperative nausea and vomiting (PONV), arrhythmia, and hypotension were calculated by using random-effect models. This systematic review and meta-analysis was registered with PROSPERO (registration number: CRD42022345488).
RESULTS
Numerous electronic databases were searched and finally 8 studies with a total of 570 patients, 303 in the DEX arm, 267 in the control arm were included. As an adjuvant to LAs, DEX significantly increased the time to first request of rescue analgesia (mean difference [MD] = 8.40, 95% confidence interval [CI] = 4.70-12.10, P < 0.00001), reduced the number of PCIA presses (MD = -4.12, 95% CI = -7.79 to -0.45, P = 0.03) and the rate of rescue analgesia (odds ratio [OR] = 0.33, 95% CI = 0.17-0.65, P = 0.002). Moreover, the combination reduced the risk of PONV (OR = 0.57, 95% CI = 0.36-0.91, P = 0.02). In addition, there was no difference in the incidence of hypotension (OR = 1.01, 95% CI = 0.37-2.74, P = 0.99) and arrhythmia (OR = 0.76, 95% CI = 0.19-3.07, P = 0.70).
CONCLUSION
DEX can reduce analgesic requirements after various surgical procedures when used as an adjuvant to LAs for ESPB. Moreover, there was no significant difference between the two groups in terms of safety indicators (arrhythmia, hypotension).
Topics: Humans; Anesthetics, Local; Dexmedetomidine; Postoperative Nausea and Vomiting; Randomized Controlled Trials as Topic; Analgesia, Patient-Controlled; Hypotension; Nerve Block
PubMed: 36849910
DOI: 10.1186/s12871-023-02019-x -
British Journal of Anaesthesia Feb 2017Dexmedetomidine has been proposed as a perineural local anaesthetic (LA) adjunct to prolong peripheral nerve block duration; however, results from our previous... (Meta-Analysis)
Meta-Analysis Review
Evidence basis for using perineural dexmedetomidine to enhance the quality of brachial plexus nerve blocks: a systematic review and meta-analysis of randomized controlled trials.
BACKGROUND
Dexmedetomidine has been proposed as a perineural local anaesthetic (LA) adjunct to prolong peripheral nerve block duration; however, results from our previous meta-analysis in the setting of brachial plexus block (BPB) did not support its use. Many additional randomized trials have since been published. We thus conducted an updated meta-analysis.
METHODS
Randomized trials investigating the addition of dexmedetomidine to LA compared with LA alone (Control) in BPB for upper extremity surgery were sought. Sensory and motor block duration, onset times, duration of analgesia, analgesic consumption, pain severity, patient satisfaction, and dexmedetomidine-related side-effects were analysed using random-effects modeling. We used ratio-of-means (lower confidence interval [point estimate]) for continuous outcomes.
RESULTS
We identified 32 trials (2007 patients), and found that dexmedetomidine prolonged sensory block (at least 57%, P < 0.0001), motor block (at least 58%, P < 0.0001), and analgesia (at least 63%, P < 0.0001) duration. Dexmedetomidine expedited onset for both sensory (at least 40%, P < 0.0001) and motor (at least 39%, P < 0.0001) blocks. Dexmedetomidine also reduced postoperative oral morphine consumption by 10.2mg [-15.3, -5.2] (P < 0.0001), improved pain control, and enhanced satisfaction. In contrast, dexmedetomidine increased odds of bradycardia (3.3 [0.8, 13.5](P = 0.0002)), and hypotension (5.4 [2.7, 11.0] (P < 0.0001)). A 50-60µg dexmedetomidine dose maximized sensory block duration while minimizing haemodynamic side-effects. No patients experienced any neurologic sequelae. Evidence quality for sensory block was high according to the GRADE system.
CONCLUSIONS
New evidence now indicates that perineural dexmedetomidine improves BPB onset, quality, and analgesia. However, these benefits should be weighed against increased risks of motor block prolongation and transient bradycardia and hypotension.
Topics: Anesthetics, Local; Brachial Plexus Block; Dexmedetomidine; Humans; Randomized Controlled Trials as Topic
PubMed: 28100520
DOI: 10.1093/bja/aew411 -
Pain Medicine (Malden, Mass.) Aug 2022Total knee arthroplasty (TKA) and total hip arthroplasty (THA) surgeries are among the most common elective procedures. Moderate to severe postoperative pain during the... (Review)
Review
Effectiveness of Pharmacological-Based Interventions, Including Education and Prescribing Strategies, to Reduce Subacute Pain After Total Hip or Knee Arthroplasty: A Systematic Review of Randomized Controlled Trials.
BACKGROUND
Total knee arthroplasty (TKA) and total hip arthroplasty (THA) surgeries are among the most common elective procedures. Moderate to severe postoperative pain during the subacute period (defined here as the period from hospital discharge to 3 months postoperatively) is a predictor of persistent pain 12 months postoperatively. This review aimed to examine the available postdischarge pharmacological interventions, including educational and prescribing strategies, and their effect on reducing pain during the subacute period after TKA or THA.
METHODS
We searched seven electronic databases from inception to April 22, 2021. Published randomized controlled trials of adults who underwent TKA or THA and received a pharmacological-based intervention commencing within 1 week after hospital discharge and conducted for up to 3 months postoperatively were compared with any treatment. Two reviewers independently extracted data on the primary outcome, pain intensity. This review was registered prospectively on PROSPERO (ID: CRD42021250384).
RESULTS
Four trials involving 660 participants were included. Interventions included changing analgesic prescribing practices upon hospital discharge and education on analgesic use. Providing multimodal non-opioid analgesia in addition to reduced opioid quantity was associated with lower subacute pain (coefficient -0.81; 95% confidence interval -1.33 to -0.29; P = 0.003). Education on analgesic use during multidisciplinary home visits was effective for reducing pain intensity during the subacute period (6.25 ± 10.13 vs 35.67 ± 22.05; P < 0.001) compared with usual care.
CONCLUSIONS
Interventions involving the provision of multimodal non-opioid analgesia and education on analgesic use show positive effects on reducing pain intensity during the subacute period after TKA and THA.
Topics: Adult; Aftercare; Analgesics; Analgesics, Opioid; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Humans; Pain, Postoperative; Patient Discharge; Randomized Controlled Trials as Topic
PubMed: 35325201
DOI: 10.1093/pm/pnac052 -
Clinics (Sao Paulo, Brazil) Sep 2015Patients frequently experience postoperative pain after a total knee arthroplasty; such pain is always challenging to treat and may delay the patient's recovery. It is... (Comparative Study)
Comparative Study Meta-Analysis Review
Patients frequently experience postoperative pain after a total knee arthroplasty; such pain is always challenging to treat and may delay the patient's recovery. It is unclear whether local infiltration or a femoral nerve block offers a better analgesic effect after total knee arthroplasty.We performed a systematic review and meta-analysis of randomized controlled trials to compare local infiltration with a femoral nerve block in patients who underwent a primary unilateral total knee arthroplasty. We searched Pubmed, EMBASE, and the Cochrane Library through December 2014. Two reviewers scanned abstracts and extracted data. The data collected included numeric rating scale values for pain at rest and pain upon movement and opioid consumption in the first 24 hours. Mean differences with 95% confidence intervals were calculated for each end point. A sensitivity analysis was conducted to evaluate potential sources of heterogeneity.While the numeric rating scale values for pain upon movement (MD-0.62; 95%CI: -1.13 to -0.12; p=0.02) in the first 24 hours differed significantly between the patients who received local infiltration and those who received a femoral nerve block, there were no differences in the numeric rating scale results for pain at rest (MD-0.42; 95%CI:-1.32 to 0.47; p=0.35) or opioid consumption (MD 2.92; 95%CI:-1.32 to 7.16; p=0.18) in the first 24 hours.Local infiltration and femoral nerve block showed no significant differences in pain intensity at rest or opioid consumption after total knee arthroplasty, but the femoral nerve block was associated with reduced pain upon movement.
Topics: Analgesia; Anesthesia, Local; Anesthetics, Local; Arthroplasty, Replacement, Knee; Femoral Nerve; Humans; Nerve Block; Pain Measurement; Randomized Controlled Trials as Topic
PubMed: 26375568
DOI: 10.6061/clinics/2015(09)09 -
Journal of the American College of... Feb 2023Procedural sedation and analgesia (PSA) and peripheral nerve blocks (NBs) are techniques to manage pain and facilitate reduction of dislocated joints or fractures....
BACKGROUND
Procedural sedation and analgesia (PSA) and peripheral nerve blocks (NBs) are techniques to manage pain and facilitate reduction of dislocated joints or fractures. However, it is unclear if either approach provides any distinct advantage in the emergency department (ED). The aim of this systematic review is to compare these 2 techniques on pain scores, adverse events, patient satisfaction, and length of stay (LOS) in the ED.
METHODS
We performed an electronic search of MEDLINE, EMBASE, and the Cochrane Library, and references were hand-searched. Randomized controlled trials (RCTs) comparing PSA with NBs for orthopedic reductions in the ED were included. Outcomes of interest included pain scores, adverse events, patient satisfaction, and LOS in the ED. A total of 2 reviewers independently screened abstracts and extracted data into a standardized form. The Cochrane risk-of-bias tool was used to evaluate study quality. The Grading of Recommendation Assessment Development and Evaluation approach was used to assess the certainty and strength of the evidence. Data on pain scores were pooled using a random-effects model and are reported as standardized mean differences (SMDs) with 95% confidence intervals (CIs).
RESULTS
A total of 6 RCTs (n = 256) were included in a qualitative review, and 4 RCTs (n = 101) were included in the meta-analysis. There was no significant difference in pain scores between the PSA and NB groups ( = 0.47; SMD, 0.45; 95% CI, -0.78 to 1.69; I = 0.94). There were less adverse events in the NB group (0%-3.3%) compared with the PSA group (0%-20%; n = 256). LOS times were consistently shorter in the NB group (n = 215). Patient satisfaction was comparable in both groups (n = 196).
CONCLUSION
Based on the available evidence, NBs performed by emergency physicians are as effective as PSA in managing pain during orthopedic reductions in the ED. NBs are associated with fewer adverse events and shorter LOS in the ED. The quality of evidence is low.
PubMed: 36704208
DOI: 10.1002/emp2.12886 -
Pain Physician Nov 2022Single-injection regional analgesia techniques can provide effective analgesia for abdominal hysterectomy. However, few randomized controlled trials (RCTs) have directly... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Single-injection regional analgesia techniques can provide effective analgesia for abdominal hysterectomy. However, few randomized controlled trials (RCTs) have directly compared these techniques for total abdominal hysterectomy (TAH), and the best strategy remains unknown.
OBJECTIVES
In this network meta-analysis, we compared the analgesic efficacy of single-injection regional analgesia techniques in patients who underwent TAH.
STUDY DESIGN
A systematic review and network meta-analysis.
METHODS
We searched the PubMed, Embase, Cochrane, and CINAHL databases for relevant trials from inception until April 2022. RCTs that examined single-injection regional analgesia techniques for TAH were included. Random-effects network meta-analyses were performed using the frequentist approach. The primary outcome was 24-hour cumulative morphine equivalent consumption. The secondary outcomes were pain scores, time to first request for rescue analgesia, and rates of postoperative nausea and vomiting (PONV).
RESULTS
In total, 36 RCTs were included. Network meta-analyses indicated that the erector spinae plane block provided superior analgesia in terms of reduced morphine consumption, low PONV incidence, and longer time to first analgesia request. Moreover, compared with control (i.e., sham or placebo), the quadratus lumborum block provided superior analgesia in terms of time to first analgesia request and resting pain scores.
LIMITATIONS
(1) Few studies have examined single-injection regional analgesia techniques other than the transversus abdominis plane block (TAPB) and wound infiltration, leading to a few indirect effect estimates. (2) Heterogeneity existed due to analgesic type/dose, plane block timing, and injection site. (3) Objective outcomes, such as length of hospital stay, were lacking; most studies only included the patient-reported subjective pain score.
CONCLUSION
Single-injection blocks are effective analgesic techniques for TAH. Among them, the erector spinae plane block and quadratus lumborum block seem to have superior effects. Further studies should evaluate techniques other than TAPB and wound infiltration to draw definitive conclusions.
Topics: Humans; Female; Pain, Postoperative; Network Meta-Analysis; Postoperative Nausea and Vomiting; Analgesics, Opioid; Morphine; Analgesia; Hysterectomy; Abdominal Muscles
PubMed: 36375182
DOI: No ID Found -
HPB : the Official Journal of the... Jan 2023This study analysed whether local anaesthetic wound catheter infiltration (LA-WCI) as an adjunct to intravenous patient-controlled analgesia (IV-PCA) provides superior... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
This study analysed whether local anaesthetic wound catheter infiltration (LA-WCI) as an adjunct to intravenous patient-controlled analgesia (IV-PCA) provides superior outcomes compared to IV-PCA alone following liver resection.
METHODS
A systematic review and meta-analysis was conducted for randomised control trials (RCTs) comparing LA-WCI with IV-PCA(LA-WCI group) versus IV-PCA alone (IV-PCA group). PubMed and the Cochrane Library were searched for relevant articles.
RESULTS
Six RCTs with a total of 440 patients were included. Opioid use in the initial 48 h was less in the LA-WCI group [MD -21.27 mg (-39.39,-3.15), p = 0.02]. Pain scores were lower in the LA-WCI group at rest at POD0 (post-operative day 0)6-8 h (p = 0.0009), POD1AM(p = 0.01), POD1PM(p = 0.02) and POD2 (p = 0.0006), and exertion at POD0 0-2 h (p = 0.05), POD1AM(p = 0.03), POD1PM(p = 0.03), POD2 (p = 0.03) and POD3 (p = 0.01). LA-WCI group had reduced length of hospital stay [MD -1.32 days (-2.23,-0.40),p = 0.005], time to ambulation [MD -5.94 h (-8.47,-3.42),p = 0.00001] and incidence of nausea and vomiting (PONV) [OR 0.17 (0.07,0.43),p = 0.0002]. No differences were observed in length of intensive care unit (ICU) stay or incidence of surgical site infections.
DISCUSSION
LA-WCI as an adjunct to opiate IV-PCA post-hepatectomy reduces opioid use, pain scores at multiple time points at rest and exertion, length of hospital stay, time to ambulation and PONV. However, LA-WCI use does not alter length of ICU stay or incidence of wound infection.
Topics: Humans; Anesthetics, Local; Analgesics, Opioid; Pain, Postoperative; Postoperative Nausea and Vomiting; Catheters; Liver
PubMed: 36347769
DOI: 10.1016/j.hpb.2022.10.006 -
The Cochrane Database of Systematic... Feb 2016Acute postoperative pain is still an issue in patients undergoing abdominal surgery. Postoperative pain and side effects of analgesic treatment, in particular those of... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Acute postoperative pain is still an issue in patients undergoing abdominal surgery. Postoperative pain and side effects of analgesic treatment, in particular those of opioids, need to be minimized. Opioid-sparing analgesics, possibly including dexmedetomidine, seem a promising avenue by which to improve postoperative outcomes.
OBJECTIVES
Our primary aim was to determine the analgesic efficacy and opioid-sparing effect of perioperative dexmedetomidine for acute pain after abdominal surgery in adults.Secondary aims were to establish effects of dexmedetomidine on postoperative nausea and vomiting (PONV), gastrointestinal function and mobilization, together with the side effect profile of dexmedetomidine.
SEARCH METHODS
We searched the following databases: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Institute for Scientific Information (ISI), Web of Science and Cumulative Index to Nursing and Allied Health Literature (CINAHL), and reference lists of articles to May 2014. We searched the Science Citation Index, ClinicalTrials.gov and Current Controlled Trials, and we contacted pharmaceutical companies to identify unpublished and ongoing studies. We applied no language restrictions. We reran the search in May 2015 and found nine studies of interest. We will deal with the studies of interest when we update the review.
SELECTION CRITERIA
We included randomized, controlled trials of perioperative dexmedetomidine versus placebo or other drug during abdominal surgery in adults. Trials included one of the following outcomes: amount of 'rescue' opioid, postoperative pain, time to 'rescue' analgesia, participants requiring 'rescue' analgesia, postoperative sedation, PONV, time to first passage of flatus and stool or time to first out-of-bed mobilization.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened the titles and abstracts for eligibility. We retrieved full trial reports if necessary, and we extracted relevant data from the included studies using a data collection form and assessed risk of bias. We resolved disagreements by discussion with the third review author. We sought additional information of relevance for risk of bias assessment or extraction of data by contacting study authors or, if necessary, co-authors from present or former studies.
MAIN RESULTS
Our systematic review included seven studies with a total of 492 participants. We included 422 participants in our analysis. Thirteen studies are awaiting classification. For the comparison dexmedetomidine versus placebo (six studies, 402 participants), most studies found a reduction in 'rescue' opioid consumption in the first 24 hours after surgery, together with in general no clinically important differences in postoperative pain (visual analogue scale (VAS) 0 to 100 mm, where 0 = no pain and 100 = worst imaginable pain) in the first 24 hours after surgery - except for one study (80 participants) with a reduction in VAS pain at two hours after surgery in favour of dexmedetomidine, with a mean difference of -30.00 mm (95% confidence interval (CI) -38.25 to -21.75). As the result of substantial heterogeneity, pooling of data in statistical meta-analyses was not appropriate. The quality of evidence was very low for our primary outcomes because of imprecision of results and risk of bias. Regarding our secondary aims, evidence was too scant in general to allow robust conclusions, or the estimates too imprecise or of poor methodological quality. Regarding adverse effects, low quality data (one study, 80 participants) suggest that the proportion of participants with hypotension requiring intervention was slightly higher in the high-dose dexmedetomidine group with a risk ratio of 2.50 (95% CI 0.94 to 6.66), but lower doses of dexmedetomidine led to no differences compared with control. Evidence for the comparison dexmedetomidine versus fentanyl was insufficient to permit robust conclusions (one study, 20 participants).
AUTHORS' CONCLUSIONS
Dexmedetomidine, when administered perioperatively for acute pain after abdominal surgery in adults, seemed to have some opioid-sparing effect together with in general no important differences in postoperative pain when compared with placebo. However the quality of the evidence was very low as the result of imprecision, methodological limitations and substantial heterogeneity among the seven included studies. The clinical importance for patients is uncertain, in as much as the influence of dexmedetomidine on patient-important outcomes such as gastrointestinal function, mobilization and adverse effects could not be satisfactorily determined. All included studies were relatively small, and publication bias could not be ruled out. Applicability of evidence was limited to middle-aged participants who were relatively free of co-morbidity and were undergoing elective abdominal surgery. A potential bias was a considerable quantity of unobtainable data from studies with mixed surgery. To detect and investigate patient-important outcomes, larger studies with longer periods of follow-up are needed.
Topics: Abdomen; Acute Pain; Adult; Analgesics, Non-Narcotic; Analgesics, Opioid; Dexmedetomidine; Fentanyl; Humans; Middle Aged; Pain Measurement; Pain, Postoperative
PubMed: 26889627
DOI: 10.1002/14651858.CD010358.pub2