Comparison of regional anesthetic techniques for postoperative analgesia after adult cardiac surgery: bayesian network meta-analysis

Background Patients usually suffer acute pain after cardiac surgery. Numerous regional anesthetic techniques have been used for those patients under general anesthesia. The most effective regional anesthetic technique was still unclear. Methods Five databases were searched, including PubMed, MEDLINE, Embase, ClinicalTrials.gov, and Cochrane Library. The efficiency outcomes were pain scores, cumulative morphine consumption, and the need for rescue analgesia in this Bayesian analysis. Postoperative nausea, vomiting and pruritus were safety outcomes. Functional outcomes included the time to tracheal extubation, ICU stay, hospital stay, and mortality. Results This meta-analysis included 65 randomized controlled trials involving 5,013 patients. Eight regional anesthetic techniques were involved, including thoracic epidural analgesia (TEA), erector spinae plane block, and transversus thoracic muscle plane block. Compared to controls (who have not received regional anesthetic techniques), TEA reduced the pain scores at 6, 12, 24 and 48 h both at rest and cough, decreased the rate of need for rescue analgesia (OR = 0.10, 95% CI: 0.016–0.55), shortened the time to tracheal extubation (MD = −181.55, 95% CI: −243.05 to −121.33) and the duration of hospital stay (MD = −0.73, 95% CI: −1.22 to −0.24). Erector spinae plane block reduced the pain score 6 h at rest and the risk of pruritus, shortened the duration of ICU stay compared to controls. Transversus thoracic muscle plane block reduced the pain scores 6 and 12 h at rest compared to controls. The cumulative morphine consumption of each technique was similar at 24, 48 h. Other outcomes were also similar among these regional anesthetic techniques. Conclusions TEA seems the most effective regional postoperative anesthesia for patients after cardiac surgery by reducing the pain scores and decreasing the rate of need for rescue analgesia. Systematic Review Registration https://www.crd.york.ac.uk/prospero/, ID: CRD42021276645


Comparison of regional anesthetic techniques for postoperative analgesia after adult cardiac surgery: Bayesian network meta-analysis Content
Notes: circles represent the intervention as a node in the network, size of circles corresponds to the number of participants included in each comparison, lines represent direct comparisons using randomized controlled trials (RCTs) and the thickness of lines corresponds to the number of RCTs included in each comparison. ESPB, erector spinae plane block; PECS, pectoral nerve block; PIFB, pecto-intercostal fascial block; PINB, parasternal intercostal nerve block; PVB, paravertebral block; SAPB, serratus anterior plane block; TEA, thoracic epidural analgesia; TTMPB, transversus thoracic muscle plane block.

Figure S4. Inconsistency test of pain scores
Pain score 2-4h at rest Pain score 6h at rest Pain score 12h at rest Pain score 12h at cough Pain score 24h at rest Pain score 24h at cough Pain score 48h at rest Provide an explicit statement of questions being addressed, with reference to participants, interventions, comparisons, outcomes, and study design (PICOS).

Protocol and registration 5
Indicate whether a review protocol exists and if and where it can be accessed (e.g., Web address); and, if available, provide registration information, including registration number.

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Eligibility criteria 6 Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale. Clearly describe eligible treatments included in the treatment network, and note whether any have been clustered or merged into the same node (with justification).

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Information sources 7 Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.

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Search 8 Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated. 4

Study selection 9
State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis).

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Data collection process 10 Describe method of data extraction from reports (e.g., piloted forms, independently, in duplicate) and any processes for obtaining and confirming data from investigators.

Data items 11
List and define all variables for which data were sought (e.g., PICOS, funding sources) and any assumptions and simplifications made.

4-5 Geometry of the network S1
Describe methods used to explore the geometry of the treatment network under study and potential biases related to it. This should include how the evidence base has been graphically summarized for presentation, and what characteristics were compiled and used to describe the evidence base to readers.

Figure S3
Risk of bias within individual studies 12 Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level), and how this information is to be used in any data synthesis.

Assessment of Inconsistency S2
Describe the statistical methods used to evaluate the agreement of direct and indirect evidence in the treatment network(s) studied.
Describe efforts taken to address its presence when found.

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Risk of bias across studies 15 Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias, selective reporting within studies).

Additional analyses 16
Describe methods of additional analyses if done, indicating which were pre-specified. This may include, but not be limited to, the following: • Sensitivity or subgroup analyses;

RESULTS † Study selection 17
Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram.

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Presentation of network structure

S3
Provide a network graph of the included studies to enable visualization of the geometry of the treatment network. Figure S3 Summary of network geometry

S4
Provide a brief overview of characteristics of the treatment network. This may include commentary on the abundance of trials and randomized patients for the different interventions and pairwise comparisons in the network, gaps of evidence in the treatment network, and potential biases reflected by the network structure.

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Study characteristics 18 For each study, present characteristics for which data were extracted (e.g., study size, PICOS, follow-up period) and provide the citations.

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Risk of bias within studies 19 Present data on risk of bias of each study and, if available, any outcome level assessment.

Results of individual studies 20
For all outcomes considered (benefits or harms), present, for each study: 1) simple summary data for each intervention group, and 2) effect estimates and confidence intervals. Modified approaches may be needed to deal with information from larger networks.

6
Synthesis of results 21 Present results of each meta-analysis done, including confidence/credible intervals. In larger networks, authors may focus on comparisons versus a particular comparator (e.g. placebo or standard care), with full findings presented in an appendix. League tables and forest plots may be considered to summarize pairwise comparisons. If additional summary measures were explored (such as treatment rankings), these should also be presented.

6-7
Exploration for inconsistency S5 7 7 Risk of bias across studies 22 Present results of any assessment of risk of bias across studies for the evidence base being studied. 7 Results of additional analyses 23 Give results of additional analyses, if done (e.g., sensitivity or subgroup analyses, meta-regression analyses, alternative network geometries studied, alternative choice of prior distributions for Bayesian analyses, and so forth).

Summary of evidence 24
Summarize the main findings, including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy-makers).

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Limitations 25 Discuss limitations at study and outcome level (e.g., risk of bias), and at review level (e.g., incomplete retrieval of identified research, reporting bias). Comment on the validity of the assumptions, such as transitivity and consistency. Comment on any concerns regarding network geometry (e.g., avoidance of certain comparisons).

Conclusions 26
Provide a general interpretation of the results in the context of other evidence, and implications for future research.

FUNDING
Funding 27 Describe sources of funding for the systematic review and other support (e.g., supply of data); role of funders for the systematic review. This should also include information regarding whether funding has been received from manufacturers of treatments in the network and/or whether some of the authors are content experts with professional conflicts of interest that could affect use of treatments in the network.

NR
PICOS = population, intervention, comparators, outcomes, study design. † Authors may wish to plan for use of appendices to present all relevant information in full detail for items in this section.