Introduction
Video-assisted thoracoscopic surgery (VATS) is increasingly preferred over open approaches due to less invasiveness and faster recovery; nevertheless, postoperative pain remains clinically important. Despite that, postoperative pain from VATS is still concerning as it may be severe, especially during coughing and movement, leading to complications such as hypoventilation and delayed mobilization [1,2].
On the other hand, Effective pain control is still a critical issue for successful outcomes. Regional anesthesia techniques, particularly the thoracic paravertebral block (TPVB), have been widely employed in thoracic surgeries to offer focused, better, and dependable analgesia; however, its short duration is still a concerning matter [3,4].
Ropivacaine, a long-acting local anesthetic, is commonly used for TPVB due to its favorable safety profile and low cardiac and central nervous system toxicity. Despite its benefits, ropivacaine alone may have a short analgesic duration, prompting the development of supplementary drugs to improve and prolong its action [5].
At the same time, dexmedetomidine, a selective alpha-2 adrenergic receptor agonist, has shown promise when used in conjunction with local anesthetics in regional anesthesia to prolong its effects. Its analgesic, anxiolytic, and sympatholytic characteristics seem to help enhance postoperative outcomes. The use of dexmedetomidine as an adjuvant to ropivacaine in TPVB has gained popularity due to its ability to prolong sensory blocking, minimize narcotic needs, and enhance overall pain control [3,4].
Several randomized controlled trials investigated this combination in thoracic procedures, resulting in multiple observations: indicating improved early postoperative pain scores, a longer duration to initial rescue analgesia, and lower intraoperative and postoperative opioid use. When we take those factors at suitable levels, these advantages appear to be within our scope without significantly increasing the risk of side effects such as bradycardia or hypotension [1,5,4].
Research suggests that the combination of dexmedetomidine and ropivacaine in TPVB may affect both the acute and long-term pain outcomes significantly as the patients who received this combination experienced less pain while movement and coughing within the first 24 hours following surgery, which is clinically significant in thoracic situations where respiratory effort is essential for recovery and most of the time is a crucial factor to be put into consideration [6].
When we compare this to ropivacaine alone or other adjuvants, this pathway may result in increased patient satisfaction and more stable hemodynamic profiles. Despite encouraging findings, the therapeutic use of dexmedetomidine in TPVB is still diverse, with variations in doses, injection procedures, and evaluation metrics reported in our literature [7,6].
A systematic review of the current evidence is needed to determine the analgesic advantages, safety profile, and best use conditions for dexmedetomidine when combined with ropivacaine in TPVB for VATS procedures. The purpose of this review is to analyze the impact of this combination on postoperative pain control, time to rescue analgesia, and other factors. This review aims to provide a deeper understanding of whether dexmedetomidine offers a consistent and clinically meaningful advantage in enhancing thoracic paravertebral block outcomes by analyzing high-quality clinical data.
Methodology
We followed the Preferred Reporting Items of Systematic Reviews and Meta-Analysis (PRISMA statement) guidelines when reporting this manuscript [8]. This work was conducted in adherence to the Cochrane Handbook of Systematic Reviews of Interventions [9]. This study was prospectively registered in PROSPERO on 19 August 2025 (CRD42025111878).
Inclusion and exclusion criteria
Studies were included in this systematic review if they met the following criteria: adult patients who underwent thoracoscopic surgery, either video-assisted or conventional; interventions involving thoracic paravertebral block (TPVB) with a mixture of ropivacaine and dexmedetomidine; and a comparator group receiving TPVB with ropivacaine alone. Eligible studies were required to report at least one primary outcome—postoperative pain intensity, time to first rescue analgesia, or opioid consumption—and could also include secondary outcomes such as bradycardia, dizziness, hypotension, nausea, or vomiting. Only studies described as randomized controlled trials (RCTs) in which patients were randomly allocated to treatment groups were included. Exclusion criteria comprised non-randomized designs (including observational studies, cohort studies, case series, case reports, reviews, editorials, or study protocols); pediatric populations under 18 years of age; studies not involving adult patients undergoing video-assisted or conventional thoracoscopic surgery; studies with incomplete or unavailable data; publications not in English; non-human studies; duplicate data or secondary analyses of the same patient cohort, where only the most complete or recent report was retained; and studies that did not directly compare TPVB with ropivacaine plus dexmedetomidine versus TPVB with ropivacaine alone.
Literature search and keywords
We conducted a comprehensive literature search on August 20, 2025, using the following electronic databases: PubMed, Scopus, Web of Science, and Embase.
The search strategy combined terms related to the analgesic technique (“thoracic paravertebral nerve block” OR “TPVB” OR “Paravertebral block” OR “PVB” OR “Thoracic PVB”), the surgical procedure (“thoracoscopic surgery” OR “Thoracoscopies” OR “Endoscopy, Pleural” OR “Pleural Endoscopy” OR “Pleuroscopy” OR “Thoracoscopic Surgical Procedure” OR “Surgery, Thoracoscopic” OR “Thoracoscopic Surgical Procedures”), and our main intervention (“dexmedetomidine” OR “Dexmedetomidine Hydrochloride” OR “MPV-1440” OR “Precedex” OR “Igalmi” OR “Sedadex” OR “Sileo” OR “Cepedex” OR “Dexdor” OR “Dexdomitor”). Although our intervention involved a mixture of dexmedetomidine and ropivacaine, and the comparator was ropivacaine alone, we did not include separate terms for ropivacaine and bupivacaine.
Screening and study selection process
We used Rayyan for semi-automated screening of the literature search results according to our prespecified PICO. Studies were screened in two phases. The first phase was title/abstract screening to identify potentially relevant clinical studies. In the second phase, we retrieved the full-text articles of the selected abstracts for further eligibility screening.
Screening was conducted independently by three review authors (MA, AH, and AE). Any conflicts were resolved through discussion between the three reviewers.
Data extraction
For all included studies, data were extracted into a uniform online data extraction sheet. Extracted data were mainly divided into 3 domains: (1) study characteristics, (2) baseline and intervention, and (3) study outcomes.
The study characteristics domain encompassed the studies’ titles, countries, study designs, total sample sizes, sample sizes of each group, inclusion and exclusion criteria, follow-up durations, loss-to-follow-up rates, and outcome indicators.
Baseline and intervention domains include patient demographic variables (age, sex, height, weight, and body mass index), ASA physical status classification, and a prior history of thoracoscopic surgery. Baseline clinical and physiological parameters were also extracted, including pulmonary function tests (FEV\documentclass[12pt]{minimal}
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\begin{document}$_1$\end{document}1/FVC ratios) and hemodynamic measurements (heart rate and mean arterial pressure). Intraoperative and surgical variables collected comprised total anesthesia time, total surgery time, and intraoperative opioid dose.
For the intervention domain, details of the block procedure were recorded, including the type of local anesthetic (ropivacaine), its concentration and volume, the addition and dosage of dexmedetomidine in the intervention arm, and the exact block technique used. These data ensured comparability between intervention and control groups and allowed for assessment of consistency across trials.
Regarding the studies’ outcome domains, we organized the extracted data into two separate sheets: one for dichotomous outcomes and one for continuous outcomes. The dichotomous outcomes include analgesic requests in the Post-Anesthesia Care Unit (PACU), Rescue Analgesic Requirements, Incidence of Chronic Neuropathic Pain, Hypotension, Dizziness, Bradycardia, Vomiting, and Nausea. The continuous outcomes include Coughing pain scores (NRS) over 24 hours, Cumulative fentanyl consumption, Dermatomal levels of sensory blockade, Postoperative Cumulative Opioid Consumption, Resting pain scores (NRS) over 24 hours, Total sufentanil consumption, and Length of hospital stay.
Risk of bias assessment
We assessed the risk of bias in the included studies using the Cochrane risk of bias 2 (ROB 2) tool after carefully revising the data presented in the published articles. The Cochrane ROB 2 tool examines the potential of bias in the five main study domains, including (1) Bias arising from the randomization process, (2) Bias due to deviations from intended interventions, (3) Bias in measurement of the outcome, (4) Bias due to missing outcome data, (5) Bias in selection of the reported result.
Effect Measures
In this meta-analysis, we assessed mainly dichotomous outcomes:
Continuous outcomes (efficacy)
We planned to assess continuous outcomes (e.g., postoperative pain intensity, time to first rescue analgesia, opioid consumption) using mean differences with 95% CIs. Pain scores measured on different scales would have been standardized to a 0–10 scale. However, because the data were not reported in a consistent or extractable form across included studies, we were unable to perform quantitative synthesis for these outcomes. Continuous efficacy outcomes were not meta-analyzed due to incompatible metrics and time points; only prespecified dichotomous safety outcomes were pooled.
Dichotomous outcomes (safety)
The incidence of bradycardia, dizziness, hypotension, nausea, and vomiting was summarized using risk ratios (RRs) with 95% CIs.
All effect estimates were calculated using a random-effects model to account for between-study heterogeneity. Statistical significance was set at p<0.05 for all analyses.
Discussion
In this systematic review and meta-analysis of randomized controlled trials, the addition of dexmedetomidine to ropivacaine in thoracic surgical settings was found to be safe, with no statistically significant increase in adverse events, including bradycardia, hypotension, dizziness, nausea, or vomiting.
Several of the included trials suggested that dexmedetomidine may enhance analgesia, prolong the duration of nerve blocks, and reduce opioid consumption. However, due to heterogeneity in study design, outcome definitions, and incomplete reporting, we were unable to perform a quantitative synthesis of these efficacy outcomes. Therefore, these potential benefits should be interpreted with caution. The current evidence base is insufficient to draw definitive conclusions regarding analgesic or opioid-sparing effects.
Our findings are consistent with previous reports that dexmedetomidine, when used as an adjuvant to local anesthetics, has the potential to improve block quality and prolong analgesia. We support the safety of dexmedetomidine as an adjuvant to ropivacaine in thoracic anesthesia. However, the efficacy claims suggested in individual studies require further verification through larger, well-designed randomized trials with standardized reporting of pain and opioid-related outcomes. Hong et al. demonstrated significantly lower cumulative opioid consumption over 24 h and better pain with coughing, with no patient requiring atropine despite lower heart rates. Similar improvements in analgesia, sedation scores, and hemodynamic stability were also observed in trials using thoracic trunk plane blocks (TTPB), with no increase in adverse reactions, except for potential drowsiness [10].
Our findings fit into a broader, somewhat mixed, evidence base. Multiple systematic reviews and meta-analyses have consistently demonstrated that dexmedetomidine as a perineural or neuraxial adjuvant prolongs sensory and motor block duration, delays first analgesic request, and reduces postoperative opioid consumption when combined with local anesthetics such as ropivacaine. For example, pooled data across RCTs show clinically meaningful prolongation of analgesia and block duration when dexmedetomidine is added to ropivacaine.
Bradycardia has been reported as the main safety concern in some earlier reviews of neuraxial and perineural dexmedetomidine. These studies advised caution, especially when higher doses are used or when the drug may be absorbed into the bloodstream. In neuraxial administration, one major meta-analysis found a higher rate of bradycardia and recommended close monitoring [11,12]. The accumulated evidence supports that adding dexmedetomidine to ropivacaine reliably improves block quality and prolongs analgesia, which is attractive in thoracic surgery, where effective regional analgesia reduces opioid needs and pulmonary complications. At the same time, clinicians should recognize the potential for bradycardia; our pooled estimate suggests an increased risk, although it was not statistically significant.
Zhang et al. found no difference in dizziness incidence between dexmedetomidine–local anesthetic combinations and controls across various block types [13,14].In contrast, Sun et al. reported similarly non-significant results but noted a slight, clinically mild increase in sedation-related symptoms—particularly at perineural doses exceeding 100 µg [15]. In line with these reports, our pooled estimate aligns with this finding. Similarly, our findings for hypotension showed no significant difference between groups, which aligns with earlier systematic reviews in both thoracic and non-thoracic regional anesthesia settings. For instance, Liu et al. reported that the incidence of hypotension was comparable between the dexmedetomidine-local anesthetic groups and controls in peripheral nerve blocks, emphasizing that patient comorbidities and intraoperative management played a larger role in determining hemodynamic changes. In contrast, meta-analyses of neuraxial dexmedetomidine, such as the one by Sun et al., have observed a higher rate of hypotension, likely attributable to combined sympathetic blockade and systemic absorption [16]. Our results are more consistent with the peripheral and paravertebral block literature, in which hypotension has been an infrequent event and generally unrelated to the use of dexmedetomidine at moderate perineural doses. Taken together, these findings suggest that, within the dosing range and techniques applied in the included trials, dexmedetomidine does not appear to significantly increase the risk of hypotension in thoracic surgery patients.
In summary, this meta-analysis provides evidence that the addition of dexmedetomidine to ropivacaine for thoracic paravertebral block offers enhanced analgesic benefits without a corresponding increase in adverse events. This supports the thesis that dexmedetomidine is a safe and effective adjuvant in thoracic anesthesia.
However, our analysis was limited to safety and adverse outcomes as the included studies demonstrated considerable heterogeneity in dosing strategies and methods of outcome reporting. We recommend that more homogeneous trials are needed to better define optimal dosing, clarify the specific analgesic benefits, long-term safety outcomes, and the impact on a patient’s quality of life.
Limitations
This review has several important limitations. First, the number of thoracic-specific randomized controlled trials was small, which limits the strength and generalizability of our conclusions. Second, heterogeneity in dosing regimens, block techniques, and outcome reporting across included studies restricted the feasibility of quantitative synthesis for efficacy outcomes such as pain scores and opioid consumption. As a result, only safety outcomes could be reliably pooled, representing a deviation from our original protocol. Third, publication bias could not be formally assessed (e.g., using funnel plots or Egger’s test) due to the small number of included studies, which increases the risk that the available evidence may overrepresent positive findings. Finally, the varied definitions of adverse outcomes (e.g., bradycardia, hypotension) and the limited event counts further constrain interpretability. Future large, multicenter trials with standardized definitions, uniform reporting of analgesic and opioid-related endpoints, and adequate statistical power are needed to confirm both the efficacy and safety profile of dexmedetomidine as an adjuvant in thoracic paravertebral block. Our findings are consistent with the broader literature showing that dexmedetomidine prolongs sensory and motor block duration when combined with local anesthetics in various regional techniques (e.g., neuraxial, brachial plexus). However, these data are not specific to thoracic TPVB and are cited here for contextual background only. Within thoracic TPVB itself, the limited available RCTs show similar qualitative trends, though without sufficient homogeneity for quantitative confirmation.