Minimum Effective Concentration of Ropivacaine for Ultrasound-Guided RISS Block in VATS: A Biased Coin Design Approach
Ping Li,1,2 Zhongsai Yang,1,3 Long Zhang,4 Ruilan Wu,2 Manhua Zhu,2 Junran Xie1 1Department of Anesthesiology, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, Hangzhou, Zhejiang Province, 310016, People’s Republic of China; 2Department of Anesthesiology, Ningbo Medical Centre Lihui...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Dove Medical Press
2025-05-01
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| Series: | Drug Design, Development and Therapy |
| Subjects: | |
| Online Access: | https://www.dovepress.com/minimum-effective-concentration-of-ropivacaine-for-ultrasound-guided-r-peer-reviewed-fulltext-article-DDDT |
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| Summary: | Ping Li,1,2 Zhongsai Yang,1,3 Long Zhang,4 Ruilan Wu,2 Manhua Zhu,2 Junran Xie1 1Department of Anesthesiology, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, Hangzhou, Zhejiang Province, 310016, People’s Republic of China; 2Department of Anesthesiology, Ningbo Medical Centre Lihuili Hospital, Ningbo, Zhejiang Province, 315040, People’s Republic of China; 3Department of Anesthesiology, Ningbo Women and Children’s Hospital, Ningbo, Zhejiang Province, 315012, People’s Republic of China; 4Department of Anesthesiology, Ningbo No.6 Hospital, Ningbo, Zhejiang Province, 315040, People’s Republic of ChinaCorrespondence: Junran Xie, Department of Anesthesiology, Sir Run Run Shaw Hospital Affiliated Hospital of Zhejiang University School of Medicine, No. 3, Qingchun East Road, Shangcheng District, Hangzhou, Zhejiang Province, 310016, People’s Republic of China, Email xiejunran@zju.edu.cnBackground: Postoperative pain management is essential after video-assisted thoracoscopic surgery (VATS). The rhomboid intercostal and sub-serratus (RISS) block is effective in providing analgesia. This study aims to determine the minimum effective concentration (MEC) of ropivacaine for ultrasound-guided RISS block in patients undergoing VATS, thereby optimizing the analgesia protocol and enhancing its clinical significance.Methods: The biased coin design sequential method and isotonic regression were used. The ropivacaine initial concentration was 0.25% with a gradient of 0.025%. If the previous patient had a negative block, the concentration for the next patient would increase by 0.025%. If positive, the concentration would be adjusted based on biased coin randomization: an 11% chance of reducing it by 0.025% and an 89% chance of keeping it unchanged. MEC90 was calculated using isotonic regression with 95% confidence intervals (CI).Results: A total of 49 patients were included in the analysis. The MEC90 of 40mL ropivacaine for RISS block in VATS was 0.220% (95% CI, 0.198 to 0.260%), the MEC95 was 0.248% (95% CI, 0.223 to 0.338%) and the MEC99 was 0.270% (95% CI, 0.261 to 0.351%). There was a negative correlation between ropivacaine concentration and VASpain at 0h, 0.5h, and 6h after surgery and the time of initial analgesia (r = – 0.396, – 0.594, – 0.309, 0.363; P = 0.005, 0.001, 0.031, 0.01). No significant correlation was observed between the VASpain at 12h and 24h after surgery and analgesia consumption (r = – 0.184, – 0.165; P = 0.205, 0.256).Conclusion: The MEC90 of 40 mL ropivacaine for RISS block was 0.220%. While the MEC95 was 0.248% and the MEC99 was 0.270%.Plain Language Summary: This study investigated the lowest effective dose of ropivacaine needed for pain relief after VATA using RISS block. Researchers used biased coin design sequential method to find the right dose of ropivacaine. They started with a certain concentration and adjusted it based on whether the previous patient’s block was successful or not. They found that a ropivacaine concentration of 0.220% was effective for 90% of the patients, while 0.248% was effective for 95% and 0.270% for 99% of the patients. Additionally, they observed that higher concentrations of ropivacaine were associated with less pain immediately after surgery and longer time before needing pain medication. No complications were reported related to this technique. In simple terms, this study helps doctors know the best dose of ropivacaine to use for pain relief after a certain type of lung surgery.Keywords: Ultrasound-guided, Ropivacaine, Rhomboid intercostal and subserratus, RISS, Minimum effective concentration, Dose finding |
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| ISSN: | 1177-8881 |